Table 5.

Standardised incidence ratios (SIRs) for all, invasive, and borderline ovarian cancers among 225 786 women who underwent assisted reproduction in Great Britain, 1991-2010, by presence or absence of known risk factors endometriosis and nulliparity

Factor	Follow-up (No of person years)	Type of ovarian cancer
		All ovarian cancer*			Invasive cancer†			Borderline tumours‡
		No of observed cancers	SIR (95% CI)		No of observed cancers	SIR (95% CI)		No of observed cancers	SIR (95% CI)
No diagnosis of endometriosis and at least one birth recorded by treatment completion	1 036 996	133	1.03 (0.86 to 1.22)		85	1.03 (0.82 to 1.27)		48	1.02 (0.75 to 1.35)
No diagnosis of endometriosis and no births recorded by treatment completion	1 039 514	217	1.57 (1.37 to 1.79)		141	1.56 (1.32 to 1.84)		76	1.57 (1.24 to 1.97)
Diagnosis of endometriosis and at least one birth recorded by treatment completion	79 870	24	2.41 (1.55 to 3.59)		14	2.22 (1.21 to 3.72)		10	2.76 (1.33 to 5.08)
Diagnosis of endometriosis and no birth recorded by treatment completion	101 368	31	2.24 (1.52 to 3.18)		24	2.64 (1.69 to 3.93)		7	1.47 (0.59 to 3.04)

^*Ovarian cancer=ICD-9 codes 1830-1839 and 2362; ICD-10 codes C56, C570-C574, C481, C482, and D391.

^†Invasive ovarian tumours=ICD-9 codes 1830-1839 (excluding morphology codes 8442/8451/8462/8472/8473) and 2362; ICD-10 codes C56, C570-C574, C481, and C482 (excluding morphology codes 8442/8451/8462/8472/8473).

^‡Borderline ovarian tumours=ICD-9 code 1830 (with morphology codes 8442/8451/8462/8472/8473) and ICD-10 codes D391 and C56 (with morphology codes 8442/8451/8462/8472/8473).