Exploring uterine niche: a systemic review on secondary infertility rates, pathophysiological correlations, impact on assisted reproduction technology (ART), and the efficacy of surgical interventions.

BACKGROUND

The rising trend of cesarean sections worldwide has resulted in an increased incidence of uterine niches, a cavity formed at the cesarean scar site due to impaired tissue healing. Secondary infertility in women with uterine niches is a hot topic in obstetrics and gynecology. Therefore, the current study aims to untwist the link between secondary infertility and uterine niche, exploring the pathophysiological correlations, effects on assisted reproduction technology, and role of surgical interventions in resuming fertility.

METHODOLOGY

PubMed, Cochrane Library, Embase, and Science Direct were searched systematically. Rayyan was employed as a semi-automated tool for study selection. Full-text articles in the English language were included. Systematic reviews, meta-analyses, or book chapters were excluded. Newcastle-Ottawa Scale assessed the quality of cohort and case-control studies, while the Cochrane Risk-of-bias tool evaluated randomized controlled trials. Data synthesis followed a thematic analysis.

RESULTS

35 articles from 3301 studies met the inclusion criteria. Among those, 25 were cohort studies, only one was a randomized controlled trial, and the rest had different study designs. The study quality assessment revealed average to good quality. The incidence of secondary infertility in women with uterine niches ranged from 27.37% (n = 95) to 75% (n = 16). Decreased residual myometrial thickness, chronic inflammatory changes at the niche site, and fluid accumulation within the niche cavity were identified as leading causes of secondary infertility. The uterine niche adversely affected assisted reproductive outcomes through multiple mechanisms. Various surgical interventions, including hysteroscopy, laparoscopy, or combined surgery, showed differing efficacies in restoring fertility.

CONCLUSION

The study provides valuable insights regarding the association between secondary infertility and uterine niche. However, smaller sample sizes, retrospective nature of study designs, reliance on observational data, and heterogeneity of study reporting have limited the ability to arrive at solid conclusions. Therefore, we encourage well-designed prospective studies, including randomized controlled trials, to further explore this trending area.

REGISTER

The study protocol was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD4204526319).