A new study published online in the journal Human Reproduction suggests that women with moderate to severe iodine deficiency are less likely to get pregnant during each menstrual cycle than women with normal iodine levels.
The study looked at 467 women in the U.S. who were trying to get pregnant. Urine samples for iodine analysis were collected from each woman at the time of enrollment. The women then kept daily journals to log relevant information, such as menstrual cycle length, home ovulation testing, and timing of intercourse. All of the women used fertility monitors to time intercourse and used home digital pregnancy tests on the day of expected menstruation.
Women with moderate to severe iodine deficiency were 46 percent less likely to get pregnant during each menstrual cycle than those with sufficient iodine levels. Even women with mild iodine deficiency had a harder time getting pregnant compared to women with normal levels.
Approximately half of all U.S. women have at least a mild iodine deficiency. In this study, 56 percent of women had sufficient iodine levels, 22 percent had a mild deficiency, and 21 percent had a moderate deficiency, and 1.7 percent had a severe deficiency.
Iodine is an important mineral that helps regulate metabolism. It is found in seafood, iodized salt, dairy products, and some fruits and vegetables (i.e. potatoes, cranberries, strawberries). Over the past several decades, the Western diet has changed and resulted in a decreased consumption of iodine.
Having sufficient iodine levels may not only help a woman increase her chance of conceiving, but are also important for a developing pregnancy. Iodine is needed for a fetus to make thyroid hormone and for normal brain development.
For women who are trying to conceive, starting prenatal vitamins, which include iodine, at least 3 months prior to conception may help. This may be especially important for women with vegetarian or vegan diets.