[Effects of dexamethasone on short-term and long-term outcomes in late preterm infants with twin pregnancy: an observational study].

Objective: To investigate the effect of prenatal dexamethasone on short-term outcomes and long-term neurological development in late preterm infants with twin pregnancy. Methods: A total of 315 pregnant women with twin pregnancy and their preterm infants who delivered in Peking University Third Hospital from January 2019 to December 2022 were retrospectively analyzed. The clinical data of pregnant women and preterm infants were collected. They were divided into non-medication group (93 pregnant women and 186 preterm infants), medication after 34 weeks group (123 pregnant women and 246 preterm infants), and medication before 34 weeks group (99 pregnant women and 198 preterm infants). Short-term outcomes of preterm infants were analyzed, including the incidence of neonatal respiratory distress syndrome (NRDS), wet lung, hypoglycemia, neonatal septicemia, intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD) and neonatal necrotizing enterocolitis (NEC). "Ages and Stages Questionnaire-Third Edition (ASQ-3) scale" was used to follow up the late neurological development of preterm infants at the corrected age of 6-54 months, and the level of neurological development was compared. Results: (1) General conditions: the gestational age at delivery in the non-medication group [36.1 weeks (35.6, 36.6 weeks)] was later than that in the medication after 34 weeks group [36.1 weeks (35.2, 36.4 weeks)] and medication before 34 weeks group [35.2 weeks (34.2, 36.2 weeks)] groups, and the differences were statistically significant (all P<0.05). After correcting for gestational age, there was no significant difference in birth weight among the three groups (H=3.808, P=0.149). There were no significant differences in gender and the proportion of small for gestational age among the three groups (all P>0.05). (2) Short-term outcome: the incidence of wet lung was 7.0% (13/186), 11.0% (27/246) and 16.2% (32/198) in the non-medication group, medication after 34 weeks group and medication before 34 weeks group, respectively, and the difference was statistically significant (P=0.018). There were no significant differences in the incidence rates of NRDS, hypoglycemia, sepsis, IVH, BPD, and NEC among the three groups (all P>0.05). Logistic regression analysis with gestational age and newborn birth weight as confounding factors showed that early gestational age (OR=0.884, 95%CI: 0.837-0.933, P<0.001) and increased incidence of selective intrauterine growth restriction type I (OR=2.967, 95%CI: 1.153-7.639, P=0.024) could both lead to an increased incidence of wet lung. (3) Long-term outcomes: a total of 109 pregnant women completed the follow-up, and 218 preterm infants with a corrected age of 6-54 months at the end of follow-up were enrolled, including 86 cases in the non-medication group, 66 cases in the medication after 34 weeks group, and 66 cases in the medication before 34 weeks group. There were no significant differences in the scores of communication, gross motor, fine motor, problem solving and personal-social among the three groups (all P>0.05). Conclusion: Prenatal administration of a single course of dexamethasone does not affect the neonatal birth weight and short-term outcomes of twin late preterm infants, and has no adverse effect on the neurological development of twin late preterm infants with a corrected age of 6-54 months.