The Fertility and IVF and IUI trial in couples with uneXplained infertility

We warmly invite you to take part in a clinical study being run across all fertility clinics in Aotearoa New Zealand to find out what the best treatment option is for couples with unexplained infertility to become pregnant

The FIIX Study is a clinical trial comparing the two main fertility procedures available through public funding in Aotearoa New Zealand – The Fertility and In Vitro Fertilisation (IVF) and Intra Uterine Insemination (IUI) trial in couples with uneXplained infertility.

Couples with unexplained infertility who have been accepted for publicly funded fertility treatment are suitable to participate.

Intrauterine insemination (IUI) involves the placement of prepared sperm into the uterus, often using ovulation induction medication. It is a less invasive procedure than IVF. We suspect that IUI will result in the same number of births as IVF.

By doing this research we hope to provide more opportunities for couples with unexplained infertility to become pregnant.

Important: the FIIX study information video below is being updated

Benefits of the study
  • You may begin treatment earlier – couples with unexplained infertility currently wait up to 15 months before their treatment commences, this time may be reduced if you participate.
  • For those assigned to the IUI group, if pregnancy is achieved then you avoid the more invasive IVF procedure.
  • Couples who agree to participate in The FIIX Study will not incur any costs. Their treatment will be publicly funded.
Participating fertility clinics
If you agree take to part in this study you will remain in the fertility clinic you have already been allocated to for publicly funded fertility treatment. These clinics are:

  • Fertility PLUS – Auckland
  • Repromed – Auckland
  • Fertility Associates – Auckland, Hamilton, Wellington, Christchurch

For Fertility PLUS and Repromed clinics, contact us: or 09 923 1281.

For all Fertility Associates clinics, contact us: or 0800 323 449.

Background literature
  • Bensdorp AJ et al. Prevention of multiple pregnancies in couples with unexplained or mild male subfertility: randomised controlled trial of in vitro fertilisation with single embryo transfer or in vitro fertilisation in modified natural cycle compared with intrauterine insemination. BMJ 2015;350:g7771.
  • Custers IM et al. Couples with unexplained subfertility and unfavorable prognosis: a randomized pilot trial comparing the effectiveness of in vitro fertilization with elective single embryo transfer versus intrauterine insemination with controlled ovarian stimulation. Fertility and Sterility 2017;96(5):1107-1111.
  • Nandi A et al. Intrauterine insemination with gonadotropin stimulation or in vitro fertilization for the treatment of unexplained subfertility: a randomized controlled trial. Fertility and Sterility 2017;107:0015-0282.
  • Farquhar CM et al. Intrauterine insemination with clomiphene citrate versus expectant management for unexplained infertility: a pragmatic open-label, randomised, controlled, two-centre trial. Lancet 2017;3;391(10119):441-450.

Meet the FIIX team






From left to right: Melissa Vercoe (Trial coordinator); Dr Lynn Sadler (Epidemiologist); Dr Lucy Prentice (Trial manager); Professor Cindy Farquhar (Principal investigator)

Information for Health Professionals

Health Professionals can find more information about the FIIX study here

Contact us

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Approved by Central Health and Disability Ethics Committee on 15 April 2019, reference code 19/CEN/40.