Influence of exposure to persistent toxic substances (PTS) on pregnancy outcomes, gender ratio and menstrual status in indigenous females of Chukotka
No associations of enhanced blood levels of persistent organic pollutants (POPs) and metals with premature births and low birth weight have been revealed; regarding POPs an inverse but not statistically significant relationship was noted. Maternal blood levels of POPs were higher in cases of stillbirths and congenital malformations. Nevertheless no increased relative risk of adverse pregnancy outcomes has been revealed in regard to any PTS and the dose range. More exposed to polychlorinated biphenyls (PCBs) and other POPs females gave birth to girls more often. Higher POPs blood levels were noted in females with earlier menarche, shortened menstrual cycle and prolonged menstrual bleeding.