According to the results of a study published in BJOG: An International Journal of Obstetrics and Gynecology, women who have a history of precancerous changes to the cervix are more likely than women in the general population to experience a preterm delivery.
Precancerous changes to the cervix are called cervical intraepithelial neoplasia (CIN). The severity of CIN is graded on a scale of 1 to 3, with 3 being the most severe. CIN2 and CIN3 are considered “high-grade” CIN and may progress to cancer if not treated.
Depending on the extent and severity of the CIN, women may be treated with techniques such as loop electrosurgical excision procedure (LEEP), conization, laser ablation, or cryotherapy.
Because CIN is often diagnosed in young women, the effect of CIN and its treatment on subsequent pregnancies is an important question. Previous studies of this question have produced inconsistent results.
To evaluate the frequency of preterm delivery (delivery before 37 weeks of gestation) among women diagnosed with precancerous cervical changes, researchers in Australia evaluated the medical records of more than 5,000 women who gave birth after a diagnosis of precancerous cervical changes.
Rates of preterm delivery among study participants were compared to rates among women in the general population.
- Overall, women who had been diagnosed with precancerous cervical changes were 70% more likely than women in the general population to experience a preterm delivery.
- Risk was increased to a greater extent among women who received treatment for their precancerous cervical changes than among women who did not receive treatment, but both groups of women had an increased risk of preterm delivery. Treated women had a twofold increased risk of preterm delivery, and untreated women had a 50% increased risk of preterm delivery.
The researchers conclude that precancerous changes to the cervix may increase a woman’s risk of having a preterm delivery, regardless of whether or not the precancerous cervical changes are treated.
Reference: Bruinsma F, Lumley J, Tan J, Quinn M. Precancerous changes in the cervix and risk of subsequent preterm birth. BJOG: An International Journal of Obstetrics and Gynecology. 2007;114:70-80.