In a recently released issue of Pediatrics, Dr. Catherine O. Buck and colleagues from the Yale University School of Medicine and the Pediatrix Center for Research, Education, Quality, and Safety aimed to compare differences in short-term morbidities and early growth among moderately preterm (32 0/7–33 6/7 weeks gestational age (GA)) and late preterm infants (34 0/7–36 6/7 weeks GA) born to mothers with and without diabetes in pregnancy and admitted to the NICU in their article, “Outcomes in Preterm Infants of Mothers With Diabetes” (10.1542/peds.2023-061285). This study utilized prospectively collected information from the Pediatrix Clinical Data Warehouse and included infants born 2008–2019 at any of the more than 385 NICUs managed by the Pediatrix Medical Group, a private health company.
The authors compared health characteristics and growth from birth through hospital discharge among 301,499 moderate and late preterm infants, of whom 14% (n=42,519) were exposed to diabetes in pregnancy. Diabetes exposures included both pre-existing type 1 and type 2 diabetes (29.6% of the diabetes group) and gestational diabetes (70.4% of the diabetes group). Infants who died, had major congenital anomalies, congenital infection, were discharged after 40 weeks postmenstrual age, or with sex not determined at birth were excluded. As the authors hypothesized, those infants with diabetes exposure had a higher incidence of morbidities as compared to non-exposed infants, with significantly higher rates of hypoglycemia and hyperbilirubinemia (p<0.001) and greater likelihood of requiring non-invasive respiratory support in the first 3 days (p=0.02).
What was unexpected and not hypothesized related to growth trajectories?
- Patterns of weight change differed across GA and with diabetes exposure—see Table 4 and Figure 2 for displays of these results.
- While diabetes-exposed versus non-exposed infants of all GA groups had faster weight loss in the first week (after birth), in the second week differences in weight change by GA appeared.
- Diabetes-exposed infants born at 32–33 weeks GA had accelerated weight gain in the second week in comparison to non-exposed infants, but those born at 35–36 weeks GA continued with weight loss (and those born at 34 weeks GA did not significantly change in either direction versus their non-exposed counterparts).
The authors reasonably suggest that differences in care and practices that depend on age (both postnatal age and gestational), but were not fully captured by the database, are responsible. The clinical implications are important, since we expect infants to be back to birthweight by the end of the second week of life—clearly more research will be needed, and this information is a great start. Looking further ahead, new research is demonstrating improved diabetic control with automated insulin delivery during pregnancy1—hopefully paving the way for parity in outcomes between infants who are and are not diabetes exposed in pregnancy in the future.
- Lee TTM, Collett C, Bergford S, Hartnell S, Scott EM, Lindsay RS, et al. Automated insulin delivery in women with pregnancy complicated by type 1 diabetes. N Engl J Med. 2023 Oct 26;389(17):1566-1578