What are Pregnancy Complications?

What are Pregnancy Complications?

Pregnancy complications are health problems that occur during pregnancy. These issues may affect the baby, the pregnant patient, or both. Sometimes pregnancy complications can occur without warning, and others can stem from existing health problems.

A high-risk pregnancy requires special care, either because of a maternal health problem, an issue with the pregnancy, or a fetal congenital disability or complication. At NewYork-Presbyterian, we provide prenatal testing, state-of-the-art imaging, and cutting-edge treatment for various pregnancy problems and conditions.

What are the Signs of Abnormal Pregnancy?


While some pregnancy symptoms—like nausea — are common, other signs may indicate a more serious health issue.

It’s important to speak with your doctor if you experience any of the following symptoms, as they may be warning signs of pregnancy complications. Your physician can determine if your symptoms point to a problem and advise you on the next steps.

Some signs of pregnancy complications include:

  • Increased blood pressure
  • Swelling
  • Severe nausea
  • Vaginal bleeding
  • Severe headaches
  • Blurred vision
  • Severe abdominal pain
  • Difficulty breathing

What are the Most Common Complications During Pregnancy?


Amniotic fluid complications

Amniotic fluid, the liquid surrounding the fetus during pregnancy, is an important part of fetal development. Too much or too little amniotic fluid can cause complications and abnormalities; the fetus’s lungs are particularly vulnerable to abnormal development due to too little amniotic fluid.


Anemia occurs when there aren't enough blood cells to carry oxygen throughout the body. It is common for pregnant women to become anemic, as the body struggles to produce more blood during pregnancy—and consequently needs more iron to produce more red blood cells. Since the fetus relies on the mother for vitamins, including iron, untreated anemia can cause developmental problems. Anemia can usually be treated with prenatal vitamins or supplements.

Ectopic pregnancy

An ectopic pregnancy occurs when a fetus develops outside of the uterus in either the fallopian tubes, cervix, abdominal cavity, or in an ovary. The fertilized egg cannot survive outside the uterus and, if left to grow, the ectopic pregnancy can cause life-threatening bleeding. A general gynecologist typically treats this condition.

Gestational diabetes

Gestational diabetes is diabetes that is first diagnosed during a woman’s pregnancy. Like other forms of diabetes, it affects how the body’s cells use and manage glucose. Gestational diabetes can increase your risk of high blood pressure and the likelihood of delivering a large baby. Keeping track of your blood sugar and diet can help manage symptoms of gestational diabetes. In many cases, medication (that’s safe to use during pregnancy) may be required to manage diabetes.

High-blood pressure (hypertension) in pregnancy

High blood pressure during pregnancy can cause several problems and should be closely monitored. Hypertension can occur prior to pregnancy and continue throughout pregnancy, or a mother can develop high blood pressure after becoming pregnant. High blood pressure can lead to premature birth, slowed fetal growth, restricted blood flow to the placenta, and future cardiovascular disease in the mother.


Miscarriage is the loss of pregnancy prior to 20 weeks. Most miscarriages occur before week 12. Signs of a miscarriage include intense cramping and blood spotting, although most bleeding early in pregnancy doesn’t point to miscarriage. In many cases, the fetus and contents of the uterus are naturally expelled by the mother’s body. If this doesn’t happen, a procedure called a dilation and curettage (D & C) may be necessary. Most general ob-gyns deal with miscarriage. A maternal fetal medicine specialist can provide care for women with recurrent pregnancy loss and help identify its cause.

Molar pregnancy

A molar pregnancy occurs when an egg and sperm join incorrectly at fertilization. As a result, the growth of the placenta is disrupted. Molar pregnancies can be complete or partial: in an entire molar pregnancy, there is no fetus. In a partial, an embryo forms with the abnormal placenta but cannot survive. Most molar pregnancies result in a miscarriage, but some mothers may require dilation and curettage to remove the tumor. Monitoring of pregnancy hormone levels may be required to make sure the condition has resolved before attempting pregnancy again. This is typically handled by a general gynecologist.

Placental complications

The placenta, the organ formed during pregnancy that provides oxygen and nutrients to a fetus, usually attaches to the uterine wall. Sometimes, the placenta detaches from the wall too soon or attaches to a part of the uterus close to the cervix. If the placenta separates too early in a pregnancy, it is called placental abruption. This condition can lead to less oxygen and nutrients reaching the fetus and may lead to your doctor choosing to deliver the baby early. If the placenta attaches close to or covers the cervix (placenta previa), behavioral or activity changes may be recommended, and you may have to undergo a cesarean to deliver the baby. Vasa previa is when unprotected umbilical vessels run through the amniotic membranes and pass over the cervix. This is a serious condition that can result in a stillbirth.


Preeclampsia is a condition causing high blood pressure. High blood pressure usually manifests after 20 weeks of gestation. Preeclampsia is a serious condition that, left untreated, can lead to problems with fetal growth, premature birth, placental abruption, and even death. Eclampsia is a further complication of preeclampsia in which the mother experiences seizures during the pregnancy.

Preterm labor or history of preterm labor

Preterm labor, which can result in premature birth, occurs when contractions lead to the cervix opening after week 20 of gestation but before week 37. In most cases, the exact cause of preterm labor isn’t clear, but in some cases, there can be an infection in the uterus. Preeclampsia is associated with preterm birth but not via preterm labor. Preterm birth happens because the obstetrician decides that delivery is necessary.

Who is at Risk for Pregnancy Complications?

Risk Factors

Though pregnancy complications can occur during any pregnancy, some risk factors can increase the likelihood of experiencing complications. These include:

  • Having a pre-existing condition
  • Advanced maternal age
  • Illegal drug use
  • Smoking
  • Alcohol consumption



 There is no way to predict if you will experience pregnancy complications. While complications can occur in any pregnancy, there are some steps you can take to reduce the likelihood of complications. These include:

  • Consult with a doctor about any unusual symptoms during pregnancy
  • Maintain a healthy diet
  • Take prenatal vitamins
  • Avoid drugs, smoking, and drinking
  • Attend routine prenatal visits
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Trust NewYork-Presbyterian for Care During Abnormal Pregnancies

The expert team at NewYork-Presbyterian can guide you through your pregnancy journey from planning to post-natal care. We have world-class facilities at several locations and options for virtual visits, so you can come to us with any concerns about pregnancy complications whenever and however convenient.

With years of experience on our side, NewYork-Presbyterian is the best choice for care during high-risk or abnormal pregnancies.