Etiologic factors include a history of previous cervical lacerations during childbirth, excessive cervical dilation for curettage or biopsy, or the woman's mother's ingestion of diethylstilbestrol (DES)during pregnancy with the woman. Multiple gestation may provide an additional stress on the cervix but alone does not produce cervical incompetency or justify prophylactic cervical cerclage A short cervix (less than 25 mm in length) is indicative of reduced cervical competence.
Reduce cervical competence is the diagnosis and is seen on ultrasound, it can be accompanied by cervical funneling ((breaking) or effacement if the internal os.
Bed rest, pessaries, antibodies, antinflammatory drugs and progesterone supplementation . A cervical cerclage may be performed. During gestation, a McDonald cerclage, a band of homologous fascia or nonabsorbable ribbon (Mersilene), may be placed around the cervix beneath the mucosa to constrict the internal os of the cervix (Fig. 28-2). A cerclage procedure can be classified according to time, or whether it is elective (prophylactic), urgent, or emergent (Cunningham, 2011).
Prophylactic cerclage is placed at 11 to 15 weeks of gestation, after which the woman is told to refrain from intercourse. She is monitored during the course of her pregnancy with ultrasound scans to assess for cervical shortening and funneling. The cerclage is electively removed (usually an office or a clinic procedure) when the woman reaches 37 weeks of gestation, or it may be left in place and a cesarean birth performed.
The woman must understand the importance of activity restriction at home and the need for close observation and supervision. She must be instructed on the importance of taking oral tocolytic medication if prescribed, the expected response, and possible side effects. Tocolytics may be given prophylactically to prevent uterine contractions and further dilation of the cervix. If home uterine monitoring is implemented, the woman is taught how to apply a uterine contraction monitor and transmit the monitor tracing by telephone to the monitoring center. Nurses at the monitoring center assess the tracing for contractions, answer questions, provide emotional support and education, and report information to the woman's physician or nurse-midwife.
The woman must be aware that strong contractions less than 5 minutes apart, ROM, severe perineal pressure, and an urge to push will warrant immediate transfer to the hospital setting. If management is unsuccessful and the fetus is born before viability, appropriate grief support should be provided. If the fetus is born prematurely, appropriate anticipatory guidance and support will be necessary.