Cervical incompetence, also known as cervical insufficiency, is a condition characterized by the inability of the cervix to retain a pregnancy in the second trimester due to structural weakness. It can result in painless cervical dilation and premature rupture of membranes, leading to midtrimester pregnancy loss or preterm birth. Risk factors include previous cervical trauma from procedures or injuries, and exposure to diethylstilbestrol in utero. Diagnosis involves assessing cervical length by ultrasound and testing for fetal fibronectin. Treatment options include cervical cerclage surgery to reinforce the cervix, a cervical pessary, and progesterone supplementation to reduce recurrent preterm birth risk.

1. Cervical Incompetence
By: Dima Lotfie
13901022

2. • Cervical insufficiency AKA cervical incompetence is defined by (ACOG) as the inability of
the uterine cervix to retain a pregnancy in the second trimester, in the absence of uterine
contractions.
• Due to structural weakness of the cervix
• PROM due to bulging of the membranes —> preterm labor/fetal death.
• It typically presents as acute, painless dilatation of the cervix, which can lead to a
midtrimester pregnancy loss.

4. ETIOLOGY
• Cervical insufficiency may occur as a result of a functional defect in the cervix, which
can be due to an anatomic abnormality or collagen disorders or In utero exposure to
diethylstilbestrol (DES)
• Acquired causes of cervical insufficiency include:
• Obstetric trauma
• Mechanical dilation of the cervix during gynecologic procedures
• Cervical conization, which may be performed via cold knife, laser, or loop.

5. SYMPTOMS
• No symptoms in the first affected pregnancy.
• The cervix dilates without any contractions
• Bulging of fetal membranes leading to PROM
• Spotting or bleeding might be there, but usually by the time the condition is detected
it is too late to stop the preterm birth.
• With a previous history, some women may present with pelvic pressure, cramping,
back pain, or increased vaginal discharge.
• Uterine contractions are typically rare or absent.

6. DIAGNOSTIC CONSIDERATIONS
• Preterm birth may result from numerous causes, including:
• Spontaneous preterm labor
• PROM
• Antepartum hemorrhage
• Multiple gestation
• Indicated preterm delivery for maternal or fetal conditions (eg, preeclampsia, fetal
growth restriction..)
• Cervical insufficiency is responsible for only 8-9% of all preterm births, compared with
40-45% with spontaneous preterm labor and 25-30% with PPROM.

7. APPROACH CONSIDERATIONS/ WORK UP
• The diagnosis of cervical insufficiency is either based on a history of midtrimester
pregnancy loss or a combination of clinical presentation, physical examination, and
sonographic measurement of cervical length.

8. ULTRASONOGRAPHY
• Sonographic measurement of cervical length, ideally done via transvaginal
ultrasonography.
• A short cervical length, which is typically defined as less than 25 mm, has been
consistently associated with an increased risk for preterm birth.
• Cervical effacement appears to begin at the internal os and proceed caudally.
• Preterm birth is unlikely to occur with a cervical length of greater than 30 mm.

9. • In asymptomatic women with a prior preterm birth, serial transvaginal cervical length
screening is typically performed starting at 16 weeks’ gestation and is repeated every
2 weeks until 26-28 weeks’ gestation.
• For women without a history of preterm delivery, (ACOG) recommends
transabdominal cervical length assessment (between 18 and 22 weeks’ gestation),
followed by transvaginal measurement if a short cervical length is suspected.

10. FETAL FIBRONECTIN TESTING
• Fetal fibronectin (fFN) is a large fetal glycoprotein that promotes cellular adhesion at
uterine-placental and decidual-fetal membrane interfaces.
• Released into cervicovaginal secretions leading to its use as a predictor of preterm
delivery.
• Its use is limited to women with a gestational age between 22 and 34 weeks, as long
as fetal membranes are intact and cervical dilatation is less than 3 cm. Sample
collection is performed by placing a swab in the posterior vaginal fornix.
• The prediction of preterm delivery is significant in women with a positive fFN and a
cervical length less than 30 mm.

11. TREATMENT
Cervical Cerclage:
• Placement of a stitch in an attempt to improve the tensile strength of the cervix.
• A cerclage can be placed from a transvaginal or transabdominal approach, with the
primary objective of reinforcing the cervix at the level of the internal os and, thus,
increasing the functional length of the cervix.
1. McDonald cerclage: Of the most commonly performed transvaginal techniques, is
a purse-string suture that passes through the cervical stroma.
2. Shirodkar cerclage: requires dissection of the bladder anteriorly and the rectum
posteriorly in order to place the stitch at the level of the internal os.
3. Transabdominal cerclage is typically reserved for patients with anatomic
limitations or those with a history of failure of a transvaginal cerclage.

12. * Cervical cerclage has not been shown to offer additional benefit for the
prevention of recurrent preterm delivery

14. CERVICAL PESSARY
• A cervical pessary is thought to alter the axis of
the cervical canal and displace the weight of
pregnant uterus away from the cervix.
• Still under research.

15. PROGESTERONE SUPPLEMENTATION
• ACOG recommends that women with a prior spontaneous preterm birth should be
offered progesterone supplementation starting at 16-24 weeks’ gestation and
continuing up to 36 weeks’ gestation, in order to reduce the risk of recurrent preterm
birth.

16. REFERENCES
• Uptodate
• ACOG