American Heart Association | 2018 | April 2 | Higher blood pressure before pregnancy may increase miscarriage risk | Science Daily
An American study from the American Heart Association has studied women who had previously experienced miscarriages and were trying to conceive. The clinical trial is the first of its kind to look at preconception blood pressure and reproductive outcomes in healthy women not diagnosed with high blood pressure or heart disease. The women took low-dose aspirin to determine if this reduced their risk of miscarriage (via Science Direct).
The women in the sample (n equal to 1,228 women) had an average age of 28.7 years, and all had experienced 1-2 pregnancy losses. They had their blood pressure (both systolic and diastolic) measured to assess their hypertension. During the study, women had their blood pressure measured when they were trying to become pregnant, during preconception and in early pregnancy, this data was used to derive mean arterial pressure.
Whether women had been randomly assigned to take low-dose aspirin as part of this clinical trial (Effects of Aspirin in Gestation and Reproduction) made no difference in the impact of blood pressure on pregnancy loss. The findings were similar for preconception and early-pregnancy blood pressure. The research indicates that preconception blood pressure among healthy women is associated with pregnancy loss, and lifestyle interventions targeting blood pressure among young women may favourably impact reproductive health.
Researchers also found:
- Every 10-point increase in diastolic blood pressure (lower number) was associated with an 18 per cent increased risk of pregnancy loss.
- Every 10-point increase in mean arterial pressure (an average of the lower and higher numbers) was associated with a 17 per cent increased risk of pregnancy loss.
Carrie J. Nobles, Ph.D., lead author of the study said: “Elevated blood pressure among young adults is associated with a higher risk of heart disease later in life, and this study suggests it may also have an effect on reproductive health.”
Elevated blood pressure in young adulthood is an early risk marker for cardiovascular disease. Despite a strong biological rationale, little research has evaluated whether incremental increases in preconception blood pressure have early consequences for reproductive health. We evaluated preconception blood pressure and fecundability, pregnancy loss, and live birth in the EAGeR trial (Effects of Aspirin on Gestational and Reproduction; 2007–2011), a randomized clinical trial of aspirin and reproductive outcomes among 1228 women attempting pregnancy with a history of pregnancy loss. Systolic and diastolic blood pressure were measured during preconception in the first observed menstrual cycle and in early pregnancy and used to derive mean arterial pressure. Fecundability was assessed as number of menstrual cycles until pregnancy, determined through human chorionic gonadotropin testing. Pregnancy loss included both human chorionic gonadotropin–detected and clinical losses. Analyses adjusted for treatment assignment, age, body mass index, race, marital status, smoking, parity, and time since last loss. Mean preconception systolic and diastolic blood pressure were 111.6 mm Hg (SD, 12.1) and 72.5 (SD, 9.4) mm Hg. Risk of pregnancy loss increased 18% per 10 mm Hg increase in diastolic blood pressure (95% confidence interval, 1.03–1.36) and 17% per 10 mm Hg increase in mean arterial pressure (95% confidence interval, 1.02–1.35) in adjusted analyses. Findings were similar for early pregnancy blood pressure. Preconception blood pressure was not related to fecundability or live birth in adjusted analyses. Findings suggest that preconception blood pressure among healthy women is associated with pregnancy loss, and lifestyle interventions targeting blood pressure among young women may favorably impact reproductive health.
The full text article can be requested by Rotherham NHS staff here
Nobles, C.J. et al | 2018 | Preconception Blood Pressure Levels and Reproductive Outcomes in a Prospective Cohort of Women Attempting Pregnancy | Hypertension |