title: First-trimester serum folate levels and subsequent risk of abortion and preterm birth among Japanese women with singleton pregnancies.
abstract: OBJECTIVE
  To determine whether a low serum folate level during the first trimester predicts subsequent late abortion, preterm birth, or fetal growth restriction (FGR).
  
  
  METHODS
  A prospective cohort study involving 5,075 women whose serum folate levels were measured during the first trimester. The participants were informed of their serum folate levels.
  
  
  RESULTS
  The pregnancy duration, birthweight, rate of late abortion/preterm birth, and the rate of FGR did not differ significantly among the four groups classified according to folate status. The mean serum folate levels did not differ among quartiles classified according to the gestational week at the time of delivery. Nineteen of the 20 women with folate deficiency gave birth at term to infants with a birthweight of 3.132 ± 321 g; only one infant had FGR.
  
  
  CONCLUSIONS
  Low serum folate levels during the first trimester were not associated with the risk of late abortion, preterm birth, or FGR.
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, Kita-ku N14 W6, Sapporo 060-8638, Japan. yamatakashi@me.com
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Mamoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Reiko
authors.initials: R
authors.lastname: Kishi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sengoku
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Endo
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Cho
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D000428:Alcohol Drinking; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology / Q000209:etiology; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D005494:Folic Acid Deficiency / Q000150:complications*; D005865:Gestational Age; D006801:Humans; D007182:Income; D011247:Pregnancy; D011248:Pregnancy Complications; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: D005492:Folic Acid