In a study of 501 couples who were trying to get pregnant without medical assistance and kept diaries on their diet and other health and behavioral habits, including fish consumption and frequency of sexual intercourse, they found that men who had two or more four-ounce servings of fish a week had a 47 percent shorter time to pregnancy, and women a 60 percent shorter time, than those who ate one or fewer servings a week. They followed the pairs for a year or until pregnancy.
Partners who ate fish also had sexual intercourse, on average, 22 percent more frequently, but the association of eating fish with pregnancy persisted even after controlling for frequency of lovemaking. By 12 months, 92 percent of couples who ate fish twice a week or more were pregnant, compared with 79 percent among those who ate less.
The study, in the Journal of Clinical Endocrinology & Metabolism, controlled for age, education level, smoking, alcohol intake, physical activity and other factors. The mechanism remains unclear. “Seafood may help in semen quality, ovulation and other markers,” said the lead author, Audrey J. Gaskins, a research associate at Harvard. “Or maybe these couples are the ones spending more time together. But if it’s fish that’s bringing them together, that’s still causal, although through a behavioral pathway, not a biological one.
The advice to eat more fish somewhat goes against conventional advice to avoid at least certain fish. According to Dr. Gaskins, “Women have been scared off fish because of the concerns about mercury, but there are low levels of contaminants in the seafood we commonly eat — canned tuna, salmon, shrimp and other shellfish.”
This is just another example of the importance of lifestyle issues to people planning and trying to conceive. Most of the issues are “don’ts,” this one is a “do.” For more information on lifestyle issues, please visit our Lifestyle & Fertility page.