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Pregnancy Complications

  1. What are pregnancy complications?
  2. Infections during pregnancy
  3. Non-infectious conditions during pregnancy
  4. Complications specific to pregnancy

What are pregnancy complications?

Pregnancy complications are health problems that occur during pregnancy, and which affect the mother, the baby or both. The majority of pregnancies proceed normally without any health issues, but it is important, even for very healthy women, to be aware of possible complications. Familiarity with possible kinds of pregnancy complications and their symptoms will contribute to the likelihood of a healthy pregnancy by enabling the expectant parent to:

  • Ensure that any necessary preventive measures are taken
  • Identify potential complications early enough to treat them successfully
  • Receive appropriate healthcare support should it be needed

This will increase the possibility of preventing pregnancy complications that do occur resulting in adverse outcomes, such as miscarriage.

The following overview of possible pregnancy complications includes some of the most common pregnancy complications, including:

  • Infections that may develop during pregnancy
  • Non-infectious conditions, possibly pre-existing, which can present complications during pregnancy
  • Complications that are specific to pregnancy

Infections during pregnancy

During pregnancy, women are more susceptible to certain infections and the complications of certain infections. Some infections may also affect the healthy development of the baby.

Chickenpox during pregnancy

The likelihood of developing chickenpox during pregnancy is relatively low, and women who do contract chickenpox are unlikely to experience serious complications. However, in some cases, chickenpox during pregnancy can cause complications for the mother and baby and be potentially life threatening.[1]

Contact a doctor or midwife in the following situations:

  • Chickenpox is contracted, or there is a suspicion of the condition
  • The mother has never had chickenpox and never been near anyone with chickenpox, even if there are no symptoms present

Food poisoning during pregnancy

Pregnant women are more likely to develop food poisoning. In most cases, a bout of food poisoning will be unpleasant for the mother, but will not affect the health of the baby. However, food poisoning can affect the baby, especially if the infection is a result of types of bacteria called listeria, which causes listeriosis, or the toxoplasma gondii parasite, which causes toxoplasmosis.

Listeriosis is a bacterial infection, often found in unpasteurised dairy products, such as milk and soft cheeses, as well as raw and cured (deli) meats. It is important to avoid these foods during pregnancy and to contact one’s doctor or midwife at the first sign of infection, which may include nausea and vomiting, diarrhoea and/or aches and pains. Diagnosis will be made with a blood test, after which a course of antibiotic treatment will usually be prescribed to prevent possible pregnancy complications. Pregnant women are particularly susceptible to Listeria infection in their third trimester.[2]

Toxoplasmosis is a parasite infection, often found in raw or undercooked meat, cat feces and contaminated soil. If a pregnant woman develops toxoplasmosis, this can pose serious health risks for the baby, including miscarriage and stillbirth.[3] The likelihood of contracting toxoplasmosis during pregnancy is thought to be very small, but pregnant women should nonetheless take care to wash their hands thoroughly with antibacterial soap and water after touching soil, for example, after gardening, and avoid undercooked meat, raw shellfish, unfiltered water and possibly contaminated fruits and vegetables. It would also be prudent to ask another person to change the cat litter box, should this be necessary. Preventive measures are the most appropriate in combating toxoplasmosis.[4]
A pregnant woman may develop no symptoms at all as a result of toxoplasmosis or may feel generally unwell and develop swollen glands.[5] If there is any concern that a pregnant woman may have contracted the infection, even when no symptoms are present, urgent medical attention should be sought.

Contact a doctor or midwife in the following situations, which may relate to food poisoning:[3]

  • The mother feels very unwell, particularly if there is severe stomach pain
  • There is a fever
  • Diarrhea lasts for longer than three days
  • Vomiting is continuous
  • The mother cannot keep fluids down
  • There is blood in the mother’s stool
  • There is bleeding from the vagina

Read more about foods to eat during pregnancy and foods to avoid during pregnancy »

Flu during pregnancy

The chances of complications are higher for women who contract the flu during pregnancy, but for most, these will not be serious. In some cases, these complications can affect the baby’s health. If you are concerned that you may be developing the flu during pregnancy, get a personal health assessment from the Ada app. A doctor should be consulted if flu-like symptoms are present.

Pregnant women are advised to have the flu vaccine to lower the chances of contracting the viral infection. Other preventive measures – such as avoiding contact with people with the flu and washing the hands regularly – should also be taken throughout the course of the pregnancy.

The flu typically begins with the following symptoms:

  • Achiness and fatigue
  • Fever
  • Cold symptoms (coughing, sore throat, runny or stuffy nose, sneezing, etc)

A doctor should be contacted as a matter of urgency if the following symptoms present themselves:[6]

  • Shortness of breath or difficulty breathing
  • There is blood in the mucus
  • Chest (abdomen) pain
  • Dizziness or confusion
  • Persistent vomiting
  • The mother cannot feel the baby moving as often as previously. This may be a symptom of miscarriage.

Read more about Influenza Infection »

Erythema infectiosum during pregnancy Parvovirus B19

Erythema infectiosum, also known as fifth disease or slapped cheek syndrome, is a common, non-serious condition caused by parvovirus B19. It is most common in children. Most women are already immune to the virus, making the chances of infection during pregnancy relatively low. However, if contracted during pregnancy, there is a chance that the virus could be passed on to the baby and cause complications, including miscarriage, especially if it develops during the first half of pregnancy.[3]

Pregnant women should seek medical attention urgently if they develop a rash or a high temperature, or if they suspect they have been in contact with others affected by parvovirus B19, even if no symptoms are present. A doctor will be able to screen for the virus, using a blood test, and advise on treatment options thereafter.[7]

Rubella during pregnancy

Rubella is typically a mild, self-limiting condition. If contracted during pregnancy, especially during the first 12 weeks of pregnancy, however, rubella can cause potentially serious harm to the baby. All pregnant women are advised to have the rubella vaccine if they have not received it previously. If a person is unsure whether they have had the vaccine or not, they should contact a doctor who will be able to check via a blood test.[8] Women who have contracted rubella during pregnancy should be counseled on maternal-fetal transmission and offered a pregnancy termination, especially when the infection is diagnosed prior to 16 weeks’ gestation.[9]

Read more about rubella and pregnancy »

Sexually transmitted diseases and infections during pregnancy

Pregnant women can get the same sexually transmitted diseases (STDs) and infections (STIs) as non-pregnant women. STDs and STIs experienced during pregnancy can result in potentially harmful consequences for both the mother and the baby, making it important for pregnant women to be regularly tested throughout their pregnancy.[10] Following a diagnosis, a doctor will be able to prescribe an appropriate treatment method.

Urinary tract infection (UTI) during pregnancy

Pregnant women are at an increased risk of developing a urinary tract infection (UTI), particularly from week 6 to week 24. If left untreated, a UTI can pose risks to the baby, including premature labor and low birth weight. If you are concerned that you may be developing a urinary tract infection during pregnancy, get a personal health assessment from the Ada app. A doctor should be consulted if any symptoms of a urinary tract infection are present.

A doctor should be contacted should any of the following symptoms occur:[11]

  • Pain or discomfort when urinating
  • Blood or mucus in the urine
  • Stomach cramps
  • Urine leakage
  • Fever

Read more about Urinary Tract Infection »

Non-infectious conditions during pregnancy

The following conditions may be pre-existing or develop for the first time during pregnancy. In either case, they may need to be specially managed during pregnancy to prevent complications for the mother or baby.

Anemia during pregnancy

Anemia involves having a low number of healthy red blood cells. Pregnant women face an increased risk of developing anemia because of the large amount of blood their bodies produce to support the growth of the baby. If detected early, anemia poses little risk to the mother or baby but it can pose health risks if left untreated.

If any of the following symptoms appear, medical attention should be sought:[12]

  • Weakness or fatigue
  • Dizziness
  • Shortness of breath
  • Irregular or rapid heartbeat
  • Pain in the chest

Read more about Anemia »

Diabetes and gestational diabetes during pregnancy

Pregnant women who have type 1 or 2 diabetes before becoming pregnant are at risk of various complications affecting both themselves and their babies. These complications include the baby developing health problems after birth, including an increased risk of also developing diabetes. Proper management of the condition is the best way to reduce the risk of complications. Pregnant women, or women planning a pregnancy, should consult their doctor or diabetes specialist for advice on how to do this.[13]

Gestational diabetes is a type of diabetes that can occur as a result of high blood sugar levels during pregnancy. If gestational diabetes is not properly managed, it can cause complications such as high birth weight, premature birth and, in rare cases, stillbirth. Gestational diabetes is normally screened for as standard, and especially so if the pregnant woman is part of one of the groups most at risk of the condition, women who are overweight, for example. If detected, the condition can be managed through lifestyle changes and medication.[14]

Read more about Diabetes »

High blood pressure (hypertension) during pregnancy

Pregnant women will be regularly screened for high blood pressure. If high blood pressure is detected, it will be mild and easily treated with medication in most cases. If a pregnant woman is already taking medication for high blood pressure, they should be sure to inform their doctor or midwife of this, as pregnancy-appropriate medication may be called for.

Read more about High Blood Pressure »

In severe cases, untreated high blood pressure can develop into a condition called preeclampsia, which can serious cause harm to the mother and baby.[3]

Read more about Preeclampsia »

Diseases of the thyroid during pregnancy

Thyroid dysfunction causes the production of too much or too little thyroid hormone, affecting the body’s processes. This can negatively impact the health of pregnant people and their babies, potentially leading to a number of complications if the condition is not effectively managed. These include congenital defects, stillbirth, preterm birth and miscarriage.

Read more about Thyroid and Pregnancy »

Carpal tunnel syndrome (CTS) during pregnancy

Carpal tunnel syndrome (CTS), a condition involving the median nerve in the wrist becoming compressed inside the carpal tunnel, can cause pain, tingling and numbness in the hands during pregnancy. The condition is most typical in pregnant women who gain a large amount of weight. Eating a healthy, balanced diet is often an effective way of helping to prevent CTS during pregnancy, as well as a good way of promoting general health. If CTS does occur, the affected person should ask their midwife about ways in which to manage the symptoms. This may involve splints worn at night, gentle hand exercises and massages.[15]

Read more about Carpal Tunnel Syndrome »

Obesity during pregnancy

Obesity, defined as having a BMI over 30, during pregnancy, can result in a number of health risks for both mother and baby. Risks associated with obesity include gestational diabetes, preeclampsia and stillbirth, as well as an increased risk of diabetes and obesity in later life for the infant. Obesity can be tackled through weight management – a doctor will be able to offer advice on how to do this in a way that is safe to undertake during pregnancy.[16]

Mental health problems during pregnancy

It is common for pregnant women, including women who have no previous history of mental health problems, to experience mental health problems during pregnancy. These problems can include anxiety and depression and may range from mild to severe. For those experiencing mental health problems, it is important to talk to their doctor or psychiatrist about what they are going through. These professionals will also be able to explain and prescribe treatment options, which may include being referred to a specialist in prenatal mental health or medication, with the treatment choice depending on the severity of symptoms and the person’s history of mental health.[17]

Complications specific to pregnancy

The following complications are specific to the course of pregnancy.

Placenta praevia

The placenta develops alongside the baby in the womb, connecting the baby to the mother’s blood system and providing it with oxygen and nourishment. Placenta praevia, or low-lying placenta, occurs when the placenta sits low in the uterus and covers part or all of the cervix, the entrance to the womb. In most cases, the placenta will move upwards as the uterus grows larger, though in some women the placenta will remain low-lying in the final stages of pregnancy. The condition will typically be identified through routine scans and monitored throughout the pregnancy. Placenta praevia can lead to bleeding in the second half of pregnancy, which will typically not be accompanied by pain. This bleeding can be heavy and, in severe cases, pose a risk to the baby’s life. The condition, however, is rarely life-threatening, though may require the mother to undergo a cesarean section at birth.[14]

Placental abruption

Placental abruption occurs when the placenta prematurely separates from the inner wall of the womb (uterus) prior to the baby being born. This separation may be partial or total and may cause bleeding from the vagina or concealed bleeding inside the womb, in which case the bleeding will not be obvious to the mother. In these cases, placental abruption will typically be identified through other symptoms, such as stomach pains.[18] In severe cases, the condition can be life-threatening.

If any of the following symptoms appear, a doctor or midwife should be contacted urgently:[19]

  • Bleeding from the vagina
  • Pain in the stomach
  • Back pain
  • Frequent contractions
  • The baby ceases to move as often as previously

Antepartum haemorrhage

Antepartum haemorrhage is bleeding from the birth canal (vagina) after the 24th week of pregnancy. Bleeding before this time results in miscarriage and bleeding, which occurs after the baby has been born, is termed postpartum haemorrhage. In around half of all cases no definite cause of antepartum haemorrhage can be identified. The most important causes of antepartum haemorrhage are placenta praevia and placental abruption, yet they are not the most common. The condition can be life-threatening for the baby, so a doctor should be contacted urgently if any vaginal bleeding occurs.[20]

Ectopic pregnancy

Ectopic pregnancy occurs when a fertilized egg implants itself outside of the womb, typically in one of the fallopian tubes. If this happens, the embryo is unable to develop properly and will usually need to be removed, using medication or a surgical procedure. Ectopic pregnancy can sometimes be symptomless – in these cases, it will only be detected during a routine scan. The following symptoms can, however, present themselves:[21]

  • Stomach pain
  • Bleeding from the vagina
  • Pain in the tip of the shoulder
  • Discomfort when using the bathroom

If any of these symptoms appear, a doctor or midwife should be contacted as a matter of urgency. Note that these symptoms may also be a sign of another condition.

Read more about Ectopic Pregnancy »

Molar pregnancy

A molar pregnancy, sometimes called a hydatidiform mole, is a rare chromosomally abnormal pregnancy resulting from a problem related to the genetic makeup of the fused egg and sperm, which occurs during conception. This causes a fluid-filled mass of tissue to grow inside the womb instead of a healthy pregnancy. A molar pregnancy will not develop into a baby.

A molar pregnancy will often have the same symptoms as a normal pregnancy in its early stages, and may go undetected until the first routine ultrasound scan, if it is not miscarried before this time. However, symptoms which could indicate a molar pregnancy, include vaginal bleeding, severe nausea and vomiting and tummy growth which is faster than normal.

Read more about Molar Pregnancy »

Hyperemesis gravidarum

Sickness and vomiting is common during pregnancy, affecting roughly 75 percent of pregnant women.[22] For most women, this will disappear at around week 14. Hyperemesis gravidarum is defined as severe vomiting during pregnancy, which may occur several times per day and impair the ability to keep down food and liquids. The condition poses little risk to the baby if managed properly, though a doctor or midwife should be contacted as soon as the condition is suspected.[23]

Low amniotic fluid (oligohydramnios)

Amniotic fluid helps the baby to develop in the womb, making it a vital part of the baby’s life-support system. If the level of amniotic fluid in the womb is low, this is a condition known as oligohydramnios. The condition can develop at any point during pregnancy, but is most common during the final trimester.

If it occurs in the first half of pregnancy, oligohydramnios can cause birth defects and an increased risk of miscarriage. If it occurs in the second half of pregnancy, complications include premature birth and problems during labor, such as cord compression. Amniotic fluid levels are monitored closely throughout pregnancy, and if oligohydramnios is detected, doctors will be able to suggest treatment methods, which, if the mother is in the final stages of pregnancy, may include inducing labor.[24]


Miscarriage occurs when an embryo or fetus dies during the first 23 weeks of pregnancy, with most miscarriages happening within the first three months. It is often difficult to identify exactly what causes miscarriage, though some known causes include gene defects, pre-existing condition, such as diabetes, and severe infection.

Read more about Miscarriage »

In some cases, there will be no apparent signs of a miscarriage, and it will only become apparent during a scan.[25] In other cases, symptoms may include vaginal bleeding, stomach pain and cramping, though these symptoms may be a sign of another condition and not miscarriage. If any of these symptoms occur, it is important to seek medical attention as soon as possible to enable a doctor to identify the problem.[26]

Read more about Signs of Miscarriage »


A stillbirth is when a baby is born dead after 24 weeks of pregnancy. The cause of stillbirth cannot always be identified, though in some cases it is linked to problems with the placenta or the health of the mother. If the baby is moving less frequently than usual or not moving at all, a doctor or midwife should be contacted urgently. They will be able to run tests and identify any problems that may be occuring.[27]

Obstetric cholestasis

Obstetric cholestasis is a relatively rare liver condition occurring when the normal level of bile exiting the liver is reduced. The main symptom of obstetric cholestasis is pruritus, itching, sparing the face, which can range in severity from mild to severe. This symptom alone is typically enough for a presumptive diagnosis. Although this itching can occur at any point during pregnancy, it is most common in the final three months. Generally, the itching will cease soon after birth and cause no long-term health problems, though skin tissue damage (excoriation) is possible. The condition has, however, been linked to premature birth and stillbirth in some cases, meaning it will be closely monitored by doctors and midwives. Birth may be induced early (after 37 or 38 weeks) to reduce the risk of stillbirth if the condition is considered to be severe.[28]

Preterm (premature) labor and birth

Preterm labor is defined as contractions beginning and the cervix shortening before week 37 of pregnancy, with most occurrences taking place between week 34 and week 37. Preterm labor is relatively common, and only roughly one in five cases of preterm labor result in premature birth. Although it is difficult for doctors to foresee which women will experience preterm labor, certain factors – such as carrying twins or triplets, having experienced preterm labor in the past and some medical conditions (high blood pressure, for example) – make it more likely.

If preterm labor begins in a pregnancy of 34 weeks or over, doctors will typically allow the birth to continue naturally, as the baby will often be sufficiently mature to survive outside of the womb. This, however, depends on the specific circumstances. If preterm labor begins in a pregnancy of under 34 weeks, doctors may use methods to delay the birth, until the baby can be given steroids to prepare it for birth, and the mother can be transferred to a specialist care unit. In some cases, labor may be halted completely, though this is generally not advised.[29]

If a baby is born before week 37 of pregnancy, they are at risk of being underdeveloped and suffering potentially lifelong health issues and disabilities, such as cerebral palsy and learning disabilities. The earlier the birth, the higher the chances of health issues, with babies born before week 34 being most vulnerable.[30]


Preeclampsia is a condition involving pregnant women developing high blood pressure and protein in the urine (proteinuria), usually after week 20 of pregnancy. These symptoms will typically only be detected during a routine check-up, though other symptoms, such as headaches, vision problems and swelling of the feet, ankles, face and hands may also occur.[31]

Should such symptoms present, pregnant women should visit their doctor to identify what is causing them. In the majority of cases, preeclampsia will result in no serious health problems for mother or baby and will disappear soon after birth. However, in rare instances, preeclampsia can result in serious health issues such as fits and blood clotting problems. Gestational hypertension can also occur without the appearance of protein in the urine (proteinuria). The condition may also result in gestational hypertension. Proper monitoring of the condition by healthcare professionals can help reduce the chances of such complications occurring.[32]

Read more about Preeclampsia »

Rhesus problems

Each person’s blood falls into one of four blood groups (A, B, AB, O) and is either rhesus (Rh) positive or negative. If a pregnant woman has rhesus negative blood and her baby has rhesus positive blood, the body’s immune system may detect these foreign blood cells and produce antibodies to attack them.

If this happens, the baby can develop rhesus disease which can cause anemia and jaundice in newborns. This, however, is rare. Newly pregnant women routinely undergo blood tests to identify whether they are rhesus positive or negative. If they are found to be rhesus negative they will be prescribed anti-D immunoglobulin injections at 28 to 32 weeks’ gestation and again within 72 hours of birth to prevent the immune system from producing antibodies to attack the baby’s blood cells.[3]

Pregnancy complications in multiple pregnancy - twins, triplets, etc.

The majority of women who are pregnant with multiple babies, whether twins, triplets or more, will experience no serious complications. However, the higher the number of babies in one pregnancy, the higher the risk of problems. Due to this, women pregnant with more than one baby will be monitored even more closely than usual.[33]

The most common complications associated with a multiple birth include:[33][34]

  • Premature labor and birth
  • Low birth weight
  • Gestational diabetes
  • Gestational hypertension
  • Anemia
  • Miscarriage
  • Congenital deformity, including anencephaly, facial clefts and malformations of the spine

If it becomes apparent that a woman is pregnant with two or more babies, doctors and midwives will advise on the necessary steps to help avoid complications.

Pregnancy complications FAQs

Q: What are the possible complications of early pregnancy?
A: In early pregnancy, generally defined as the first trimester, complications are commonly due to the pregnancy not forming properly and consequently becoming unviable. This will typically occur before the mother becomes aware she is pregnant, or very soon afterwards, and cause miscarriage. Abdominal pain and vaginal bleeding are common signs of early pregnancy miscarriage; if this occurs, women are advised to contact a doctor urgently. Vaginal bleeding and abdominal cramping can also occur in otherwise healthy pregnancies, so are not necessarily signs of miscarriage.[35]

Q: Can a vegan or vegetarian diet cause complications during pregnancy?
A: Research suggests that people who follow a vegan or vegetarian diet may be at higher risk of having a baby with birth defects. This is thought to be due to a deficiency of vitamin B12, which is commonly found in animal products. Vegan or vegetarian women who are trying to become pregnant should talk to a doctor, who will be able to advise on ways in which to mitigate this risk. This will usually be through supplementation.[35]

Q: Can an IUD cause pregnancy complications?
A: An intrauterine device, otherwise known as an IUD or coil, is a device fitted in the uterus to prevent pregnancy. Although IUDs are one of the most effective methods of contraception, in rare instance, a woman can become pregnant despite use of the device. If this occurs, the IUD will be immediately removed. Research suggests that if a pregnancy occurs in this way, there is no significant risk of the pregnancy being miscarried or of the baby being born with defects.[36]

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  2. UpToDate. “Epidemiology and pathogenesis of Listeria monocytogenes infection.” April 17, 2018. Accessed May 30, 2018.

  3. Patient. “Pregnancy Complications.” October 30, 2017. Accessed May 9, 2018.

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  5. Patient. “Toxoplasmosis.” October 3, 2016. Accessed May 9, 2018.

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  8. NCBI. “Rubella (German measles) during pregnancy.” November, 2007. Accessed May 9, 2018.

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  10. CDC. “STDs during Pregnancy - CDC Fact Sheet.” Accessed May 9, 2018.

  11. American Pregnancy Association. “Urinary Tract Infection During Pregnancy.” March 10, 2017. Accessed May 9, 2018.

  12. American Pregnancy Association. “Anemia During Pregnancy.” October 16, 2016. Accessed May 9, 2018.

  13. NHS Choices. “Diabetes and pregnancy.” April 12, 2018. Accessed May 9, 2018.

  14. NHS Choices. “Gestational diabetes.” August 5, 2016. Accessed May 9, 2018.

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  16. NCBI. “The Impact of Maternal Obesity on Maternal and Fetal Health.” 2008. Accessed May 9, 2018.

  17. NHS Choices. “Mental health problems and pregnancy.” April 4, 2018. Accessed May 9, 2018.

  18. BMJ Best Practice. “Placental abruption.” February, 2018. Accessed May 10, 2018.

  19. Babycentre. “Placental abruption.” April, 2015. Accessed May 10, 2018.

  20. Patient. “Antepartum haemorrhage.” March 11, 2016. Accessed May 10, 2018.

  21. NHS Choices. “Ectopic pregnancy.” February 3, 2016. Accessed May 10, 2018.

  22. BMJ Best Practice. “Nausea and vomiting during pregnancy.” March, 2018. Accessed May 30, 2018.

  23. NHS Choices. “Severe vomiting in pregnancy.” September 14, 2016. Accessed May 10, 2018.

  24. American Pregnancy Association. “Low Amniotic Fluid Levels: Oligohydramnios.” May 26, 2017. Accessed May 10, 2018.

  25. Planned Parenthood. “Miscarriage.” Accessed May 10, 2018.

  26. Planned Parenthood. “How do I know if I’m having a miscarriage?” Accessed May 10, 2018.

  27. NHS Choices. “Stillbirth.” February 8, 2018. Accessed May 10, 2018.

  28. British Liver Trust. “Intrahepatic Cholestasis of Pregnancy (ICP).” Accessed December 11, 2018.

  29. Patient. “Premature Labour.” November 2, 2017. Accessed May 10, 2018.

  30. ACOG. “Preterm (Premature) Labor and Birth: Resource Overview.” November, 2016. Accessed May 10, 2018.

  31. NHS Choices. “Pre-eclampsia: Overview.” June 2, 2015. Accessed May 10, 2018.

  32. NHS Choices. “Pre-eclampsia: Complications.” June 2, 2015. Accessed May 10, 2018.

  33. Patient. “Multiple Pregnancy.” September 27, 2017. Accessed July 30, 2018.

  34. University of Rochester Medcial Center. “Complications of Multiple Pregnancy.” Accessed July 30, 2018.

  35. The Royal Women’s Hospital. “Early pregnancy problems.” Accessed July 30, 2018.

  36. NCBI. “Pregnancy despite IUD: adverse effects on pregnancy evolution and fetus.” July, 2003. Accessed July 30, 2018.