Diagnosis
What is the definition of a "short cervix?"
<2.5cm before 24 weeks of pregnancy
CONE/LEEP
Is there data that a prophylactic cerclage would be indicated in someone with a prior LEEP/Cone biopsy?
Evidence is lacking for the benefit of cerclage solely for the following indications: prior loop electrosurgical excision procedure, cone biopsy, or müllerian anomaly.
Types of transvaginal cerclages
McDonald vs Shirodkar
When do you place a cerclage most often?
Cerclage should be limited to pregnancies in the second trimester before fetal viability has been achieved.
Can you diagnose cervical insufficiency based on cervical length?
No, short cervical length has been shown to be a marker of preterm birth in general rather than a specific marker of cervical insufficiency. Nonetheless, cerclage may be effective in particular circumstances when a short cervix is found.
What type of congenital/genetic conditions predispose to cervical insufficiency?
-in utero exposure to DES
Can you use a vaginal pessary for cervical insufficiency?
yes! data is limited in high risk patients though.
Which cerclage type is this?
simple purse-string suture of non-resorbable material is inserted at cervicovaginal junction
dissection of the vesicocervical mucosa in an attempt to place the suture as close to the cervical internal os as possible
1) mcdonald
2) shirodkar
What GA do you remove a mcdonald cerclage?
36–37 weeks of gestation
For cesarean delivery patients at or beyond 39 weeks of gestation, cerclage removal at the time of delivery may be performed; however, the possibility of spontaneous labor between 37 weeks and 39 weeks should be taken into consideration
How to diagnose cervical insufficiency?
Diagnosis is based on a history of painless cervical dilation after the first trimester with subsequent expulsion of the pregnancy in the second trimester, typically before 24 weeks of gestation, without contractions or labor and in the absence of other clear pathology (eg, bleeding, infection, ruptured membranes).
What physical exam findings would warrant a cerclage?
Painless cervical dilation in the second trimester.
Limited data from one small randomized trial and retrospective studies have suggested the possibility of benefit from cerclage placement in these women.
- First rule out uterine activity, or intraamniotic infection.
Are activity restriction, bed rest, and pelvic rest effective for treatment of cervical insufficiency?
Not effective treatment of cervical insufficiency and their use is discouraged
What are the complications of a cerclage?
rupture of membranes
chorioamnionitis
cervical lacerations
suture displacement
increased risk if someone is ruptured or already dilated
What is cervical funneling?
Painless dilation of the internal cervical os that occurs when the amnion bulges into the uterus.
The cervix takes on a funnel shape, while the external os remains closed.
U- or V-shaped funnel is more ominous and indicates more advanced cervical ripening
What are the criteria for history indicated cerclage?
History of one or more second-trimester pregnancy losses related to painless cervical dilation and in the absence of labor or abruptio placentae
Prior cerclage due to painless cervical dilation in the second trimester
By an average of five weeks and may reduce the chance of delivery before 34 weeks by two-fold
- risky, does not always work, placed when a patient is periviable
What is the PREGNANT trial?
PREGNANT trial was a randomized, placebo-controlled, multicenter trial designed to determine the efficacy and safety of vaginal progesterone (VP) to reduce the risk of birth <33 weeks and of neonatal complications in women with a sonographic short cervix (10 to 20 mm) in the mid-trimester (19 to 23 6/7 wk). Patients allocated to receive VP had a 45% lower rate of preterm birth.
How successful is a cerclage and preventing preterm delivery due to cervical insufficiency?
90% of cases
How does progesterone work on the cervix?
Vaginal progesterone works on the cervix by directly interacting with its cells through progesterone receptors, essentially "quieting" the cervix by inhibiting the production of substances that would promote ripening and dilation.
Mifepristone BLOCKs progesterone- which makes a patient dilate!
What US finding would indicate a cerclage?
Current singleton pregnancy, prior spontaneous preterm birth at less than 34 weeks of gestation, and short cervical length (less than 25 mm) before 24 weeks of gestation.
Cerclage is associated with significant decreases in preterm birth outcomes, as well as improvements in composite neonatal morbidity and mortality, and may be considered in women with this combination of history and ultrasound examination findings.
Cerclage placement in women without a history of prior spontaneous preterm birth and with a cervical length less than 25 mm detected between 16 weeks and 24 weeks of gestation has not been associated with a significant reduction in preterm birth. --> can recommend vaginal progesterone in this situation
When is a transabdominal cervicoisthmic cerclage indicated?
reserved for patients in whom cerclage is indicated based on the diagnosis of cervical insufficiency but cannot be placed because of anatomical limitations or in the case of failed transvaginal cervical cerclage procedures that resulted in second-trimester pregnancy loss
abdominal cerclage procedures usually are performed in the late first trimester or early second trimester (10–14 weeks of gestation).
The stitch can be left in place between pregnancies with subsequent cesarean delivery.
If a patient has twins and a documented short cervix, would you recommend a cerclage?
No- Cerclage may increase the risk of preterm birth in women with a twin pregnancy and an ultrasonographically detected cervical length less than 25 mm and is not recommended.