Precancerous changes and preterm births
Issue 01: 8 Jan 2007
Source: BJOG: An International Journal of Obstetrics and Gynaecology 2007;114:70-80
A study has provided new insights into the association between precancerous changes in the cervix and the risk of subsequent preterm birth. The findings suggest that diagnosis of precancerous changes, regardless of the treatment given, is associated with a significantly increased risk of delivery before 37 weeks’ gestation.
Researchers at centers in Carlton, Australia, conducted a retrospective cohort study, investigating the records of 5,548 women who:
1. Were referred to a cervical dysplasia clinic at the Royal Women’s Hospital in Carlton between 1982 and 2000 for assessment of an abnormality detected on a routine Pap smear or for evaluation of a cervix that appeared abnormal; and
2. Subsequently had a birth recorded in the Victoria state perinatal data collection system. The birth studied was the first after the referral, for women who were untreated, and the first after treatment, for women who received treatment.
The follow-up period for the women ranged from 2 years to 20 years after referral.
The researchers report their findings in a new paper published in the BJOG: An International Journal of Obstetrics and Gynaecology. Overall, there were 533 observed preterm births in the cohort of 5,548 women, significantly higher than the 312 cases expected based on national figures.
The main findings included the following:
* The risk of preterm birth (defined as within 37 weeks of gestation) was significantly higher for both treated and untreated women compared with the general population.
* The risk of preterm birth was significantly higher among the treated women than among the untreated women.
* Other factors significantly associated with an increased risk of preterm birth were a history of induced or spontaneous abortion, illicit drug use during pregnancy, and a major maternal medical condition. In terms of treatment, cone biopsy, loop electrosurgical excision procedure (LEEP), and diathermy were associated with preterm birth; after adjustment for potentially confounding factors, only the association between diathermy and preterm birth remained statistically significant.
* Women treated with laser ablation did not have a significantly increased risk of preterm birth.
Discussing their findings, the researchers say the study is the largest to date examining pregnancy outcomes following diagnosis and treatment for precancerous changes in the cervix. They conclude: “Women presenting with precancerous changes in the cervix are at an increased risk for preterm birth, a risk that appears to be increased by treatments that remove or destroy substantial amounts of cervical tissue.”
They suggest that, in light of these findings, there needs to be a re-evaluation of treatment programmes involving a “see and treat” policy for the management of abnormal Pap smear results. In addition, “the use of ablative techniques such as laser ablation need revisiting,” the researchers state.
