7 Blood Pressure Changes During Pregnancy That Are Actually Normal

If you are pregnant and monitoring your blood pressure at home, prepare yourself: the readings are going to do things that seem alarming. Blood pressure during pregnancy follows a unique pattern that looks nothing like the steady numbers most adults experience. Understanding what is normal can prevent weeks of unnecessary worry. Here are seven blood pressure changes that are expected during a healthy pregnancy.

1. Blood Pressure Drops in the First and Second Trimesters

This surprises nearly everyone. During the first 24 weeks of pregnancy, blood pressure typically falls by 5-10 mmHg from pre-pregnancy levels. Some women see drops of 15 mmHg or more. The cause is progesterone, which relaxes the smooth muscle in blood vessel walls, reducing resistance to blood flow. Simultaneously, new blood vessels develop to supply the placenta, creating additional capacity in the vascular system. A reading of 95/60 that would concern a non-pregnant person is often perfectly normal at 20 weeks. This drop can cause dizziness when standing quickly, which is why pregnant women are advised to rise slowly from seated or lying positions.

Why it matters for your metabolic age: Pregnancy temporarily resets many metabolic parameters. After delivery, how quickly your blood pressure returns to baseline is an important signal about your long-term metabolic health.

2. Blood Pressure Gradually Rises Back in the Third Trimester

Starting around week 24-28, blood pressure begins climbing back toward pre-pregnancy levels. By the third trimester, most women’s blood pressure returns to or slightly exceeds their pre-pregnancy baseline. This is driven by increasing blood volume (which rises by 40-50% during pregnancy), the growing demands of the fetus, and hormonal shifts as delivery approaches. A gradual rise of 5-10 mmHg in the third trimester is expected. What is not normal: a sudden jump of 15 mmHg or more over a short period, which could indicate preeclampsia and requires immediate medical evaluation.

3. Readings Differ Dramatically Between Arms and Positions

During pregnancy, positional blood pressure changes are exaggerated. Lying on your back can cause the uterus to compress the vena cava (the large vein returning blood to your heart), suddenly dropping blood pressure. Readings taken lying on your left side will be lower than seated readings, which will be lower than standing readings. The difference between arms can also be more pronounced during pregnancy. For consistent monitoring, always measure in the same position – ideally seated with your left arm supported at heart level. Do not compare a reading taken lying down to one taken standing up; they may differ by 20 mmHg or more and both can be normal.

Why it matters for your metabolic age: Position-dependent blood pressure changes during pregnancy are temporary, but they highlight the importance of consistent measurement technique for accurate metabolic age tracking at any life stage.

4. Heart Rate Increases, Which Can Make Blood Pressure Readings Confusing

Resting heart rate increases by 15-20 beats per minute during pregnancy to accommodate the additional blood volume. This higher heart rate can influence blood pressure readings, particularly with automatic monitors that use oscillometric technology. Some home monitors become less accurate at higher heart rates. If your readings seem inconsistent, try measuring after sitting quietly for five minutes when your heart rate has settled. The American College of Obstetricians and Gynecologists recommends that pregnant women use upper-arm cuff monitors rather than wrist monitors, which are less reliable during pregnancy.

5. Blood Pressure Fluctuates More Throughout the Day

The normal daily blood pressure rhythm – lower in the morning, higher in the afternoon, dipping during sleep – becomes more exaggerated during pregnancy. A 2018 study in Pregnancy Hypertension found that the average daily blood pressure range (difference between highest and lowest readings) was 15-20 mmHg in pregnant women compared to 8-12 mmHg in non-pregnant women. This means a single reading tells you less than usual. If you are monitoring at home during pregnancy, taking two readings at different times of day and averaging them over a week gives a much more reliable picture than any single measurement.

6. Swelling Does Not Always Mean Dangerously High Blood Pressure

Swollen ankles, hands, and feet are extremely common in late pregnancy and often trigger blood pressure anxiety. While swelling can accompany preeclampsia (which also involves high blood pressure and protein in urine), mild to moderate swelling alone is usually caused by the 50% increase in blood volume and fluid retention driven by progesterone. About 75% of pregnant women experience some swelling, and most have normal blood pressure. The distinguishing signs of preeclampsia-related swelling are rapid onset (developing over hours rather than days), facial swelling (especially around the eyes), and accompanying symptoms like severe headache, vision changes, or upper abdominal pain.

Why it matters for your metabolic age: Preeclampsia is a metabolic event, not just a blood pressure event. Women who develop it often have underlying metabolic vulnerabilities that persist after pregnancy.

7. Blood Pressure May Be Higher Than Pre-Pregnancy Levels for Weeks After Delivery

Many women expect blood pressure to normalize immediately after birth. In reality, blood pressure often rises in the first 3-5 days postpartum before gradually declining over 6-12 weeks. This postpartum rise is driven by fluid shifts as the body reabsorbs the extra blood volume of pregnancy, hormonal fluctuations, sleep deprivation, and the stress of new parenthood. A 2019 study in the American Journal of Obstetrics and Gynecology found that 12% of women had elevated blood pressure at six weeks postpartum, even among those with no hypertension during pregnancy. Postpartum blood pressure monitoring is recommended at the one-week and six-week checkups, and any severe headaches or vision changes in the weeks after delivery warrant immediate blood pressure assessment.

Track Your Metabolic Recovery After Pregnancy

Pregnancy is a metabolic stress test. How quickly your blood pressure, blood sugar, and weight normalize after delivery reveals important information about your long-term metabolic health. Penlago’s MetaAge calculator gives you a metabolic age score based on these metrics, helping you track your recovery and set goals for the months ahead.

Find out your metabolic age in 60 seconds – free at penlago.com.