Women who gain weight between pregnancies have an increased risk of developing recurrent disorders marked by high blood pressure in a second pregnancy, researchers from Iceland report.

Dr. Sigrun Hjartardottir of Landspitali University Hospital in Reykjavik and colleagues looked at the medical records of 869 women who developed what doctor’s call a “hypertensive disorder of pregnancy” (HDP) in their first pregnancy. All had of them delivered at least two singleton infants.

They found that recurrence of HDP was common, but did not necessarily recur as the same type of high blood pressure disorder.

Depending on the first type of HDP, recurrence in the second pregnancy ranged from 58 percent to 94 percent.

Among women who developed high blood pressure while pregnant, a condition known as gestational hypertension, the risk of HDP in the second pregnancy was 70.1 percent.

Among women who in their first pregnancy developed pre-eclampsia - a condition marked by high BP, fluid retention, and protein in urine - the risk of HDP in the second pregnancy was 58.3 percent.

Being heavy, with a body mass index (BMI) of 25 or higher, increased the risk of HDP recurrence by 82 percent, while weight gain of more than 2 BMI units more than doubled the risk, Hjartardottir’s team reports in the American Journal of Obstetrics and Gynecology.

A diagnosis of HDP at or before the 34th week of pregnancy increased subsequent HDP risk by 85 percent. When proteinuria (protein in the urine) was present with early hypertension, the risk of HDP more than tripled.

Women who develop a disorder of high blood pressure in their first pregnancy should be told they are at risk for a similar situation in the next pregnancy, the investigators conclude. “If the woman is overweight, she should be offered advice on lifestyle adjustment,” they add.

SOURCE: American Journal of Obstetrics and Gynecology, April 2006.