SexRatBrth sex ratio, male, female, birth SexRatBrth.Year The sex ratio at birth is the comparison of male births to female births (term singletons only). The expected sex ratio at birth (male to female) is 1.05, or 5% more males born than females. Number of live male births in a specific period of time Number of live female births in a specific period of time Sex ratio at birth was calculated using resident births (regardless where the birth occurred), term (37-42 weeks), and singletons only. 11/14/2018 The expected sex ratio at birth (male to female) is 1.05, or 5% more males born than females. Population growth is, in part, related to the number of live male children. Numerous studies have reported changes in the ratio of males to females at birth; many of the studies have found a reduction in male relative to female births in different countries throughout the world. Some factors can affect the sex of a newborn. Decreases in male births have been shown to be inversely related to parental smoking, gestation length, parental age, and birth order. Reproductive practices and social constructs regarding sex preferences - males over females, for example - can affect the observed sex ratio. Although the mechanism which determines the sex of the infant is not completely understood, some environmental studies have suggested that environmental hazards can affect how many males are born. Biological parent(s) and/or the fetus can come in contact with and become exposed to different hazards referred to as endocrine disruptors. Fewer males are conceived when exposure to endocrine disruptors results in a decrease in testosterone. The Office of Vital Records and Statistics at the Utah Department of Health records all birth records along with their associated sex. Office of Vital Records and Statistics, Utah Department of Health ELS_Env slefevre@utah.gov A 11/29/2018 NCDM required indicator "Male to Female sex ratio at birth (term singletons only), annual, state and by county" 3 x 11/29/2018 Status changed by: kneerings@utah.gov 11/29/2018 SexRatBrth.Year by Year, 1989-2017 Male to Female Sex Ratio at Birth (Term Singletons Only)