Determination of the Normal Anal Location in Neonates: A Prospective Cross-Sectional Study

Abstract

Aim: Anterior displacement of the anus might be a form of anorectal malformations. The study aims to measure the anal position index (API) in neonates with a modified method. Methods: The study was conducted between March 1, and December 31, 2019, in the neonatal unit at Tekirdag Namik Kemal University Hospital. The neonates between 35 and 42 gestational weeks and those without congenital malformation were included in the study. Four hundred five neonates were evaluated prospectively. API was determined by using distances between posterior fourchette - anus and posterior fourchette - coccyx in girls; scrotum - anus, and scrotum - coccyx in boys. Results: Of 405 participants, there were 230 males. API was found 0.52 +/- 0.05 and 0.39 +/- 0.04 in boys and girls, respectively. For the diagnosis of the anterior location of the anus, the lower limit was 0.33 cm in girls and 0.43 cm in boys. According to these results, nine boys (3.9%) and seven girls (4%) had an anteriorly located anus. Conclusion: API could be measured more accurately by the modified method and this resulted in a lower incidence of anterior location when compared with the previously defined techniques.