The Association between Seafood Intake and Fecundability: Analysis from Two Prospective Studies

Abstract

Background: Seafood is an important source of omega-3 fatty acids, which have been associated with improved oocyte quality and embryo morphology in some studies. However, seafood is also a source of persistent organic pollutants and heavy metals, which may adversely affect fecundity. Previous studies of seafood intake and fecundity have generated inconsistent results. Methods: In two prospective cohort studies of 7836 female pregnancy planners from Denmark (Snart Foraeldre, n = 2709) and North America (PRESTO, n = 5127), we evaluated the association of dietary intake of total seafood and marine-sourced long-chain omega-3 fatty acids (eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid) with fecundability. Participants completed a baseline questionnaire on sociodemographics, behavioral factors, anthropometrics, and medical history, and a food frequency questionnaire. Pregnancy status was updated bimonthly for up to 12 months or until reported conception. We estimated fecundability ratios (FRs) and 95% confidence intervals (CIs) using proportional probabilities regression models, adjusted for energy intake and other potential confounders. We restricted analyses to women with ≤6 menstrual cycles of attempt time at enrollment. Results: Intake of total seafood or marine-sourced long-chain omega-3 fatty acids was not appreciably associated with fecundability in either cohort (≥200 vs. <50 g/week total seafood: FR = 0.94, 95% CI: 0.79–1.10 in Snart Foraeldre; FR = 1.00, 95% CI: 0.90–1.13 in PRESTO; marine fatty acids: ≥90th vs. <25th percentile: FR = 1.00, 95% CI: 0.85–1.18 in Snart Foraeldre; FR = 0.97, 95% CI: 0.86–1.09 in PRESTO). In PRESTO, where we collected additional data on seafood preparation, we observed an inverse association between fecundability and fried shellfish (≥10 g/week vs. none: FR = 0.77, 95% CI: 0.61–0.98), but not unfried shellfish (≥20 g/week vs. none: FR = 0.98, 95% CI: 0.89–1.07); in Snart Foraeldre, there was no association with total shellfish intake. Conclusions: We found little association between seafood intake and fecundability overall, but greater intake of fried shellfish was associated with reduced fecundability among North American participants.

Lifestyle and fertility-specific quality of life affect reproductive outcomes in couples undergoing in vitro fertilization

“…Although there are a relatively large number of reports about dietary habits including consumption of seafood and fish, there are no consistent reports about whether seafood consumption positively affects fertility (5,(37)(38)(39). The reason for these inconsistent results may be that seafood contains both fertilityenhancing and -damaging substances.…”

Dietary Folate Intake and Fecundability in Two Preconception Cohorts

“…Details of the study methods have been described elsewhere (Mikkelsen et al, 2016;Wise et al, 2020). In brief, enrollment is ongoing and began in June 2011 for SF and June 2013 for PRESTO, which was modeled after SF.…”

Prepregnancy adherence to plant-based diet indices and exploratory dietary patterns in relation to fecundability

“…Locally, in Singapore, the time required to achieve a clinical pregnancy exceeds a year for about 15% of couples (5). Existing studies have reported modest associations between intakes of specific foods/ beverages (such as dairy (6), seafood (7), diet soda and fruit juice (8)] or nutrients [such as total fat, specific types of fats and fatty acids (9), glycemic load, added sugar (10) and iron (11)]) and fecundability. However, studies examining overall diets, which takes into account the synergistic effects of individual dietary components on diet-fecundability associations, are limited.…”