Preterm Labor

Preterm birth is birth from 20 0/7 through 36 6/7 weeks. Preterm labor is generally defined by regular uterine contractions accompanied by cervical dilation or effacement change, or regular contractions with cervical dilation of at least 2 cm at initial assessment. Wolters KluwerWolters KluwerPractice Bulletin No. 171: Management of Preterm... : Obstetrics & Gynecology

Clinical diagnosis is imprecise: fewer than 10% of patients given a clinical diagnosis of preterm labor deliver within 7 days. This low short-term event rate supports avoiding reflexive treatment of contractions without cervical change and instead using a structured assessment of delivery risk and potential benefit of intervention. Wolters Kluwer+1Wolters KluwerPractice Bulletin No. 171: Management of Preterm... : Obstetrics & GynecologyWolters KluwerPractice Bulletin No. 171 Summary: Management of... : Obstetrics & Gynecology

Do not conflate intact-membrane preterm labor with all preterm birth. Preterm prelabor rupture of membranes and maternal or fetal conditions requiring indicated preterm delivery have distinct management pathways. Wolters KluwerWolters KluwerPractice Bulletin No. 171: Management of Preterm... : Obstetrics & Gynecology

When delivery appears likely and no maternal or fetal contraindication exists, acute care should focus on completing antenatal corticosteroid exposure, providing magnesium sulfate for fetal neuroprotection when applicable, and arranging in-utero transfer to a center equipped for the anticipated gestational age and neonatal needs. BMJ+1BMJManagement and outcomes of extreme preterm birth | The BMJBMJPerinatal management of extreme preterm birth before 27 ...

Tocolysis may be useful when short-term delay is safe and permits timely antenatal corticosteroids or maternal transfer. However, a systematic review found that tocolytics have not been shown to improve neonatal outcomes directly, even though they can delay delivery sufficiently for antenatal corticosteroids. BMJ+1BMJManagement and outcomes of extreme preterm birth | The BMJBMJTocolytic therapy for preterm delivery: systematic review ...

Available trial evidence includes beta-adrenergic agonists, cyclooxygenase inhibitors, calcium-channel blockers, oxytocin-receptor antagonists, magnesium sulfate, and nitric-oxide donors. Reviews describe calcium-channel blockers such as nifedipine as having a comparatively favorable effectiveness and safety profile relative to some less effective or more harmful alternatives, but the supplied evidence does not support a U.S. dosing regimen, hierarchy, or contraindication list. BMJ+1BMJSupplemental materialWileyTherapeutic role of nifedipine in threatened preterm labor ...

Transvaginal cervical-length assessment between 16 and 24 weeks is a reasonably accurate predictor of spontaneous preterm birth. In symptomatic patients, cervical assessment can help distinguish patients with contractions from those with a cervical phenotype more consistent with evolving preterm labor. ScienceDirectScienceDirectPredicting preterm birth: Cervical length and fetal fibronectin

Qualitative fetal fibronectin testing has traditionally been used to identify patients with threatened preterm labor who may be at risk for imminent delivery. Its clinical role is risk stratification rather than replacement for cervical examination or assessment for membrane rupture, infection, abruption, or indicated delivery. ScienceDirect+1ScienceDirectis the combination of fetal fibronectin and cervical length in ...Wolters KluwerPractice Bulletin No. 171: Management of Preterm... : Obstetrics & Gynecology

The supplied sources do not provide validated cervical-length cutoffs, fetal-fibronectin test thresholds, or a testing algorithm. Avoid applying local thresholds as if they were established by the evidence excerpts reviewed here.

Because most patients diagnosed clinically with preterm labor will not deliver within 7 days, treatment based solely on contractions risks overtreatment. Reassess cervical change and use adjunctive risk stratification when appropriate before committing patients to interventions intended for imminent birth. Wolters Kluwer+1Wolters KluwerPractice Bulletin No. 171: Management of Preterm... : Obstetrics & GynecologyWolters KluwerPractice Bulletin No. 171 Summary: Management of... : Obstetrics & Gynecology

The purpose of tocolysis is commonly misunderstood. It is not evidence-based as a stand-alone strategy to improve neonatal outcomes; its defensible role is a brief, goal-directed delay for corticosteroids or transfer when maternal and fetal conditions permit. BMJ+1BMJManagement and outcomes of extreme preterm birth | The BMJBMJTocolytic therapy for preterm delivery: systematic review ...

Magnesium sulfate should not be described simply as another routine tocolytic in this setting. In contemporary extreme-preterm management, its cited role is peripartum fetal neuroprotection. BMJ+1BMJManagement and outcomes of extreme preterm birth | The BMJBMJPerinatal management of extreme preterm birth before 27 ...