Background: Cigarette contains more than 4,000 toxins and is suspected of having endocrine-disrupting properties. Anogenital distance (AGD) is an important biomarker of fetal androgen exposure and intrauterine masculinization. There are limited number of studies examining whether AGD is affected by prenatal smoke-exposure. The aim of this study is to investigate the effects of maternal smoking during pregnancy on newborn infants' AGD.
Method: Fifty-six female and sixty-four male newborn infants from mothers who smoked during pregnancy were included in this study. The control group for each sex was selected from infants whose mothers had no active or passive (in either the household or the workplace) smoke exposure before or during pregnancy. Questionnaire data on maternal demographic characteristics and information about cigarette use were collected. We assessed genital anthropometry which included AGD for both male and female neonates, and stretched penile length (SPL), penile girth for males within the first 48 hours after birth. In boys, AGD has been measured from anus to posterior insertion of the penis (AGDapp), scrotum (AGDas), and cephalad insertion of the penis (AGDap). In girls, AGD has been measured from anus to posterior insertion of the clitoris (AGDapc), base of the posterior fourchette (AGDaf), and the top of the clitoris (AGDac). AGD(app/apc) were also normalized according to birthweight (AGD/weight in grams), length (AGD/CRL in millimeters), and ponderal index [AGD/(weight in grams/CRL in cubic centimeters)]. Anogenital index (AGI) was calculated by dividing the AGDapp/apc by cube root of birthweight.
Results: Prenatal smoke exposure was associated with significantly increased weight-adjusted AGD in female infants at birth (P = 0.03). There was also a significant correlation between mothers' daily smoking rates and weight-adjusted AGD (r = 0.27 / P = 0.03). Fetal smoke-exposure was not associated with any AGD measurements, SPL and penil width in boys.
Discussion: A significant increase in weight-adjusted AGD in female infants exposed to maternal smoking may be an indicator of antenatal androgen exposure and may pose a risk for short and long-term endocrine and metabolic problems. In this context, more extensive studies are needed to explain the relationship between maternal smoking and AGD change.
Keywords: Anogenital distance, Fetal smoke-exposure, Androgenic effect, Endocrine disruptors
19 - 21 Sep 2019
European Society for Paediatric Endocrinology