Among women undergoing in vitro fertilization (IVF) treatment, those who have stage 1 or 2 hypertension prior to the initiation of ovarian stimulation may have reduced chances of a live birth and increased risks of pregnancy complications, according to a large retrospective study.
Analysis of data from more than 40,000 women showed that the live birth rate decreased in a dose-dependent manner across increasing prepregnancy blood pressure (BP) categories: 49.2 percent for normal BP, 47.9 percent for elevated BP, 46.1 percent for stage 1 hypertension, and 41.4 percent for stage 2 hypertension (p<0.001). [Hypertension 2026;doi:10.1161/HYPERTENSIONAHA.125.25872]
Stage 1 and stage 2 hypertension were associated with a modest but significant decrease in the likelihood of live birth compared with normal BP (adjusted relative ratio [aRR], 0.97, 95 percent confidence interval [CI], 0.937–0.996; p=0.027 and aRR, 0.91, 95 percent CI, 0.85–0.98; p=0.009, respectively).
When BP was analysed as a continuous variable, the chances of live birth decreases by 1 percent for each 10-mm Hg increase in systolic BP (aRR, 0.99, 95 percent CI, 0.98–0.99; p=0.001) and diastolic BP (aRR, 0.99, 95 percent CI, 0.98–1.00; p=0.090), as well as for each 5-mm Hg increase in mean arterial pressure (aRR, 0.99, 95 percent CI, 0.988–0.998; p=0.010).
Adverse pregnancy outcomes
Prepregnancy hypertension was also associated with an increased risk of adverse pregnancy outcomes, including total pregnancy loss (stage 1: aRR, 1.06, 95 percent CI, 1.01–1.13; p=0.033; stage 2: aRR, 1.14, 95 percent CI, 1.02–1.28; p=0.025) and preterm delivery (stage 1: aRR, 1.15, 95 percent CI, 1.04–1.27; p=0.005; stage 2: aRR, 1.40, 95 percent CI, 1.16–1.69; p=0.001).
Furthermore, stage 1 hypertension was linked to higher risks of gestational hypertension (aRR, 2.90; p<0.001) and pre-eclampsia (aRR, 2.33; p<0.001), while stage 2 hypertension was associated with increased risks of low birth weight (aRR, 1.58; p=0.019) and small for gestational age (aRR, 2.20; p<0.001) for singleton infants.
These findings suggest that “hypertension in women of reproductive age is not only associated with an increased risk of long-term cardiovascular diseases but also with adverse reproductive outcomes,” the investigators said.
It is important that hypertension be identified early in this population, “since even stage 1 hypertension may adversely affect reproductive outcomes… Reproductive endocrinologists need to work closely with cardiologists to manage hypertension in women of childbearing age,” they added.
The investigators also underscored the need for additional research to assess whether antihypertensive strategies before pregnancy, particularly for stage 1 hypertension, could improve reproductive outcomes.
The present study included 43,629 women (mean age 32.3 years) who were undergoing IVF treatment. Of these, 30,743 (70.5 percent) had normal BP, 6,206 (14.2 percent) had elevated BP, 5,594 (12.8 percent) had stage 1 hypertension, and 1,086 (2.5 percent) had stage 2 hypertension.
Compared with women with normal BP, those with elevated BP or stage 1 or 2 hypertension had higher BMI (24.9, 25.7, and 27.1 vs 23.3 kg/m2, respectively; p<0.001) and were more likely to be diagnosed with polycystic ovary syndrome (16.3 percent, 19.6 percent, and 21.3 percent vs 12.8 percent; p<0.001). The median endometrial thickness before embryo transfer and median number of oocytes retrieved were similar across the BP categories.