High Ratios of C20:4n-6/C20:5n-3 and Thromboxane B2 /6-Keto-Prostaglandin F1α in Placenta Are Potential Risk Contributors for Neural Tube Defects: A Case-Control Study in Shanxi Province, China.

BACKGROUND

Neural tube defects (NTDs) are severe congenital malformations. Folate supplementation can reduce the risk, but cannot prevent all NTDs, suggesting other reasons for folate-resistant NTDs. The present study assesses placental fatty acid composition, eicosanoids, and cytokines as risk factors for NTDs in a Chinese population with highly incident NTDs.

METHODS

Seventy-seven aborted fetuses with NTDs during the third trimester were cases and 142 healthy newborns were controls. Placental fatty acid composition, eicosanoids, and cytokines were determined by standard methods.

RESULTS

The placental C20:4n-6/C20:5n-3 and thromboxane B2 (TXB2 )/6-keto-prostaglandin F1α (6-keto-PGF1α ) ratios were significantly higher for cases than controls (p < 0.001 and 0.05, respectively). For the top versus the lowest tertiles of placental C20:4n-6/C20:5n-3 and TXB2 /6-keto-PGF1α , odds ratios for NTD occurrence were 3.79 (95% confidence interval, 1.60-8.96) (p for trend < 0.01) and 5.52 (95% confidence interval, 2.07-14.74) (p for trend < 0.001), respectively, adjusted for fetal sex as well as maternal age, occupation, parity, smoking, passive smoking, periconceptional folate supplementation, conception season, and tea drinking. The C20:4n-6/C20:5n-3 and TXB2 /6-keto-PGF1α ratios were positively correlated (r = 0.14; p < 0.05). The proportions of C18:2n-6, C18:3n-6, C20:3n-6, C18:3n-3, C20:3n-3, C20:5n-3, and C22:5n-3 were significantly lower in cases than controls, and all negatively associated with NTD occurrence (tertile-specific odds ratios); after adjustment for the potential confounders, these associations remained significant (p for trend < 0.05) except for C20:3n-3.

CONCLUSION

High placental ratios of C20:4n-6/C20:5n-3 and TXB2 /6-keto-PGF1α are risk factors for neural tube defects.Birth Defects Research 109:550-563, 2017.© 2017 Wiley Periodicals, Inc.