ORIGINAL RESEARCH article
Front. Reprod. Health
Sec. Assisted Reproduction
Anoscrotal Distance and Urogenital Anomalies in ART-Conceived Male Infants: A Retrospective Cohort Study
Provisionally accepted
- Acibadem Universitesi, Istanbul, Türkiye
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Assisted reproductive technology (ART) is increasingly used worldwide, yet concerns remain about its potential effects on neonatal male genital development. Anoscrotal distance (ASD) is a marker of prenatal androgen exposure and may be altered in ART-conceived infants. This study compared ASD and the prevalence of urogenital anomalies in male newborns conceived via frozen–thawed embryo transfer (FET) using either natural-cycle (tNC) or hormone-replacement therapy (HRT) protocols, with those conceived naturally (NC). In this retrospective cohort of 432 singleton male births (156 NC, 132 FET–tNC, 144 FET–HRT) delivered between 2021 and 2023, neonatal outcomes—including ASD, hypospadias, and undescended testes (UDT)—were compared across groups using standard statistical tests. Median ASD was significantly longer in NC infants (26.2 mm) compared with FET–tNC (24.9 mm) and FET–HRT (24.6 mm) (p < 0.001). No ASD difference was observed between the two FET groups. Hypospadias was less frequent in FET–HRT compared with FET–tNC (p = 0.031), whereas UDT was more common in NC than in FET–tNC infants (p = 0.041). Exploratory modelling identified ASD as the strongest discriminator between groups. Male infants conceived via FET consistently exhibited shorter ASD compared with naturally conceived infants, suggesting subtle alterations in androgen-sensitive genital development. These findings highlight the clinical importance of incorporating careful genital assessment and appropriate ART-related counseling into neonatal care for families using assisted reproduction.
Keywords: anoscrotal distance, frozen–thawed embryo transfer, hormonereplacement therapy cycle, Hypospadias, Natural cycle, Urogenital anomalies
Received: 23 Oct 2025; Accepted: 28 Nov 2025.
Copyright: © 2025 Aygün and Kahraman. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Elif Ganime Aygün
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