Assistant professor University of South Alabama Mobile, Alabama, United States
Background: We have previously reported that the mortality rates of infants born at 22 weeks of estimated gestational age (GA) have decreased from 1998 to 2008, while a reduction in neurodevelopmental (ND) impairments has also been observed in infants born at GA of 23 to 24 weeks. Objective: To determine whether a similar decrease in mortality and a parallel decline in ND morbidity occurred in periviable infants (GA < 25 weeks) admitted to our neonatal intensive care unit over a more recent decade. Design/Methods: In this retrospective, single-center study, we compared all periviable infants born between January 2015 and December 2020 (Epoch 2) with infants born between January 2009 and December 2014 (Epoch 1) who were managed at our institution, all of whom had parents requesting neonatal interventions. We further classified the infants into two subgroups based on their GA: 22-23 weeks and 24-25 weeks. ND outcomes were assessed using the Bayley scales of Infant-Toddler Development (3rd or 4th edition) at a corrected age of 2 years. Moderate or severe ND impairment (NDI) was diagnosed if the following occurred: moderate or severe cerebral palsy, deafness, blindness, or a cognitive composite score < 85. Results: Out of the 672 periviable infants in the study, 517 (76.9%) survived hospital discharge. Epoch 2 included a larger proportion of infants with birthweight of < 400 grams than in Epoch 1 (11% vs 6%, respectively, P< 0.05). A very small number of infants ( < 1%) died in the delivery room during both epochs and across subgroups. Survival to hospital discharge remained unchanged between Epoch 1 and Epoch 2, with rates of 66.4% and 71.5%, respectively, in the 22–23-week subgroup and 84.8% and 85%, respectively, in the 24–25-week subgroup. Among the survivors, the rate of ND follow-up declined significantly during Epoch 2 compared to Epoch 1 (40.1% vs. 74.6%, respectively, p < 0.01). Among the assessed infants, 53% in Epoch 2 and 37% in Epoch 1 had moderate or severe NDI, p < 0.01. However, after correcting for the following pertinent variables such as gestational age, retinopathy of prematurity needing any treatment (type 1 ROP), bronchopulmonary dysplasia grade 2 or 3 (BPD), and severe intraventricular hemorrhage, there was no difference in the rate of moderate or severe NDI between the two Epochs. Rates of BPD and ROP significantly increased in Epoch 2 vs. Epoch 1.
Conclusion(s): During the recent decade, the survival and NDI rates of periviable infants have remained unchanged. Interventions to improve rates of BPD and ROP are currently ongoing.
