What is the most common cause of preterm labor?

Infection is recognized as the most common cause of preterm labor due to its ability to trigger inflammatory responses leading to contractions and cervical changes. Various types of infections, including urinary tract infections, bacterial vaginosis, and sexually transmitted infections, can stimulate the release of pro-inflammatory cytokines, which in turn can initiate labor prematurely.

The presence of infection leads not only to direct effects on the uterine environment but also can provoke systemic responses that impact both maternal and fetal health. Close monitoring and prompt treatment of infections during pregnancy can help to mitigate the risk of preterm labor and improve outcomes for both the mother and the infant.

Uterine anomalies and multiple gestations can certainly contribute to a higher risk of preterm labor, but they are less common compared to infections. Dehydration can affect uterine activity but does not represent the primary cause of preterm labor in clinical practice. Therefore, while the other options can be factors in preterm labor, infections stand out as the most prevalent and clinically significant cause.