Cervical insufficiency: a treatable cause of second-trimester loss

What it is

The cervix is meant to stay closed until labour. In cervical insufficiency it begins to shorten and open in the second trimester without contractions, which can lead to loss or very preterm birth.

The classic history is a painless loss between about 16 and 24 weeks, often with a sensation of pressure, an increase in discharge, or waters breaking with little warning.

Risk factors: a previous second-trimester loss or very preterm birth, previous cervical surgery (including LEEP or cone biopsy), cervical injury from a previous delivery or procedure, and certain uterine abnormalities.

Diagnosis and treatment

Diagnosis is usually made from the history plus transvaginal ultrasound measurement of cervical length, typically monitored from around 16 weeks in women at risk. A short cervix on scan is what prompts action.

Cervical cerclage — a stitch placed around the cervix — is the main treatment. It may be placed because of history (usually 12 to 14 weeks), because of a short cervix found on scan, or as an emergency where the cervix has already begun to open. It is removed at around 36 to 37 weeks, or earlier if labour starts.

Vaginal progesterone is used, alone or alongside, particularly for a short cervix.

Some women are advised a pessary, and activity restriction is sometimes recommended — though strict bed rest is no longer routinely advised and carries its own risks.

If you have had a second-trimester loss, ask specifically about cervical length monitoring in the next pregnancy. It is the intervention most often missed, and it is the one that changes outcomes.

When to see a doctor

Go to hospital immediately for: bleeding that soaks a pad an hour or more, severe or one-sided abdominal pain, dizziness or fainting, shoulder-tip pain, fever with chills, or foul-smelling discharge. A positive pregnancy test with one-sided pain and bleeding needs assessment the same hour — an ectopic pregnancy is life-threatening. Call 108 if you cannot travel quickly.

Same-day in the second trimester, particularly with any risk factor: pelvic pressure or a feeling of heaviness, a change or increase in vaginal discharge, spotting, backache that comes in waves, or any sensation that something is wrong. These are the warnings that precede painless cervical change, and they are easy to dismiss.

And immediately: leaking fluid, bleeding, or regular tightening before 37 weeks.

Grief after a pregnancy loss is real grief, at any number of weeks. If you are struggling — persistent low mood, hopelessness, panic, an inability to function, or any thought of harming yourself — that deserves help rather than endurance. Tele-MANAS on 14416 is free, confidential and answers round the clock in Indian languages.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your or your child's health, please consult your doctor.

Frequently asked questions

Q: Could this have been prevented? — In a first pregnancy it is rarely diagnosed before it happens, because there is no history to suggest it. In subsequent pregnancies it is highly treatable, which is why the diagnosis, however late, is genuinely useful information.

Q: Does a cerclage guarantee the pregnancy will continue? — No, and it substantially improves the odds in the right patients. Your obstetrician will explain what it means in your case.

Q: Will I need a caesarean? — Not usually. The stitch is removed around 36 to 37 weeks and vaginal delivery is expected unless there is another reason.

Q: Can I work and exercise with a cerclage? — Follow your own doctor's advice, which varies by situation. Blanket bed rest is not routinely recommended, and specific restrictions are individual.