Risk factors of ovarian pregnancy following assisted reproductive technology: a matched case-control study

Objective To investigate the risk factors on ovarian pregnancy (OP) patients following assisted reproductive technology (ART). Methods In this retrospective matched case-control study from 1 January 2007 to 1 June 2018, 7 women diagnosed with OP were matched as the case group, women with intrauterine pregnancy (IUP) (n=28) and with tubal pregnancy (TP) (n=28) were matched as controls at the ratio of 1∶4∶4. Results There were no differences observed in age, body mass index (BMI), educational attainment and occupation. Compared with the IUP group, the risk factors of OP included a adnexal surgery history (adjusted OR1=10.22, 95% CI=1.57-66.37, P=0.01) and tuberculosis (TB) history (adjusted OR1=12.85, 95% CI=1.40-117.73, P=0.02). A significant difference was found in serum β-human chorionic gonadotropin (hCG) level among the three groups (P<0.001). Conclusion No significant difference is found in the baseline characteristics of OP infertile women following ART. The risk factors of OP include previous adnexal surgery and TB. β-hCG levels on the 14th day after embryo transfer are higher in OP patients than those in TP patients. Key words: Risk factor; Ovary; Tubal pregnancy; Reproductive techniques, assisted