Association between fetal sex and metabolic syndrome in women 40 and older: the REACTION study

Aims: The purpose of this study was to determine if fetal sex has an effect on risk of metabolic syndrome (MetS) in women in China. Methods A cohort of 3758 singleton pregnant Chinese women, aged 40 years or older were included. For each of these women, registry data on all pregnancies and miscarriages were obtained. This was a retrospective cohort study that aimed to determine whether fetal sex was associated with metabolic syndrome. We defined MetS as meeting five criteria, namely ineffective insulin metabolism, reduced glucose tolerance, high blood pressure, dyslipidemia and large waist size. Results Among 3758 singleton pregnant women 40 and older in Luzhou city, there were 1018 (27.1%) participants with incident MetS. Mothers carrying a male fetus(male group) had higher triglyceride(TG) and total cholesterol(TC) and showed greater diabetes background than the women carrying a female fetus (female group) ( P   0.05). MetS frequency was statistically more in the male group than female group in postmenopausal women ( P  < 0.05). MetS occurred significantly less frequently in premenopausal compared to postmenopausal women in both the male and female group ( P  < 0.05). MetS occurred more often in the male group in postmenopausal women, showing statistical significance ( P  < 0.05). Conclusions Our study found that fetal sex was not associated with MetS in Chinese women 40 and older. But in postmenopausal women, MetS was seen statistically more often in the male group. We should pay more attention to postmenopausal women who have a male fetus and take early measures to prevent related chronic diseases.