Assessing Catch-Up Growth in Extremely Low Birth Weight Over Two Years in a Tertiary Hospital in South Africa

Abstract

Background: Data on catch-up growth of extremely low birth weight infants (ELBWI) in low- and middle-income countries (LMIC) is lacking. Multiple factors affect growth in ELBWI, and catch-up growth is noted to impact neurodevelopment. Objectives: The aims of this study were to determine the rate of catch-up growth in surviving ELBWI post-discharge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH)and to determine the relationship between catch-up growth and neurodevelopmental outcome at two years corrected age in ELBWI. Methods: This was a retrospective, descriptive study of surviving ELBWI infants at CMJAH, a tertiary hospital in Gauteng. Data was obtained from the university database of ELBWI attending the follow-up clinic, born between 1 January 2015 and 31 December 2020. Results: 97 ELWBI were included in the final sample size. The mean gestational age was 27.5 weeks, and the mean weight was 877g. The primary outcome was catch-up growth. At 18 months,90% of females achieved catch-up growth > -2SD for weight, 79% for length, and 92% of females achieved catch-up growth for HC. Males achieved 76%, 67%, and 88%, respectively. Sepsis was associated with being -2SD for weight at 18 months, trending towards statistical significance OR = 4.64 (95%CI: 1.12, 31.71), p-value = 0.0587. Sepsis was also significantly associated with being -2SD for length at 18 months OR = 5.47 (95%CI: 1.54, 26.34), p-value = 0.0158. When looking at the relationship between Bayley scores and growth parameters, weight and length were associated with abnormal Bayley scores at 9-12 months. Infants with normal Bayley scores at 9-12 months had higher weights and were taller than infants with abnormal Bayley scores at this point of assessment. This association was not shown at 18-24 months. Conclusion: Most ELBWI catch up to -2SD or above by 18 months corrected age for weight, length, and head circumference for age with good neurodevelopmental outcome. Sepsis is a significant risk factor for poor catch-up growth. These results should be interpreted with caution as there was a significant loss to follow-up.