Gestational hypertension is a relatively mild hypertensive disorder that normally does not compromise a woman's pregnancy. Mild hypertension develops after the 20th week of pregnancy and resolves after delivery. In most cases, the only potential complication of mild gestational hypertension is the need to induce labor, resulting in a slightly higher rate of caesarean delivery (C-section). However, there are several instances when gestational hypertension may compromise a women's pregnancy. When diagnosed before 30 weeks, there is a higher chance that gestational hypertension will progress to preeclampsia. When women with gestational hypertension develop severe blood pressure elevations (>160/110), headaches, vision changes, abnormal blood tests, or growth restriction of the baby, they are treated as if they have preeclampsia.

Table 1. Hypertension Diagnosed Before 37 Weeks-Risk of Complications
Infant growth restriction 5-17%5-17%
Preterm delivery 2-14%2-14%

Risk Factors

Risk factors for gestational hypertension and preeclampsia include women who are pregnant for the first time, women who are pregnant with twins or triplets, and women who have had gestational hypertension or preeclampsia in a prior pregnancy. The rate of occurrence also increases in women who are overweight before the pregnancy.

Gestational hypertension cannot definitively be diagnosed until after delivery. Prior to delivery, seemingly benign hypertension may worsen rapidly and progress to preeclampsia or eclampsia. If you are diagnosed with hypertension during pregnancy, your doctor closely monitors you for signs that the hypertension is developing into a more serious condition. Proteinuria (protein in the urine), rapid weight gain caused by edema (excessive swelling-especially of the hands and face) are all signals that preeclampsia is developing. When hypertension is diagnosed before the 37th week, the chances of other complications, specifically preeclampsia and eclampsia, significantly increase.

Gestational hypertension may affect women after delivery. Women who develop gestational hypertension may be three times more likely to develop essential hypertension in the future.