Nonsense. 350 pregnancies over 6 years. Gestation is complex. Much of the data are self-reported. The result is clinically insignificant anyway — e.g., 2.9 day longer average gestation in treated group.
“University of Kansas researchers have found that the infants of mothers who were given 600 milligrams of the omega-3 fatty acid DHA during pregnancy weighed more at birth and were less likely to be very low birth weight and born before 34 weeks gestation than infants of mothers who were given a placebo. This result greatly strengthens the case for using the dietary supplement during pregnancy.”