The Nomogram of Clitoral Length and Width in Iranian Term and Preterm Neonates

Background and Objectives: Clitoromegaly is an important parameter in the evaluation of ambiguous genitalia in neonates, but the normative data for clitoral size in newborns have racial/ethnic differences. The present study aimed to determine clitoral length (CL) and clitoral width (CW) values and establish cutoff measurement to define clitoromegaly in both term and preterm Iranian neonates for the first time. Methods: A total number of 580 female newborn infants delivered at 28–42 weeks of gestation were enrolled in the study, and their CL and CW were measured on the first 72 h of birth. Data about birth weight (BW), body length (BL), and head circumference (HC) of newborns; mothers' age; and gestational age (GA) were recorded, too. Results were presented as mean ± standard deviation (SD) for quantitative variables and were summarized by frequency (percentage) for categorical variables. Backward stepwise regression analysis was used for prediction of CL and CW. Results: Among 580 Iranian female newborns studied, 187 were term neonates and the other 393 newborns were preterm. Mean ± SD values of CL were 6.11 ± 0.39 mm in term infants and 5.45 ± 0.64 mm in preterm infants (P < 0.001). Mean ± SD values of CW were 4.22 ± 0.43 in term infants and 3.68 ± 0.53 in preterm infants (P < 0.001). Regression analysis showed that CL was correlated with GA considered by last menstrual period, BL, BW, and HC; and CW was associated with GA, BL, and BW. Conclusion: This study suggests normative values (mean + 1, 2, and 3 SD) of CL and CW according to GA, which can be used as a reference for Middle East's newborns, especially Iranian newborn babies.