Gestational hypertension: high blood pressure that starts in pregnancy

Gestational hypertension is high blood pressure that first appears after 20 weeks of pregnancy, when your blood pressure was normal before. ACOG defines it as 140 over 90 or higher. ACOG says most women only have a small rise, and it usually goes away after the birth. It is watched closely because it raises your chance of pre-eclampsia.

Gestational hypertension, chronic hypertension or pre-eclampsia?

The three get mixed up on antenatal notes. ACOG separates them by timing and by what else is going on:

• Chronic hypertension: high blood pressure before pregnancy or before 20 weeks.
• Gestational hypertension: new high blood pressure after 20 weeks without protein in the urine. SingHealth's HealthXchange also calls it pregnancy-induced high blood pressure.
• Pre-eclampsia: KKH describes it as high blood pressure from week 20 together with protein in the urine. The NHS says it can affect the kidneys, liver and brain.

HealthXchange says pre-eclampsia affects about 4% of pregnancies in Singapore, and that gestational high blood pressure puts you at higher risk of it.

How it is checked and managed

You usually feel nothing. The NHS says high blood pressure does not usually make you feel unwell, which is why it is measured, and your urine tested for protein, at every antenatal visit.

Once you are diagnosed, ACOG says you will usually be checked weekly for signs of pre-eclampsia. You may be asked to measure your blood pressure at home and count your baby's movements every day. Our kick counter makes that easier to track.

Severe hypertension is 160/110 or higher. ACOG says it puts you at risk of very serious complications, and the NHS says it is treated until the reading comes down below that line.

Weight, age and your risk

HealthXchange says gestational hypertension is more likely in older and overweight mothers. KKH says being overweight raises your risk of high blood pressure and pre-eclampsia, and a BMI of 30 or more makes pre-eclampsia 2 to 4 times as likely as a BMI under 25.

HealthXchange suggests a balanced diet, 150 minutes of moderate exercise a week and 6 to 8 hours of sleep to help keep blood pressure in check. Our pregnancy weight gain calculator shows a healthy gain for your starting BMI.

Warning signs to act on the same day

These can mean pre-eclampsia. KKH asks you to seek help at once, at your delivery hospital or your gynae's clinic, if you have any combination of:

• severe headaches
• changes in your vision
• severe nausea and vomiting
• pain on the right side of your upper tummy
• sudden swelling of your ankles or feet
• sudden puffiness of your face

After your baby is born

ACOG says gestational hypertension usually goes away after childbirth, but it may raise your chance of high blood pressure later in life, and that healthy eating, weight loss and regular exercise may help prevent it. The NHS offers a blood pressure check 6 to 8 weeks after the birth. In Singapore, ask for yours at your 6-week postnatal review.

Frequently asked questions

What is pregnancy induced hypertension?

It is another name for gestational hypertension: high blood pressure that starts in pregnancy, after 20 weeks, without protein in the urine. HealthXchange uses both names.

Is gestational hypertension dangerous for my baby?

It can be. HealthXchange says it can lead to premature delivery and very low-weight babies. Weekly checks are there to catch problems early, and the main risk is that it turns into pre-eclampsia.

Will I need to deliver early?

Not always. ACOG says that with gestational hypertension or pre-eclampsia without severe features, you and your doctor may talk about delivery at 37 weeks, or sooner if tests show your baby is not doing well.

Can I still have a normal delivery with high blood pressure?

Usually, yes. The NHS says that as long as your blood pressure stays within target levels, it should not stop you having a vaginal birth. Your blood pressure is checked regularly during labour.

Related terms

• Pre-eclampsia: High blood pressure in pregnancy, usually with protein in the urine, most often from 20 weeks.
• Gestational Diabetes: High blood sugar that starts in pregnancy. Singapore screens every mum-to-be with a glucose test at 24 to 28 weeks.
• Antenatal (also Prenatal): Antenatal means before birth. Antenatal care is the check-ups, scans and tests you get while you are pregnant.
• Induction of Labour: Starting labour with medical help, such as a pessary, balloon or drip, instead of waiting for it to begin.
• 6-Week Postnatal Review: Your own check-up with a doctor four to six weeks after birth, covering healing, mood, feeding and contraception.
• Preterm (Premature) Birth: A baby born alive before 37 completed weeks of pregnancy. In Singapore, about 8.5% of babies arrive this early.

See every term in the glossary