A 2016 systematic review and meta-analysis of 3 RCTs that included 3200 women with late preterm labor (between 34 weeks 0 days and 36 weeks 6 days) found that women who were given betamethasone had a significantly lower incidence of transient tachypnea of the newborn
(number needed to treat [NNT]=37; relative risk [RR] =0.72; 95% confidence interval [CI], 0.56-0.92), severe respiratory distress syndrome (NNT=114; RR=0.60; 95% CI, 0.33-0.94), and use of surfactant (NNT=92; RR=0.61; 95% CI, 0.38-0.99).
The incidence of respiratory morbidity, including respiratory distress syndrome (RDS) and transient tachypnea of the newborn
(TTN), with an increasing rate of neonatal intensive care unit (NICU) admissions, are higher in the late preterm infants, compared to term infants.2,3
The primary outcome, a composite of respiratory morbidities (including transient tachypnea of the newborn
, surfactant use, and need for resuscitation at birth) within the first 72 hours of life, had significant differences between groups, occurring in 165 of 1,427 infants (11.6%) in the betamethasone-treated group and 202 of 1,400 (14.4%) in the placebo group (relative risk in the betamethasone group, 0.80; 95% confidence interval, 0.66-0.97; P = .02).
Additionally, in the "unknown" category there were 175 elective deliveries with no other maternal-fetal or obstetric complications, "and together these 1,044 soft or elective precursors made up 6.9%, or approximately 1 in 15, of all late preterm deliveries," they noted, adding that the "adjusted risk of oxygen use, transient tachypnea of the newborn
, mechanical ventilation, respiratory distress syndrome, pneumonia or newborn sepsis, and admission to the NICU all were significantly decreased for neonates with soft or elective precursors delivered at 37, 38, 39, and 40 weeks of gestation compared with late preterm."
Chapter 28 deals with major pulmonary disorders in the neonate such as transient tachypnea of the newborn
, pneumonia, meconium aspiration and apnea of prematurity while Chapter 29 covers congenital and surgical disorders that affect respiration.