Planning a Pregnancy: Look at Prescribed Medications and Supplements

Family planning is a joyous task for many people of childbearing age, but for some, conceiving a child can be difficult. Researchers are learning more about the preconception period and factors that affect the ability to conceive.

The journal Reproductive Sciences looks at 1 potential factor of interest to pharmacists in the preconception period: use of prescription medication and supplements. This is particularly germane at this time because the FDA has promulgated the 2015 Pregnancy and Lactation Labeling Rule, requiring labeling that addresses medication and supplement effect on fertility.

In this large prospective cohort study, the researchers enrolled 501 couples who were trying to conceive and had not been diagnosed with infertility. At baseline, they found that approximately 20% of participants (women and men) used 1 medication, and 7% used 2 or more.

Overall, participants were most likely to use asthma and allergy medications. When the researchers looked at participants by sex, women were most likely to take medication for hypothyroidism, mood disorder, or anxiety. Men were most likely to take medication for hypertension and elevated lipids.

Supplement use was common, with participants reporting frequent use of multivitamins, fish oil, protein shakes, echinacea, and vitamin C. Among women, prenatal vitamins and calcium supplements were common and not unexpected.

The researchers noted that at baseline, some female participants were taking levothyroxine and metformin, and that sometimes, clinicians prescribe these medications to increase fertility. Levothyroxine is used to correct hypothyroidism, which decreases female fertility, and metformin increases the likelihood of clinical pregnancy in women with polycystic ovary syndrome.

Little information is currently available about the impact of many medications on the ability to conceive. Of the medications identified here, the most available data relates to antidepressants. They may decrease fertility in a number of ways (eg. sexual dysfunction). The researchers noted that most of the evidence is preliminary and requires further study.

Supplement use is expected in this population, and the US Preventive Services Task Force recommends that women initiate prenatal vitamins and folic acid at least 1 month before conceiving.

More studies on this topic are underway in response to the new labeling requirements.

Reference

Palmsten K, Flores KF, Chambers CD, Weiss LA, Sundaram R, Buck Louis GM. Most Frequently Reported Prescription Medications and Supplements in Couples Planning Pregnancy: The LIFE Study. Reprod Sci. 2018 Jan;25(1):94-101.