Multifetal gestation and long-term maternal health

Multifetal gestations account for 2% to 3% of births in high-resource settings and impose substantially greater cardiovascular and metabolic stress than singleton pregnancies. Women carrying twins experience approximately 15% higher cardiac output, greater plasma volume expansion, and elevated placental angiogenic factors, translating into approximately twofold higher rates of hypertensive disorders of pregnancy and variable rates of gestational diabetes mellitus. The early postpartum period represents heightened cardiovascular and mental health vulnerability, with increased rates of cardiopulmonary hospitalization and severe maternal mental illness during the first year following delivery. Despite these acute risks, current evidence does not demonstrate that multifetal gestation per se increases long-term cardiovascular mortality. Large population-based cohort studies consistently show that twin pregnancy, after adjustment for pregnancy complications, is not independently associated with long-term cardiovascular disease (CVD). Pregnancy complications occurring in multifetal gestations appear to carry different long-term prognostic significance than identical complications in singleton pregnancies. Women with preeclampsia in twin pregnancy demonstrate substantially lower risk of future CVD compared with preeclampsia in singleton pregnancies, potentially reflecting pathophysiology driven by excessive hemodynamic burden rather than intrinsic maternal vascular pathology. Similarly, gestational diabetes in twin pregnancy confers lower long-term diabetes risk than in singletons. Twin pregnancy imposes greater mechanical stress on pelvic floor structures, with higher rates of stress urinary incontinence persisting beyond the immediate postpartum period, though long-term outcomes remain incompletely characterized. Triplet and higher-order pregnancies present extreme physiological demands with markedly elevated acute maternal morbidity; however, their long-term maternal health implications have not been systematically studied. Critical knowledge gaps persist, particularly regarding pregnancies conceived through assisted reproductive technology and the need for extended cardiometabolic follow-up to inform evidence-based postpartum surveillance strategies for women who experience multifetal gestation.