Doctors have been urged to be cautious in prescribing oral fluconazole to women in their first trimester as it appears to raise the risk of congenital musculoskeletal malformations.

Even though the absolute risk was small, the researchers said topical anti-fungals should be considered in treating vulvovaginal candidiasis in early pregnancy.

“Oral fluconazole during the first trimester, especially prolonged treatment at higher than commonly used doses, should be prescribed with caution, and topical azoles should be considered as an alternative treatment,” the US researchers write.

Using Medicaid data from the US, the researchers examined almost 2 million pregnancies between 2000 and 2014, including prescribing information to assess the risk of congenital malformations associated with oral fluconazole exposure.