High Blood Pressure Can Seriously Affect Pregnancy

Risk of pregnancy complications increased with chronic high blood pressure

(RxWiki News) High blood pressure during pregnancy puts pressure on both the baby and the mom. At the moment, there has yet to be a consistent strategy for prenatal care in women with high blood pressure.

A recent review found that pregnant women with chronic high blood pressure were more likely to have pregnancy complications such as preterm birth, low birth weight and newborn death.

The researchers believe doctors should pay more attention to pregnant women with chronic high blood pressure. Such attention might include pre-pregnancy counseling.

"Tell your OB/GYN if you have chronic high blood pressure."

The lead author of this study review was Kate Bramham, clinical research fellow from the Division of Women's Health in the Women's Health Academic Centre at King's College Long and King's Health Partners at St. Thomas' Hospital — both in London, United Kingdom.

This review included 55 previously published studies from 25 different countries on the association between chronic high blood pressure and pregnancy complications.

The studies were published between 1970 and 2013 and included 795,221 pregnancies that resulted in 812,772 infants.

The findings showed that among women with chronic high blood pressure, 26 percent developed superimposed preeclampsia (high blood pressure and increased protein in urine during pregnancy), 41 percent had a caesarean section and 28 percent had babies born before 37 weeks of pregnancy (preterm birth).

In addition, 17 percent had babies that weighed less than 5.5 pounds when born, 21 percent had babies that had to be admitted to the neonatal unit after birth and 4 percent experienced perinatal death (fetal death after 20 weeks of pregnancy and death up to one month after birth).

The researchers determined that the women with chronic high blood pressure were 7.7 times more likely to develop superimposed preeclampsia than the pregnant women who did not have chronic high blood pressure.

Chronic high blood pressure during pregnancy was associated with a 30 percent increased risk of having a caesarean section.

Compared to the women who did not have chronic high blood pressure, those with chronic high blood pressure had a 2.7 times increased risk of having a baby born before 37 weeks and 2.7 times increased risk of having a baby weighing under 5.5 pounds.

The findings revealed that the women with chronic high blood pressure were 3.2 times more likely to have their newborn admitted into the neonatal unit and 4.2 times more likely to experience perinatal death.

The researchers mentioned a few limitations of their study. First, most of the studies did not provide relevant baseline demographics of the study participants. Second, many of the studies did not use a control group for comparison. Third, there was not any data on the effects of anti-high blood pressure medicine on birth outcomes. Lastly, all data was taken from databases, so treatment and outcomes could not be confirmed.

This study review was published on April 15 in BMJ.

The National Institute for Health Research provided funding.

Review Date: 
April 15, 2014