Since the tragedy associated with the use of thalidomide in pregnant women in the early 1960s, much attention has been paid to the risk of adverse effects of drugs taken by a pregnant woman on the fetus. However, the number of women receiving drug therapy during pregnancy is very high. According to the World Health Organization, in Europe the proportion of these pregnant women is around 80%. 12.3% of women take anti-infective drugs during pregnancy. The risk of fetal malformations with the use of pharmacotherapy by pregnant women may be overestimated, and it is therefore necessary to study the safety of the most used drugs. In several studies, no adverse effects of amoxicillin / clavulanate have been observed in the fetus when the drug is used in pregnant women for various indications. However, the number of patients in these studies was relatively small. In the prospective study presented in Israel, the safety of using amoxicillin / clavulanate in the first trimester was studied in a fairly large group of pregnant women.

The study looked at 382 women taking amoxicillin / clavulanate or amoxicillin during the first trimester of pregnancy. Two groups, 191 women each, were compared in terms of the incidence of malformations in the fetus. The antibiotic was prescribed for both groups of patients according to similar indications (tonsillitis, otitis media, sinusitis, pneumonia, urinary tract infections, skin infections, dental abscess). In the first group, amoxicillin / clavulanate was used (average dose 1500 ± 250 mg, course duration 7.9 ± 3.7 days), in the second group, amoxicillin (average dose 1500 ± 350 mg, course duration 7 ± 2 days). Amoxicillin was chosen as the comparator due to the fact that it is a penicillin derivative, and the absence of teratogenicity has been proven in this drug.

The two groups of pregnant women were similar in age and bad habits (addiction to smoking and alcohol consumption). The weight of newborns, the gestation period during childbirth, the number of live births and abortions were comparable in two groups. The frequency of cesarean sections in the amoxicillin / clavulanate group was statistically significantly higher (p = 0.04).

The frequency of severe malformations was lower than the level observed in the general population and was 3/158 (1.9%) in the amoxicillin / clavulanate group and 5/163 (3.1%) in the amoxicillin group, and the differences were not statistically significant (p = 0.49, relative risk 0.62; 95% confidence interval 0.15-2.55).

Thus, the use of amoxicillin / clavulanate during pregnancy is harmless to the fetus and is not accompanied by an increased risk of malformations.