title: Maternal lipids at mid-pregnancy and the risk of preterm delivery.
abstract: OBJECTIVE
  This study examined associations between maternal lipid levels at mid-pregnancy and preterm delivery, medically indicated or spontaneous.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Women were recruited from 52 clinics in five Michigan, USA communities (1998-2004).
  
  
  METHODS
  Pregnant women were enrolled at 15-27 weeks' gestation and followed to delivery (n=3019).
  
  
  METHODS
  A single blood sample was obtained at study enrollment. Blood lipids, i.e. total cholesterol (TC), high-density lipoprotein (HDLc), low-density lipoprotein (LDLc) cholesterol, and triglycerides (TG), were measured on a sub-cohort (n=1309).
  
  
  METHODS
  There were 221 spontaneous, 100 medically indicated preterm deliveries and 988 term deliveries. Polytomous logistic regression models examined relationships among cholesterol levels (Low: <10(th) percentile, Referent: 10(th) -<70(th) percentile, High: ≥70(th) percentile), quartiles of TG (Referent: first quartile) and delivery outcome (Referent: term).
  
  
  RESULTS
  Odds of medically indicated preterm delivery were increased among women with low TC (adjusted odds ratio (aOR)=2.04, 95% confidence interval (CI): 1.12, 3.72), low HDLc (aOR=1.89, 95%CI: 1.04, 3.42) or low LDLc (aOR=1.96, 95%CI: 1.09, 3.54). Odds of spontaneous preterm delivery were increased among women with high TC (aOR=1.51, 95%CI: 1.06, 2.15), high LDLc (aOR=1.42, 95%CI: 0.99, 2.04) or high TG (aOR=1.90, 95%CI: 1.21, 2.97 and aOR=1.72, 95%CI: 1.06, 2.78 for third and fourth quartiles, respectively).
  
  
  CONCLUSIONS
  Extremely low TC, HDLc, and LDLc were associated with a modest increase in risk of medically indicated preterm delivery, whereas high TC, LDLc and TG modestly increased the risk of spontaneous preterm delivery. Further research is needed to uncover explanations for these associations and to identify optimal ranges for maternal lipids.
authors.affiliation: Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC, USA.
authors.forename: Lanay M
authors.initials: LM
authors.lastname: Mudd
authors.forename: Claudia B
authors.initials: CB
authors.lastname: Holzman
authors.forename: Janet M
authors.initials: JM
authors.lastname: Catov
authors.forename: Patricia K
authors.initials: PK
authors.lastname: Senagore
authors.forename: Rhobert W
authors.initials: RW
authors.lastname: Evans
mesh_terms: D015992:Body Mass Index; D050171:Dyslipidemias / Q000453:epidemiology; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood*; D016015:Logistic Models; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood*; D047928:Premature Birth / Q000097:blood* / Q000453:epidemiology*; D011446:Prospective Studies
chemical_list: D008055:Lipids