High blood pressure in pregnancy
Updated: January 2020
Why can high blood pressure be a problem during pregnancy?
Some women, around 5 percent, experience high blood pressure when they’re pregnant. This may develop before, during, or after the pregnancy.
Chronic hypertension is high blood pressure that occurs either before you become pregnant, or during the first twenty weeks. Gestational hypertension happens after about twenty weeks.
Neither of these conditions is necessarily cause for concern, but your doctor will monitor your situation with particular care. High blood pressure during pregnancy may be a problem for two main reasons:
- It can reduce the blood supply to the placenta, so that your baby receives less oxygen and fewer nutrients. This may reduce its growth rate and/or result in premature birth.
- It may increase the risk of placental abruption, where the placenta separates from the wall of the uterus and causes bleeding.
And then there’s preeclampsia. What’s that?
Preeclampsia affects around 5 - 8 percent of all pregnancies. It tends to occur after about twenty weeks, and involves a combination of high blood pressure and, in most cases, high levels of protein in the urine. It’s seven to eight times more common in women with long-term high blood pressure.
The noticeable symptoms of preeclampsia include headaches, vision problems, abdominal pain, nausea or vomiting, and shortness of breath. Its exact causes are unclear, but there is evidence that it’s the result of an abnormally implanted placenta. Preeclampsia is also much more common in women who are pregnant for the first time. If left untreated, it may lead to eclampsia, potentially dangerous seizures.
Is it OK to get pregnant when having high blood pressure?
It’s important to talk to your doctor if you have hypertension and want to start a family. In the vast majority of cases you and your baby will be fine, but it’s still important to be aware of the risk factors involved. Chronic high blood pressure increases your risk of preeclampsia by around 25 percent, and you’re also more likely to have a caesarean delivery.
Another potential complication is that some blood pressure medications, such as ACE inhibitors, should not be taken during pregnancy. But your doctor will prescribe the safest doses of the safest drugs, and it’s important to follow his or her instructions and keep your high blood pressure under control.
How to lower blood pressure whilst pregnant?
Apart from taking medication, there’s a lot you can do to keep your blood pressure at a healthy level. During pregnancy, you should make a plan in alignment with your doctor’s advice. You can:
- Lose weight. Even a reduction of a few kilograms can significantly reduce your risk of hypertension.
- Exercise daily. Ideally, this should be aerobic exercise that gets your heart beating faster, such as brisk walking, running, cycling, or swimming. But anything is better than nothing.
- Eat a better diet. Take a closer look at those traffic-light symbols on food packaging. Eat less salt, sugar, and saturated fat, and make fruit and vegetables your friend. Eat more oily fish, such as sardines and mackerel, and increase your calcium and potassium intake with foods like nuts and skimmed milk.
- Drink no alcohol and stop smoking. These can harm your baby anyway.
- Avoid stressful situations if you can, for example by reducing your workload at the office.
Monitoring blood pressure during pregnancy
Some underlying conditions like pregnancy can put you at a risk of heart disease and can require you to monitor your blood pressure regularly. It’s important to take your blood pressure measurements using a monitor that is clinically tested and validated, by a medical society such as the European Society of Hypertension, for use with specific condition for accurate results.
Whilst blood pressure checks are an essential part of prenatal care, you can also keep an eye on your own blood pressure between visits to the doctor. There’s a wide variety of affordable monitors available. OMRON’s EVOLV, for example, is clinically validated for use during pregnancy.
Bupa (2018). High blood pressure. Retrieved from www.bupa.co.uk/health-information/heart-blood-circulation/high-blood-pressure-hypertension
Mayo Clinic (2018). High blood pressure and pregnancy: Know the facts. Retrieved from www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20046098
American Pregnancy Association (2017). Preeclampsia: Symptoms, risks, treatment and prevention. Retrieved from americanpregnancy.org/pregnancy-complications/preeclampsia/