Adverse pregnancy outcomes are associated with long-term risk for cardiometabolic disease in women and their offspring, according to a new analysis of more than 18 million pregnancies.
The authors conducted a cross-sectional analysis of maternal and fetal data from the National Center for Health Statistics, sharing their findings in the European Journal of Preventive Cardiology.
Date from the study revealed that cardiovascular risk factors such as obesity, hypertension, smoking and diabetes in women prior to pregnancy have been linked with higher risk for maternal and neonatal morbidity and mortality.
The authors also found that the probability of key pregnancy complications—maternal ICU admission, preterm birth, low birthweight and fetal death—increased incrementally with the number of pre-pregnancy cardiovascular risk factors.
More than 60% of women included in the analysis had one or more pre-pregnancy cardiovascular risk factors (52.5%, 7.3%, 0.3%, and 0.02% had 1, 2, 3, and 4 risk factors, respectively).
Compared to women with no pre-pregnancy risk factors, those with all four risk factors (3,242 women) had an approximately 5.8-fold higher risk for ICU admission, 3.9-fold higher risk for preterm birth, 2.8-fold higher risk for low birthweight, and 8.7-fold higher risk for fetal death.
“Individual cardiovascular risk factors, such as obesity and hypertension, present before pregnancy have been associated with poor outcomes for both mother and baby,” lead author Sadiya Khan, MD, with the department of preventive medicine at Northwestern University Feinberg School of Medicine, said in a prepared statement from the European Society of Cardiology (ESC). “Our study now shows a dose-dependent relationship between the number of risk factors and several complications. These data underscore that improving overall heart health before pregnancy needs to be a priority.”
Compared to women with no risk factors, women with one or more risk factors attained lower educational levels and had less experience with prenatal care. Multiparity and prior spontaneous or induced pregnancy loss were also more common among this group.
In addition, the group observed consistent and marked graded associations between greater pre-pregnancy risk factor burden and a higher risk of adverse maternal and fetal outcomes.
For example, the risk ratios of maternal ICU admission (compared to women with no pre-pregnancy risk factors) were 1.12 for one risk factor, 1.86 for two risk factors, 4.24 for three risk factors, and 5.79 for four risk factors.
“Levels of pre-pregnancy obesity and high blood pressure are rising and there are some indications that women are acquiring cardiovascular risk factors at earlier ages than before," Khan said in the ESC statement. "In addition, pregnancies are occurring later in life, giving risk factors more time to accumulate. Taken together, this has created a perfect storm of more risk factors, earlier onset, and later pregnancies."
According to the authors, future studies should be conducted that incorporate measures of cholesterol and lifestyle factors, as well as key non-modifiable risk factors such as family history of cardiovascular disease, which has been tied to pregnancy loss and may deserve increased attention to optimizing pre-pregnancy cardiovascular health.
“Assessment of cardiovascular risk factors on the individual level could be applied before pregnancy, when prevention may have a greater benefit than during pregnancy when the time period to intervene is limited,” they wrote.
Read the full study here.