Hypertension and pregnancy risks: does pre-pregnancy blood pressure management have an impact?

This study investigated if managing blood pressure in the first trimester of pregnancy reduced prevented hypertension and pregnancy risk later on.

They found that managing blood pressure levels in early pregnancy reduced the rate of severe hypertension and other pregnancy complications.

Hypertension or high blood pressure is a condition that requires strict blood pressure control. Hypertension can cause a number of complications including heart disease, kidney disease and death.  During pregnancy, hypertension can be dangerous for both the mother and baby.

Evidence suggests that women with chronic (long-term) hypertension have a high risk of developing severe hypertension and preeclampsia (high blood pressure and organ damage). There may also be a risk of the baby being small for its gestational (birth) age. It is unknown if patients taking medication to reduced blood pressure prior to becoming pregnant have the same risk. 

This study investigated the effects of pre-pregnancy hypertension on the rates of severe hypertension, preeclampsia and babies being small for gestational age.

This study included 586 women with pre-pregnancy hypertension. Patients were separated into 3 groups: Group 1 patients had blood pressure less than 140/90 mmHg without anti-hypertensive medication; Group 2 had blood pressure less than 140/90 mmHg with anti-hypertensive medication;  Group32 had blood pressure greater than 140/90 mmHg despite anti-hypertensive medication. The rate of severe hypertension (greater than 160/110 mmHg), preeclampsia and being small for gestational age was monitored in all patients.

Overall, women with pre-pregnancy hypertension have a high rate of severe hypertension (27%), preeclampsia (23%) and small for gestational age (SGA) birthweight (17%). Patients in Group 1 had the lowest risk of severe hypertension (11%), preeclampsia (7%) and SGA birthweight (13%). In comparison, Patients in Group 2 had a higher risk of severe hypertension (22%), preeclampsia (16%) and SGA birthweight (18%) . The greatest risk was observed in Group 3, with 52% with severe hypertension, 20% with preeclampsia and 21% with SGA birthweight.

This study concluded that managing blood pressure levels in early pregnancy reduces the rate of severe hypertension and other pregnancy complications.

In group 2 and 3 patients had a significantly higher body mass index (this can affect blood pressure management). A significant number of women (61.3%) in this group were of black racial origin. The results may not extend to the wider population. 

If you have any concerns regarding blood pressure management and pregnancy risks, please discuss this with your physician.