Objective: To determine whether exposure during pregnancy to two types of lozenges used for treatment of sore throat [Kalgaron® (Rafa Laboratories, Jerusalem, Israel) or Strepsils® (Boots Healthcare International, Nottingham, UK)] was associated with an increased risk of malformations, spontaneous abortions or decreased birthweight. Design: Prospective, controlled, observational study. Study participants: The study group included 54 women who received Kalgaron® or Strepsils® during the first trimester of pregnancy. The control group included 54 women exposed to non-teratogenic drugs. Results: The rate of major malformations in the study group (3.84%) did not differ from that of the control group (3.92%) [p = 0.98; relative risk 0.98, 95% confidence interval 0.14 to 6.7]. The rate of minor malformations in the study group (1.92%) did not differ statistically from that of the control group (0%) [p = 0.32]. There were also no statistically significant differences in birthweight, rate of live births and rate of spontaneous abortions among the two groups. Conclusions: The use of Kalgaron® or Strepsils® during pregnancy was not associated with an increased risk of malformations, spontaneous abortions or decreased birthweight. However, larger studies are needed to confirm the safety of these medications during pregnancy.