Cervical cone biopsy (conisation): why it is done, the procedure and recovery
In brief
A cone biopsy (conisation) removes a small, cone-shaped piece of the cervix to treat a high-grade precancerous lesion (CIN 2 or 3) and examine it under the microscope. It is performed through the vagina, usually with an electric wire loop (LEEP/LLETZ) as a day-case procedure. The risk of a persistent or recurrent lesion is about 7%. The main things to know are a risk of bleeding for about two weeks and a slightly higher risk of preterm birth in later pregnancies.
Why would I need a cone biopsy?
A cone biopsy is a procedure in preventive gynaecological cancer care. It is offered when colposcopy and biopsies have shown a high-grade precancerous lesion (CIN 2 or CIN 3), or a glandular lesion (adenocarcinoma in situ). It may also be recommended when a smear test is very abnormal but the lesion cannot be fully seen at colposcopy, or to treat some very early (microinvasive) cancers.
It has two aims:
- to treat: removing the whole abnormal area to prevent it from progressing to cancer;
- to diagnose: full analysis of the tissue confirms the type of lesion, checks that there is no invasive cancer and shows whether the margins are clear.
Low-grade lesions (CIN 1) do not usually need a cone biopsy, because they most often clear up on their own. To understand these different grades, read our article on precancerous lesions of the cervix.
How is a cone biopsy done?
- Where: in the operating theatre, as a day case (you go home the same day) in the vast majority of cases, at Hôpital privé Geoffroy Saint-Hilaire (Paris 5th), Clinique de la Muette (Paris 16th) or Clinique Ambroise Paré (Neuilly-sur-Seine).
- Anaesthesia: local, regional or a short general anaesthetic, depending on your situation, the anaesthetist’s advice and your preferences.
- Technique: the procedure is carried out through the vagina, with no scar. The cervix is examined with a colposcope, then the abnormal area is removed, most often with a diathermy loop, a thin electric wire that cuts and seals at the same time. A cold scalpel or laser is used less often.
- Duration: the procedure itself takes about fifteen minutes.
The size of the cone is tailored to the lesion and the shape of the cervix, aiming to remove the whole lesion while preserving as much of the cervix as possible, especially in women who want a pregnancy. The tissue is then sent to the pathology laboratory.
How should I prepare?
- An anaesthetic consultation is scheduled a few days beforehand, unless only local anaesthesia is used.
- Plan the procedure outside your period.
- Arrange your journey home: after a general or regional anaesthetic, you must not drive and someone should accompany you.
- Bring your latest smear test, colposcopy and biopsy results.
What is recovery like after a cone biopsy?
Recovery is usually straightforward. For 2 to 3 weeks it is normal to have:
- discharge or light bleeding, sometimes brownish;
- mild discomfort, similar to period pain, relieved by simple painkillers;
- around day 8 to 15, slightly heavier discharge when the healing scab comes away.
Advice after a cone biopsy
| Activity | As a guide |
|---|---|
| Sex, tampons, menstrual cup | Avoid for about 4 weeks, while the cervix heals |
| Baths, swimming pool, sea | Avoid for about 4 weeks; showers are fine |
| Sport | Can be resumed soon, except swimming |
| Long-distance travel | Avoid during the first 15 days, because of the risk of delayed bleeding |
| Work | 3 days (desk work) to 5 days (physical work) |
Your next periods may be slightly heavier or come at a different time; this is nothing to worry about. If you have an intrauterine device (coil), it can usually be left in place.
What are the risks of a cone biopsy?
Complications are uncommon:
- Bleeding: this is the main complication. It can occur in the hours after the procedure or later, up to about 15 days. It is usually treated with a vaginal pack or dressing, and rarely needs a further procedure.
- Infection: rare; signs are fever, foul-smelling discharge and pain.
- Cervical stenosis (narrowing): uncommon, it can obstruct menstrual flow or make later follow-up more difficult, and is usually treated by simple dilatation.
- Incompletely removed lesion: the margins are not clear in about one case in four. This does not mean the treatment has failed: follow-up with an HPV test can detect a persistent lesion. A repeat cone biopsy is not automatic.
Before the procedure, tell us about any bleeding disorder and any blood-thinning medication (anticoagulants, aspirin, antiplatelet drugs), including over-the-counter medicines.
Can I get pregnant after a cone biopsy?
Yes. A cone biopsy does not noticeably reduce fertility, and most women go on to have normal pregnancies. However, because the cervix is shorter, the risk of preterm birth is higher.
A meta-analysis of more than 6 million women found a rate of birth before 37 weeks of 10.7% after treatment, compared with 5.4% without treatment. This risk increases with the depth of the cone and the number of procedures, and it is lower with a diathermy loop than with a cold scalpel. This is why as little tissue as possible is removed and low-grade lesions are not treated.
In a later pregnancy, tell your doctor or midwife that you have had a cone biopsy: an ultrasound measurement of cervical length may be offered to adapt your monitoring. It is generally advised to wait for healing and a first check-up before trying for a pregnancy: the interval before a new pregnancy is discussed at the post-operative appointment.
What follow-up is needed after a cone biopsy?
- Post-operative appointment: to check healing and explain the results of the tissue analysis. If an invasive cancer were found, which is rare, your case would be discussed at a multidisciplinary team meeting (RCP).
- Check-up at about 6 months: an HPV test is carried out, sometimes with cytology and colposcopy. A large meta-analysis showed that the HPV test predicts residual disease better than the state of the margins: after a negative HPV test, the risk of a high-grade lesion is below 1%.
- Afterwards: check-ups at longer intervals, then a gradual return to routine screening, following the guidelines of the French National Cancer Institute (INCa).
When should I seek urgent care after a cone biopsy?
- Bleeding heavier than a period, with clots, or that does not stop: contact the unit where you had your procedure straight away or go to a gynaecological emergency department. If you feel faint, call 15 (or 112) in France, or your local emergency number.
- Fever above 38 °C, foul-smelling discharge, increasing lower abdominal pain: see a doctor promptly.
Frequently asked questions
Is a cone biopsy painful?
The procedure is done under anaesthesia and is not painful. Afterwards, there is at most some discomfort similar to period pain, relieved by simple painkillers.
Does a cone biopsy cure HPV?
It removes the abnormal area, which often helps the body clear the virus, but it does not guarantee that the virus disappears. This is why a follow-up HPV test is done about 6 months later.
Do I need a repeat cone biopsy if the margins are not clear?
Not necessarily. Close follow-up with an HPV test and colposcopy is often enough; a further procedure is only offered if a lesion persists or in certain specific situations.
Does my partner need treatment?
No. There is no treatment for HPV in men without a visible lesion, and no screening test is recommended for them.
How much rest and time off work will I need after a cone biopsy?
As a guide, a cone biopsy is generally done as a day case and time off work is 3 days (desk work) to 5 days (physical work). Sex, tampons, baths and swimming should be avoided for about 4 weeks. This advice is tailored to your situation at the consultation.
How much does a cone biopsy cost?
The surgeon’s fees are set out in a quote given to you before the procedure.
References
- Kyrgiou M, et al. Adverse obstetric outcomes after local treatment for cervical preinvasive and early invasive disease according to cone depth: systematic review and meta-analysis. BMJ, 2016. doi:10.1136/bmj.i3633 — PMID 27469988
- Arbyn M, et al. Incomplete excision of cervical precancer as a predictor of treatment failure: a systematic review and meta-analysis. Lancet Oncol, 2017. doi:10.1016/S1470-2045(17)30700-3 — PMID 29126708
- Brun JL, et al. [Management of women with abnormal cervical cytology: Update of INCa recommendations after the implementation of HPV screening]. Gynecol Obstet Fertil Senol, 2025. doi:10.1016/j.gofs.2024.11.006 — PMID 39884805
Dr Olivier KadochObstetrician-gynaecologist and gynaecological surgeon in Paris (16th and 5th arrondissements). Former chef de clinique-assistant (senior registrar) at the Paris public hospitals (AP-HP); individually accredited by the French National Authority for Health (HAS). RPPS 10003957809. Background and practice locations
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