Modified endometriosis fertility index Is more accurate to predict the
non-ART pregnancy rate following surgery: a cohort of Chinese women
Abstract
Objective: To examine whether a modified endometriosis fertility index
(EFI) can better predict the rate of pregnancy without assisted
reproductive technologies (ART) after laparoscopic surgery in infertile
women with endometriosis. Design: Retrospective cohort study. Setting: A
university medical center. Population: 564 infertile patients who
received laparoscopic surgery for endometriosis. Methods: 472 patients
were used to modify the EFI based on new, optimal cutoffs for its
predictor variables. The predictive accuracy of the modified EFI was
examined in the other 92 patients. Main outcome measures: post-surgical
non-ART pregnancy. Results: Among the patients for the EFI modification,
the multivariable Cox regression results showed that historical factors
were more contribution in predicting non-ART pregnancy rate than
surgical factors both in modified EFI (C-index: historical factors 0.617
vs surgical factors 0.558) and the original EFI (C-index: historical
factors 0.600 vs surgical factors 0.549). No significant relationship
between the prior pregnancy and post-operative non-ART pregnancy rates
was detected by both modified EFI and original EFI (P=0.530 and 0.802,
respectively). In the patients for assessing the modified EFI, the
predictive accuracy of two modified EFI models (C-index: 0.627 and
0.632, respectively) for non-ART pregnancy rates were superior to that
of the original EFI (C-index: 0.602). Conclusions: A modified EFI based
on population-specific optimal cutoffs and weight might be more suitable
for estimating the rate of non-ART pregnancy after laparoscopic surgery
in infertile women with endometriosis. Funding: This study received no
external funding. Key words: endometriosis fertility index / pregnancy
rate / predicting factors / model