title: Serum 25-hydroxyvitamin D in pregnant women during preterm labor.
abstract: OBJECTIVE
  Pregnancy complications hypothesized to be related to vitamin D include preeclampsia, gestational diabetes, low birth weight, preterm delivery, Cesarean section and infectious disease. There have been a few studies which have demonstrated maternal serum vitamin D to be associated with preterm labor. The objective was to evaluate the serum vitamin D concentrations in Thai pregnant women with and without preterm labor and to find the prevalence of vitamin D deficiency and insufficiency in both groups.
  
  
  METHODS
  Blood samples were collected from pregnant women with and without preterm labor (matched for gestational age). Serum 25-hydroxyvitamin D (25-OHD) concentrations were measured by chemiluminescence method.
  
  
  RESULTS
  A total of 60 pregnant women were included into the study, 30 patients in the preterm labor group and another 30 patients in the control group. The serum 25-OHD concentration was 21.0±7.5 ng/mL and the prevalence of vitamin D deficiency was 48.3% in total group of pregnant women. The serum 25-OHD concentrations were not different between the preterm labor and the control groups (20.9±8.4 vs 21.2±6.7 ng/mL, p=0.91). The prevalence of vitamin D deficiency and insufficiency were not different between the preterm labor and the control groups (53.3% vs 43.3%, p=0.44 and 83.3% vs 90%, p=0.45, respectively).
  
  
  CONCLUSIONS
  The serum 25-hydroxyvitamin D concentrations and the prevalence of vitamin D deficiency and insufficiency were not different between the preterm labor and the control groups. The serum 25-OHD could not predict preterm labor in this Thai population.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Nalina
authors.initials: N
authors.lastname: Bhupornvivat
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Email: vorapong.p@chula.ac.th.
authors.forename: Vorapong
authors.initials: V
authors.lastname: Phupong
mesh_terms: D000328:Adult; D001724:Birth Weight; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007752:Obstetric Labor, Premature / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D013785:Thailand / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D