By Rachael Zimlich, BSN, RN 

 Medically reviewed by Monique Rainford, MD

High blood pressure (hypertension) can increase the risk of complications for pregnant people and their babies.

High blood pressure during pregnancy can affect the development of the placenta, which provides nutrients and oxygen to the baby.1 This can lead to an early delivery, low birth weight, placental separation (abruption), and other complications for the baby.

As many as 8% of mothers around the world struggle with high blood pressure during pregnancy, and about 2% experience high blood pressure after delivery.2

With the proper management of high blood pressure, though, pregnant people with this condition can minimize the risk of these complications. Your healthcare provider will also closely monitor your condition and pregnancy if you have high blood pressure.

High Blood Pressure and Fertility

Fertility issues related to high blood pressure can affect both parents. Besides the condition itself, medications used to treat high blood pressure can have an impact on fertility as well.

Females living with high blood pressure have been found to have more trouble conceiving. One study revealed that the risk of pregnancy loss, or miscarriage, increased by 18% for every 10 mmHg increase in a person’s diastolic blood pressure.3

Chronic high blood pressure before pregnancy has also been linked to poor egg quality due to excessive estrogen production, which is known to affect fertility.4 If a poor-quality egg is fertilized, the embryo may not be able to implant in the uterus. Even if the embryo succeeds at implanting, it may not be able to develop properly and may result in a miscarriage.

Similarly, males with high blood pressure were found to have a lower semen volume, sperm motility (the ability of the sperm to move properly), total sperm count, and motile sperm count compared to people without the condition.5

Sperm must be able to swim up to the fallopian tube to fertilize the egg for conception to occur. If sperm move too slowly or not at all, conception may not happen.

Additionally, medications to control high blood pressure like angiotensin receptor inhibitors and calcium channel blockers could impact fertility.4

The use of beta-blockers, another type of antihypertensive drug, was associated with lower semen volume, concentration, motility, total sperm count, and total motile sperm count.5

Is High Blood Pressure Hereditary?

An estimated 30% to 50% of cases of hypertension are linked to genetics.6 Make sure you talk to your doctor about your family history and any health risks you may have if you are trying to become pregnant, especially if you are having trouble conceiving.

High Blood Pressure and Gestation

High blood pressure may increase your risk of complications during pregnancy.

You can have hypertension in pregnancy either as a continuation of a chronic problem that you had before you were pregnant or as a new problem that develops during your pregnancy, which is called gestational hypertension or preeclampsia.

Hypertensive disorders occur in 6% to 8% of pregnancies around the world, and about a quarter of hospital admissions for mothers during their pregnancy.4

Risks

High blood pressure during pregnancy can prevent the placenta from receiving enough blood, which can lead to a low birth weight.1 Other complications can occur from high blood pressure during pregnancy, including:

• Seizures in the mother

• Stroke

• Kidney failure

• Liver problems

• Blood clotting problems

• Placental abruption, where the placenta pulls away from the wall of the uterus, causing distress to the baby and bleeding in the mother

• Premature delivery of the baby

Treatment

Whether or not high blood pressure is treated in pregnancy depends on a woman's blood pressure ranges, and there can be challenges even if medications are used.

Ideally, pregnant people will have already stopped smoking or consuming alcohol. Other lifestyle changes that can help lower blood pressure include dietary changes like limiting salt intake and exercise, but they should only be done under the direction of your healthcare provider. Stress reduction and meditation may be helpful, too.

Medications that could be used to treat high blood pressure during pregnancy include:4

• Methyldopa

• Labetalol

• Procardia (nifedipine)

Your healthcare provider may also recommend more prenatal visits, ultrasounds, and other tests—such as monitoring your baby’s heart rate or activity—to ensure the baby’s well-being.1

Concerning Symptoms

If your blood pressure becomes high, such as the case with preeclampsia, you may experience symptoms that could indicate more extreme complications for your pregnancy.

Signs and symptoms of severe hypertension include:7

• Blood pressure above 160/110 mmHg

• Impaired liver or kidney function

• Increased levels of protein in urine samples

• Low platelet counts

• Severe headache

• Vision changes

What Are Recommended Blood Pressure Ranges During Pregnancy?

Some increases in blood pressure are expected because your blood volume will increase and the pregnancy will be more demanding on your cardiovascular system in general. A normal blood pressure is a systolic blood pressure less than 120 mmHg and a diastolic blood pressure less than 80 mmHg.

The American College of Obstetricians and Gynecologists (ACOG) recommends treatment for high blood pressure if your systolic blood pressure is 160 mmHg or higher or if you have a diastolic blood pressure of 110 mmHg or higher. Sometimes treatment is recommended at lower levels in women who have other risk factors.8

There is no clear way to prevent preeclampsia, but those at higher risk may be advised to take daily low-dose aspirin starting after 12 weeks of pregnancy to reduce their chances of developing this condition.9

In severe cases, your healthcare provider may decide to deliver your baby. This is a decision between you and your doctor based on your individual risks and how your blood pressure is affecting the health of you and your baby.

High Blood Pressure and Postpartum

Even after delivery, your healthcare team will continue to monitor your blood pressure closely. Your blood volume and fluid levels shift dramatically in the postpartum period, and this can cause significant fluctuations in blood pressure. Eclampsia or preeclampsia can develop up to six weeks after delivery.4

Impact on Recovery

If you develop complications of high blood pressure, especially if they advance to things like blood clotting or preeclampsia, you may not be discharged right away.

In some cases, high blood pressure that develops in pregnancy may even become chronic. In about 10% of cases, your doctor may find another reason for your hypertension after delivery, but if high blood pressure continues, you may need antihypertensive medications.10

People who suffer from preeclampsia during one pregnancy have an increased risk of having the same complication in future pregnancies. Beyond pregnancy, the chances of developing chronic hypertension are also higher among these people compared to those who didn’t develop the condition during pregnancy. Additionally, the risks of ischemic heart disease and stroke are roughly doubled in women who developed preeclampsia during a pregnancy.11

Breastfeeding

Medications used to control blood pressure are generally secreted into breast milk at very low levels that won’t harm your baby, but there are some medications that doctors prefer to avoid to be extra cautious. These include Norvasc (amlodipine), diuretics, Tenormin (atenolol), and methyldopa.

These medications can cause postnatal depression or a decrease in milk supply for breastfeeding mothers. This means that medications you take to control blood pressure during pregnancy, like methyldopa, may have to be replaced with other medications after delivery.

Suggested medications to treat blood pressure in breastfeeding mothers include:11

• Labetalol

• Procardia (nifedipine)

• Enalapril

Summary

High blood pressure and some medications used to treat the condition can affect fertility in males and females, making it more difficult to conceive. It can also increase the risk of complications for you and your baby. Keeping your blood pressure under control can reduce that risk, and your healthcare provider will help you come up with the best plan during and after your pregnancy.

Sources

Cleveland Clinic. High blood pressure (hypertension) during pregnancy.

Sharma KJ, Kilpatrick SJ. Postpartum hypertension: etiology, diagnosis, and management. Obstet Gynecol Surv. 2017;72(4):248-252. doi:10.1097/OGX.0000000000000424

Nobles CJ, Mendola P, Mumford SL, et al. Preconception blood pressure levels and reproductive outcomes in a prospective cohort of women attempting pregnancy. Hypertension. 2018;71(5):904-910. doi:10.1161/HYPERTENSIONAHA.117.10705

Barekat M, Ahmadi S. Hypertensive disorders in pregnant women receiving fertility treatments. Int J Fertil Steril. 2018;12(2):92-98. doi:10.22074/ijfs.2018.5232

Guo D, Li S, Behr B, Eisenberg ML. Hypertension and male fertility. World J Mens Health. 2017;35(2):59-64. doi:10.5534/wjmh.2017.35.2.59

Russo A, Di Gaetano C, Cugliari G, Matullo G. Advances in the genetics of hypertension: the effect of rare variants. Int J Mol Sci. 2018;19(3):688. doi:10.3390/ijms19030688

Gestational hypertension and preeclampsia. Obstet Gynecol. 2020;135(6):1492-1495. doi:10.1097/AOG.0000000000003892

American College of Obstetricians and Gynecologists. Preeclampsia and high blood pressure during pregnancy.

U.S. Preventive Services Task Force. Aspirin use to prevent preeclampsia and related morbidity and mortality: U.S. Preventive Services Task Force recommendation statement.

Powles K, Gandhi S. Postpartum hypertension. CMAJ. 2017;189(27):E913. doi:10.1503/cmaj.160785

Bramham K, Nelson-Piercy C, Brown MJ, Chappell LC. Postpartum management of hypertension. BMJ. 2013;346:f894. doi:10.1136/bmj.f894

University of Michigan Health. HELLP syndrome and preeclampsia.

By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.