Congenital uterine malformations are associated to increased blood pressure in pregnancy

To assess the relationship between congenital uterine malformations and blood pressure in pregnancy.

Twenty-four-hour automated ambulatory blood pressure monitoring (readings every 30 min) was performed in 16 normotensive, nonproteinuric, primigravidae with congenital uterine malformations (5 uterus septus, 9 uterus bicornis, 2 uterine didelphys) between 20 and 30 weeks. From the 24-hr blood pressure report, we calculated 24-hr mean, daytime and nighttime means. The results were compared with 16 primigravidae, matched for age and gestation, who were and remained normotensive throughout pregnancy, and tested for statistics with t-test; significance assessed at p < 0.001.

Although they were within the normotensive range, all blood pressure measurements considered were significantly higher in pregnant women with congenital uterine malformations, compared to normal pregnant women. Namely, 24-hr, daytime, and nighttime systolic (mean +/- SD) were 121.1 +/- 8.4, 124.4 +/- 8.8, 114.0 +/- 7.7 mmHg, respectively, in women with uterine malformations and 108.0 +/- 7.4, 109.2 +/- 7.3, 102.1 +/- 8.5 mmHg, respectively, in normal pregnant women. Twenty-four-hour diastolic, daytime, and nighttime diastolic (mean +/- SD) 74.1 +/- 10.2, 77.1 +/- 10.6, 68.1 +/- 9.2 mmHg, in women with uterine malformations and 64.1 +/- 5.7, 66.0 +/- 5.7, 58.2 +/- 6.3 mmHg, in normal pregnant women (all differences p < 0.001). Fifteen of the fetuses from women with congenital uterine malformations showed intrauterine growth retardation. No differences were found 6 months after delivery.

Although the blood pressure levels remained within the normotensive range, pregnant women with congenital uterine anomalies have a higher blood pressure than normal women. Elevated blood pressure can result from altered uterine circulation and reduced blood supply to the placenta. This pathogenesis or the poor placentation may result in a foetal growth retardation.