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Secondary Infertility and the Family You Didn't Plan For

2026-09-11

If you wanted a second child and couldn’t have one, you already know the particular shape of that grief. It doesn’t look like the grief of never having a child at all, and it rarely gets talked about the same way.

It’s more common than the silence around it suggests

A 2026 study in Population and Development Review followed roughly 11,000 people across ten countries into their late 40s and asked a simple question: did you end up with the number of children you actually wanted? Among people who had exactly one child, about three in four had not reached their stated ideal family size, and infertility was a major reason why, raising the odds of falling short by 12–19% on its own (Lazzari & Beaujouan, 2026).

That number lines up with what this site’s own readers already told us. In our 2026 poll of over 6,000 parents (What Parents of Only Children Are Actually Afraid Of), infertility was the second most-picked reason for having one child, at 14.9%, behind only “wanted it that way” at 17.3%. Group it with “other medical reason” (8.9%) and medical circumstance accounts for 23.8%, edging out choice once the two medical categories are combined. Two independent data sets, one an international academic study, one our own reader base, land on the same basic picture: “only child by choice or by circumstance” undersells how often it’s really the second one.

That framing matters because it makes it sound like a fork in the road two people arrive at together, deliberately. For a lot of families, it’s closer to a door that quietly closes after the first child, one nobody chose exactly, and one that often didn’t come with a single moment to grieve.

What actually predicts secondary infertility

A 2024 case-control study of 690 women in Frontiers in Medicine looked specifically at who develops secondary infertility, infertility after already having a successful pregnancy, as distinct from never having conceived at all. The strongest single predictor was a prior pregnancy loss (roughly 12 times higher odds), followed by living in a joint/extended-family household and reported strain in the marital relationship; marrying earlier was mildly protective (Fatima et al., 2024). The sample was Pakistan-based, so exact numbers may not transfer directly to a Western population, but the basic shape, that secondary infertility often follows a loss, not just “time running out”, is consistent with what shows up in this site’s own forum archive, and with the real testimony already collected in Only Child Family — When Not By Choice.

The grief doesn’t stay in the past

Maybe the most useful finding for anyone in the middle of this right now comes from a small but carefully done 2025 study in Frontiers in Psychology that followed ten couples who’d conceived via donor insemination, checking back in roughly 25 years later. How a couple processed their original infertility grief at the time was still measurably connected, decades on, to how openly they talked with their child about their origins and to how satisfied they were with their family life (Camps, Arias-Pujol & Anguera, 2025).

The finding isn’t really about donor conception specifically. It’s that unresolved grief over the family you didn’t get to have doesn’t just fade into the background once you’ve made peace with the family you did get. It tends to keep showing up, quietly, in how open and settled a family feels years later. That’s a reason to actually process it, not white-knuckle past it.

Three kinds of evidence, one picture

Our own poll (What Parents of Only Children Are Actually Afraid Of) tells you how many parents are in this situation and why, in their own words, from a multiple-choice list. The academic research above tells you what predicts it and how it echoes over decades, the mechanism our poll wasn’t designed to capture. And the real testimony in Only Child Family — When Not By Choice tells you what it actually feels like. None of the three replaces the other two; together they’re a fuller picture than any one of them alone.

Sources cited:

  • Lazzari & Beaujouan (2026), “Infertility and Unrealized Ideal Family Size,” Population and Development Review, 52(1):70-93
  • Fatima, Akhtar, Hanif, Gilani & Farooq (2024), “Predicted risk factors associated with secondary infertility in women,” Frontiers in Medicine
  • Camps, Arias-Pujol & Anguera (2025), “Infertility grief and filiation experiences 25 years later,” Frontiers in Psychology
  • Only Child Project reader poll (2026), n=6,021 for “reason for one child” question, see What Parents of Only Children Are Actually Afraid Of