Preterm labor - Pathogenesis and diagnosis

Pathogenesis of preterm labor:
-Maternal infections leading to release of interleukin-6,
-Maternal or fetal stress leading to release of CRH(carticotropin releasing hormone),
-Chorio-decidual bleeding leading to formation of thrombin or abnormal placentation leading to release of prostaglandins all these will lead to activation of common pathway of parturition.
In common pathway of parturition myometrial activation, membrane activation and cervical ripening occur which will lead to spontaneous preterm labor with intact membranes or spontaneous preterm rupture of the fetal membranes or incompetent cervix.

 Diagnosis of preterm labor:
The main symptom of preterm labor is establishment of uterine contractions.
Regular uterine contractions at least 4 in 20 minutes or 8 in 60 minutes are indicative of preterm labor.
Main sign of preterm labor is presence of cervical changes.

Digital examination showing,
-Cervix 80% effaced with 3 cm dilatation indicates advanced preterm labor.
-Cervix 80% effaced with dilatation between 1 to 3 cm indicates early preterm labor.
-Cervix <80% effaced with dilatation < 1cm with transvaginal ultrasound showing cervical length < 2.5cm indicates threatened preterm labor.
-Cervix <80% effaced with dilatation < 1cm with transvaginal ultrasound showing cervical length = 2.5cm indicates false labor.


Preterm labor-etiologicalfactors
Preterm labor-pathogenesis and diagnosis
Preterm labor-investigations
Preterm labor-prediction
Preterm labor-complications
Preterm labor -prevention
Preterm labor-bacterialvaginosis
Preterm labor-progesterone.html
Preterm labor-cervical circlage
Pretem labor-management
Preterm labor-tocolytics
Preterm labor-with premature rupture of membranes