Pregnancy Complications Women Need to Watch For

While the vast majority of pregnancies have no major issues, the entire system of prenatal care is designed to screen for potential complications and help prevent those that can be avoided. Through a series of prenatal checks—monitoring your blood pressure, urine, blood, and weight; measuring your fundus (top of the uterus), and a variety of other things—your doctor tries to keep you and your baby healthy so that you can have the safest pregnancy and birth possible. These checks also help your healthcare practitioner to hopefully find and treat potential pregnancy complications early on before they become bigger problems.

There are some pregnancy complications that are more common than others. While they may still only affect a small percentage of pregnant women, they can be painful and potentially dangerous to both mother and/or baby.

Here is a starter list of complications you might be screened for in an average pregnancy.

Your doctor or midwife is also personalizing a list of screenings for you based on your medical and familial history to provide you with the best care possible.

Rh Factor

Everyone has both a blood group type and an Rh factor. In addition to the blood group (A, B, O, AB), the Rh factor is written as either positive (present) or negative (absent). Most people (85 percent) are Rh-positive. This factor does not affect your health and doesn't typically matter—except when you're pregnant.

A pregnant woman is at risk when she has a negative Rh factor and her partner has a positive Rh factor. This combination can produce a child who is Rh-positive. If the mother and baby's blood mix, this can cause the mother to create antibodies against the Rh factor, thus treating the baby as an intruder in her body. Typically the blood from the mother and baby do not mix; there are certain times there is a slight chance of it, like in birth, some prenatal tests (like an amniocentesis), or after a miscarriage. The drug RhoGAM is given to help prevent this sensitization.

If you and your partner are both Rh negative, this is not something that will be problematic in your pregnancy. Don't be concerned if you don't know your blood type. This is something that will be checked early on in your prenatal care.

Gestational Diabetes

Gestational diabetes (GD) is high blood sugar (glucose levels) during pregnancy; about 4 percent of pregnant women develop it. Most mothers will need to be screened using blood work, which typically happens in the twenty-eighth week of pregnancy. If you need additional screening with a glucose tolerance test (GTT), it will be done at this point. If you have GD, your labor may be induced as you get closer to the 40-week mark.

You will need to monitor your blood sugar from the point out your diagnosis until the end of your pregnancy if you have gestational diabetes, and your doctor will teach you how and when do to this. Diet and exercise will be key components of your blood sugar control strategy. Medications are only used if diet and exercise don't work. You will typically see a nutritionist for help with this process, in addition to your healthcare practitioner.


Preeclampsia, or pregnancy-induced hypertension (PIH), is a high blood pressure disorder of pregnancy. It has long been one of the major problems for mothers in pregnancy, and it affects 7 percent of first-time mothers. Labor may be induced early if you suffer from severe PIH.

According to guidelines set forth by the American College of Obstetricians and Gynecologists, the diagnosis of preeclampsia no longer requires the detection of high levels of protein in the urine (proteinuria), as it once did. Evidence shows that related problems with the kidneys and liver can occur without signs of protein and that the amount of protein in the urine does not predict how severely the disease will progress.

Preeclampsia is now to be diagnosed by persistent high blood pressure that develops during pregnancy or during the postpartum period that is associated with a lot of protein in the urine or the new development of decreased blood platelets, trouble with the kidney or liver, fluid in the lungs, or signs of brain trouble such as seizures and/or visual disturbances.

Considering the potential ramifications of this complication, it is screened for from the beginning of pregnancy. The earlier it appears, the more severe it tends to be. Your doctor will monitor your blood pressure and other signs and symptoms to determine how long to suggest you allow your pregnancy to continue. There is obviously a desire to have you carry your baby for as close to term as possible and protect your health, so a fine balance that must be struck, which is different for every pregnant woman.

Placenta Previa

Placenta previa is when all or part of the placenta covers the cervix or opening of the uterus. True placenta previa occurs in about one in 200 pregnancies. Many times early ultrasounds show placenta previa, but the condition resolves itself later on as the uterus grows. If the issue is still present at the end of pregnancy, a Cesarean section may be performed to prevent bleeding during birth.

Most mothers will not have any signs or symptoms of placenta previa, though some mothers may experience bleeding. This is why it's important to talk to your practitioner if you're experiencing any level of bleeding during your pregnancy.

Oligohydramnios (Low Amniotic Fluid Volume)

Oligohydramnios, or low amniotic fluid, is diagnosed through ultrasound, but that ultrasound may be ordered after your practitioner notices a difference in the growth of your uterus from the measurements taken at your prenatal visits. There is some indication that amniotic fluid levels drop as the time of birth comes near. Many practitioners will have you drink fluids (to ensure that the low fluid is not due to poor hydration) and reexamine you via ultrasound before moving to talking about induction of labor or other interventions.

Polyhydramnios (High Amniotic Fluid Volume)

Polyhydramnios is the opposite of oligohydramnios, meaning it is the presence of excessive amniotic fluid. This occurs in fewer than percent of all pregnancies.

While some feel that polyhydramnios is a cause for preterm labor because of uterine distension, high amniotic fluid in and of itself is such a predictor. Rather, it can hint at whether or not the pregnancy will go to term.

Polyhydramnios is more likely to occur when:

  • There is a multiple gestation
  • There is maternal diabetes
  • There is a congenital malformation or certain birth defects

While some practitioners try to drain some of the fluid from the uterus through a needle, this is often not a long-term solution, as the fluid replaces itself. This may mean that there isn't much done to treat the issue during pregnancy. As polyhydramnios can increase the risk of something like a prolapsed cord when the water breaks during labor, you will be monitored when labor begins.

Breech and Other Malpositions

Breech babies are not in the normal head-down position. This happens about 3 percent to 4 percent of all births at the end of pregnancy. Babies are usually in malpositions for a variety of reasons, including:

There is also a position known as a transverse lie, meaning that the baby is lying sideways in the uterus. Since it would be difficult to give birth to a baby in this way, your practitioner may do an external version, where the baby is turned from the outside, or recommend that you have a Cesarean section. There are also some practitioners who will do vaginal breech births for certain women and babies in certain breech positions.

Preterm Labor

Preterm labor is a very serious complication of pregnancy. Early detection can help prevent premature birth, possibly enable you to carry your pregnancy to term or give your baby a better chance of survival. There are many reasons for preterm labor including infection, problems with the uterus, multiple babies, and maternal disease. No matter what the cause of the preterm labor, it is important to know what the signs are so that you can get prompt care.

You should call your doctor or midwife if you have any of the following signs of preterm labor:

There may be other signs your practitioner tells you to look for; be sure to call if you are concerned. If you cannot get a hold of your practitioner, you may seek care from the emergency department.

Incompetent Cervix

An incompetent cervix is basically a cervix that is too weak to stay closed during a pregnancy, which results in preterm birth and possibly the loss of the baby (due to shortened gestational length). It is believed that cervical incompetence is the cause of 20 percent to 25 percent of all second trimester losses. This issue generally shows up in the early part of the second trimester, but it can be detected as late as the beginning of the third trimester. Diagnosis can be made either manually or with ultrasonography.

If a Problem Is Suspected

If you or your practitioner think that there is a problem, a conversation about an action plan is in order. This may lead to special tests for your specific or suspected condition. It may also include watchful waiting. The latter can sometimes be very difficult. Of course, you want to act—but that may not always be best. Regardless, a suspected or confirmed problem will usually involve more frequent prenatal care visits.

What Happens If You Have a Complication

The good news is that with good prenatal care, most complications can be prevented, identified early, and/or successfully treated. Some require additional care during or after pregnancy, and sometimes well into your future, while others do not. After your baby is born, it is best to schedule a time to talk to your practitioner before planning another pregnancy to see what can be done prior to pregnancy to help lower your risk of a repeat of the complication or to manage it earlier.

High-Risk Specialists

Sometimes, if your complication is out of the ordinary or severe enough to be labeled a high-risk pregnancy, you may need a higher level of care. If you are working with a midwife, this may mean working in conjunction with a physician or possibly even transferring your care to a physician entirely. If you are seeing an OB/GYN, you may also wind up needing to transfer your care to a high-risk specialist known as a maternal-fetal medicine (MFM) specialist.

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Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Robin Elise Weiss, PhD, MPH
Robin Elise Weiss, PhD, MPH is a professor, author, childbirth and postpartum educator, certified doula, and lactation counselor.