title: The timing of placental competence in pregnancy after oocyte donation.
abstract: OBJECTIVE
  To test the timing of placental support of pregnancy.
  
  
  METHODS
  Steroid levels in blood and urine were determined in pregnancy after ET into women with ovarian failure.
  
  
  METHODS
  The study was carried out in a private IVF clinic and a university endocrine department.
  
  
  METHODS
  Four patients with ovarian failure were treated by IVF using donor oocytes.
  
  
  METHODS
  Estrogen and P were given, up to the point of ET, to achieve the hormonal levels in the ranges for normal menstrual cycles. Pregnancy was supported in the first trimester by exogenous steroids.
  
  
  RESULTS
  The four pregnancies went to term, and each resulted in singleton livebirths.
  
  
  RESULTS
  Increases in plasma P concentrations and in urinary pregnanediol excretion rates were indications for a placental contribution to the hormone pool.
  
  
  CONCLUSIONS
  One hundred mg of P were probably a supraphysiological dose to support pregnancy 6 to 8 weeks after conception. The fetoplacental unit was competent from 10 to 12 weeks' gestation.
authors: University College and Middlesex School of Medicine (UCMSM), Middlesex Hospital, London, United Kingdom.
authors: M A
authors: MA
authors: Schneider
authors: M C
authors: MC
authors: Davies
authors: J W
authors: JW
authors: Honour
mesh_terms: D000328:Adult; D004958:Estradiol / Q000097:blood / Q000627:therapeutic use; D005260:Female; D005307:Fertilization in Vitro; D005865:Gestational Age; D006801:Humans; D007247:Infertility, Female / Q000503:physiopathology; D009865:Oocytes; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D011256:Pregnancy Outcome; D011276:Pregnanediol / Q000652:urine; D011374:Progesterone / Q000097:blood / Q000627:therapeutic use; D014019:Tissue Donors
chemical_list: D011374:Progesterone; D004958:Estradiol; D011276:Pregnanediol