title: Pregnancy in dark winters: implications for fetal bone growth?
abstract: OBJECTIVE
  To prospectively examine the prevalence of hypovitaminosis D in pregnancy and to correlate maternal and fetal vitamin D to fetal anthropometry.
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  Tertiary referral maternity hospital.
  
  
  METHODS
  Sixty pregnant women.
  
  
  METHODS
  Serum 25-hydroxyvitamin D (25OHD) was measured in early pregnancy, at 28 weeks, and in cord blood at delivery.
  
  
  METHODS
  The prevalence of hypovitaminosis D and the relationship between fetal growth and serum 25OHD concentrations.
  
  
  RESULTS
  Two subgroups were analyzed to examine results in the context of seasonal variation in 25OHD: a winter and a summer cohort. Fetal anthropometry was assessed at 20 and 34 weeks, and at delivery the neonatal anthropometry was recorded. There was a high prevalence of hypovitaminosis D ranging from 33% to 97%, with a marked seasonal variation. Fetal 25OHD concentrations correlated with all biometry at 20 weeks. In the winter cohort, a correlation was found between early pregnancy 25OHD and femur length at 20 weeks, and between 28-week 25OHD and femur length at 34 weeks. Infant length was shorter in those with early pregnancy 25OHD less than the median (52.1 vs. 53.6 cm).
  
  
  CONCLUSIONS
  The high prevalence of maternal hypovitaminosis D during winter months in northern latitudes may have detrimental effects on fetal skeletal growth.
authors.affiliation: UCD Obstetrics and Gynaecology, School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Dublin, Ireland.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Walsh
authors.affiliation: St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Mark
authors.initials: M
authors.lastname: Kilbane
authors.affiliation: UCD Obstetrics and Gynaecology, School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Dublin, Ireland.
authors.forename: Ciara A
authors.initials: CA
authors.lastname: McGowan
authors.affiliation: St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Malachi J
authors.initials: MJ
authors.lastname: McKenna
authors.affiliation: UCD Obstetrics and Gynaecology, School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Dublin, Ireland. Electronic address: fionnuala.mcauliffe@ucd.ie.
authors.forename: Fionnuala M
authors.initials: FM
authors.lastname: McAuliffe
mesh_terms: D000328:Adult; D000886:Anthropometry; D001846:Bone Development / Q000502:physiology*; D001842:Bone and Bones / Q000196:embryology*; D015331:Cohort Studies; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D006801:Humans; D008027:Light; D011247:Pregnancy / Q000097:blood / Q000502:physiology*; D015995:Prevalence; D011446:Prospective Studies; D012621:Seasons; D062606:Tertiary Care Centers; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D