title: Fetal sex dependency of maternal vascular adaptation to pregnancy: a prospective population-based cohort study.
abstract: OBJECTIVE
  To investigate fetal sex dependency of maternal vascular adaptation to pregnancy as assessed by uteroplacental vascular resistance and maternal blood pressure.
  
  
  METHODS
  Prospective population-based cohort study.
  
  
  METHODS
  Rotterdam, the Netherlands.
  
  
  METHODS
  In total, 8224 liveborn singleton pregnancies were included.
  
  
  METHODS
  Maternal vascular adaptation was assessed in all trimesters of pregnancy. Pregnancies were stratified into being either complicated by the placental syndrome (i.e. pre-eclampsia, fetal growth restriction or preterm birth, n = 1229) or uncomplicated (n = 6995).
  
  
  METHODS
  First trimester: blood pressures. Second trimester: blood pressures, pulsatility index of the uterine artery (PI-UtA). Third trimester: blood pressures, PI-UtA, presence of notching in the uterine artery.
  
  
  RESULTS
  In women carrying a male fetus PI-UtA was higher than in women with a female fetus in the total group (second trimester P < 0.001, third trimester P = 0.005). Effect estimates differed between women with or without the placental syndrome. In the total group, women with a male fetus more often showed notching in the Doppler resistance pattern (odds ratio 1.42, 95% confidence interval 1.17-1.72). Different blood pressure patterns were observed between pregnant women with a male fetus and pregnant women with a female fetus and between complicated pregnancies and uncomplicated pregnancies.
  
  
  CONCLUSIONS
  Fetal sex is significantly associated with maternal vascular adaptation to pregnancy with differential effects in uncomplicated pregnancies and in pregnancies complicated by the placental syndrome.
  
  
  CONCLUSIONS
  Fetal sex is significantly associated with maternal vascular adaptation to pregnancy.
authors.affiliation: Department of Obstetrics and Gynaecology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Z A
authors.initials: ZA
authors.lastname: Broere-Brown
authors.affiliation: Department of Obstetrics and Gynaecology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Schalekamp-Timmermans
authors.affiliation: Department of Epidemiology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Epidemiology, Erasmus Medical Centre, Rotterdam, the Netherlands.|Department of Paediatrics, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Vwv
authors.initials: V
authors.lastname: Jaddoe
authors.affiliation: Department of Obstetrics and Gynaecology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Eap
authors.initials: E
authors.lastname: Steegers
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D001724:Birth Weight / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D008297:Male; D008423:Maternal Age; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D011264:Pregnancy Trimesters; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D012737:Sex Factors; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D055988:Uterine Artery / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology*; D055815:Young Adult
keywords: Blood pressure; fetal growth restriction; fetal sex; notching; pre-eclampsia; pulsatility index; spontaneous preterm birth