Obstetric history-based diagnosis of cervical insufficiency
Women with a history of ≥2 consecutive prior second-trimester pregnancy losses/extremely preterm births (ie, <28 weeks) associated with no or minimal mild symptoms. The presence of risk factors for structural cervical weakness support the diagnosis. Most of these cases are pregnancy losses before 24 weeks.
Ultrasound-based diagnosis of cervical insufficiency
In asymptomatic women with a past history of a preterm birth associated with no or minimal mild symptom, TVS examinations at 14-16wk & 18-20wk with cervical length is ≤25 mm before 24 week.
Mean cervical length at 24weeks is 38 mm to 42mm
For women with history-based diagnosis of cervical insufficiency, cervical cerclage at 12 to 14 weeks of gestation rather than ultrasound monitoring of cervical length. These women also need progesterone supplementation weekly from 16 to 36 weeks of gestation.
For women with an ultrasound-based diagnosis of cervical insufficiency, cervical cerclage at 14 to 16 weeks. For women with a prior spontaneous preterm birth, progesterone supplementation beginning at 16 to 20 weeks of gestation (which may be before or after cerclage placement) and continued through 36 weeks. Progesterone supplementation given via IM Hydroxyprogesterone Caproate 250mg/ml
For women with a successful history-based cerclage, a repeat cervical cerclage in subsequent pregnancies.
For women with a successful ultrasound-indicated cerclage, serial TVS cervical length in subsequent pregnancies and repeat ultrasound-indicated cervical cerclage if cervical length is ≤25 mm. If the previous ultrasound-indicated cerclage was unsuccessful, cervical cerclage at 12 to 14 weeks of gestation in the subsequent pregnancy.
IM Dexamethasone 12mg in 2 doses for fetal lung maturity is given after 26 weeks.