The influence of tocolytic drugs usage in the third trimester of pregnancy on obstetric and neonatal outcomes

Abstract The occurrence of preterm labor is the cause of 75% of preterm births. Prematurity is the leading cause of mortality of children under four weeks of age. Tocolytic drugs are used widely in the treatment of preterm labor. The aim of this study was to assess the impact of the tocolytic therapy on obstetric and neonatal outcomes. The prospective, cohort study included 499 pregnant women The study enrolled women who met certain criteria of age, with singleton pregnancy, having no chronic diseases. After delivery the following data were obtained: sociodemographic profile (including data on occupational activity), body height and weight before pregnancy, weight gain, duration of pregnancy, mode of delivery, obstetric complications, medications, anthropometric parameters and state of health of newborns. A group of patients treated with tocolytic drugs and a control group were identified. Then obstetric and neonatal outcomes in both groups were subjected to statistical analysis. There was no statistically significant difference between the two groups in terms of the following variables: mother's age, her education, professional activity of mothers in the first and second trimester of pregnancy, weight gain during pregnancy, parity, exposure to passive smoking during pregnancy, method of pregnancy termination. We found a statistically significant difference between the groups with respect to maternal weight before pregnancy (lower in the group using tocolytics), the average duration of pregnancy (lower in the group using tocolytics), the frequency of preterm birth (higher in the group using tocolytics) and neonatal anthropometric parameters and the number of points in the Apgar score at 5 minutes of age (lower in the group using tocolytics). Low pregestational weight is a risk factor for preterm labor. Term birth rate in pregnant women treated for preterm labor is significantly smaller compared to the general population, which may indicate low efficacy of tocolytic drugs. There was no positive correlation found between the professional activity of pregnant women and the risk of threatening preterm labor.