Changing sex ratio in Iran, 1976–2000
- 1Department of Community Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- 2Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
- Correspondence to: Dr M Saadat, Department of Biology, College of Sciences, Shiraz University, Shiraz 71454, Iran
- Accepted 11 March 2002
Sex ratio—that is, the ratio of male to total live births—is a subject of scientific interest but little is known about the factors that affect the sex ratio of humans. Many demographic and environmental factors have been suggested to affect the sex ratio. Some of these include birth order, race, coital rate, certain hormonal treatment,1,2 parental age,1,3 and exposure to environmental toxins.2 Studies on secular trends in the human sex ratio at birth have shown that there are rapid increase during and just after war.4 The sex ratio can vary between populations and changes within populations over time, for example it has been reported that it decreased in recent decades in some countries such as Denmark 5 and the United States 6 and increased in Italy 3 and Japan.7 There is no investigation about the sex ratio in Iran. To determine if the sex ratio has …
