Role of dilatation and curettage performed for spontaneous or induced abortion in the etiology of endometrial thinning.

ABSTRACT

AIM: The aim of this study was to clarify the role of dilatation and curettage (D&C) performed for spontaneous or induced abortion in the etiology of endometrial thinning. METHODS: This was a retrospective and cross-sectional study of 310 infertile patients from January 2013 through December 2015. Endometrial thickness observed 5-7 days after ovulation in a natural menstrual cycle was correlated with the number of D&C noted in each patient's history. RESULTS: Study 1 was an investigation of patients without D&C (group A n = 232) and patients with D&C performed for spontaneous abortion (group B n = 46). Study 2 was an investigation of patients in group A and patients with D&C performed for induced abortion (group C n = 32). A significant negative correlation (P < 0.01) between endometrial thickness and number of D&C was observed in both studies. The mean endometrial thickness of the patients in group A was 10.9 ± 2.1 mm. The mean endometrial thickness of the patients in group B with one and ≥two D&C was 7.9 ± 2.3 and 6.9 ± 2.9 mm, respectively. The mean endometrial thickness of the patients in group C with one and ≥two D&C was 9.1 ± 2.3 and 7.8 ± 2.0 mm, respectively. There was a tendency toward gradual endometrial thinning following repeated procedures and the number of previous D&C was significantly associated with endometrial thinning (P < 0.001) in both studies. CONCLUSION: D&C performed for spontaneous or induced abortion may play a causal role in endometrial thinning.