The association between maternal height and pregnancy outcomes in twin gestations.

OBJECTIVE: We sought to assess the association between maternal height and the risk of preterm birth, fetal growth restriction and mode of delivery in twin gestations.

STUDY DESIGN: Cohort study of patients with twin pregnancies delivered from 2005 to 2014. We compared pregnancy outcomes between patients of short stature ≤159 cm to those of normal stature ≥160 cm. Patients with monoamniotic twins and major fetal anomalies were excluded. Pearson's correlation, Chi-square and Student's t-test were used as appropriate.

RESULTS: Six hundred and sixty-six patients were included, 159 (23.9%) of whom had short stature (mean height 155.8 ± 2.5 cm) and 507 (76.1%) of whom had normal stature (mean height 167.2 ± 5.5 cm). There were no differences in outcomes between the groups in regards to preterm birth, gestational age (GA) at delivery, birth weight of either twin, preeclampsia, gestational diabetes or cesarean section rate. Results were similar when the groups were stratified by parity. As a continuous variable, maternal height did not correlate with GA at delivery (p= 0.388), cesarean delivery (p = 0.522) nor the birth weight of the larger (p = 0.206) or smaller (p = 0.307) twin.

CONCLUSION: In twin pregnancies, maternal short stature is not associated with preterm birth, fetal growth restriction or cesarean section rate. This suggests that although anthropometric measurements have long been used to counsel patients in regards to outcomes, patients of short stature should be reassured that their height does not appear to lead to adverse twin pregnancy outcomes.