This retrospective longitudinal cohort study used saline infusion sonohysterography to track uterine scar morphology in 25 women after 2–9 consecutive cesarean deliveries, comparing 40 paired procedures where the second used an endometrium-free closure — either following a standard closure (Transition Group, n=9) or a prior endometrium-free closure (Successive Group, n=31).
55% of pairs (22/40) ended without a niche after the second endometrium-free closure. The Transition Group showed 4.67-fold higher odds of new niche development vs. the Successive Group (OR=4.67; 95% CI: 0.71–30.77; p=0.109), which did not reach statistical significance. De novo niches developed in 6/40 pairs (15%), with mean depth 4.2 mm.
- Very small sample (25 women, 40 pairs), underpowered for the comparisons made. - Single observer measurements with no reproducibility assessment. - No clinical outcomes (e.g., symptoms, fertility, scar pregnancy) were reported; the ±2 mm morphologic threshold was operationally defined, not clinically validated.
Endometrium-free uterine closure appears to preserve favorable scar morphology in most women across repeat cesareans, but its benefit may diminish with repeated surgery in some cases. These findings are hypothesis-generating only and should not change current practice pending larger prospective trials.
