Medical Research

"Unexplained" Infertility & Conceiving Naturally

Nearly half of all couples with fertility issues are classified as having either “unexplained” infertility or a mild male factor condition. Many patients are led to believe that because no underlying issue can be identified, their odds of conceiving naturally are low and so only more advanced treatments, like IVF, can help them conceive.

What’s New

A Dutch team of researchers re-opened an old study that looked at how 600 couples with “unexplained” infertility, who were slated to have IVF, fared. The team paid particular attention to the percentage of patients who managed to conceive naturally before their cycles began, or between treatment cycles.

What The Study Showed

Of the 600 couples enrolled, 342 achieved an ongoing pregnancy, of which 77 conceived naturally (the others conceived through IVF). From this the researchers made a number of adjustments and calculations, deducing that over a 12 month period, ~24% of couples with "unexplained" infertility would be able to conceive naturally. The investigators observed a relationship between the odds of conception, the age of the woman, and the number of years the couple had been trying to conceive:


While this study is heartening, there are some shortcomings. First, as always, we find ongoing pregnancy rates to be short of the standard we like to set: live birth rate. It’s certainly possible miscarriage rates are also higher in this group and ultimately drive live birth rates below this 24% figure. At the end of the day, we care about having a baby, not just getting pregnant.

Next, the sample sizes are relatively small here and most of the observation was based upon only 77 recorded pregnancies. Given that there is no shortage of patients with an “unexplained” diagnosis, we’d prefer to see the estimates based off a far more robust dataset.

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