title: Elevated first-trimester serum relaxin concentrations in pregnant women following ovarian stimulation predict prematurity risk and preterm delivery.
abstract: OBJECTIVE
  To determine whether ovarian stimulation would result in higher circulating relaxin concentrations and whether this hyperrelaxinemia would be associated with prematurity.
  
  
  METHODS
  Two groups of women were studied: 1) women achieving pregnancy after ovarian stimulation (n = 114) and 2) women achieving pregnancy without treatment (n = 37). Serum was obtained at 6-12 weeks' gestational age; fetal number was determined by transvaginal ultrasound. Prematurity risk or preterm delivery was determined from the obstetric record. A specific human relaxin enzyme-linked immunosorbent assay was used to measure serum relaxin concentrations. Hyperrelaxinemia was defined as levels greater than 3 standard deviations above the weighted mean of levels in normal unstimulated singleton pregnancies at 6-12 weeks' gestation.
  
  
  RESULTS
  An association was found between prematurity risk or premature delivery and peripheral relaxin concentrations during weeks 6-12 of pregnancy in women having ovarian stimulation and in women having multiple gestations. Circulating relaxin concentrations greater than 16 ng/mL in women having ovarian stimulation and levels greater than 7 ng/mL in women who had multiple gestations predicted prematurity risk or premature delivery in 50% of the women.
  
  
  CONCLUSIONS
  These data demonstrate that after ovarian stimulation, some women have highly elevated circulating first-trimester relaxin concentrations. First-trimester hyperrelaxinemia identifies a group of women at risk for prematurity who can be monitored aggressively.
authors.affiliation: Department of Obstetrics and Gynecology, New Jersey Medical School, Newark.
authors.forename: G
authors.initials: G
authors.lastname: Weiss
authors.forename: L T
authors.initials: LT
authors.lastname: Goldsmith
authors.forename: R
authors.initials: R
authors.lastname: Sachdev
authors.forename: S
authors.initials: S
authors.lastname: Von Hagen
authors.forename: K
authors.initials: K
authors.lastname: Lederer
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D016015:Logistic Models; D007752:Obstetric Labor, Premature / Q000097:blood* / Q000209:etiology*; D016017:Odds Ratio; D010062:Ovulation Induction / Q000009:adverse effects*; D010298:Parity; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012065:Relaxin / Q000097:blood*; D012307:Risk Factors
chemical_list: D012065:Relaxin