257389 Maternal Vitamin D Status and Preterm Delivery

Tuesday, October 30, 2012 : 2:35 PM - 3:10 PM

Cynthia D. Ferre, MA, PhD(abd), Dipl Acu , Division of Reproductive Health, CDC, Atlanta, GA
Claudia Holzman, DVM, MPH, PhD , Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI
Anna Maria Siega-Riz, PhD, RD , Gillings School of Public Health, University of North Carolina, Chapel Hill, NC
Daniel Enquobahrie, PhD, MPH, MD , Center for Perinatal Studies, Swedish Medical Center, Seattle, WA
Michelle A. Williams, ScD , Department of Epidemiology, Harvard School of Public Health, Boston, MA
Nancy Dole, PhD , Carolina Population Center, University of North Carolina, Chapel Hill, NC
Dale Rhoda, MAS, MS, MPP , Centers for Public Health Research and Evaluation, Battelle Memorial Institute, Columbus, OH
Stephanie Buehler, PhD , Centers for Public Health Research and Evaluation, Battelle Memorial Institute, Columbus, OH
Mark Newman , ZRT Laboratory, Beaverton, OR
Background: Identification of interventions for preterm delivery (PTD) prevention is a public health priority. Methods: We conducted a pooled nested case-control study from three prospective cohort studies to determine the association between maternal 25-hydroxyvitamin D (25OHD), a measure of vitamin D status, and singleton PTD. Participating cohorts are the Omega study (Washington), Pregnancy, Infection, and Nutrition Study (North Carolina) and Pregnancy Outcomes and Community Health study (Michigan). Maternal antenatal 25OHD levels were determined in banked blood specimens at a central laboratory using liquid chromatography-tandem mass spectrometry. PTD cases (n=870) were matched to term controls (n=1713) on cohort, maternal race (non-Hispanic black/white), gestational week at blood draw (median 19 weeks), and within 45 days. Serum 25OHD levels were categorized as <12 ng/ml (‘deficient'); 12-20 ng/ml (‘insufficient'); and >20 ng/ml (‘sufficient' and referent category). Spontaneous, and medically-indicated PTD were analyzed at <37 and <32 weeks. Conditional logistic regression analyses, which included adjustment for matching factors, were conducted. Results: Prevalence of 25OHD deficiency was 8.2% among all preterm cases and 6.5% among term controls. These levels varied by race: 26.2% among black cases and 22.9% among black controls; 2.0% among white cases and 1.1% among white controls. Significant odds ratios (OR) were observed for deficient 25OHD and medically-indicated PTD at <37 weeks: OR 2.3 (95% Confidence Interval 1.2, 4.2); and at <32 weeks: OR 6.6 (1.4, 31.3). Conclusions: Vitamin D deficiency is associated with increased risk of medically-indicated preterm birth. Improving maternal vitamin D status may reduce risk of preterm birth.

Learning Areas:
Basic medical science applied in public health
Public health biology
Public health or related research

Learning Objectives:
Describe the association between maternal antenatal 25-hydroxyvitamin D status and risk of preterm birth.

Keywords: Pregnancy Outcomes, Maternal Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have worked nationally as a perinatal epidemiologist for over 25 years. I initiated and developed the study to be presented and served as a co-principal investigator. I have expertise in the epidemiology of preterm birth, low birth weight, and infant mortality, especially among minority populations.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.