Wednesday 17 November 2010

Previous preterm birth and future management

Risk facotrs : The primary risk factors for recurrent spontaneous preterm birth (SPTB) are a history of SPTB and a short cervical length (CL) found on second trimester transvaginal ultrasound (TVU).


In women with prior SPTB or a short CL, the most frequently used interventions to prevent preterm birth (PTB) are cerclage and progesterone supplementation.

1.200 mg of daily vaginal/rectal  progesterone beginning as early as 16 weeks' gestation and continuing  through 36 weeks.

2.The best evidence that progesterone reduces the risk of prematurity among women with a short cervix comes from the trial of Fonseca et al, in which women with a CL of 15 mm or less in the midtrimester were randomly allocated to receive 200 mg of daily vaginal progesterone or matching placebo from 24 to 34 weeks' gestation. In this trial, the 125 women allocated to progesterone had a significantly reduced risk of prematurity before 34 weeks (the primary study outcome) than the 125 allocated to placebo, 19% versus 34%.

3. For women with a prior SPTB (spontaneous preterm birth), regardless of their CL (cervix length), 17P is indicated. Furthermore, 17P should not be withheld from women who undergo cerclage for a history of prior SPTB and a short cervix

Ref : 17-Alpha-Hydroxyprogesterone Caproate for the Prevention of Preterm Birth in Women With Prior Preterm Birth and a Short Cervical Length, Obstet.Gynaecol Survey 2010 Nov

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