title: Human chorionic gonadotropin, fetal sex and risk of hypertensive disorders of pregnancy: A nested case-control study.
abstract: OBJECTIVE
  To assess whether human chorionic gonadotropin (HCG) and fetal sex are two independent risk factors for hypertensive pregnancy in the early second-trimester of pregnancy.
  
  
  METHODS
  This was a retrospective nested case-control study based on a cohort of 2521 singleton pregnancies, among whom we recruited 98 hypertensive pregnancies (subdivided into severe preeclampsia, n=34; mild preeclampsia, n=29 and gestational hypertension, n=35) and 196 normotensive pregnancies. Maternal serum HCG levels were measured at 15-20 weeks of gestation and fetal sex was determined from the neonatal record. Mann-Whitney U and chi-square tests were performed to assess differences of HCG levels and fetal sex between groups. Logistic regressions were performed to evaluate the effect of HCG and fetal sex on hypertensive pregnancy.
  
  
  RESULTS
  There were 35 male and 63 female fetuses in the hypertensive group, and 102 male and 94 female fetuses in the normotensive group (p=0.008). HCG (MoM) levels were significantly higher in only severe preeclamptic pregnancies (n=34) (p=0.013). There were no significant differences of the HCG (MoM) levels between male and female fetuses in each sub-group. aOR for increased maternal HCG levels and female fetus were 2.4 (95% CI: 1.434-3.954) and 2.9 (95% CI: 1.227-6.661) respectively in severe preeclamptic pregnancies compared with normotensive pregnancies.
  
  
  CONCLUSIONS
  There is a female preponderance in hypertensive pregnancies. Increased HCG levels and female fetus are two independent risk factors for severe preeclampsia in the early second-trimester of pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen 518036, China; Shantou University Medical College, Shantou 515041, China.
authors.forename: Qizhen
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen 518036, China; Shenzhen Key Laboratory of Gynaecology Diagnostic Technology Research, Shenzhen, China. Electronic address: dengyuqing666@163.com.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen 518036, China.
authors.forename: Shilin
authors.initials: S
authors.lastname: Zhong
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen 518036, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shi
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D006063:Chorionic Gonadotropin / Q000097:blood*; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D015854:Up-Regulation
chemical_list: D006063:Chorionic Gonadotropin
keywords: Gender differences; Human chorionic gonadotropin; Hypertensive pregnancy; Placenta