Deaton 1990.

Methods	Trial design: cross‐over (after 4 cycles) Single centre, USA
Participants	Couples with unexplained subfertility and couples with surgically treated endometriosis N randomised: 67; N analysed: 51 total, unexplained: 24 Age: 33 years (± 4.0) Duration of subfertility: 3.5 years (±1.7) Basic fertility work‐up normal, semen normal according to WHO criteria 1987 Previous treatment: not stated
Interventions	Comparison: IUI + OH versus TI + NC Stimulation method: 50 mg CC/day, day 5 to day 9 Timing: Natural cycle: urinary LH and BBT timed intercourse Stimulated cycle: 10,000 IU hCG when lead follicle was estimated to be at least 18 mm. IUI 36 hr after hCG injection No cancellation criteria were given Duration of treatment: 8 cycles max
Outcomes	Ongoing pregnancy rate Multiple pregnancies Ectopic pregnancies Miscarriage rate OHSS Pregnancy: not further defined
Notes	ITT analysis: not possible Participants with unexplained subfertility and endometriosis were included in this study; 3 participants with moderate and no participants with severe endometriosis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Sequence generation not stated
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding was not possible because of the nature of the interventions
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding was not possible because of the nature of the interventions and non‐blinding was not likely to affect the outcomes of interest
Incomplete outcome data (attrition bias) All outcomes	Low risk	16/67 participants excluded from analysis due to anovulation, poor semen quality or inability to follow the treatment protocol. Of the remaining 51 participants, 6 couples did not complete treatment because of illness or relocation. 4/51 dropped out before cross‐over
Selective reporting (reporting bias)	Unclear risk	Live birth rate was not reported
Other bias	Unclear risk	Insufficient information available to evaluate this risk domain