The SUPER study: protocol for a randomised controlled trial comparing follicle-stimulating hormone and clomiphene citrate for ovarian stimulation in intrauterine insemination

Follicle stimulating hormone versus clomiphene citrate in intrauterine insemination for unexplained subfertility: a randomized controlled trial

STUDY QUESTION

Is FSH or clomiphene citrate (CC) the most effective stimulation regimen in terms of ongoing pregnancies in couples with unexplained subfertility undergoing IUI with adherence to strict cancellation criteria as a measure to reduce the number of multiple pregnancies?

SUMMARY ANSWER

In IUI with adherence to strict cancellation criteria, ovarian stimulation with FSH is not superior to CC in terms of the cumulative ongoing pregnancy rate, and yields a similar, low multiple pregnancy rate.

WHAT IS ALREADY KNOWN

FSH has been shown to result in higher pregnancy rates compared to CC, but at the cost of high multiple pregnancy rates. To reduce the risk of multiple pregnancy, new ovarian stimulation regimens have been suggested, these include strict cancellation criteria to limit the number of dominant follicles per cycle i.e. withholding insemination when more than three dominant follicles develop. With such a strategy, it is unclear whether the ovarian stimulation should be done with FSH or with CC.

STUDY DESIGN, SIZE, DURATION

We performed an open-label multicenter randomized superiority controlled trial in the Netherlands (NTR 4057).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We randomized couples diagnosed with unexplained subfertility and scheduled for a maximum of four cycles of IUI with ovarian stimulation with 75 IU FSH or 100 mg CC. Cycles were cancelled when more then three dominant follicles developed. The primary outcome was cumulative ongoing pregnancy rate. Multiple pregnancy was a secondary outcome. We analysed the data on intention to treat basis. We calculated relative risks and absolute risk difference with 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

Between July 2013 and March 2016, we allocated 369 women to ovarian stimulation with FSH and 369 women to ovarian stimulation with CC. A total of 113 women (31%) had an ongoing pregnancy following ovarian stimulation with FSH and 97 women (26%) had an ongoing pregnancy following ovarian stimulation with CC (RR = 1.16, 95% CI: 0.93-1.47, ARD = 0.04, 95% CI: -0.02 to 0.11). Five women (1.4%) had a multiple pregnancy following ovarian stimulation with FSH and eight women (2.2%) had a multiple pregnancy following ovarian stimulation with CC (RR = 0.63, 95% CI: 0.21-1.89, ARD = -0.01, 95% CI: -0.03 to 0.01).

LIMITATIONS, REASONS FOR CAUTION

We were not able to blind this study due to the nature of the interventions. We consider it unlikely that this has introduced performance bias, since pregnancy outcomes are objective outcome measures.

WIDER IMPLICATIONS OF THE FINDINGS

We revealed that adherence to strict cancellation criteria is a successful solution to reduce the number of multiple pregnancies in IUI. To decide whether ovarian stimulation with FSH or with CC should be the regimen of choice, costs and patients' preferences should be taken into account.

STUDY FUNDING/COMPETING INTEREST(S)

This trial received funding from the Dutch Organization for Health Research and Development (ZonMw). Prof. Dr B.W.J. Mol is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for Merck, ObsEva and Guerbet. The other authors declare that they have no competing interests.

TRIAL REGISTRATION NUMBER

Nederlands Trial Register NTR4057.

TRIAL REGISTRATION DATE

1 July 2013.

DATE OF FIRST PATIENT’S ENROLMENT

The first patient was randomized at 27 August 2013.

Growing body of evidence supports intrauterine insemination as first line treatment and rejects unfounded concerns about its efficacy, risks and cost effectiveness

IUI has been practiced for five decades but only three unconvincing trials attempted to demonstrate the superiority of IUI over sexual intercourse (SI). In the absence of evidence of its effectiveness, the National Institute for Clinical Excellence (NICE) recommended IVF over IUI after 2 years of unprotected SI. High-quality recent data in well-constructed studies suggest that biases against IUI procedures and in favour of IVF are invalid. It is unethical to continue to misinform patients and stakeholders. The well-constructed randomised controlled trials (RCT) show IUI procedure to be efficient, with minimal risk, and above all improved cost-effectiveness when compared to IVF for live birth. IUI as first-line treatment should be offered to most patients, while funding agencies and stakeholders need to be urgently informed of the cost-benefit in offering IUI. Fertility clinics, IVF interest groups, and regulatory bodies should amend their patient information and guidance to state that IUI should be the first line treatment and that IVF should be offered only when essential. Reappraising and promoting IUI based on evidence enhances patient autonomy, choices, and trust, while allowing the fertility industry to operate within an ethical and acceptable framework not seen as exploitative toward vulnerable patients.