title: Undetectable maternal serum unconjugated estriol levels in the second trimester: risk of perinatal complications associated with placental sulfatase deficiency.
abstract: OBJECTIVE
  Our purpose was to determine the prevalence of undetectably low second-trimester maternal serum unconjugated estriol levels and the association with increased perinatal morbidity or mortality in pregnancies at risk for placental sulfatase deficiency.
  
  
  METHODS
  Nine centers in New England identified singleton pregnancies with undetectably low unconjugated estriol levels. Each unexplained case was matched with four controls; pregnancy outcome information was sought.
  
  
  RESULTS
  Among 130,295 pregnancies surveyed, undetectably low unconjugated estriol levels were identified in 167 (13/10,000). Explanations included fetal death (53), overestimated gestational age (50), nonpregnancy (12), and chromosome abnormalities (5). The 41 unexplained cases were compared with 163 matched controls. Male offspring were more frequent (85%) among cases than among controls (55%). Although rates of perinatal complications were not significantly different, primary cesarean sections occurred about twice as often among cases. No perinatal deaths occurred.
  
  
  CONCLUSIONS
  Neither severity of symptoms nor perinatal morbidity or mortality currently warrant routine interpretation of unexplained undetectably low unconjugated estriol levels as a marker for placental sulfatase deficiency.
authors.affiliation: Foundation for Blood Research, Scarborough, ME 04070-0190, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Bradley
authors.forename: J A
authors.initials: JA
authors.lastname: Canick
authors.forename: G E
authors.initials: GE
authors.lastname: Palomaki
authors.forename: J E
authors.initials: JE
authors.lastname: Haddow
mesh_terms: D016022:Case-Control Studies; D004964:Estriol / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second / Q000097:blood*; D012744:Sex Ratio; D013429:Sulfatases / Q000172:deficiency*
chemical_list: D013429:Sulfatases; D004964:Estriol