Study Finds Prevalent Risk of Hypertensive Disorders of Pregnancy

Valérie Olié, PhD

Previous studies show that hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and fetal morbidity and mortality.

Investigators, led by Valérie Olié, PhD, French Public Health Agency, found that HDP occurred in 7.4% of pregnancies in France, with women with preexisting hypertension at high risk to develop preeclampsia during pregnancy.

The team conducted the prospective cohort CONCEPTION (Cohort of Cardiovascular diseases in Pregnancy) study using the French National Health Insurance Information System (SNDS) to estimate the prevalence of HDP in France.

Study

Investigators included all pregnant women in France who delivered between January 2010 – December 2018 in a study cohort.

The team identified the patients using hospital stay information including a delivery procedure with a gestational age over 22 weeks of gestation.

The women were followed up with during the pregnancy and 6 weeks of postpartum.

Investigators identified HDP using various algorithms in the databased, based on the delivered antihypertensive medication delivered and following hospital diagnosis.

The team estimated the prevalence of each HDP during the study period by dividing the number of women with the disorder by the number of women who delivered at the same point in time.

Further, Olié and colleagues estimated incidence ratio (IRR) and 95% confidence interval for preeclampsia among women with preexisting or gestational hypertension (GH) using Poisson regression and adjustments for age.

Results

The team identified 7,022,789 deliveries in the hospital discharge database. After exclusion for not meeting criteria, they included 6,302,810 deliveries corresponding to 4,459,322 women.

Data show 45% of pregnancies included were nulliparous (n = 2,833,376).

Women with HDP were older and low socioeconomic status, obesity, diabetes, gestational diabetes, and personal history of cardiovascular disease had frequent observance in pregnancies with HDP (P <.0001).

The team found HDP occurred in 7.4% of pregnancies, including 8.4% of nulliparous and 6.5% of multiparous pregnancies.

They noted after adjustment for age, the prevalence of preexisting chronic hypertension was higher in nulliparous than in multiparous pregnancies, including 1.8% versus 1.6%, all P <.0001.

Data show preeclampsia and GH affected 2.0% and 4.2% of pregnancies, respectively.

Most preeclampsia cases occurred without prior HDP, while HELLP syndrome represented 10.4% of preeclampsia cases.

In comparison to nulliparous pregnancies without HDP prior preeclampsia, the team found the age-adjusted IRR of preeclampsia was 6.2 (95% CI, 6.1 – 6.4) in nulliparous pregnancies without preexisting hypertension.

Further, the IRR was 2.9 (95% CI, 2.8 – 3.0) in nulliparous pregnancies with GH.

Conclusion

Investigators concluded that HDP occurred in 7.4% of all pregnancies, with preeclampsia complicating 2% of nulliparous and 1.2% of multiparous pregnancies.

They noted that women with preexisting hypertension have higher risk of developing preeclampsia during pregnancy.

“The identification of different HDP and their association is still a major issue for risk stratification in pregnant women in order to reduce the risk of complications related to these HDP by tailoring monitoring and management of these women,” investigators wrote.

The study, “Prevalence of hypertensive disorders during pregnancy in France (2010-2018): The nationwide CONCEPTION study,” was published online in The Journal of Clinical Hypertension.