Which anthelmintic is not recommended for use in pregnant women?

Albendazole is not recommended for use in pregnant women because it is a category C drug, meaning that animal reproduction studies have shown an adverse effect on the fetus, and there are no adequate and well-controlled studies in humans. The use of albendazole may pose risks during the first trimester when the development of the fetus is most critical. Therefore, alternative treatments that are considered safer for pregnant women are typically preferred during this sensitive time.

In contrast, mebendazole and ivermectin are generally considered to be safer during pregnancy, particularly mebendazole, which has been used without significant concerns related to teratogenic effects. Praziquantel has also been used in pregnant women with some studies supporting its safety in certain conditions, although its use should still be cautiously evaluated. Thus, albendazole stands out as the anthelmintic that is advised against during pregnancy due to safety concerns for both the mother and the developing fetus.