Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration.
The high birthweights and long duration of pregnancy in the Faroe Islands led us to suggest that a high intake of marine-fat-derived n-3 fatty acids might prolong pregnancy by shifting the balance of production of prostaglandins involved in parturition. We have compared the effects on pregnancy duration, birthweight, and birth length of a fish-oil supplement, a control olive-oil supplement, and no supplementation. 533 healthy Danish women in week 30 of pregnancy were randomly assigned in a ratio of 2/1/1 to fish oil (four 1 g Pikasol capsules [containing 2.7 g n-3 fatty acids] per day), olive oil (four 1 g capsules per day), or no supplement. The three groups differed in mean length of gestation (p = 0.006), which was highest in the fish-oil group and lowest in the olive-oil group; the result was similar when the analysis was restricted to women with an estimate of gestation length based on early ultrasound findings (443 women). Pregnancies in the fish-oil group were on average 4.0 (95% confidence interval 1.5-6.4) days longer than those in the olive-oil group; the difference in birthweight was 107 (1-214) g. The effect of supplementation on length of gestation was influenced by intake of fish and of fish oil: the difference between fish-oil and other groups was increased by a low fish intake at baseline. Fish-oil supplementation in the third trimester seems to prolong pregnancy without detrimental effects on the growth of the fetus or on the course of labour.
Olsen
S F
SF
Institute of Epidemiology and Social Medicine, University of Aarhus, Denmark.
Sørensen
J D
JD
Secher
N J
NJ
Hedegaard
M
M
Henriksen
T B
TB
Hansen
H S
HS
Grant
A
A
D000328:Adult; D001724:Birth Weight; D001827:Body Height; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007231:Infant, Newborn; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology; D011247:Pregnancy / Q000187:drug effects*; D011256:Pregnancy Outcome; D011263:Pregnancy Trimester, Third; D013997:Time Factors
D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D010938:Plant Oils