Hypertension is the most common medical problem during pregnancy. Some women have high blood pressure before becoming pregnant and others develop it during pregnancy. A woman is considered to have high blood pressure if the measurement is above 140 mmHg systolic (the first BP number) or above 90 mmHg diastolic (the second BP number). Hypertension that develops during pregnancy is called Gestational Hypertension.
Severe hypertension occurs when BP rises above 160 mmHg systolic or above 100 mmHg during pregnancy, and if it persists for 15 minutes or longer is considered a hypertensive emergency requiring immediate treatment. Hospitalization and intravenous medications are sometimes required to prevent the serious complications that can result to the mother and developing baby. If hypertension is associated with abnormal kidney function, edema and/or neurologic signs, the condition is known as Preeclampsia, which, if left untreated, can be fatal for both.
The problem with hypertension during pregnancy is that over time it causes a decrease in the blood supply through the vessels of the placenta, reducing the oxygen and nutrients going to the baby. This can stunt the baby’s growth, resulting in a condition known as Fetal Growth Restriction (“FGR”). FGR results in the baby being born abnormally small with lesser ability to withstand the stress of labor and delivery than a normal size and normally-oxygenated baby.
Women should periodically measure their blood pressure during pregnancy with a simple BP monitor in between prenatal office visits. If a pressure reading is found above 140 mmHg systolic or above 90 mmHg diastolic, the obstetrician should be notified and further assessment for gestational hypertension and pre-eclampsia performed.