[The possible effect of ampicillin treatment in preventing preterm birth]

To study the possible association between oral ampicillin treatment during pregnancy and pregnancy complications, in addition delivery outcomes, particularly preterm birth.

The authors evaluated the so-called control newborn infants without congenital abnormalities in the population based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities.

Of 38,151 newborn infants, 2630 (6.9 %) had mothers with ampicillin treatment during pregnancy. Some pregnancy complications, particularly preeclampsia showed a higher prevalence in pregnant women with ampicillin treatment. Mean gestational age was slightly longer but it resulted in a significant reduction in the prevalence of preterm birth (7.1% vs 9.3 %; adjusted POR with 95 degrees % CI: 0.8, 0.7-0.9). The preterm birth preventive effect of ampicillin was most obvious after the use of the drug in the first trimester of pregnancy. Similar difference was not seen in the reduction of low birth weight.

Ampicillin treatment, particularly in the first trimester of gestation can reduce the proportion of preterm birth in pregnant women with acute infectious diseases.