Fatty acid desaturase variants tied to gestation duration
An association exists between fatty acid desaturase (FADS) variants and gestation duration, suggesting that long-chain polyunsaturated fatty acids (LC-PUFAs) may play a potential role in gestation duration, reports a study that utilizes a Mendelian randomization approach.
The investigators genotyped 35 genetic variants in FADS1, FADS2 and FADS3 in 898 mothers and 1,103 offspring as part of a triethnic mother-offspring cohort in Singapore, as well as measured maternal plasma n–3 and n–6 PUFA concentrations at 26–28 weeks of gestation. An ultrasound dating scan in early pregnancy and from birth date was used to obtain gestation duration. Birth length and weight were also measured.
The investigators selected eight FADS variants through a tagging-SNP approach and examined these in association with PUFA concentration, gestation duration among spontaneous labours, and birth size using ethnicity-adjusted linear regressions and survival models that accounted for the competing risks of induced labour and prelabour caesarean delivery.
Tagging for eight other variants located on FADS1 and FADS2, maternal FADS1 variant rs174546 was strongly associated with plasma n–6 but not n–3 LC-PUFA concentrations. Among women who had spontaneous labour, offspring and maternal FADS3 variants correlated with gestation duration. Each copy of rs174450 minor allele C correlated with a shorter gestation by 2.2 days (95 percent CI, 0.9–3.4) for maternal variants and 1.9 days (0.7–3.0) for offspring variants.
Survival models showed that rs174450 minor vs major allele homozygotes had reduced time to delivery after spontaneous labour (mothers: hazard ratio [HR], 1.51; 1.18–1.95; offspring: HR, 1.51; 1.20–1.89).
“In randomized trials, supplementation of n–3 LC-PUFAs during pregnancy has resulted in increased size at birth, which is attributable to longer gestation,” the investigators noted.