Effect of Cervical Cancer Screening Programs on Preterm Birth: A Decision and Cost-Effectiveness Analysis.

OBJECTIVE: To assess the effect of age at initiation and interval of cervical cancer screening in women of reproductive age on the risk of future preterm birth and subsequent adverse neonatal outcome relative to maternal life-years gained and cost of both screening and preterm birth. METHODS: In this decision and cost-effectiveness analysis, we compared eight cytology-based screening programs varying in age of onset (21, 24, 25, 27, or 30 years) and screening interval (3 or 5 years) in a fictive cohort of 100,000 women. We used the microsimulation screening analysis model to estimate number of cervical intraepithelial neoplasia diagnoses, large loop excisions of the transformation zone (LLETZs), life-years gained, cervical cancer cases, deaths, and costs of screening and treatment. We used the number of LLETZs to calculate additional preterm births, subsequent neonatal morbidity, mortality, and associated costs. RESULTS: The number of LLETZs per 100,000 women varied from 9,612 for the most intensive screening (every 3 years from age 21 years) to 4,646 for the least intensive screening (every 5 years from age 30 years). Compared with the least intensive program, the most intensive program increased maternal life-years gained by 9% (10,728 compared with 9,839), decreased cervical cancer cases by 67% (52 compared with 158), and cervical cancer deaths by 75% (four compared with 16) at the expense of 250% (158 compared with 45) more preterm births and 320% (four compared with one) more neonatal deaths while increasing total costs by $55 million ($77 compared with $23 million). The number of maternal life-years gained per additional preterm birth varied from 68 to 258 with subsequent total costs per maternal life-years gained of $7,212 and $2,329. CONCLUSION: Cervical cancer screening every 3 years and subsequent treatment in women aged younger than 30 years yield limited life-years but may have substantial perinatal adverse effects. Consequently, women who plan to have children may benefit from a more cautious screening approach, taking into account their risk for both cancer and preterm birth.

The risk of preterm birth of treated versus untreated cervical intraepithelial neoplasia (CIN): a systematic review and meta-analysis.

Cervical surgery is associated with preterm birth (PTB) and neonatal morbidity. However, it is unknown whether this increased risk is due to the surgery itself or to the cervical intraepithelial neoplasia (CIN) underlying the surgery. Our objective was to assess the risk for PTB in women with treated and untreated CIN. We performed an electronic literature search in MEDLINE, Embase and CENTRAL for studies that reported on pregnancy outcome after treated and untreated CIN. The methodological quality was scored using the STROBE combined checklist for observational studies. We extracted data on PTB<37 weeks, very PTB<32 weeks, spontaneous PTB<37 weeks, (preterm) premature rupture of membranes ((P)PROM), perinatal mortality and section caesarean each before and after treatment for CIN. We used the Mantel-Haenszel method to estimate summarizing odds ratios. Our search identified 620 studies, of which 20 were reporting on pregnancy outcome for a total of 12,159,293 women. There were 20,832 women who gave birth after treatment for CIN before pregnancy, 52 women who gave birth after treatment for CIN during pregnancy, 64,237 women with CIN who gave birth before treatment, and 8,902,865 women who gave birth without CIN. Compared to women with untreated CIN, women treated for CIN before or during pregnancy, had a significantly higher risk of PTB<37 weeks (OR 1.7, 95% CI 1.0-2.7). When comparing women treated for CIN before pregnancy (n=20,832) to women with untreated CIN (n=64,162), we found an OR of 1.4 with a 95% confidence interval of 0.85-2.3. Women treated during pregnancy had a clearly increased risk for PTB (OR 6.5, 95% CI 1.1-37), and (P)PROM (OR 1.8, 95% CI 1.4-2.2). In women with cervical surgery, the risks for spontaneous PTB<37 weeks (OR 0.87, 95% CI 0.54-1.4), caesarean section (OR 1.0, 95% CI 0.71-1.5) and perinatal mortality (OR 1.0, 95% CI 0.38-2.8) were not increased. The increased risk of PTB in women who underwent cervical surgery for CIN is especially increased when performed during pregnancy. When performed before pregnancy the risk of PTB is increased, although insignificant.