Hypertension During Pregnancy

The treatment of hypertension during pregnancy has been a controversial area for many

years. Treatment of the mother is also treatment of the baby even though the unborn

has no medical issues of hypertension. Additionally, the issue of potential teratogenic effects from

medications need to be considered. Untreated hypertension however has been associated

with an increased risk of eclampsia and an increased risk of placental abruption. A

study led by researchers at the University of Alabama looked specifically at this problem.

The CHAP study (Chronic Hypertension and Pregnancy) looked at women with mild hypertension

(defined as BP less than 160/100) to see if treatment of this population group

would be beneficial and safe for both mother and baby. Patients were treated with any one

of 4 anti-hypertensive medications; labetalol, nifedipine, amlodipine or methyldopa.

It is estimated that 2% of US women enter pregnancy with elevated BP. Of those, up to 80%

have mild chronic hypertension. Rates are rising due to older age at childbirth and obesity.

Results of the study showed a lower incidence of preeclampsia and a lower incidence of low-

birth weight infants in the treatment group. The conclusion of this study is that treatment of

mild hypertension (BP of 160/100) is beneficial to both mother and baby, even accounting

for the potential of birth defects in the treatment group. The study was awarded a government

grant to extend the study for up to 10 years so this subject will continue to be looked at for years

to come.