Birth Weight of Term Born Offspring in relation to Long-Term Maternal Cardiovascular Morbidity and Mortality

Background Previous studies have identified associations between offspring birthweight and future maternal cardiovascular health, but many studies lack sufficient adjustment for confounders such as pregnancy complications, gestational age, maternal body mass index (BMI), and smoking. This study aimed to assess whether the association between term offspring BW and maternal cardiovascular risk is independent of these factors. Methods We used data from the Copenhagen Perinatal Cohort (1959–1961). After excluding women with diabetes, preeclampsia, preterm births, and twin pregnancies, 5,766 women remained. Cardiovascular outcomes were obtained from Danish national registries with up to 45 years of follow-up. Hazard ratios (HR) with 95% confidence intervals (CI) were estimated using Cox regression, adjusting for smoking during pregnancy, maternal BMI, hypertension, and gestational age. Additional analyses were conducted in populations stratified by smoking status and adjusted for cigarette consumption per day. Results Offspring BW below 3000 grams was associated with higher maternal cardiovascular mortality (< 2500 grams: 2.16 [1.54–3.03], 2500–2999 grams: 1.41 [1.09–1.81]) compared to the reference category (offspring BW 3500–3999 grams). The risk of maternal major cardiovascular events and stroke was higher when offspring BW was below 2500 grams (1.35 [1.01–1.79], 1.51 [1.09–2.08]) and lower if offspring BW was above 3999 (0.78 [95% CI 0.61–0.99], 0.78 [0.59–1.03]) compared to the reference. No association was found with ischemic heart disease. Associations persisted after stratification by smoking. Conclusions Lower BW of term offspring from uncomplicated, singleton pregnancies is inversely associated with long-term maternal cardiovascular risk, independent of smoking during pregnancy.