Long-term outcomes of twins based on gestational age at delivery

Prematurity is associated with adverse outcomes. However, there are less data regarding long-term outcomes of twins based on gestational age at delivery. Our objective was to identify the association between gestational age at delivery and long-term outcomes in twins.

All patients with a twin pregnancy ≥24 weeks delivered by a single Maternal Fetal Medicine practice from 2005 to 2014 were surveyed regarding pediatric outcomes at or after 2 years of life. We excluded twins with aneuploidy or major fetal anomalies. The survey was mail-based, with phone follow-up for nonresponses or for clarification. Using logistic regression analysis, we compared long-term outcomes between twins born in four gestational age groups: 24 to 27-6/7 weeks, 28 to 31-6/7 weeks, 32 to 35-6/7 weeks, and 36 weeks or later.

Six hundred fifty-three twin deliveries met inclusion criteria and 425 (65.1%) mothers responded. Mean age at the time of survey completion was 6.0 ± 2.4 years. Earlier gestational age was significantly associated with neonatal death (14, 2, 0, and 0% in the four groups, respectively, p < .001). Prematurity was associated with a composite of major adverse outcomes (death; cerebral palsy; necrotizing enterocolitis; chronic renal, heart, or lung disease) (14, 7, 4, and 2% in the four groups, p = .036), as well as minor adverse outcomes (learning disability; need for speech, occupational, or physical therapy) (83, 69, 54, and 38%, p < .001).

Long-term morbidity in twin pregnancies is inversely related to gestational age at delivery. However, for twins born after 28 weeks, neonatal death and severe long-term morbidity are rare.