Cervical incompetence, also known as cervical insufficiency, describes a painless structural weakness of the cervix that cannot hold a pregnancy to term. As the fetus grows during the second trimester, the weight causes the cervix to shorten, dilate, and efface without any noticeable uterine contractions. This typically results in recurrent mid-trimester pregnancy losses or extremely preterm births. Midwives often encounter patients who experienced sudden, painless rupture of membranes or rapid fetal expulsion in a previous pregnancy, which strongly points toward this condition. Diagnosis relies heavily on a detailed obstetric history of painless second-trimester losses, alongside transvaginal ultrasound measurements showing a short cervical length or funneling of the internal os.
A cervical stitch, or encircle, is not meant for every pregnant woman with a history of early loss. Selection depends on specific clinical histories and ultrasound findings.
Two primary surgical techniques are used to reinforce the incompetent cervix. Both aim to tie a purse-string suture around the cervix, but their execution differs significantly.
| Feature | Shirodkar Technique | McDonald Technique |
|---|---|---|
| Dissection | Requires pushing the bladder up and dissecting the mucosa | No surgical dissection of the mucosa |
| Suture Placement | Placed high up at the level of the internal os | Placed as a simple purse-string around the vaginal epithelium |
| Complexity | More complex, takes longer, and bleeds more | Simpler, faster, and causes less tissue trauma |
| Removal | Often requires a small incision if buried | Easily snipped in the clinic without an incision |
Despite these differences, studies show similar success rates for both methods in preventing preterm birth.
Immediately following the procedure, the patient requires close monitoring in the recovery area. Midwives must check vital signs regularly and watch for signs of active vaginal bleeding, leakage of amniotic fluid, or uterine irritability. Analgesia is administered as prescribed since mild cramping or backache is common after cervical manipulation. The fetal heart rate must be auscultated to confirm fetal well-being before discharge. Patients are generally advised to rest for the first twenty-four hours, avoid heavy lifting, and abstain from sexual intercourse for a specified period determined by the attending physician.
Although cervical encircling is generally safe, it carries risks that every attending midwife must monitor during antenatal visits. Infection is a primary concern, manifesting as foul-smelling vaginal discharge, maternal fever, or uterine tenderness. Suture displacement or tearing can happen if the cervix begins to dilate despite the stitch, which may lead to partial tearing of the cervical tissue. Premature rupture of membranes and chorioamnionitis are severe complications that require immediate removal of the stitch and active management. Midwives must educate patients on these warning signs so they report symptoms early.
The timing of suture removal depends on whether the pregnancy progresses normally or if complications arise. For a planned delivery, the stitch is typically removed electively around 36 to 37 weeks of gestation to allow for safe vaginal delivery. Removal is usually a quick, straightforward outpatient procedure performed in the examination room without anesthesia, where the clinician cuts the knot and pulls the thread out. If a patient experiences preterm labor contractions that cannot be stopped, or if she develops chorioamnionitis or preterm premature rupture of membranes, the stitch must be removed immediately to prevent severe cervical laceration and uterine trauma.