Pediatric Resident Physician Atrium Health Wake Forest Baptist Winston Salem, North Carolina, United States
Background: Both Fenton and WHO growth charts are widely used to determine whether a baby is small, appropriate, or large for gestational age at birth. Small-and large-for-gestational-age size determinations impact clinical management during the newborn hospitalization, e.g. hypoglycemia protocol, CMV testing. Objective: To compare the Fenton and WHO classification of small, appropriate, or large for gestational age (SGA, AGA, or LGA) at birth among term infants and impact on clinical assessments during birth hospitalization. Design/Methods: We collected data on all infants born 37-41 weeks gestational age at three hospitals (one suburban, one rural, and one academic) in North Carolina born from January 2020 through December 2022. We electronically pulled birth weight, length, head circumference, sex, hypoglycemia protocol utilization, number of glucose gels received, any CMV testing, hearing screen results, maternal diabetes (any type), and maternal hypertension. We ascertained Fenton and WHO assessment for gestational age at birth. We identified those that had concordant results for SGA, AGA, or LGA and those with discordant results. We compared concordance by gestational age and by sex using chi-square analysis. Results: Among all 10,834 term infants, 50% were female; 98% singleton; gestational age was 15% 37 weeks, 20% 28 weeks, 43% 39 weeks, 18% 40 weeks, and 4% 41 weeks. Most (71%) had concordant birth weight SGA, AGA, or LGA assessments for gestational age by Fenton and WHO growth charts. Notably, the concordance increased by gestational age from 57% at 37-38 weeks, to 74% at 39 weeks, to 84% at 40 weeks, and 94% at 41 weeks with p< 0.001. Furthermore, the concordance for all term infants was higher for females at 72% than for males at 69% with p< 0.001. Male infants who were SGA on both WHO and Fenton weight growth charts received more glucose gels than female infants (p= 0.016). When male infants were SGA on Fenton charts and AGA on WHO charts, they again received significantly more glucose gels than female counterparts (p = 0.002). Of note, there is ongoing analysis with the data we have collected, which will be resulted and presented as part of this study.
Conclusion(s): Given that the assessment of SGA, AGA, and LGA for gestational age at birth impacts clinical assessments, the difference in Fenton and WHO weight growth charts among infants born at 37-39 weeks, and between male and female infants, is important. There is ongoing analysis to further describe differences, including CMV testing and blood culture collection, that may also be impacted. Results on additional analyses will be presented.
