RESUMO
Periviable infants (PIs) born at 22-25 weeks gestational age (wGA) have a variable survival rate (49.7-86.2%) among hospitals. One factor involved in this difference may be the definition of the threshold of viability. The American Academy of Pediatrics revised the neonatal resuscitation program in late 2015 (NRP 2015) and altered the threshold of viability from 23 to 22 wGA. The impact on the survival of PIs after the guideline alteration has seldom been discussed. Since 2016, the unit of this study has implemented the renewed guideline for PIs. We retrospectively reviewed and analyzed the survival and clinical variables of PIs before and after implementation of the guideline, which included a 10-year cohort in a single center in Taiwan. There were 168 PIs enrolled between 2010 and 2019 (Epoch-I, 2010-2015; Epoch-II, 2016-2019), after excluding those with congenital anomalies and parent-decided comfort care. Compared to those in Epoch-I, the PIs in Epoch-II had significantly higher odds ratios (2.602) (95% confidence interval: 1.170-5.789; p = 0.019) for survival. Younger gestational age, small size for gestational age, cesarean delivery, low blood pH at birth, and surfactant therapeutic treatment were found to be significant risk factors associated with the survival of PIs (p < 0.05 for each). The altered threshold of viability by NRP 2015 may impact the survival of PIs. However, long-term follow-up for surviving PI is required in the future.
RESUMO
Primary congenital hypothyroidism is a disease associated with low serum thyroxine and elevated thyroid-stimulating hormone (TSH) levels. The processes of screening and treating congenital hypothyroidism, in order to prevent neurodevelopmental impairment (NDI) in newborns, have been well investigated. Unlike term infants, very preterm infants (VPIs) may experience low thyroxine with normal TSH levels (<10.0 µIU/mL) during long-stay hospitalization. In the current literature, thyroxine treatment has been evaluated only for TSH-elevated VPIs. However, the long-term impact of low thyroxine levels in certain VPIs with normal TSH levels deserves more research. Since July 2007, VPIs of this study unit received screenings at 1 month postnatal age (PNA) for serum TSH levels and total thyroxine (TT4), in addition to two national TSH screenings scheduled at 3-5 days PNA and at term equivalent age. This study aimed to establish the correlation between postnatal 1-month-old TT4 concentration and long-term NDI at 24 months corrected age among VPIs with serial normal TSH levels. VPIs born in August 2007-July 2016 were enrolled. Perinatal demography, hospitalization morbidities, and thyroid function profiles were analyzed, and we excluded those with congenital anomalies, brain injuries, elevated TSH levels, or a history of thyroxine treatments. In total, 334 VPIs were analyzed and 302 (90.4%) VPIs were followed-up. The postnatal TT4 concentration was not associated with NDI after multivariate adjustment (odd ratios 1.131, 95% confidence interval 0.969-1.32). To attribute the NDI of TSH-normal VPIs to a single postnatal TT4 concentration measurement may require more research.