In the US, there was a decline in spontaneous deliveries associated with an overall decline in neonatal mortality, according to a recent study. Although clinician-initiated deliveries increased at 39 to 40 weeks, neonatal mortality at that gestation declined. A retrospective cohort analysis was conducted of 22 million singleton live births without major malformations in the US from 2006 to 2013. Researchers found:

• Among total births, 12,493,531 (56.7%) were spontaneous and 9,557,815 (43.3%) were clinician-initiated deliveries.
• Among spontaneous deliveries, the proportion of births at 20 to 27, 28 to 31, 32 to 33, 34 to 36, and 37 to 38 weeks declined.
• Among clinician-initiated deliveries, the proportion of births at 34 to 36 and 37 to 38 weeks declined and the proportion at 39 to 40 weeks increased.
• Among spontaneous deliveries, overall neonatal mortality rates declined from 1.8 to 1.3 per 1,000 live births, mainly at 20 to 27 weeks (adjusted annual decline, 1%) and 28 to 31 weeks (adjusted annual decline, 6%).
• Among clinician-initiated deliveries, overall mortality rates remained unchanged (2.1 to 2.2 per 1,000 live births).