Regardless of having known high blood pressure/chronic hypertension before delivery, your blood pressure will experience changes due to pregnancy.

Early in pregnancy, your blood pressure actually drops. Your blood pressure can decrease as early as seven weeks of your pregnancy, and your blood pressure reaches its lowest point around 16-18 weeks of your pregnancy. The decrease in diastolic blood pressure could be by as much as 20 mm Hg and is more noticeable than the decrease in systolic blood pressure. Over the course of the pregnancy, your blood pressure will rise to your pre-pregnancy levels. It will often reach pre-pregnancy levels in the third trimester. (Source: ACOG Chronic Hypertension Practice Bulletin)

If you know your blood pressure has been high in the past, it is important to tell your health care provider as soon as you can. Knowing about any history of high blood pressure will help your health care provider detect elevated blood pressures in early prenatal care.

People who have high blood pressure before pregnancy often carry a diagnosis of chronic hypertension. Approximately 0.9-1.5% of pregnant women are diagnosed with chronic hypertension.

A diagnosis of chronic hypertension occurs when a pregnant woman had known hypertension before pregnancy or a new diagnosis prior to 20 weeks of pregnancy.

Blood pressure criteria:

The current criteria for chronic hypertension in pregnancy is a systolic blood pressure of 140 mm Hg or more, a diastolic blood pressure of 90 mm Hg or more, or both on two occasions at least four hours apart.

However, the American College of Cardiology (ACC) and the American Heart Association (AHA) have changed the criteria for diagnosing hypertension in adults. The new guidelines include classifying blood pressure into four categories:

1. Normal (systolic blood pressure less than 120 mm Hg and diastolic blood pressure less than 80 mm Hg)
2. Elevated (systolic blood pressure of 120–129 mm Hg and diastolic blood pressure less than 80 mm Hg)
3. Stage 1 hypertension (systolic blood pressure of 130–139 mm Hg or diastolic blood pressure of 80–89 mm Hg)
4. Stage 2 hypertension (systolic blood pressure of 140 mm Hg or more or diastolic blood pressure of 90 mm Hg or more).

It is unknown at this time if treating women with stage 1 hypertension with medication is recommended in pregnancy. You may need a higher degree of observation throughout your pregnancy. You should discuss this with your obstetric care provider.

Listen to Dr. Kara Hoppe discuss chronic hypertension on the Women’s Healthcast: Apple Podcasts / Spotify / Podbean

Having chronic hypertension does increase the risk to the mother, fetus, and baby after birth. It is important to consider a pre-pregnancy consultation with an obstetrics provider to discuss any medication use/type of medication needed to control your blood pressure. Your doctor may also consider tests to help determine your risk and any treatments you may need to address hypertension during pregnancy. (Source: ACOG Chronic Hypertension Practice Bulletin)

Maternal Risks:

• Death
• Stroke
• Pulmonary edema
• Kidney injury
• Heart attack
• Preeclampsia
• Placental abruption
• Cesarean delivery
• Hemorrhage after birth

Fetal/Neonatal Risks:

• Fetal or neonatal death
• Growth restriction
• Preterm delivery
• Birth defects

Yes, your blood pressure is influenced by many things.

Your blood pressure may temporarily be higher if you use tobacco, drink caffeinated drinks like coffee or tea, or use drugs such as cocaine and amphetamines.

Additionally, some people’s blood pressure may be influenced by stress and anxiety, a full bladder, the wrong cuff size and crossed legs.

Though there are not clear recommendations to do so, we recommend taking control of monitoring your blood pressure from home throughout your pregnancy. This allows for earlier detection of increasing or worrisome blood pressures, most commonly starting around the second trimester.

It is important to know how to take your blood pressure because poor technique can influence the measurements. The video below includes instructions for how to take an accurate blood pressure measurement at home. In addition, consider taking in your blood pressure machine to your clinic to verify that your readings are similar to the in-office values. Your blood pressures will be checked at all your prenatal visits.

Yes, women who do not have underlying chronic hypertension may develop blood pressures exceeding the above blood pressure criteria during their pregnancy. (Systolic blood pressure of 140 mm Hg or more, a diastolic blood pressure of 90 mmHg or more, or both on two occasions at least 4 hours apart).

There are two distinct hypertension disorders of pregnancy:

1. gestational hypertension
2. preeclampsia

Gestational hypertension is elevated blood pressure with no protein in the urine, lab abnormalities, or concerning clinical exam findings.

Preeclampsia has elevated blood pressures with either protein in the urine or, in the absence of protein in the urine, lab abnormalities (low platelet counts, abnormal kidney function, abnormal liver function) or other concerning clinical exam findings (fluid in the lungs or a headache/vision changes).

To learn more about these conditions:

Listen to Dr. Kara Hoppe discuss preeclampsia on the Women’s Healthcast:

Apple Podcasts / Spotify / Podbean

Visit preeclampsia.org.

Learn more about risk factors for preeclampsia from the American College of Ob-Gyns:

Gestational Hypertension and Preeclampsia - ACOG

Women who have underlying chronic hypertension are also at risk of developing preeclampsia. This is called superimposed preeclampsia.

There are several risk factors for preeclampsia, including:

• Never having given birth before (nulliparity)
• A pregnancy with two or more fetuses (multifetal gestation, such as twins or triplets)
• Preeclampsia in a previous pregnancy
• Chronic hypertension
• Having diabetes before you become pregnant
• Diabetes that develops while you are pregnant (gestational diabetes)
• Blood disorders that increase your risk for blood clots (thrombophilia)
• Pre-pregnancy body mass index greater than 30
• Being 35 years or older
• Kidney disease
• Obstructive sleep apnea
• Systemic lupus erythematosus
• Antiphospholipid antibody syndrome
• Assisted reproductive technology

Learn more about risk factors for preeclampsia from the American College of Ob-Gyns:

Preeclampsia and Pregnancy - ACOG

Gestational Hypertension and Preeclampsia - ACOG

Having a hypertension-related condition during your pregnancy increases your risk of having increasing blood pressures after hospital discharge (in the first six weeks at home). This is where home blood pressure monitoring on your own or through a program like STAC can help identify women who have increasing blood pressures that may lead to dangerous events like stroke or death.

Increasing blood pressures and other cardiovascular-related conditions are among the most common reasons women get readmitted to the hospital after birth.

In addition, having high blood pressure during pregnancy or delivery does increase the long-term risk of developing chronic hypertension and the life-long risk of cardiovascular related death.

Yes, women who have had pregnancy-related hypertension diagnoses in a prior pregnancy are at risk of developing it again. The earlier and more severe your hypertension was likely increases your risk of experiencing high blood pressure in a future pregnancy. It is possible, though, to have a future pregnancy without a recurrence of pregnancy-related blood pressure complications.

Aspirin is recommended to reduce the risk of high blood pressure during pregnancy for anyone who experienced high blood pressure in a previous pregnancy. Discuss with your obstetrics health care provider to learn more.

Watch this video produced by UnityPoint Health-Meriter Hospital to learn more about safe pregnancy with high blood pressure.

Yes, we recommend a follow-up visit with your primary care provider within one year of your delivery. Additionally, annual evaluations of your overall health and specifically your blood pressure should be a long-term health priority. Lastly, consider a preconception evaluation with your OB provider before a future pregnancy to identify any concerns related to your pregnancy-related hypertension, chronic hypertension and any preventative strategies that will increase your chance of having a healthy pregnancy.