Abstract\n\n79% of the American and 87.2% of the Iranian pregnant women suffer from sleep disorders. These disorders are the result of physiological, hormonal, and physical changes occurring in pregnancy due todifferent causes such as fetal Sex.This study aimed to evaluate the association of fetal sex and common complaints of pregnancy in pregnant women with sleep disorder. \nThis is a cross-sectional study conducted on 972 pregnant women with sleep disorders referring to two selected health care centers in Makou affiliated to Urmia University of Medical Sciences during June-Oct 2012. Data collection tools included demographic characteristics and Pittsburgh Standard Sleep Quality. Sampling was done by convenient sampling. Pregnant women with sleep disorders (Based on the PSQI) were selected as the subjects then demographic characteristics and beck depression standard questionnaires was completed by women, and statistical methods used to analysis. \nThe results indicated that there were significant association (p≤ 0.05) between fetal sex to backache (r=0.129) and vomiting(r=0.204). Women with female fetus’s more than male experienced backpain and vomiting. Other complaints were not significantly different. \nFetal gender is independently associated with adverse pregnancy outcome. Although the added risk is relatively small, further investigation of the mechanisms underlying this association may contribute to our understanding of the pathophysiology of pregnancy complications such as sleep disorders.