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How common is preterm labor after LEEP?

LEEP (Loop Electrosurgical Excision Procedure) is a procedure used to remove abnormal cells from the cervix that could potentially lead to cervical cancer. It is a common and effective way to treat precancerous cervical lesions. However, there are some risks associated with the procedure, including the potential for preterm labor and delivery in future pregnancies. Preterm birth, defined as delivery before 37 weeks gestation, can have serious health implications for the baby. Therefore, it is important for women who have had a LEEP to understand their individual risk of preterm labor and take preventative measures if needed. In this article, we will explore the current research on how common preterm labor is after LEEP procedures.

Overview of LEEP

During a LEEP procedure, a thin wire loop electrode is used to remove abnormal cervical tissue. The loop is heated electrically and used to excise both the abnormal tissue and a margin of healthy tissue around it. This ensures that all precancerous cells are removed. LEEP only removes tissue from the cervix surface (the portion that extends into the vagina); it does not involve removing any tissue from inside the uterus.

LEEP is done in a doctor’s office or clinic and only takes about 10-20 minutes. It is typically performed under local anesthesia. Most women report only mild discomfort during the procedure.

LEEP has a high success rate, with cure rates for dysplasia (precancerous cells) estimated at 85 to 95 percent. It is one of the most common and effective ways to treat high grade squamous intraepithelial lesions (HSIL) and cervical intraepithelial neoplasia (CIN 2/3).

Preterm Birth Risks After LEEP

While LEEP is considered safe overall, one well-established complication is an increased risk for preterm birth in future pregnancies.

When tissue is removed from the cervix during LEEP, scar tissue forms as the area heals. This scar tissue makes the cervix less strong and flexible. A weakened cervix may begin to shorten and dilate prematurely in subsequent pregnancies, leading to early labor and delivery.

Research on Preterm Birth Rates

Numerous studies have found an association between LEEP and preterm birth:

– A 2018 BJOG meta-analysis looked at data from 28 studies involving over 2 million women. Women who had a LEEP had a subsequent preterm birth rate of 10.8%, compared to 6.8% in women who did not have the procedure. This equates to around a 60% increased risk.

– A 2021 systematic review in the American Journal of Obstetrics and Gynecology analyzed 36 studies with over 3 million participants. They found that across all studies, women who had a LEEP had a 1.5 to 2-fold higher risk of spontaneous preterm birth compared to those without a LEEP history.

– A large 2021 population cohort study published in JAMA Network Open followed over 4000 women in Scotland for up to 10 years after LEEP. The preterm birth rate before 34 weeks was 8.1% in the LEEP group, compared to 3.4% in the control group who did not have LEEP.

The increased risk has been confirmed in both retrospective and prospective studies. Although exact figures vary between studies, the majority find around a 1.5 to 2 times higher risk of early delivery in women post-LEEP. This appears consistent across different population groups and healthcare settings as well.

Risk Factors For Preterm Birth After LEEP

While all women who undergo LEEP see an increased preterm birth risk on average, some characteristics and procedural factors can further modulate that risk:

– **Number of procedures** – Women who have undergone more than one LEEP have higher risks than those who have had just one.

– **Depth of excision** – Deeper excisions removing more cervical tissue confer greater preterm risks.

– **Cervical length** – Women with a short cervix after LEEP are more prone to early dilation and labor.

– **Prior preterm birth** – Women who have had a previous preterm delivery are more likely to have another after LEEP.

Risk Factor Level of Increased Risk
Multiple LEEP procedures 2-3 times higher risk versus single procedure
Depth of excision > 10mm 2 times higher risk versus less excision
Cervical length 3 times higher risk versus longer cervix
Prior preterm birth 2 times higher risk of recurrence

These factors can be assessed during prenatal visits to determine which women are most at risk after having LEEP.

Preventing Preterm Birth After LEEP

The increased risks of preterm birth do not mean that women absolutely cannot have a healthy, full-term pregnancy after having LEEP. There are several steps women can take to help lower risks:

Allow Time Between LEEP and Pregnancy

Ideally, women should wait at least 6 months, and optimally 12 months after having LEEP before trying to conceive. This allows more time for the cervix to heal before undergoing the demands of pregnancy. Studies show women who wait longer have lower preterm birth rates compared to those who become pregnant soon after LEEP.

Carefully Monitor Cervical Length

All obstetric providers should check the cervical length of women with a history of LEEP starting early in the second trimester. This can be done with a transvaginal ultrasound. If the cervix is very short it indicates a higher risk for preterm changes.

Consider Preventative Cerclage

For women at particularly high risk, a cervical cerclage may be recommended. This is a minor surgical procedure in which a suture is placed around the cervix and tightly stitched shut. This keeps the cervix closed and provides structural support. Studies show cerclage reduces preterm birth rates in at-risk women by 30 to 60%. It is most effective when placed in the early second trimester before any cervical changes begin.

Progesterone Supplements

Progesterone helps keep the cervix and uterus relaxed and closed during pregnancy. Women with a prior preterm birth or short cervix may benefit from daily progesterone supplements starting in the first trimester. Progesterone has been shown to reduce the risk of recurrent preterm birth by up to 45%.

Lifestyle Factors

Women should also adopt good prenatal habits known to lower preterm birth risks, like quitting smoking, avoiding alcohol/drugs, managing stress, staying hydrated, getting sufficient rest, and treating any vaginal infections promptly.


Preterm birth is a well-established potential complication of having a LEEP procedure to treat cervical dysplasia. On average, women who have a LEEP have around a 1.5 to 2 times higher risk of spontaneous preterm delivery compared to those who did not have the procedure.

However, the increased risk does not mean preterm birth is inevitable. By understanding their individual risk factors, undergoing careful monitoring of cervical length during prenatal care, and taking advantage of preventative options like cerclage and progesterone, many women can still achieve a full-term delivery after LEEP. Women should discuss their history of LEEP with their obstetric provider early in pregnancy to develop a management plan tailored to their unique risk profile.