Complications of pregnancy explained
Complications of pregnancy |
Field: | Obstetrics |
Complications: | Numerous biological and environmental complications |
Risks: | Numerous biological and environmental conditions |
Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.[1] [2] [3]
Common complications of pregnancy include anemia, gestational diabetes, infections, gestational hypertension and pre-eclampsia.[4] [5] Presence of these types of complications can have implications on monitoring lab work, imaging, and medical management during pregnancy.
Severe complications of pregnancy, childbirth, and the puerperium are present in 1.6% of mothers in the US,[6] and in 1.5% of mothers in Canada.[7] In the immediate postpartum period (puerperium), 87% to 94% of women report at least one health problem.[8] [9] Long-term health problems (persisting after six months postpartum) are reported by 31% of women.[10]
In 2016, complications of pregnancy, childbirth, and the puerperium resulted globally in 230,600 deaths, down from 377,000 deaths in 1990. The most common causes of maternal mortality are maternal bleeding, postpartum infections including sepsis, hypertensive diseases of pregnancy, obstructed labor, and unsafe abortion.[11] [12]
Complications of pregnancy can sometimes arise from abnormally severe presentations of symptoms and discomforts of pregnancy, which usually do not significantly interfere with activities of daily living or pose any significant threat to the health of the birthing person or fetus. For example, morning sickness is a fairly common mild symptom of pregnancy that generally resolves in the second trimester, but hyperemesis gravidarum is a severe form of this symptom that sometimes requires medical intervention to prevent electrolyte imbalances from severe vomiting.
Maternal problems
The following problems originate in the mother, however, they may have serious consequences for the fetus as well.
Gestational diabetes
Gestational diabetes is when a woman, without a previous diagnosis of diabetes, develops high blood sugar levels during pregnancy.[13] There are many non-modifiable and modifiable risk factors that lead to the devopment of this complication. Non-modifiable risk factors include a family history of diabetes, advanced maternal age, and ethnicity. Modifiable risk factors include maternal obesity.[14] There is an elevated demand for insulin during pregnancy which leads to increased insulin production from pancreatic beta cells. The elevated demand is a result of increased maternal calorie intake and weight gain, and increased production of prolactin and growth hormone. Gestational diabetes increases risk for further maternal and fetal complications such as development of pre-eclampsia, need for cesarean delivery, preterm delivery, polyhydramnios, macrosomia, shoulder dystocia, fetal hypoglycemia, hyperbilirubinemia, and admission into the neonatal intensive care unit. The increased risk is correlated with the how well the gestational diabetes is controlled during pregnancy with poor control associated with worsened outcomes. A multidisciplinary approach is used to treat gestational diabetes and involves monitoring of blood-glucose levels, nutritional and dietary modifications, lifestyle changes such as increasing physical activity, maternal weight management, and medication such as insulin.[14]
Hyperemesis gravidarum
Hyperemesis gravidarum is the presence of severe and persistent vomiting, causing dehydration and weight loss. It is similar although more severe than the common morning sickness.[15] [16] It is estimated to affect 0.3–3.6% of pregnant women and is the greatest contributor to hospitalizations under 20 weeks of gestation. Most often, nausea and vomiting symptoms during pregnancy resolve in the first trimester, however, some continue to experience symptoms. Hyperemesis gravidarum is diagnosed by the following criteria: greater than 3 vomiting episodes per day, ketonuria, and weight loss of more than 3 kg or 5% of body weight. There are several non-modifiable and modifiable risk factors that predispose women to development of this condition such as female fetus, psychiatric illness history, high or low BMI pre-pregnancy, young age, African American or Asian ethnicity, type I diabetes, multiple pregnancies, and history of pregnancy affected by hyperemesis gravidarum. There are currently no known mechanisms for the cause of this condition. This complication can cause nutritional deficiency, low pregnancy weight gain, dehydration, and vitamin, electrolyte, and acid-based disturbances in the mother. It has been shown to cause low birth weight, small gestational age, preterm birth, and poor APGAR scores in the infant. Treatments for this condition focus on preventing harm to the fetus while improving symptoms and commonly include fluid replacement and consumption of small, frequent, bland meals. First-line treatments include ginger and acupuncture. Second-line treatments include vitamin B6 +/- doxylamine, antihistamines, dopamine antagonists, and serotonin antagonists. Third-line treatments include corticosteroids, transdermal clonidine, and gabapentin. Treatments chosen are dependent on severity of symptoms and response to therapies.[17]
Pelvic girdle pain
Pelvic girdle pain (PGP) disorder is pain in the area between the posterior iliac crest and gluteal fold beginning peri or postpartum caused by instability and limitation of mobility. It is associated with pubic symphysis pain and sometimes radiation of pain down the hips and thighs. For most pregnant individuals, PGP resolves within three months following delivery, but for some it can last for years, resulting in a reduced tolerance for weight bearing activities. PGP affects around 45% of individuals during pregnancy: 25% report serious pain and 8% are severely disabled.[18] [19] Risk factors for complication development include multiparity, increased BMI, physically strenuous work, smoking, distress, history of back and pelvic trauma, and previous history of pelvic and lower back pain. This syndrome results from a growing uterus during pregnancy that causes increased stress on the lumbar and pelvic regions of the mother, thereby, resulting in postural changes and reduced lumbopelvic muscle strength leading to pelvic instability and pain. It is unclear whether specific hormones in pregnancy are associated with complication development. PGP can result in poor quality of life, predisposition to chronic pain syndrome, extended leave from work, and psychosocial distress. Many treatment options are available based on symptom severity. Non-invasive treatment options include activity modification, pelvic support garments, analgesia with or without short periods of bed rest, and physiotherapy to increase strength of gluteal and adductor muscles reducing stress on the lumbar spine. Invasive surgical management is considered a last-line treatment if all other treatment modalities have failed and symptoms are severe.
High blood pressure
See main article: Hypertensive disease of pregnancy. Potential severe hypertensive states of pregnancy are mainly:
Women who have chronic hypertension before their pregnancy are at increased risk of complications such as premature birth, low birthweight or stillbirth.[26] Women who have high blood pressure and had complications in their pregnancy have three times the risk of developing cardiovascular disease compared to women with normal blood pressure who had no complications in pregnancy. Monitoring pregnant women's blood pressure can help prevent both complications and future cardiovascular diseases.[27] [28]
Venous thromboembolism
Venous thromboembolism, consisting of deep vein thrombosis and pulmonary embolism, is a major risk factor for postpartum morbidity and mortality, especially in highly developed countries. A combination of pregnancy-exacerbated hypercoagulability and additional risk factors such as obesity and thrombophilias makes pregnant women vulnerable to thrombotic events[29] T.he prophylactic measures that include the usage of low molecular weight heparin, in fact, can significantly reduce risks associated with surgery, particularly in high-risk patients. Awareness among healthcare givers and prompt response in early identification and management of venous thromboembolism during pregnancy and the postpartum period are both crucial for prompt response. Deep vein thrombosis, a form of venous thromboembolism, has an incidence of 0.5 to 7 per 1,000 pregnancies, and is the second most common cause of maternal death in developed countries after bleeding.[30]
Anemia
See main article: Anemia in pregnancy. Anemia is a globally recognized complication of pregnancy worldwide and is a condition with a low hemoglobin amount in one of the trimesters. Such physiological modifications are more pronounced among individuals who suffer from undernutrition as well as chronic diseases associated with hemoglobin rehoming, like sickle cell anemia. Prevention of anemia during pregnancy is complicated, and is often treated by a team effort of dietary supplementation, iron therapy, and continuous assessment of mother and fetal indices in a multidisciplinary approach.[31] As an additional measure, emphasis is placed on the astute determination of the respective triggering points, and the application of optimal prenatal care to better maternal and fetal outcome.
Levels of hemoglobin are lower in the third trimesters. According to the United Nations (UN) estimates, approximately half of pregnant individuals develop anemia worldwide. Anemia prevalences during pregnancy differed from 18% in developed countries to 75% in South Asia; culminating to a global rate of 38% of pregnancies worldwide.[32] [5] [33]
Treatment varies due to the severity of the anaemia, and can be used by increasing iron containing foods, oral iron tablets or by the use of parenteral iron.[13]
Infection
See main article: Susceptibility and severity of infections in pregnancy. Pregnancy is a critical period for the expectant mom to experience additional dangers associated with infections. Moreover, a mother and baby's health is exposed to danger when she is in this condition. The prenatal physiology complexity and immunity modulation inherently increase the risk of influenza, hepatitis E, and cytomegalovirus transmission.[34] Avoidance actions like vaccines and strict infectious control protocols can be given priority in the policies aimed at limiting the risk of transmission among high-risk populations. In addition, it is early diagnosis and management of maternal infections are among the main methods to flatline vertical transmission and fetal aberrations.A pregnant woman is more susceptible to certain infections. This increased risk is caused by an increased immune tolerance in pregnancy to prevent an immune reaction against the fetus, as well as secondary to maternal physiological changes including a decrease in respiratory volumes and urinary stasis due to an enlarging uterus.[35] Pregnant individuals are more severely affected by, for example, influenza, hepatitis E, herpes simplex and malaria.[35] The evidence is more limited for coccidioidomycosis, measles, smallpox, and varicella.[35] Mastitis, or inflammation of the breast, occurs in 20% of lactating individuals.[36]
Some infections are vertically transmissible, meaning that they can affect the child as well.[37]
Peripartum cardiomyopathy
Peripartum cardiomyopathy is a heart failure caused by a decrease in left ventricular ejection fraction (LVEF) to <45% which occurs towards the end of pregnancy or a few months postpartum. Symptoms include shortness of breath in various positions and/or with exertion, fatigue, pedal edema, and chest tightness. Risk factors associated with the development of this complication include maternal age over 30 years, multi gestational pregnancy, family history of cardiomyopathy, previous diagnosis of cardiomyopathy, pre-eclampsia, hypertension, and African ancestry. The pathogenesis of peripartum cardiomyopathy is not yet known, however, it is suggested that multifactorial potential causes could include autoimmune processes, viral myocarditis, nutritional deficiencies, and maximal cardiovascular changes during which increase cardiac preload. Peripartum cardiomyopathy can lead to many complications such as cardiopulmonary arrest, pulmonary edema, thromboembolisms, brain injury, and death. Treatment of this condition is very similar to treatment of non-gravid heart failure patients, however, safety of the fetus must be prioritized. For example, for anticoagulation due to increased risk for thromboembolism, low molecular weight heparin which is safe for use during pregnancy is used instead of warfarin which crosses the placenta.[38]
Hypothyroidism
See main article: Thyroid disease in women. Hypothyroidism (commonly caused by Hashimoto's disease) is an autoimmune disease that affects the thyroid by causing low thyroid hormone levels. Symptoms of hypothyroidism can include low energy, cold intolerance, muscle cramps, constipation, and memory and concentration problems.[39] It is diagnosed by the presence of elevated levels of thyroid stimulation hormone or TSH. Patients with elevated TSH and decreased levels of free thyroxine or T4 are considered to have overt hypothyroidism. While those with elevated TSH and normal levels of free T4 are considered to have subclinical hypothyroidism.[40] Risk factors for developing hypothyroidism during pregnancy include iodine deficiency, history of thyroid disease, visible goiter, hypothyroidism symptoms, family history of thyroid disease, history of type 1 diabetes or autoimmune conditions, and history of infertility or fetal loss. Various hormones during pregnancy affect the thyroid and increase thyroid hormone demand. For example, during pregnancy, there is increased urinary iodine excretion as well as increased thyroxine binding globulin and thyroid hormone degradation which all increase thyroid hormone demands.[41] This condition can have a profound effect during pregnancy on the mother and fetus. The infant may be seriously affected and have a variety of birth defects. Complications in the mother and fetus can include pre-eclampsia, anemia, miscarriage, low birth weight, still birth, congestive heart failure, impaired neurointellectual development, and if severe, congenital iodine deficiency syndrome. This complication is treated by iodine supplementation, levothyroxine which is a form of thyroid hormone replacement, and close monitoring of thyroid function.
Fetal and placental problems
The following problems occur in the fetus or placenta, but may have serious consequences on the mother as well.
Ectopic pregnancy
Ectopic pregnancy is implantation of the embryo outside the uterus. This form of complicated pregnancy, which is a non-implication of a normally fertilized egg at any spot other than the uterus, involves operation failure, which can cause life-threatening conditions. However, the underlying reasons for this are not exactly known. This phenomenon is often accompanied by PID (pelvic inflammatory disease) or salpingectomy (surgery).
- Caused by: Unknown, but risk factors include smoking, advanced maternal age, and prior surgery or trauma to the fallopian tubes.
- Risk factors include untreated pelvic inflammatory disease, likely due to fallopian tube scarring.[42]
- Treatment: In most cases, keyhole surgery must be carried out to remove the fetus, along with the fallopian tube. If the pregnancy is very early, it may resolve on its own, or it can be treated with methotrexate, an abortifacient.[43]
Miscarriage
Miscarriage is the loss of a pregnancy prior to 20 weeks.[44] [45] In the UK, miscarriage is defined as the loss of a pregnancy during the first 23 weeks.[46] Comprehensive support, consists of the consultation of the genomics as well as the provision of the medical or surgical operations required. The psychological relevance of family members, relatives, and friends to the bereaved ones is also a necessity. The most effective tools that can be used to minimize the psychological implications of the mourners include autopsy and bereavement counseling.
Approximately 80% of pregnancy loss occurs in the first trimester, with a decrease in risk after 12 weeks gestation. Some variables, such as the mother's being older or chromosomal abnormalities, possess a higher likelihood of causing multiple miscarriages.[47] Spontaneous abortions can be further categorized into complete, inevitable, missed, and threatened abortions:
- Complete: Vaginal bleeding occurs followed by the complete passing of conception products through the cervix.
- Inevitable: Vaginal bleeding occurs; the cervical os is closed indicating that conception products will pass in the near future.
- Missed: Vaginal bleeding occurs and some products of conception may have passed through the cervix; the cervical os is closed and ultrasound shows a nonviable fetus and remaining products of conception.
- Threatened: Vaginal bleeding occurs; the cervical os is closed and ultrasound shows a viable fetus.
Stillbirth
Stillbirth is defined as fetal loss or death after 20 weeks gestation. Early stillbirth is between 20 and 27 weeks gestation, while late stillbirth is between 28 and 36 weeks gestation. A term stillbirth is when the fetus dies 37 weeks and above.[48] This phenomenon can go beyond grief and can lead to worries about strange maternal feelings or postpartum treatment regarding complications of childbirth.[49] Such parents would require more than empathy; generally, adequate medical programs should be considered for parents having such unbearable grief. Along with psychiatric help, counseling, and peer support, which should be useful in the process of assisting parents who have lost their children.
- Epidemiology: There are over 2 million stillbirths a year and there are about 6 stillbirths per 1000 births (0.6%)[50]
- Clinical presentation: Fetal behavioral changes like decreased movements or a loss in fetal sensation may indicate stillbirth, but the presentation can vary greatly.
- Risk factors: Maternal weight, age, and smoking, as well as pre-existing maternal diabetes or hypertension
- Treatment: If fetal passing occurs before labor, treatment options include induced labor or cesarean section. Otherwise, stillbirths can pass with natural birth.
Placental abruption
Placental abruption defined as the separation of the placenta from the uterus prior to delivery, is a major cause of third trimester vaginal bleeding and complicates about 1% of pregnancies.[13] [51] Symptomatic presentations are variable: Some women can entirely ignore the symptoms, while others have mild bleeding or abdominal discomfort and pain. Hence, though symptom severity variance and precipitous placental separation are not relevant, they can still cause the diagnosis and clinical management to be complicated.
Several contributors may result in placental abruption. This includes: pre-existing maternal factors (e.g., smoking, hypertension, advanced age),[52] as well as pregnancy-related factors such as multiple pregnancies or the presence of in-utero infections. Identifying risk factors beforehand in order to take steps and make quick reactions to minimize the likelihood of unfavorable outcomes for the mother or the fetus is essential. The therapy techniques of placental rupture are based on the fetal gestation age and the status of both the mother and the baby. Instant delivery should be medically warranted for full-term babies (36 weeks or more) and in case of distress. Milder cases with immature embryos being monitored closely, any necessary intervention is done in time after careful observation.
The implementation of preventive measures, which include pre-conception counseling to deal with the modifiable risk factors, can significantly contribute to the reduction of incidents of placental abruption. Knowing the long-term impacts on the mother and the baby after giving birth is essential. Continuous research and evidence-based approaches help in providing management that works. Collaboration between healthcare providers and patients is the core of the outcomes of placenta abruption.
- Clinical Presentation: Varies widely from asymptomatic to vaginal bleeding and abdominal pain.
- Risk factors: Prior abruption, smoking, trauma, cocaine use, multifetal gestation, hypertension, preeclampsia, thrombophilias, advanced maternal age, preterm premature rupture of membranes, intrauterine infections, and hydramnios.
- Treatment: Immediate delivery if the fetus is mature (36 weeks or older), or if a younger fetus or the mother is in distress. In less severe cases with immature fetuses, the situation may be monitored in hospital, with treatment if necessary.
Placenta previa
Placenta previa is a condition that occurs when the placenta fully or partially covers the cervix.[13] Placenta previa can be further categorized into complete previa, partial previa, marginal previa, and low-lying placenta, depending on the degree to which the placenta covers the internal cervical os. Placenta previa is primarily diagnosed by ultrasound, either during a routine examination or following an episode of abnormal vaginal bleeding, often in the second trimester of pregnancy. Most diagnosis of placenta previa occurs during the second-trimester.
Treatments are adapted according to their severity and the mother's state of health, from strict monitoring to cesarean section.
- Risk Factors: prior cesarean delivery, pregnancy termination, intrauterine surgery, smoking, multifetal gestation, increasing parity, maternal age.[53]
Placenta accreta
Placenta accreta is an abnormal adherence of the placenta to the uterine wall.[54] Specifically, placenta accreta involves abnormal adherence of the placental trophoblast to the uterine myometrium.[55]
Placenta accreta risk factors include placenta previa, abnormally elevated second-trimester AFP and free β-hCG levels, and advanced gestational parent age, specifically over the age of 35.[56] [57] Furthermore, prior cesarean delivery is one of the most common risk factors for placenta accreta, due to the presence of a uterine scar leading to abnormal decidualization of the placenta.[58]
Due to abnormal adherence of the placenta to the uterine wall, cesarean delivery is often indicated, as well as cesarean hysterectomy.
Multiple pregnancies
Multiple births may become monochorionic, sharing the same chorion, with resultant risk of twin-to-twin transfusion syndrome. Monochorionic multiples may even become monoamniotic, sharing the same amniotic sac, resulting in risk of umbilical cord compression and entanglement. In very rare cases, there may be conjoined twins, possibly impairing function of internal organs. Control of multiple pregnancies, such as special prenatal care and birth plans, can help in the control of placenta accreta.[59] Moreover, early detection and response to the health problems arising from multiple pregnancies can help both the expectant parents and medical care providers deal with this particular aspect of reproductive health consciously.
Mother-to-child transmission
Since the embryo and fetus have little or no immune function, they depend on the immune function of their mother. Several pathogens can cross the placenta and cause (perinatal) infection. Often microorganisms that produce minor illness in the mother are very dangerous for the developing embryo or fetus. This can result in spontaneous abortion or major developmental disorders. For many infections, the baby is more at risk at particular stages of pregnancy. Problems related to perinatal infection are not always directly noticeable.
The term TORCH complex refers to a set of several different infections that may be caused by transplacental infection:
- T - Toxoplasmosis
- O - other infections (i.e. Parvovirus B19, Coxsackievirus, Chickenpox, Chlamydia, HIV, HTLV, syphilis, Zika)
- R - Rubella
- C - Cytomegalovirus
- H - HSV
Babies can also become infected by their mother during birth. During birth, babies are exposed to maternal blood and body fluids without the placental barrier intervening and to the maternal genital tract.[60] Because of this, blood-borne microorganisms (hepatitis B, HIV), organisms associated with sexually transmitted disease (e.g., gonorrhoea and chlamydia), and normal fauna of the genito-urinary tract (e.g., Candida) are among those commonly seen in infection of newborns. Furthermore, vaccination, commitment to safe birth practices, and prenatal screening and treatment of infections are also strategic measures that can help reduce the risk of newborn infections.
General risk factors
Factors increasing the risk (to either the pregnant individual, the fetus/es, or both) of pregnancy complications beyond the normal level of risk may be present in the pregnant individual's medical profile either before they become pregnant or during the pregnancy.[61] These pre-existing factors may related to the individual's genetics, physical or mental health, their environment and social issues, or a combination of those.[62]
Biological
Some common biological risk factors include:
- Age of either parent
- Adolescent parents: Young mothers are at an increased risk of developing certain complications, including preterm birth and low infant birth weight.[63]
- Older parents: As they age, both mothers and fathers are at an increased risk for complications in the fetus and during pregnancy and childbirth. Complications for those 45 or older include increased risk of primary Caesarean delivery (i.e. C-section).[64]
- Height: Pregnancy in individuals whose height is less than 1.5 meters (5 feet) correlates with a higher incidence of preterm birth and underweight babies. Also, these individuals are more likely to have a small pelvis, which can result in such complications during childbirth as shoulder dystocia.
- Weight
- Low weight: Individuals whose pre-pregnancy weight is less than 45.5 kilograms (100 pounds) are more likely to have underweight babies.
- High weight: Obese individuals are more likely to have very large babies, potentially increasing difficulties in childbirth. Obesity also increases the chances of developing gestational diabetes, high blood pressure, preeclampsia, experiencing postterm pregnancy and requiring a cesarean delivery.
- Pre-existing disease in pregnancy, or an acquired disease: A disease and condition not necessarily directly caused by the pregnancy.
- Risks arising from previous pregnancies: Complications experienced during a previous pregnancy are more likely to recur.[65] [66]
- Multiple pregnancies: Individuals who have had greater than five previous pregnancies face increased risks of rapid labor and excessive bleeding after delivery.
- Multiple gestation (having more than one fetus in a single pregnancy): These individuals have an increased risk of mislocated placenta.
Environmental
Some common environmental risk factors during pregnancy include:
- Exposure to environmental toxins
- Exposure to recreational drugs
- Social and socioeconomic factors: Generally speaking, unmarried individuals and those in lower socioeconomic groups experience an increased level of risk in pregnancy, due at least in part to lack of access to appropriate prenatal care.[73]
- Unintended pregnancy: Unintended pregnancies preclude preconception care and delays prenatal care. They preclude other preventive care, may disrupt life plans and on average have worse health and psychological outcomes for the mother and, if birth occurs, the child.[74] [75]
- Exposure to pharmaceutical drugs: Certain anti-depressants may increase risks of preterm delivery.[76]
- Stress
- An elevated level of stress during pregnancy leads to notorious pregnancy outcomes, including preterm birth, low birth weight, and mental health problems for the mother.
- Prolonged effects of chronic stressors such as discrimination, intimate partner violence, housing issues, and poverty lead to widespread maternal health issues and adverse pregnancy outcomes.
- Culture
- Cultural norms, convictions, and traditions connected to pregnancy and childbirth lead people to establish perceptions, habits, and treatment-seeking. Cultural determinants affect the assessment of prenatal care utilization, childbirth practice, dietary habits and reproductive health beliefs, which are direct outcomes of pregnancy and health situations.
High-risk pregnancy
Some disorders and conditions can mean that pregnancy is considered high-risk (about 6-8% of pregnancies in the USA) and in extreme cases may be contraindicated. High-risk pregnancies are the main focus of doctors specialising in maternal-fetal medicine. Serious pre-existing disorders which can reduce a woman's physical ability to survive pregnancy include a range of congenital defects (that is, conditions with which the woman herself was born, for example, those of the heart or reproductive organs, some of which are listed above) and diseases acquired at any time during the woman's life.
List of complications (complete)
Obstetric complications are those complications that develop during pregnancy. A woman may develop an infection, syndrome or complication that is not unique to pregnancy and that may have existed before pregnancy. Pregnancy often is complicated by preexisting and concurrent conditions. Though these pre-existing and concurrent conditions may have great impact on pregnancy, they are not included in the following list.
See also
Further reading
- Book: Leveno K . Williams manual of pregnancy complications . McGraw-Hill Medical . New York . 2013 . 978-0071765626 .
External links
Notes and References
- Stevens . Gretchen A . Finucane . Mariel M . De-Regil . Luz Maria . Paciorek . Christopher J . Flaxman . Seth R . Branca . Francesco . Peña-Rosas . Juan Pablo . Bhutta . Zulfiqar A . Ezzati . Majid . 2013-07-01 . Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995–2011: a systematic analysis of population-representative data . The Lancet Global Health . 1 . 1 . e16–e25 . 10.1016/s2214-109x(13)70001-9 . 2214-109X . 4547326 . 25103581.
- Lozano . Rafael . Naghavi . Mohsen . Foreman . Kyle . Lim . Stephen . Shibuya . Kenji . Aboyans . Victor . Abraham . Jerry . Adair . Timothy . Aggarwal . Rakesh . Ahn . Stephanie Y . AlMazroa . Mohammad A . Alvarado . Miriam . Anderson . H Ross . Anderson . Laurie M . Andrews . Kathryn G . 2012-12-15 . Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010 . The Lancet . 380 . 9859 . 2095–2128 . 10.1016/s0140-6736(12)61728-0 . 0140-6736 . 10790329 . 23245604. 10292/13775 .
- Liu . Li . Johnson . Hope L . Cousens . Simon . Perin . Jamie . Scott . Susana . Lawn . Joy E . Rudan . Igor . Campbell . Harry . Cibulskis . Richard . Li . Mengying . Mathers . Colin . Black . Robert E . 2012-06-09 . Global, regional, and national causes of child mortality: an updated systematic analysis for 2010 with time trends since 2000 . The Lancet . 379 . 9832 . 2151–2161 . 10.1016/s0140-6736(12)60560-1 . 22579125 . 0140-6736.
- Book: Obstetrics and gynecology. . 2010 . Lippincott Williams & Wilkins . Charles R. B. Beckmann, American College of Obstetricians and Gynecologists . 978-0-7817-8807-6 . 6th. Baltimore, MD . 298509160.
- O'Toole . F.E . Hokey . E. . McAuliffe . F.M . Walsh . J.M . 2024-06-01 . The Experience of Anaemia and Ingesting Oral Iron Supplementation in Pregnancy: A Qualitative Study . European Journal of Obstetrics & Gynecology and Reproductive Biology . 297 . 111–119 . 10.1016/j.ejogrb.2024.03.005 . 38608353 . 0301-2115. free .
- Web site: Severe Maternal Morbidity in the United States . live . https://web.archive.org/web/20150629114443/http://www.cdc.gov/reproductivehealth/MaternalInfantHealth/SevereMaternalMorbidity.html . 2015-06-29 . 2015-07-08 . CDC.
- Web site: Severe Maternal Morbidity in Canada . dead . https://web.archive.org/web/20160309111959/http://sogc.org/wp-content/uploads/2013/05/Morbidity-EN-Final-PDF.pdf . 2016-03-09 . 2015-07-08 . The Society of Obstetricians and Gynaecologists of Canada (SOGC).
- Glazener CM, Abdalla M, Stroud P, Naji S, Templeton A, Russell IT . Postnatal maternal morbidity: extent, causes, prevention and treatment . British Journal of Obstetrics and Gynaecology . 102 . 4 . 282–287 . April 1995 . 7612509 . 10.1111/j.1471-0528.1995.tb09132.x . 38872754 .
- Thompson JF, Roberts CL, Currie M, Ellwood DA . Prevalence and persistence of health problems after childbirth: associations with parity and method of birth . Birth . 29 . 2 . 83–94 . June 2002 . 12051189 . 10.1046/j.1523-536X.2002.00167.x .
- Borders N . After the afterbirth: a critical review of postpartum health relative to method of delivery . Journal of Midwifery & Women's Health . 51 . 4 . 242–248 . 2006 . 16814217 . 10.1016/j.jmwh.2005.10.014 .
- Global, regional, and national age-sex specific mortality for 264 causes of death, 1980-2016: a systematic analysis for the Global Burden of Disease Study 2016 . Lancet . 390 . 10100 . 1151–1210 . September 2017 . 28919116 . 5605883 . 10.1016/S0140-6736(17)32152-9 . GBD 2016 Causes of Death Collaborators . Naghavi . Mohsen . Abajobir . Amanuel Alemu . Abbafati . Cristiana . Abbas . Kaja M. . Abd-Allah . Foad . Abera . Semaw Ferede . Aboyans . Victor . Adetokunboh . Olatunji . Afshin . Ashkan . Agrawal . Anurag . Ahmadi . Alireza . Ahmed . Muktar Beshir . Aichour . Amani Nidhal . Aichour . Miloud Taki Eddine . Aichour . Ibtihel . Aiyar . Sneha . Alahdab . Fares . Al-Aly . Ziyad . Alam . Khurshid . Alam . Noore . Alam . Tahiya . Alene . Kefyalew Addis . Al-Eyadhy . Ayman . Ali . Syed Danish . Alizadeh-Navaei . Reza . Alkaabi . Juma M. . Alkerwi . Ala'a . Alla . François . Allebeck . Peter . Allen . Christine . 1 .
- Say L, Chou D, Gemmill A, Tunçalp Ö, Moller AB, Daniels J, Gülmezoglu AM, Temmerman M, Alkema L . 6 . Global causes of maternal death: a WHO systematic analysis . The Lancet. Global Health . 2 . 6 . e323–e333 . June 2014 . 25103301 . 10.1016/s2214-109x(14)70227-x . free . 1854/LU-5796925 . free .
- Web site: Pregnancy complications . womenshealth.gov. 2018-11-07. 2016-12-14.
- Lende M, Rijhsinghani A . Gestational Diabetes: Overview with Emphasis on Medical Management . International Journal of Environmental Research and Public Health . 17 . 24 . 9573 . December 2020 . 33371325 . 7767324 . 10.3390/ijerph17249573 . free .
- Summers A . Emergency management of hyperemesis gravidarum . Emergency Nurse . 20 . 4 . 24–28 . July 2012 . 22876404 . 10.7748/en2012.07.20.4.24.c9206 .
- Goodwin TM . Hyperemesis gravidarum . Obstetrics and Gynecology Clinics of North America . 35 . 3 . 401–17, viii . September 2008 . 18760227 . 10.1016/j.ogc.2008.04.002 .
- Austin K, Wilson K, Saha S . Hyperemesis Gravidarum . Nutrition in Clinical Practice . 34 . 2 . 226–241 . April 2019 . 30334272 . 10.1002/ncp.10205 . 52987088 .
- Wu WH, Meijer OG, Uegaki K, Mens JM, van Dieën JH, Wuisman PI, Ostgaard HC . Pregnancy-related pelvic girdle pain (PPP), I: Terminology, clinical presentation, and prevalence . European Spine Journal . 13 . 7 . 575–589 . November 2004 . 15338362 . 3476662 . 10.1007/s00586-003-0615-y .
- Walters C, West S, A Nippita T . Pelvic girdle pain in pregnancy . Australian Journal of General Practice . 47 . 7 . 439–443 . July 2018 . 30114872 . 10.31128/AJGP-01-18-4467 . 52018638 . free .
- Book: Villar J, Say L, Gulmezoglu AM, Meraldi M, Lindheimer MD, Betran AP, Piaggio G . Eclampsia and pre-eclampsia: a health problem for 2000 years. . Pre-eclampsia . Critchly H, MacLean A, Poston L, Walker J . London . RCOG Press . 2003 . 189–207 .
- Abalos E, Cuesta C, Grosso AL, Chou D, Say L . Global and regional estimates of preeclampsia and eclampsia: a systematic review . European Journal of Obstetrics, Gynecology, and Reproductive Biology . 170 . 1 . 1–7 . September 2013 . 23746796 . 10.1016/j.ejogrb.2013.05.005 .
- Web site: High Blood Pressure in Pregnancy . medlineplus.gov . 28 September 2022.
- Haram K, Svendsen E, Abildgaard U . The HELLP syndrome: clinical issues and management. A Review . BMC Pregnancy and Childbirth . 9 . 8 . February 2009 . 19245695 . 2654858 . 10.1186/1471-2393-9-8 . live . https://web.archive.org/web/20111112031619/http://www.biomedcentral.com/content/pdf/1471-2393-9-8.pdf . 2011-11-12 . free .
- Mjahed K, Charra B, Hamoudi D, Noun M, Barrou L . Acute fatty liver of pregnancy . Archives of Gynecology and Obstetrics . 274 . 6 . 349–353 . October 2006 . 16868757 . 10.1007/s00404-006-0203-6 . 24784165 .
- Reyes H, Sandoval L, Wainstein A, Ribalta J, Donoso S, Smok G, Rosenberg H, Meneses M . 6 . Acute fatty liver of pregnancy: a clinical study of 12 episodes in 11 patients . Gut . 35 . 1 . 101–106 . January 1994 . 8307428 . 1374642 . 10.1136/gut.35.1.101 .
- Al Khalaf SY, O'Reilly ÉJ, Barrett PM, B Leite DF, Pawley LC, McCarthy FP, Khashan AS . Impact of Chronic Hypertension and Antihypertensive Treatment on Adverse Perinatal Outcomes: Systematic Review and Meta-Analysis . Journal of the American Heart Association . 10 . 9 . e018494 . May 2021 . 33870708 . 8200761 . 10.1161/JAHA.120.018494 .
- 2023-11-21 . Pregnancy complications increase the risk of heart attacks and stroke in women with high blood pressure . NIHR Evidence . Plain English summary . National Institute for Health and Care Research . 10.3310/nihrevidence_60660. 265356623 .
- Al Khalaf S, Chappell LC, Khashan AS, McCarthy FP, O'Reilly ÉJ . Association Between Chronic Hypertension and the Risk of 12 Cardiovascular Diseases Among Parous Women: The Role of Adverse Pregnancy Outcomes . Hypertension . 80 . 7 . 1427–1438 . July 2023 . 37170819 . 10.1161/HYPERTENSIONAHA.122.20628 . free .
- Sarkar . Monika . Brady . Carla W. . Fleckenstein . Jaquelyn . Forde . Kimberly A. . Khungar . Vandana . Molleston . Jean P. . Afshar . Yalda . Terrault . Norah A. . January 2021 . Reproductive Health and Liver Disease: Practice Guidance by the American Association for the Study of Liver Diseases . Hepatology . en . 73 . 1 . 318–365 . 10.1002/hep.31559 . 32946672 . 0270-9139.
- Venös tromboembolism (VTE) – Guidelines for treatment in C counties. Bengt Wahlström, Emergency department, Uppsala Academic Hospital. January 2008
- Taher . Ali T. . Iolascon . Achille . Matar . Charbel F. . Bou-Fakhredin . Rayan . de Franceschi . Lucia . Cappellini . Maria Domenica . Barcellini . Wilma . Russo . Roberta . Andolfo . Immacolata . Tyan . Paul . Gulbis . Beatrice . Aydinok . Yesim . Anagnou . Nicholas P. . Bencaiova . Gabriela Amstad . Tamary . Hannah . August 2020 . Recommendations for Pregnancy in Rare Inherited Anemias . HemaSphere . en-US . 4 . 4 . e446 . 10.1097/HS9.0000000000000446 . 32885142 . 7437563 . 2572-9241.
- Stevens . Gretchen A . Finucane . Mariel M . De-Regil . Luz Maria . Paciorek . Christopher J . Flaxman . Seth R . Branca . Francesco . Peña-Rosas . Juan Pablo . Bhutta . Zulfiqar A . Ezzati . Majid . 2013-07-01 . Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995–2011: a systematic analysis of population-representative data . The Lancet Global Health . 1 . 1 . e16–e25 . 10.1016/s2214-109x(13)70001-9 . 2214-109X . 4547326 . 25103581.
- Book: Wang S, An L, Cochran SD . Women . Detels R, McEwen J, Beaglehole R, Tanaka H . Oxford Textbook of Public Health . Oxford University Press . 2002 . 1587–601 . 4th.
- https://www.cell.com/immunity/pdf/S1074-7613(22)00184-4.pdf
- Kourtis AP, Read JS, Jamieson DJ . Pregnancy and infection . The New England Journal of Medicine . 370 . 23 . 2211–2218 . June 2014 . 24897084 . 4459512 . 10.1056/NEJMra1213566 .
- Kaufmann R, Foxman B . Mastitis among lactating women: occurrence and risk factors . Social Science & Medicine . 33 . 6 . 701–705 . 1991 . 1957190 . 10.1016/0277-9536(91)90024-7 . free . 2027.42/29639 .
- Web site: What infections can affect pregnancy? . NIH . 27 April 2021 . March 6, 2023.
- Davis MB, Arany Z, McNamara DM, Goland S, Elkayam U . Peripartum Cardiomyopathy: JACC State-of-the-Art Review . Journal of the American College of Cardiology . 75 . 2 . 207–221 . January 2020 . 31948651 . 10.1016/j.jacc.2019.11.014 . 210701262 . free .
- Web site: Thyroid Disease & Pregnancy NIDDK . 2022-03-12 . National Institute of Diabetes and Digestive and Kidney Diseases . en-US.
- Sullivan SA . Hypothyroidism in Pregnancy . Clinical Obstetrics and Gynecology . 62 . 2 . 308–319 . June 2019 . 30985406 . 10.1097/GRF.0000000000000432 . 115198534 .
- Taylor PN, Lazarus JH . Hypothyroidism in Pregnancy . Endocrinology and Metabolism Clinics of North America . 48 . 3 . 547–556 . September 2019 . 31345522 . 10.1016/j.ecl.2019.05.010 . Pregnancy and Endocrine Disorders . 71053515 .
- Lemire F . [Not Available] . Canadian Family Physician . 67 . 10 . 791 . October 2021 . 34649907 . 8516186 . 10.46747/cfp.6710791 . 238861265 . free .
- Web site: Ectopic pregnancy – Treatment – NHS Choices. www.nhs.uk. 2017-07-27.
- Web site: Pregnancy complications . www.womenshealth.gov . 2016-11-13 . live . https://web.archive.org/web/20161114002619/https://www.womenshealth.gov/pregnancy/you-are-pregnant/pregnancy-complications.html . 2016-11-14 .
- Book: Dugas C, Slane VH . Miscarriage . 2022 . http://www.ncbi.nlm.nih.gov/books/NBK532992/ . StatPearls . Treasure Island (FL) . StatPearls Publishing . 30422585 . 2022-09-12 .
- Web site: Miscarriage. NHS Choice. NHS. https://web.archive.org/web/20170215140413/http://www.nhs.uk/conditions/Miscarriage/Pages/Introduction.aspx. 2017-02-15. live. 2017-02-13.
- Web site: du Fossé . Nadia A . van der Hoorn . Marie-Louise P . van Lith . Jan M M . le Cessie . Saskia . Lashley . Eileen E L O . 2020-05-02 . Advanced paternal age is associated with an increased risk of spontaneous miscarriage: a systematic review and meta-analysis . 2024-08-11 . Human Reproduction Update . 650–669 . 10.1093/humupd/dmaa010 . 7456349 . 32358607.
- Marufu TC, Ahankari A, Coleman T, Lewis S . Maternal smoking and the risk of still birth: systematic review and meta-analysis . BMC Public Health . 15 . 1 . 239 . March 2015 . 25885887 . 4372174 . 10.1186/s12889-015-1552-5 . 5241108 . free .
- https://www.obgyn.theclinics.com/article/S0889-8545(20)30035-8/abstract
- Page JM, Silver RM . Evaluation of stillbirth . Current Opinion in Obstetrics & Gynecology . 30 . 2 . 130–135 . April 2018 . 29489503 . 10.1097/GCO.0000000000000441 . 3607787 .
- Oyelese Y, Ananth CV . Placental abruption . Obstetrics and Gynecology . 108 . 4 . 1005–1016 . October 2006 . 17012465 . 10.1097/01.aog.0000239439.04364.9a . 960903 .
- Associations of maternal smoking and drinking with fetal growth and placental abruption . 10.1016/j.ejogrb.2020.07.018 . European Journal of Obstetrics & Gynecology and Reproductive Biology . October 2020 . 253 . 95–102 . Odendaal . Hein . Wright . Colleen . Schubert . Pawel . Boyd . Theonia K. . Roberts . Drucilla J. . Brink . Lucy . Nel . Daan . Groenewald . Coen . 32862031 .
- Oyelese Y, Smulian JC . Placenta previa, placenta accreta, and vasa previa . Obstetrics and Gynecology . 107 . 4 . 927–941 . April 2006 . 16582134 . 10.1097/01.AOG.0000207559.15715.98 . 22774083 .
- Wortman AC, Alexander JM . Placenta accreta, increta, and percreta . Obstetrics and Gynecology Clinics of North America . 40 . 1 . 137–154 . March 2013 . 23466142 . 10.1016/j.ogc.2012.12.002 .
- Silver RM, Branch DW . Placenta Accreta Spectrum . The New England Journal of Medicine . 378 . 16 . 1529–1536 . April 2018 . 29669225 . 10.1056/NEJMcp1709324 . 81685472 .
- Hung TH, Shau WY, Hsieh CC, Chiu TH, Hsu JJ, Hsieh TT . Risk factors for placenta accreta . Obstetrics and Gynecology . 93 . 4 . 545–550 . April 1999 . 10214831 . 10.1016/S0029-7844(98)00460-8 .
- Risk Factors, Pattern and Outcome of Third Trimester Bleeding in a Tertiary Care Hospital . Coimbatore Medical College, Coimbatore . May 2022 . masters . en . M. . Anuselvi.
- Web site: Placenta Accreta Spectrum . 2022-09-16 . www.acog.org . en.
- A comparison of recent guidelines in the diagnosis and management of placenta accreta spectrum disorders . 10.1016/j.bpobgyn.2020.06.007 . 32698993 . 2021 . Jauniaux . E. . Kingdom . J. C. . Silver . R. M. . Best Practice & Research. Clinical Obstetrics & Gynaecology . 72 . 102–116 .
- Kumar . Manoj . Saadaoui . Marwa . Al Khodor . Souhaila . 2022 . Infections and Pregnancy: Effects on Maternal and Child Health . Frontiers in Cellular and Infection Microbiology . 12 . 10.3389/fcimb.2022.873253 . free . 35755838 . 9217740 . 2235-2988.
- Web site: Health problems in pregnancy . Medline Plus . US National Library of Medicine . live . https://web.archive.org/web/20130813100208/http://www.nlm.nih.gov/medlineplus/healthproblemsinpregnancy.html . 2013-08-13 .
- Web site: Merck . Risk factors present before pregnancy . Merck Manual Home Health Handbook . Merck Sharp & Dohme . live . https://web.archive.org/web/20130601003348/http://www.merckmanuals.com/home/womens_health_issues/pregnancy_at_high-risk/risk_factors_present_before_pregnancy.html . 2013-06-01 .
- Koniak-Griffin D, Turner-Pluta C . Health risks and psychosocial outcomes of early childbearing: a review of the literature . The Journal of Perinatal & Neonatal Nursing . 15 . 2 . 1–17 . September 2001 . 12095025 . 10.1097/00005237-200109000-00002 . 42701860 .
- Bayrampour H, Heaman M . Advanced maternal age and the risk of cesarean birth: a systematic review . Birth . 37 . 3 . 219–226 . September 2010 . 20887538 . 10.1111/j.1523-536X.2010.00409.x .
- Brouwers L, van der Meiden-van Roest AJ, Savelkoul C, Vogelvang TE, Lely AT, Franx A, van Rijn BB . Recurrence of pre-eclampsia and the risk of future hypertension and cardiovascular disease: a systematic review and meta-analysis . BJOG . 125 . 13 . 1642–1654 . December 2018 . 29978553 . 6283049 . 10.1111/1471-0528.15394 .
- Lamont K, Scott NW, Jones GT, Bhattacharya S . Risk of recurrent stillbirth: systematic review and meta-analysis . BMJ . 350 . h3080 . June 2015 . 26109551 . 10.1136/bmj.h3080 . free . free . 2164/4642 .
- Williams PM, Fletcher S . Health effects of prenatal radiation exposure . American Family Physician . 82 . 5 . 488–493 . September 2010 . 20822083 . 22400308 .
- Denny CH, Acero CS, Naimi TS, Kim SY . Consumption of Alcohol Beverages and Binge Drinking Among Pregnant Women Aged 18-44 Years - United States, 2015-2017 . MMWR. Morbidity and Mortality Weekly Report . 68 . 16 . 365–368 . April 2019 . 31022164 . 6483284 . 10.15585/mmwr.mm6816a1 .
- Web site: Centers for Disease Control and Prevention . 2007 . Preventing Smoking and Exposure to Secondhand Smoke Before, During, and After Pregnancy . https://web.archive.org/web/20110911020755/http://www.cdc.gov/nccdphp/publications/factsheets/Prevention/pdf/smoking.pdf . 2011-09-11 .
- Web site: Substance Use During Pregnancy . 2013-10-26 . live . https://web.archive.org/web/20131029204538/http://www.cdc.gov/reproductivehealth/tobaccousepregnancy/index.htm . 2013-10-29 . Centers for Disease Control and Prevention . 2009 .
- Web site: New Mother Fact Sheet: Methamphetamine Use During Pregnancy . North Dakota Department of Health . 7 October 2011 . dead . https://web.archive.org/web/20110910221317/http://www.ndmch.com/ . 2011-09-10 .
- Della Grotta S, LaGasse LL, Arria AM, Derauf C, Grant P, Smith LM, Shah R, Huestis M, Liu J, Lester BM . 6 . Patterns of methamphetamine use during pregnancy: results from the Infant Development, Environment, and Lifestyle (IDEAL) Study . Maternal and Child Health Journal . 14 . 4 . 519–527 . July 2010 . 19565330 . 2895902 . 10.1007/s10995-009-0491-0 .
- Grand-Guillaume-Perrenoud . Jean Anthony . Origlia . Paola . Cignacco . Eva . 2022-02-01 . Barriers and facilitators of maternal healthcare utilisation in the perinatal period among women with social disadvantage: A theory-guided systematic review . Midwifery . 105 . 103237 . 10.1016/j.midw.2021.103237 . 34999509 . 0266-6138.
- Book: The best intentions: unintended pregnancy and the well-being of children and families. Eisenberg L, Brown SH . National Academy Press. 1995. 978-0-309-05230-6. Washington, D.C . 2011-09-03. registration.
- Web site: Family Planning - Healthy People 2020. https://web.archive.org/web/20101228012908/http://www.healthypeople.gov/2020/topicsobjectives2020/overview.aspx?topicid=13. 2010-12-28. live. 2011-08-18.
- Gavin AR, Holzman C, Siefert K, Tian Y . Maternal depressive symptoms, depression, and psychiatric medication use in relation to risk of preterm delivery . Women's Health Issues . 19 . 5 . 325–334 . 2009 . 19733802 . 2839867 . 10.1016/j.whi.2009.05.004 .
- Web site: Chromosome Abnormalities Fact Sheet. National Human Genome Research Institute (NHGRI). 14 May 2017.
- Kirk E, Bottomley C, Bourne T . Diagnosing ectopic pregnancy and current concepts in the management of pregnancy of unknown location . Human Reproduction Update . 20 . 2 . 250–261 . 1 March 2014 . 24101604 . 10.1093/humupd/dmt047 .
- Web site: Pregnancy Loss: Condition Information. www.nichd.nih.gov. 14 May 2017.
- Cluver C, Gyte GM, Sinclair M, Dowswell T, Hofmeyr GJ . Interventions for helping to turn term breech babies to head first presentation when using external cephalic version . The Cochrane Database of Systematic Reviews . 2015 . 2 . CD000184 . February 2015 . 25674710 . 10.1002/14651858.CD000184.pub4 . 10363414 . free . 10019.1/104301 .
- Web site: Uterine Rupture in Pregnancy: Overview, Rupture of the Unscarred Uterus, Previous Uterine Myomectomy and Uterine Rupture. reference.medscape.com. 14 May 2017.
- Bowman JM, Chown B, Lewis M, Pollock JM . Rh isoimmunization during pregnancy: antenatal prophylaxis . Canadian Medical Association Journal . 118 . 6 . 623–627 . March 1978 . 77714 . 1818025 .
- Web site: Public Education Pamphlets. sogc.org. 15 May 2017. https://web.archive.org/web/20180706163239/https://sogc.org/publications-resources/public-information-pamphlets.html?id=33. 6 July 2018. dead.
- Harden CL, Hopp J, Ting TY, Pennell PB, French JA, Hauser WA, Wiebe S, Gronseth GS, Thurman D, Meador KJ, Koppel BS, Kaplan PW, Robinson JN, Gidal B, Hovinga CA, Wilner AN, Vazquez B, Holmes L, Krumholz A, Finnell R, Le Guen C . 6 . Practice parameter update: management issues for women with epilepsy--focus on pregnancy (an evidence-based review): obstetrical complications and change in seizure frequency: report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society . Neurology . 73 . 2 . 126–132 . July 2009 . 19398682 . 3475195 . 10.1212/WNL.0b013e3181a6b2f8 .
- Web site: ICD-10 Version:2016. International Statistical Classification of Diseases and Related Health Problems 10th Revision. 16 May 2017.