Fertility help for unexplained infertility: IVF first brought babies sooner

If you and your partner are trying for a baby and tests show nothing wrong, there is good news about fertility treatment. Starting with one full round of IVF got more couples to a baby sooner. And whichever path you choose, about 7 in 10 couples had a baby by the end of the study.

That is what researchers found when they compared two common ways to begin treatment for unexplained infertility. Doctors use that term when the tests look normal, but pregnancy still hasn’t happened.

How the study worked

Researchers in Australia and New Zealand followed 737 couples with unexplained infertility. A coin-flip-style draw put each couple on one of two paths. One path started with IUI (up to four cycles), the other with a single complete cycle of IVF. The study was a randomized trial, the fairest way to compare treatments, and it appeared in the New England Journal of Medicine on Oct. 27, 2026. Couples who were in the first stage during COVID lockdowns were left out of the main first-stage count.

What are IUI and IVF?

With IUI, the woman takes medicine to help her ovaries release eggs. Then prepared sperm is placed right into the uterus. It is simpler and usually costs less.

With IVF, eggs are collected and fertilized in a lab. The embryos are then placed in the uterus. It involves more steps, but it works better per try.

What they found

In the first 7 months, about 55 in 100 couples who started with IVF had a baby. Among couples who started with IUI, about 31 in 100 did. The exact figures were 55% (164 births among 297 couples) for IVF and 31% (89 births among 288 couples) for IUI.

Then the study kept going. Couples without a baby or ongoing pregnancy after 7 months could continue. Those who began with IUI could move on to IVF, and those who began with IVF could try one more IVF cycle.

By 20 months, the two groups landed in the same place: 70% for the IUI-first group and 71% for the IVF-first group.

That means the early lead for IVF was about speed. Many couples who began with IUI got to IVF later and had babies too. The result is good news either way: most couples in both groups ended up with a baby.

Serious side effects were uncommon but did happen. They showed up in 6 couples in the IUI group and 14 couples in the IVF group. Most were linked to egg collection or to the ovaries reacting strongly to the medicine.

What this means for your choice

You are not choosing between a good path and a bad one. You are choosing between a faster path and a gentler first step, and both can lead to a baby.

IVF first can make sense if time matters to you. IUI first can make sense if you prefer a simpler start and are comfortable with a longer road. Cost, comfort with the process and how much time you have all count.

What you can do today

Write down three questions for your next fertility visit. What are our chances each month with each option? How long might each path take? What will each one cost us, and what does our insurance cover? Bring the list and ask your clinic to go through both paths with you.