[Tocolysis: indications and contraindications. When to start and when to stop]

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine
• Pharmacology

Background:

• Tocolytic agents like beta mimetics, atosiban, and indometacine, excluding magnesium sulfate, are proven to extend pregnancy duration compared to placebo.
• These agents reduce delivery rates at 24 hours, 48 hours, and 7 days, but lack evidence of improving perinatal or neonatal outcomes.

Purpose of the Study:

• To review the evidence for tocolytic agent efficacy and contraindications in obstetric practice.
• To evaluate the current evidence regarding the use of tocolysis in late preterm pregnancies and its impact on neonatal outcomes.

Main Methods:

• Systematic review of clinical trials and available literature on tocolytic agents.
• Analysis of studies evaluating tocolysis effectiveness, contraindications, and impact on neonatal outcomes, particularly after 34 weeks of gestation.

Main Results:

• Most tocolytic agents extend pregnancy duration but do not demonstrate benefits for neonatal outcomes.
• Contraindications for tocolysis are often based on clinical judgment rather than strict evidence-based medicine.
• Limited randomized trials exist for tocolysis use after 34 weeks, and evidence for specific agents or use beyond 48 hours is scarce.

Conclusions:

• Tocolysis primarily extends pregnancy duration without proven neonatal benefits.
• Evidence-based guidelines for tocolysis use, especially in later preterm stages and for specific maternal/fetal conditions, are insufficient.
• Management of complex tocolysis cases often relies on empirical approaches due to a lack of robust clinical trial data.