Methyldopa

THE SAFETY OF METHYLDOPA DURING PREGNANCY OR BREASTFEEDING

The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

THIS MEDICATION CAN CAUSE HARM TO YOUR BABY:

Methyldopa should only be taken during pregnancy if medically necessary, as determined by your doctor. This medication crosses the placenta and can expose your baby to its effects. Some studies have found that moms who took methyldopa were more likely to have pregnancy complications, including premature birth and delivering a baby with a small head size. High blood pressure during pregnancy can also increase the risk of pregnancy complications, including premature birth, low birth weight, birth defects, and miscarriage or stillbirth. Your doctor will help you choose a treatment plan that is safe for both you and your baby.

What is Methyldopa?

Methyldopa is a heart medication that can help lower blood pressure. It is available as oral tablets that are typically taken twice daily. It is only available by prescription.

What is Methyldopa used to treat?

Methyldopa is used to treat high blood pressure (hypertension). When blood flows through your body, it pushes on the walls of your blood vessels with a certain force.This force is called your blood pressure. High blood pressure occurs when this force is consistently higher than normal. It is often called a “silent killer” because some people have no symptoms and are unaware that they have this disease. Over time, high blood pressure can injure your heart and kidneys, or lead to a stroke or heart attack.

How does methyldopa work?

Methyldopa affects certain chemicals in your brain that help relax blood vessels and lower heart rate.

If I am taking methyldopa, can it harm my baby?

Methyldopa should only be taken during pregnancy if medically necessary, as determined by your doctor. Methyldopa crosses the human placenta and can expose your baby to its effects. No adequate and well-controlled studies have looked at the safety of this medication in expecting moms. High blood pressure during pregnancy increases the risk of birth defects, premature delivery, low birth weight, and miscarriage, stillbirth, or death of the newborn. It can also lead to many health problems in the mom, including a stroke or heart attack. In some cases, your doctor may determine that the benefits of treatment outweigh the potential risks to your baby. According to the American College of Obstetricians and Gynecologists (ACOG), methyldopa may be a less favorable treatment option for pregnant women with high blood pressure because it is less effective than other options and causes side effects in the woman. It is also not recommended for treatment after delivery, as it is associated with a higher rate of depression in new mothers. Your doctor will help you select a treatment plan that is safe for both you and your baby.

Animal studies

Studies in rats, rabbits, and mice given methyldopa at 1.7, 3.3, and 16.6 times the maximum recommended human dose showed no evidence of harm to the offspring.

Human evidence

Very little information is available on the use of methyldopa during the first trimester of pregnancy. One study looked at 261 pregnant women who took methyldopa during the first trimester of pregnancy and compared pregnancy outcomes to moms without high blood pressure. A slightly higher rate of birth defects was observed in the babies of women who took methyldopa during pregnancy, but this higher risk was not considered to be significant. The study found that moms who took methyldopa tended to have a higher risk of miscarriage or stillbirth. However, the authors indicated that high blood pressure and other conditions the women had at the time of pregnancy may have contributed to this higher risk. Taking methyldopa during pregnancy was also associated with a higher risk of premature birth and lower birth weight in the newborn. Furthermore, this study found that baby boys whose moms took methyldopa during pregnancy had significantly smaller heads.

A small study looked at 3 pregnancy outcomes for expecting moms who had taken methyldopa. Methyldopa was associated with 3 types of birth defects that all occurred in 1 baby.

Another study looked at women who took methyldopa during the second trimester of pregnancy. The study found that these women tended to give birth to babies with slightly smaller heads. At 7 years of age, intelligence and development in the children of moms treated with methyldopa was not significantly different than in untreated moms.

Several other reports have described the use of methyldopa during pregnancy. No side effects in the newborns were associated with methyldopa. One report described reduced blood pressure in the newborn after delivery, but this was not considered significant.

The manufacturer’s label describes 5 studies that looked at 332 expecting moms with high blood pressure. Treatment with methyldopa was associated with improved pregnancy outcomes. However, most of the women studied started taking methyldopa in the third trimester of pregnancy.

Bottom line: Methyldopa should only be taken during pregnancy if medically necessary, as determined by your doctor. This medication crosses the placenta and can expose your baby to its effects. Some studies have found that moms who took methyldopa were more likely to have pregnancy complications or deliver a baby with health problems. Expecting moms with high blood pressure have a higher risk of many pregnancy complications, including premature birth, low birth weight, birth defects, and miscarriage or stillbirth. Your doctor will determine if treatment with methyldopa is medically necessary and help you choose a treatment plan that is safe for both you and your baby.

If I am taking methyldopa and become pregnant, what should I do?

If you become pregnant while taking methyldopa, you should contact your doctor immediately. Your doctor will determine if treatment with methyldopa is medically necessary or if your medications should be adjusted.

If I am taking methyldopa, can I safely breastfeed my baby?

Caution should be used if methyldopa is given to women who are breastfeeding. This medication passes into breast milk and can expose your baby to its effects. Experts have indicated that the amount of methyldopa that your baby would be exposed to through breast milk is small, and this medication would not be expected to cause harm to the breastfed baby. Very little information is available on the use of methyldopa in breastfeeding moms. Reports have described 15 babies whose moms took methyldopa while nursing; no side effects were reported in their breastfed babies. The American Academy of Pediatrics classifies methyldopa as a medication that is usually compatible with breastfeeding. The ACOG recommends avoiding the use of methyldopa during the postpartum period (after the birth of your baby), as this medication increases the risk of depression in the mother. 

Bottom line: Caution should be used if methyldopa is given to moms who are breastfeeding. This medication passes into breast milk, and very little data is available on its effects in the breastfed baby. Experts do not recommend the use of methyldopa in new moms, as it can lead to depression in the mom.

If I am taking methyldopa, will it be more difficult to get pregnant?

No studies have been found that have looked at the effects of methyldopa on fertility in men and women. Animal studies found no evidence of impaired fertility when methyldopa was given to male and female rats at 1.7 times the maximum recommended human dose by weight. However, higher doses of methyldopa were found to reduce sperm count and male fertility index in male rats.

If I am taking methyldopa, what should I know?

Methyldopa should only be taken during pregnancy if medically necessary, as determined by your doctor. This medication crosses the placenta and can expose your baby to its effects. Although some studies have found that moms who took methyldopa were more likely to have pregnancy complications or deliver a baby with health problems, other reports have indicated that methyldopa may improve pregnancy outcomes in moms with high blood pressure. The ACOG has indicated that other treatment options may be preferred for expecting moms with high blood pressure, as methyldopa is not as effective as other medications and is associated with
side effects in the mom. Your doctor will help you choose a treatment plan that is safe for both you and your baby.

Caution should be used if methyldopa is given to moms who are breastfeeding. This medication passes into breast milk, and the data available on its use while nursing only consists of a few case reports. Experts do not recommend the use of methyldopa in new moms, as it can lead to depression in the mother.

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of methyldopa during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert reports about high blood pressure here and hypertension here and reports on the various medications used to treat heart condtions here.  Additional information can also be found in the links below. 

For more information about methyldopa during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links:

Lexicomp: Methyldopa: Drug information

American Heart Association: The Facts About High Blood Pressure

American Heart Association: Why High Blood Pressure is a “Silent Killer.”

Read the whole report
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.