Rs. Hartley et al., Perinatal mortality and neonatal morbidity rates among twin pairs at different gestational ages: Optimal delivery timing at 37 to 38 weeks' gestation, AM J OBST G, 184(3), 2001, pp. 451-458
OBJECTIVE: The aim of this study was to determine the gestational age at de
livery associated with the lowest rates of perinatal mortality, respiratory
distress syndrome, and long hospital stays among twins, with pair rates us
ed to account for both infants in each twin pregnancy.
STUDY DESIGN: We conducted a population-based retrospective study that anal
yzed linked birth certificates, fetal and infant death certificates, and ho
spital discharge data for 8150 twin pairs born in Washington State during 1
987 through 1997. The chi (2) or Fisher exact test was used to assess the s
tatistical significance.
RESULTS: The nadirs of perinatal mortality rate, respiratory distress syndr
ome incidence, and long hospital stay rate were seen at delivery dates of 3
9, 40, and 38 weeks' gestation, respectively. Restriction to pairs delivere
d vaginally without the induction of labor revealed that the perinatal mort
ality rate was lowest for delivery at 37 weeks' gestation, the gestational
age at which the highest numbers of such spontaneously timed pairs were bor
n.
CONCLUSION: Induction of labor should be routinely considered for twins at
37 to 38 weeks' gestation.