Complications can arise in pregnancies for many reasons. Sometimes a woman’s existing health conditions contribute to problems. Other times, new conditions arise because of hormonal and body changes that occur during pregnancy.

Always talk to your doctor if you have any concerns about your risk of complications during pregnancy. Some of the most common complications include the following.


Miscarriage is the loss of a pregnancy in the first 20 weeks of pregnancy. The reasons for miscarriage are not always known. Most miscarriages occur in the first trimester, which is the first 13 weeks of pregnancy. Chromosomal abnormalities can prevent proper development of the fertilized egg. Or physical problems with a woman’s reproductive system can make it difficult for a healthy baby to grow.

Miscarriage is sometimes called spontaneous abortion, as the body rids itself of the fetus much like a procedural abortion. The most common sign of miscarriage is abnormal vaginal bleeding.

Other symptoms can include lower abdominal pain and cramping, and a disappearance of pregnancy symptoms, such as morning sickness.

Most miscarriages don’t require surgical intervention. When a miscarriage occurs under 12 weeks, the tissue will often dissolve or pass spontaneously without the need for further intervention. Some will require medicine or a minor procedure in the office or operating room to help with the passage of tissue.

Ectopic pregnancy

A fertilized egg implanted outside of the uterus is an ectopic pregnancy. The egg generally settles in one of the fallopian tubes. Because of the space limitations and the lack of nurturing tissues there, a fetus cannot properly grow. An ectopic pregnancy can cause severe pain and damage to a woman’s reproductive system, and is potentially life-threatening. As the fetus continues to grow, it can cause the fallopian tube to burst, leading to severe internal bleeding (hemorrhage).

The fetus will not survive in an ectopic pregnancy. Surgery and/or medication are necessary, as well as careful monitoring of a woman’s reproductive system by a gynecologist. Causes of ectopic pregnancy include a condition in which cell tissue that usually grows in the uterus grows elsewhere in the body (endometriosis), and scarring to the fallopian tubes from a previous sexually transmitted infection.

Gestational diabetes

Gestational diabetes is a form of diabetes that is diagnosed during pregnancy. It means that you are also at higher risk for diabetes after pregnancy. Like type 2 diabetes, gestational diabetes is caused by insulin resistance (your body doesn’t respond correctly to the hormone insulin). For most women, gestational diabetes doesn’t cause any noticeable symptoms.

While the majority of women with gestational diabetes give birth to healthy babies, the condition can increase the risk that the baby will have a larger-than-normal body.

Other health risks to the baby include:

  • jaundice
  • respiratory distress syndrome
  • abnormally low levels of minerals in the blood
  • hypoglycemia

Gestational diabetes is treated through changes in diet and close monitoring of blood sugar levels. Oral medication to lower glucose levels may also be necessary. The goal is to keep the mother’s sugar levels within a normal range for the remainder of the pregnancy.

Incompetent cervix

A growing baby puts continual pressure on a pregnant woman’s cervix. In rare cases, the pressure becomes too much for the cervix to handle. This will cause the cervix to open before the baby is ready to be born, which is called cervical insufficiency or an incompetent cervix. Women who have previously had a pregnancy complicated by cervical insufficiency or who have had surgery on their cervix are most susceptible.

Symptoms are often vague and nonspecific. Most women who have cervical insufficiency have no idea that their cervix is thinning or shortening. The hallmark of this condition is that it’s painless. However, some women do report a feeling of pressure or mild cramping.

Cervical insufficiency is diagnosed by measuring the length of the cervix with ultrasound. The treatment may include bed rest, vaginal suppositories of the hormone progesterone, or a procedure called cerclage. A cerclage is a minor surgery in which bands of strong thread are stitched around the cervix to reinforce it and hold it closed.

The treatment for cervical insufficiency will depend on many factors, including the length of your cervix, your gestational age, and the outcome in previous pregnancies if you have been pregnant before.

Placental abruption

Placental abruption occurs when the placenta completely or partially separates from the uterus before a baby is born. This separation means a fetus cannot receive proper nutrients and oxygen. A placental abruption happens most commonly in the third trimester of pregnancy. Common symptoms include vaginal bleeding, contractions, and abdominal pain.

There is no definitive answer as to why abruptions occur. It’s thought that physical trauma can disrupt the placenta. High blood pressure can also damage the connection between the placenta and the uterus.

A number of factors can increase your risk for abruption. Pregnant women with high blood pressure are much more likely to have an abruption. This is true for blood pressure problems that are unrelated to pregnancy, like chronic hypertension, and pregnancy-related problems like toxemia (preeclampsia).

The likelihood of abruption is closely related to the number and nature of your previous pregnancies. The more babies you’ve had, the greater your risk of abruption. More importantly, if you’ve had one abruption in the past, you have about a 1 in 10 chance of having an abruption with your next pregnancy.

Other factors that may increase the risk for placental abruption include cigarette smoking and drug use.

Low-lying placenta

Placenta previa is a rare pregnancy complication that occurs if the placenta attaches to the bottom part of a woman’s uterine wall, partially or completely covering the cervix. When it occurs, it usually happens during the second or third trimester.

Some women have a low-lying placenta in early pregnancy, however. A doctor will monitor the condition. But often the placenta moves to the appropriate place without any intervention.

Placenta previa becomes a more serious condition in the second or third trimesters. It can result in heavy vaginal bleeding. If left untreated, placenta previa can lead to bleeding heavily enough to cause maternal shock or even death. Luckily, most cases of the condition are recognized early on and treated appropriately.

Low or excess amniotic fluid

Amniotic fluid cushions the womb to keep a fetus safe from trauma. It also helps maintain the temperature inside the womb. Having too little amniotic fluid (oligohydramnios) or too much amniotic fluid (polyhydramnios) interferes with some of the normal functions of the womb.

Low amniotic fluid can prevent a baby from properly developing muscles, limbs, lungs, and affect the digestive system.

Most cases of excess amniotic fluid are mild and don’t cause problems. In rare cases, too much amniotic fluid can cause:

  • premature rupture of amniotic membranes
  • placental abruption
  • preterm labor and delivery
  • postpartum hemorrhage (bleeding after delivery)

An absence or excess of fluids is usually detected during the second trimester when the fetus begins to practice breathing and sucks in amniotic fluid. For those with too little amniotic fluid, saline solution may be pumped into the amniotic sac to help reduce the risk of compression or injury to the child’s organs during delivery.

For those with too much amniotic fluid, medication can be used to reduce fluid production. In some cases, a procedure to drain excess fluids (amnioreduction) may be required. In either case, if these treatments prove ineffective, an induced pregnancy or cesarean delivery may be required.


Preeclampsia is a condition marked by high blood pressure and high protein levels in a woman’s urine. Through it commonly develops in later pregnancy, after 20 weeks gestation, it can develop earlier in the pregnancy, or even postpartum. Doctors are not sure what causes preeclampsia, and it can range from mild to severe. In serious cases, symptoms may include:

  • severe headaches
  • blurred or temporary loss of vision
  • upper abdominal pain
  • nausea
  • vomiting
  • dizziness
  • decreased urine output
  • sudden weight gain
  • swelling in the face and hands

You should call your doctor or go to the emergency room immediately if you have severe headaches, blurred vision, or pain in your abdomen.

For most women, preeclampsia will not affect the health of the baby. However, some cases of preeclampsia can prevent the placenta from getting enough blood. Preeclampsia can cause serious complications in both mother and baby. Some complications include:

  • slow growth
  • low birth weight
  • preterm birth
  • breathing difficulties for the baby
  • placental abruption
  • HELLP syndrome
  • eclampsia, or seizures

The recommended treatment for preeclampsia is delivery of the baby and placenta to prevent the disease from progressing. Your doctor will discuss the risks and benefits regarding timing of delivery. Your doctor may advise waiting to deliver so that the baby can mature further. In this case, close monitoring would take place to ensure safety for you and baby.

Medications for high blood pressure (antihypertensives) are sometimes taken, and corticosteroids can be used to help mature a baby’s lungs to prepare for an early delivery. Antiseizure medication is taken in many cases. Seizures can be a common and serious complication for both mother and child.

Premature labor

Labor is considered preterm when it occurs after 20 weeks and before 37 weeks of pregnancy. Traditionally, the diagnosis is made when regular uterine contractions are associated with either opening (dilation) or thinning out (effacement) of the cervix.

The majority of premature labor and birth cases occur spontaneously. However, up to one-fourth are a result of an intentional decision. These cases are generally due to complications in either the mother or the baby. They are best treated by proceeding with delivery, despite the fact that the mother is not yet at her due date.

Preterm labor requires prompt medical attention. A woman who experiences symptoms of premature labor may be put on bed rest or be given medication to stop contractions. Many actually go on to deliver at term.

There are a host of risk factors associated with premature labor and delivery, including:

  • smoking
  • inadequate prenatal care
  • a history of multiple abortions
  • a history of preterm births
  • an incompetent cervix
  • uterine fibroids
  • urinary tract and other infections

Venous thrombosis

Venous thrombosis is a blood clot that normally develops in a vein in a leg. Women are susceptible to clots throughout pregnancy and delivery, and particularly afterward (postpartum). The body increases the blood’s clotting ability during childbirth, and sometimes the enlarged uterus makes it difficult for blood in the lower body to return to the heart. Clots near the surface are more common. Deep vein thrombosis is much more dangerous and far less common.

Women have a greater risk of developing clots if they:

  • have a family history of thrombosis
  • are over 30
  • have had three or more previous deliveries
  • have been confined to a bed
  • are overweight
  • have had a cesarean delivery in the past
  • smoke

Molar pregnancy

A molar pregnancy is an abnormality of the placenta. It’s when an abnormal mass, instead of a normal embryo, forms inside the uterus after fertilization. Also called gestational trophoblastic disease, molar pregnancies are rare.

There are two types of molar pregnancies: complete and partial. Complete molar pregnancies occur when the sperm fertilizes an empty egg. The placenta grows and produces the pregnancy hormone hCG, but there is no fetus inside. A partial molar pregnancy occurs when a mass forms that contains both the abnormal cells and an embryo that has severe defects. In this case, the fetus will quickly be overcome by the growing abnormal mass.

A molar pregnancy requires immediate dilation and curettage (D&C), and careful follow-up, as the molar tissue can start growing again and even develop into cancer.

Fetal alcohol syndrome

Fetal alcohol syndrome occurs when there are mental and physical defects that develop in a fetus when a mother drinks alcohol during pregnancy. Alcohol crosses the placenta, and this has been linked to stunted growth and brain development.

HELLP syndrome

HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) is a condition characterized by liver and blood abnormalities. HELLP syndrome can occur on its own or in association with preeclampsia. Symptoms often include:

  • nausea
  • gastrointestinal pain
  • headaches
  • severe itching

Treatment of HELLP usually requires immediate delivery, as there is increased risk of serious health complications for the mother. Complications include permanent damage to her nervous system, lungs, and kidneys.


Eclampsia occurs when preeclampsia progresses and attacks the central nervous system, causing seizures. It’s a very serious condition. If left untreated, it can be fatal for both mother and baby. However, with proper prenatal care, it’s very rare for the more manageable preeclampsia to progress into eclampsia.