title: Periconceptional use of folic acid and risk of miscarriage - findings of the Oral Cleft Prevention Program in Brazil.
abstract: OBJECTIVE
  We report on the risk of miscarriage with high- and low-dosage periconceptional folic acid (FA) supplementation from a double-blind randomized clinical trial for prevention of orofacial cleft recurrence in Brazil.
  
  
  METHODS
  Women at risk of recurrence of orofacial clefts in their offspring were randomized into high (4 mg/day) and low (0.4 mg/day) doses of FA supplementation. The women received the study pills before pregnancy, and supplementation continued throughout the first trimester. Miscarriage rates were compared between the two FA groups and with the population rate.
  
  
  RESULTS
  A total of 268 pregnancies completed the study protocol, with 141 in the 4.0-mg group and 127 in the 0.4-mg group. The miscarriage rate was 14.2% in the low-dose FA group (0.4 mg/day) and 11.3% for the high-dose group (4 mg/day) (P=0.4877). These miscarriage rates are not significantly different from the miscarriage rate in the Brazilian population, estimated to be around 14% (P=0.311).
  
  
  CONCLUSIONS
  These results indicate that high-dose FA does not increase miscarriage risk in this population and add further information to the literature on the safety of high FA supplementation for prevention of birth defect recurrence.
authors.affiliation: Centro UniversitárioUnijorge Avenida Anita Garibaldi, 1901, Garibaldi Prime Federação,Salvador Bahia 40210-750, Brazil. camivnova@gmail.com
authors.forename: Camila
authors.initials: C
authors.lastname: Vila-Nova
authors.forename: George L
authors.initials: GL
authors.lastname: Wehby
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Queirós
authors.forename: Hrishkesh
authors.initials: H
authors.lastname: Chakraborty
authors.forename: Temis M
authors.initials: TM
authors.lastname: Félix
authors.forename: Norman
authors.initials: N
authors.lastname: Goco
authors.forename: Janet
authors.initials: J
authors.lastname: Moore
authors.forename: Eduardo V
authors.initials: EV
authors.lastname: Gewehr
authors.forename: Lorene
authors.initials: L
authors.lastname: Lins
authors.forename: Carla M C
authors.initials: CM
authors.lastname: Affonso
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Murray
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D002971:Cleft Lip / Q000517:prevention & control*; D002972:Cleft Palate / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016742:Preconception Care / Q000379:methods*; D011247:Pregnancy; D012008:Recurrence; D055815:Young Adult
chemical_list: D005492:Folic Acid