Objective: To determine factors affecting obstetric outcomes in pregnancies after conization by loop electrosurgical excision procedure (LEEP) or cold-knife conization (CKC) due to cervical intraepithelial neoplasia (CIN).
Material and methods: The maternal and clinical characteristics and obstetric outcomes of CKC, LEEP and control groups were evaluated and compared. Risk factors for adverse pregnancy outcomes were evaluated using multiple logistic regression analyses.
Results: The incidence of preterm delivery, PPROM, low APGAR scores, fetal mortality, and late-period spontaneous abortus was highest in patients who underwent CKC (p<0.05). Cone depth of CKC was longer than LEEP (p=0.025). Cervical length (CL) at pregnancy was CKC<LEEP<controls (p=0.003). Shorter CL at pregnancy and time from conization to pregnancy (t-CP) was correlated with a high incidence of preterm delivery and PPROM (p<0.05). To predict preterm delivery, t-CP <14 months had 63.16% sensitivity and 77.42% specificity (AUC=0.714, 95% CI: [0.603-0.809]; p=0.005), and CL at pregnancy <31 mm had 65% sensitivity and 71.78% specificity (AUC=0.731, 95% CI: [0.675-0.782]; p<0.001). To predict PPROM, t-CP <15 months had 85.71% sensitivity and 65.22% specificity (AUC=0.730, 95% CI: [0.603-0.809]; p=0.024), and CL <32 mm had 72.73% sensitivity and 61.89% spcificity (AUC=0.685, 95% CI: [0.675-0.782,p=0.007).
Conclusion: Compared with CKC, LEEP has shorter cone depth and fewer adverse pregnancy outcomes. The t-CP<14 months was a risk for preterm delivery and <15 months was a risk for PPROM. CL at pregnancy <31 mm was a risk for preterm delivery and <32 mm was a risk for PPROM.
Keywords: Cervical intraepithelial neoplasia; cold-knife conization; conization; loop electrosurgical excision procedure; obstetric outcome.