Childhood growth of singletons conceived following assisted reproductive technology - does gonadotropin stimulation matter?

Abstract Purpose: To investigate whether gonadotropin stimulation influences growth or weight gain of children conceived following assisted reproductive technology.Methods: We conducted a single-center, prospective cohort study (2010–2017) including children (n = 139) born after natural-cycle intracytoplasmic sperm injection (NC-ICSI) or conventional gonadotropin stimulated intracytoplasmic sperm injection (c-ICSI) treatment. Growth parameters up to 24 months were collected. Standard deviation scores based on growth references were calculated.Results: The median birth weight in NC-ICSI children was 3.4kg (0.1 standard deviation score (SDS)) compared to 3.3kg (-0.3 SDS) in c-ICSI children (p = 0.61). Median length at birth was 50cm in both groups (NC-ICS (-0.5 SDS), c-ICSI children (-0.8 SDS), p = 0.48). At age 24 months, median weight in NC-ICSI children was 12.2kg (0.3 SDS) versus 12.2kg (0.2 SDS) in c-ICSI children (p = 0.82) and median length 87.5cm (0.1 SDS) versus 88.0cm (0.4 SDS) (p = 0.43).Conclusion: We found no difference in growth between children conceived after stimulated and unstimulated ICSI. Growth parameters of both treatment groups did not differ from Swiss national growth references. One of the main limitations of our study was the small sample size (N = 139) and the high drop-out rate of 49% (68/139).