Thyroid problems should be tested for in women who have fertility issues, according to a new study review.

A team of researchers found that 2.3 percent of women with fertility problems also had an overactive thyroid. Menstrual irregularity was also linked to thyroid issues in the study, reported WebMD. 

"Abnormalities in thyroid function can have an adverse effect on reproductive health and result in reduced rates of conception, increased miscarriage risk and adverse pregnancy and neonatal outcomes," said study co-author Amanda Jefferys in a journal news release.  

The thyroid produces hormones that play key roles in growth and development, which is why the researchers believe that changes in thyroid function can have a major effect on reproductive function. The effects on the reproductive system were visable before, during and after conception, reported WebMD.

During the study review the researchers also noted that thyroid problems are linked to an increased risk of problems during pregnancy, including miscarriage, preeclampsia, poor fetal growth, premature birth and stillbirth.

"Both overactive and underactive thyroid can have significant effects on reproductive function," Dr. Alan Copperman, director of the Division of Reproductive Endocrinology and Infertility at The Mount Sinai Hospital in New York City, said in the release. "Treating even minor disease may improve the chance of pregnancy, may decrease the miscarriage risk, and may improve the health of the baby."

Treatment for thyroid problems usually includes taking one pill a day, the study authors wrote. 

An estimated 20 million Americans have some form of thyroid disease and up to 60 percent of those with thyroid disease are unaware of their condition, according to the American Thyroid Association. 

The study was published Jan. 23 in the journal The Obstetrician & Gynaecologist.