Maternal morbidity and obstetric complications in triplet pregnancies and quadruplet and higher-order multiple pregnancies

OBJECTIVE: The purpose of this study was to assess the risk of maternal morbidity and obstetric complications in women with triplet pregnancies and quadruplet and higher-order multiple pregnancies. STUDY DESIGN: We compared the outcomes in women with triplet pregnancies (n=5491) and quadruplet and higher-order multiple pregnancies (n=423) with women with twin pregnancies (n=152,238), with the use of the 1995 to 1997 Multiple Birth File of the United States. RESULTS: After an adjustment was made for important confounding factors, the risks of pregnancy-associated hypertension and eclampsia, anemia, diabetes mellitus, abruptio placenta, premature rupture of membrane, and cesarean delivery were increased in women with triplet pregnancies and quadruplet and higher-order multiple gestations than in women with twin pregnancies. A dose-response relationship was observed for pregnancy-associated hypertension, diabetes mellitus, and placental abruption, with higher odds ratios in women with quadruplet and higher-order multiple gestations than in women with triplet pregnancies. CONCLUSION: The risks of maternal morbidity and obstetric complications are increased in triplet pregnancies and quadruplet and higher-order multiple pregnancies than in twin pregnancies; for certain outcomes, there is a dose-response relationship.