Obese women at higher risk of Hypertensive disorders of Pregnancy, finds study

When Compared with non obese women, the risk of hypertensive disorders of pregnancy is significantly increased among women with increased class of obesity, finds a recent study. The study was published in the journal 'Obstetrics and Gynaecology' 2020. 

Obesity is a risk factor independent of comorbidities in pregnancy and can increase the risk of fetal and maternal morbidity in pregnancy.

Researchers from the University of Texas Health Science Centre evaluated the relationship between maternal body mass index (BMI) at delivery and the rates of early-onset and late-onset hypertensive disorders of pregnancy. They performed a population-based, retrospective cohort study using U.S. Vital Statistics period-linked birth and infant death certificates from 2014 to 2017.

The study included women who delivered a non anomalous singleton live neonate from 24 to 41 completed weeks of gestation. Women with chronic hypertension and those with BMIs less than 18.5 were excluded from the study. Maternal BMI was classified as nonobese (referent group) among those whose BMI was between 18.5-29.9; class 1 obesity whose BMI was 30.0-34.9, class 2 obesity whose BMI was 35.0-39.9, and class 3 obesity as BMI 40.0 or greater. Hypertensive disorders of pregnancy like gestational hypertension, preeclampsia, or eclampsia at less than 34 weeks of gestation or at 34 weeks or more were taken as the primary outcomes of measurement.

The key findings of the study were:

• Nearly 15.8 million women with live births during the study period were examined.

• Of these 14.0 million (88.6%) met inclusion criteria, and 825,722 (5.9%) had hypertensive disorders of pregnancy.

• The risk of early-onset hypertensive disorders of pregnancy was significantly higher in women with class 1 obesity (aRR 1.13), class 2 obesity (aRR 1.57), and class 3 obesity (aRR 2.18) compared with non obese women.

• The risk of late-onset hypertensive disorders of pregnancy was also significantly increased in women with class 1 obesity (aRR 1.71), class 2 obesity (aRR 2.60), and class 3 obesity (aRR 3.93) compared with non obese women.

Thus, the researchers concluded that Compared with nonobese women, the risk of early-onset and late-onset hypertensive disorders of pregnancy is significantly and progressively increased among women with increased class of obesity.