Adverse Obstetrical Outcomes Associated With Treatment of Dysplastic Lesions of the Cervix in a Universally Funded, Single-Payer Health Care System.

OBJECTIVES

This study aimed to investigate the relationship between adverse obstetrical outcomes and cervical dysplasia treatments.

METHODS

This study used linked health care databases through the Institute of Clinical Evaluative Sciences in Ontario Canada, between 2005 and 2019. We conducted a population-based retrospective cohort study of pregnant women who had undergone previous colposcopy and subsequently had a pregnancy, comparing the no treatment cohort with patients who had a cervical excisional procedure (CEP) or cervical ablative procedure (CAP). The primary outcome was preterm birth (PTB). The secondary outcomes included preterm premature rupture of membranes, low birthweight, spontaneous abortion, stillbirth, and cervical incompetence. Cox proportional hazard models were used to calculate hazard ratios (HRs). We used unadjusted logistic regression to compare outcomes between those who underwent CEP versus CAP. ORs with 95% CIs were calculated.

RESULTS

We included 515 726 pregnant patients. After exclusion criteria, 109 930 patients remained. There were 74 291 patients in the control group, 24 133 patients in the CEP group, and 11 506 patients in the CAP group. In the control group 2620 patients (5.7%) had a PTB versus 1321 (7.6%) and 592 (6.5%) in the CEP and CAP groups, respectively (OR 1.18; 95% CI 1.07-1.31, P < 0.01). After controlling for age, there was a 32% increased risk of PTB with a CEP (HR 1.32; 95% CI 1.24-1.40, P < 0.001). For a CAP, there was no increased risk in PTB (HR 1.01; 95% CI 0.94-1.09, P = 0.74).

CONCLUSIONS

In this large Ontario data set of pregnant patients who underwent previous colposcopy, CEP was associated with PTB.