An accurate method to determine estrogen levels in infants using babies and more than 5,000 of children diapers by researchers at Emory University.

Researchers know very little about hormone levels during human infancy. The noninvasive method will help researchers understand the link between estrogen levels in human infants and their long-term reproductive development. It also will help researchers on the development of sex-specific behaviors such as toy preference.

Researchers from Emory University generated data from fecal samples collected from cotton diapers used by infants. It included 32 infants, aged 7 days to 15 months. The infants’ parents did not dispose the soiled diapers after each change, which was collected and frozen and stored at - 80 degree Celsius. They were analyzed 24 hours to 12 months after collection.The earlier method was to measure hormones in blood, urine and saliva.

“The development of robust, noninvasive methods to measure these hormones in infants allows us to further investigate the association between postnatal hormone production and the development of sex-specific biology and behavior,” said Michelle Lampl, PhD, MD, Emory University Samuel Candler Dobbs professor of anthropology, and senior author of a paper in Frontiers in Systems Biology describing the new method. The study is being published in Frontiers in Systems Biology.

“The development of an assay to measure estrogen from diapers might initially strike one as unnecessary or strange, but the need is real,” says Sara Berga, MD, James Robert McCord professor and chairman, Department of Gynecology and Obstetrics, Emory University School of Medicine.

“These observations are the first report of human infant fecal estradiol levels and they provide a new tool for investigating early human development", said Lampl. “Because infant diapers are plentiful, fecal samples can be collected frequently and over a long period of time. Future longitudinal studies will allow the association between fecal levels of steroids and physiological measures to be assessed.”