Duration of pregnancy influenced by supplementation of fish oil

09.11.2007

Pregnancy duration can vary greatly and little is known about what causes this variation. In this research the association between exposure to fish intake and gestation length was examined, with 8,729 pregnant Danish women participating.

It has been hypothesised that an increased intake of long-chain omega-3 fatty acids can delay timing of spontaneous delivery, possibly by influencing the prostaglandins involved in the initiation of delivery. This has been supported by some but far from all observational studies and controlled trials. This hypothesis was examined in the research. The research also examined the relation between low consumption of fish or fish oil and preterm delivery, i.e. earlier than three weeks before expected date of delivery, which is the main problem in obstetrics today.

The risk of postterm delivery and of elective delivery was raised in the high fish strata, a pattern which agrees with the hypothesis that marine n-3 fatty acids delay the timing of spontaneous delivery. Never consuming fish in the first two trimesters of pregnancy appeared to be a strong risk factor for preterm delivery in Danish women. Other subsequent studies have not been able to confirm these findings but those were however unable to clearly define a group of women with zero fish intake as the Danish study did.

S F Olsen et al (2007) Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil. European Journal of Clinical Nutrition, 61, 976-985.

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