If you have chronic hypertension during pregnancy, you need close prenatal care whether your hypertension is mild or severe, and whether or not you take on anti-hypertensive medications. This prenatal care should include careful monitoring for worsening hypertension, preeclampsia, and fetal growth restriction.
Mild to Moderate Hypertension (Blood Pressure Less than 150/100 mm Hg)
In pregnant women with mild to moderate chronic hypertension and no evidence of kidney disease, serious medical complications are rare. If you have mild to moderate hypertension, you should be monitored regularly in your doctor's office for any signs of worsening hypertension or preeclampsia. You may require medication to control your high blood pressure.
In general, your prenatal visits are scheduled every two to four weeks. After your 34th or 36th week, you will see your doctor weekly.
In addition to checking your blood pressure and testing for protein in your urine (a key sign of preeclampsia), your doctor also carefully monitors your baby's growth. Babies born to women with chronic hypertension, regardless of the cause, are at increased risk for poor fetal growth. Several ultrasounds will be performed during your pregnancy:
- early in your pregnancy to confirm the due date and to ensure that your baby is healthy;
- throughout pregnancy, if necessary, to monitor your baby's growth; and
- during your third trimester, just prior to labor and delivery.
Severe Hypertension (Blood Pressure Greater than 150/100 mm Hg)
If you have severe hypertension, you will receive careful prenatal care throughout your pregnancy. You will also require blood pressure medication to reduce your risk of heart disease and stroke. As part of your prenatal care:
- at each visit, your doctor checks your blood pressure and urine protein and monitors your baby's growth;
- your doctor screens for warning signs of preeclampsia, such as headache, vision changes, and abdominal pain;
- after the 28th week of pregnancy, an ultrasound is done every three to five weeks to check for signs of fetal growth restriction;
- if there is evidence of kidney disease, your creatinine clearance and 24-hour protein excretion (the amount of protein in urine collected over a 24-hour period) is measured each trimester; and
- antepartum testing (ultrasound and fetal heart monitoring) usually starts by your 34th week.
With few exceptions, most women with severe hypertension deliver before their 40th week of pregnancy.
The next steps in the management of chronic hypertension in pregnancy depend on whether your doctor finds evidence of fetal growth restriction during your scheduled exams.