Maternal Micronutrient Status and Preterm Versus Term Birth for Black and White US Women

Abstract

Objective. Micronutrient deficiencies are hypothesized to play a role in spontaneous preterm birth (PTB; <37 weeks of gestation) and possibly the racial disparity in rates of PTB between black and white women. Yet relatively few studies have addressed the role of micronutrient deficiencies in spontaneous PTB among black and white women in the United States. The purpose of this study was to investigate whether 25-hydroxy vitamin D (25-OH-D), folate, and omega-6/omega-3 fatty acid status are associated with spontaneous PTB among black and white women in the United States. Methods. Biospecimens and medical record data for this study were derived from a subsample of the 1547 women enrolled into the Nashville Birth Cohort during [2003][2004][2005][2006]. We randomly selected 80 nulliparous and primiparous women for whom stored plasma samples from the delivery admission were available and analyzed the stored plasma for 25-OH-D, folate, and total omega-6/omega-3 fatty acids. We used multivariate logistic regression to assess the odds of spontaneous PTB among women with 25-OH-D <20 ng/mL, folate <5 ug/L, and omega-6/omega-3 >15. Results. An omega-6/omega-3 ratio >15 was significantly associated with spontaneous PTB for white (adjusted odds ratio [aOR] 4.25, 95% confidence interval [CI] 1.25-14.49) but not black women (aOR 1.90, 95% CI: 0.69-5.40), whereas no significant relationships were observed for folate and 25-OH-D status and PTB for black or white women. Conclusion. Maternal plasma total omega-6/ omega-3 fatty acid ratio >15 at delivery was significantly associated with spontaneous PTB for white, but not black, women.

Retracted: Folic acid supplementation, dietary folate intake during pregnancy and risk for spontaneous preterm delivery: a prospective observational cohort study

“…This information might be important, especially if the risk of early PTD is found to be associated with folate status, as suggested by this study and that of Bukowski et al [21]. Although PTD is a heterogeneous pregnancy outcome with distinct etiologies for different subgroups [25], not all studies analyzed clearly defined subgroups such as spontaneous PTD [20,21,37,40,47,52]. …”

Vitamin D and risk of preterm birth: Up‐to‐date meta‐analysis of randomized controlled trials and observational studies

“…The score for one article, however, was unable to be evaluated because the full text was not available, and three RCT had low risk of bias. Table 1 lists the characteristics of the 18 observational studies 9,[12][13][14][15][16][17][18][19][20][21][22][23][24][30][31][32] and six RCT. [33][34][35][36][37][38] There was some disparity in the definition of PTB between studies.…”

“…11 Most observational studies, however, did not show a significant relationship. 9,[12][13][14][15][16][17][18][19][20][21][22][23][24] A trial of vitamin D supplementation suggested that 25-OHD serum concentration > 100 nmol/L (vs <50 nmol/L) could significantly reduce the risk of PTB. 25 Other studies, however, did not obtain the same results.…”

Folic acid supplementation, dietary folate intake and risk of preterm birth in China

“…Earlier epidemiological studies investigating the associations between PB and folic acid supplements/dietary folate intake have provided conflicting results [17][18][19][20][21][22][23][24][25][26][27][28][29][30]42]; among them, Dunlop et al [43] investigated plasma level of folate. While ten studies have reported a protective effect of folic acid supplements/dietary folate intake on PB [18][19][20][21][22][23][24][25][26][27], one study reported that risk of PB associated with folic acid supplement use varied by time periods of use (preconception, first trimester, and second trimester) [17] and four studies found no association [28][29][30]42]. Variations in dosage of folic acid use, selected pregnancy period of use, definitions of PB by gestational age, and lack of consideration of PB clinical subtypes among different populations might partially contribute to the inconsistent results.…”