Oil-based versus water-based contrast media for hysterosalpingography in infertile women of advanced age, with ovulation disorders or a high risk for tubal pathology: study protocol of a randomized controlled trial (H2Oil2 study)

Table 1 SPIRIT figure

Time-point	Study period
	Enrollment	Allocation	Post-allocation
	t−1	t0	t1	t2	t3
Enrollment
Eligibility screen	X
Informed consent	X
Allocation		X
Interventions
HSG with oil-based contrast			X
HSG with water-based contrast			X
Assessments
Demographics		X
APAIS			X
Pain score (VAS)			X
HSG procedure and results			X
Adverse effects			X
iPCQ				X
Treatments				X
Pregnancies				X
Pregnancy follow-up					X

t−1: Prior to inclusion; t0: Study inclusion; t1: HSG procedure, usually within 4 weeks of inclusion (t0); t2: end of initial follow-up 6 months after randomization; t3: pregnancy follow-up, at last 9 months after t2

ISSN: 1472-6874