 [ Symptoms ] how common are high blood pressure and preeclampsia in pregnancy [ Disease ] high blood pressure problems occur in 6 to 8 of all pregnancies in the u s about 70 of which are first time pregnancies although the proportion of pregnancies with gestational hypertension and eclampsia has remained about the same in the u s over the past decade the rate of preeclampsia has increased by nearly one third this increase is due in part to a rise in the numbers of older mothers and of multiple births where preeclampsia occurs more frequently