Secondary Infertility and Low AMH: When Donor Eggs Come Up Before the Answers Do
If you conceived your first child without much difficulty, and you are now being told your AMH is low or that donor eggs may be your realistic next step, the speed of that conversation can be hard to take in. The first time, your body did what it was supposed to do. Now the same body is being described as the problem, and no one has explained what changed in the years between.
The number is real, and it matters. What usually gets skipped is the question of what shifted in that interval, because a standard secondary-infertility workup rarely looks there. You are also not unusual in this. Secondary infertility affects up to 11% of couples in the United States, which makes it about as common as primary infertility, and in roughly a third of those cases, a male factor is part of the picture.
Listen to the episode: Low AMH and Failed IVF? Pregnant Naturally at AMH 0.27
In that episode, I walk through Natalie's case. Her AMH was 0.27 ng/mL. She had a failed IVF cycle behind her, she was navigating secondary infertility, and she had been told donor eggs might be her realistic next step. One of the patterns that stood out was inflammation. Her hs-CRP was 1.3 mg/L, read as within range by conventional standards, while sitting above a functional fertility target, with something underneath driving it. She conceived naturally, not because the number changed, but because the systems shaping egg development were finally looked at.
Some of the changes between a first pregnancy and a second attempt is age and time have passed. But pregnancy, birth, and the period of caring for a young child also draw heavily on the systems that shape the environment in which your eggs develop. This does not mean a previous pregnancy lowered your AMH. It means the picture behind the number may be more workable than a single result suggests. Here are four shifts that can sit between an easy first pregnancy and secondary infertility, and that a standard workup rarely checks.
Nutrient stores that pregnancy and postpartum draw down
Pregnancy and breastfeeding place real demands on iron, B12, vitamin D, and other nutrients, and those stores do not always recover on their own. In a Norwegian population study, about 39% of women were iron-deficient by serum ferritin at 14 weeks postpartum, and postpartum anaemia affects 10 to 30% of women in high-income countries. A standard panel may read ferritin as within range while it sits well below a functional fertility target. These nutrients are part of how an egg matures in the months before ovulation, so it is fair to ask whether your full nutrient status has been looked at, not just whether you are anemic.
A thyroid that shifted after your first pregnancy
The postpartum period is one of the most common windows for thyroid function to change. Postpartum thyroiditis occurs in roughly 5 to 10% of women; the risk is much higher in women who carry thyroid antibodies, and about one in five of those who become hypothyroid stay that way. Many women are told their thyroid is fine on the basis of TSH alone. Thyroid antibodies and reverse T3 can be part of the picture even when TSH is in range, and because thyroid function is connected to ovulation and egg quality, a full panel is a reasonable request when you are trying again, and outcomes have changed.
The stress and nervous system load is higher now than it was before
You are not the same nervous system you were before your first child. You are likely managing more, on less sleep, while trying to conceive on a timeline that feels short. A sustained stress load shows up downstream, in sleep, in progesterone, and in the environment your ovaries are working in. This rarely appears on a standard workup, which can leave you sensing there is more to look at without knowing what to ask for.
Your partner's picture, which can also change over time
Secondary infertility is not automatically a question about you. About a third of secondary infertility cases involve a male factor, and sperm quality can shift over several years with age and lifestyle. A current semen analysis, including DNA fragmentation where relevant, is part of a complete picture when a couple who conceived once is struggling to do it again.
None of this means your first pregnancy was luck, or that the body that did it once cannot do it again. It means AMH was never measuring the environment in which your eggs develop, and that environment is what a secondary-infertility workup rarely reviews before donor eggs come up. That is a layer you can ask about, and in many cases, support.
The Case for a Second Opinion
We review your timeline, your existing labs, and your history, including your first pregnancy and your partner's results, and we identify what may have been missed before the next decision gets made. We are not a substitute for your medical team. We work alongside them.
š Book a Functional Fertility Second Opinion here: https://fabfertile.com/pages/book
If you are not ready for a call but want to understand what a complete workup includes, download What Your Clinic Missed.
š Email hello@fabfertile.ca, subject line MISSED
Related reading:
Low AMH in Context. https://fabfertile.com/blogs/learn/low-amh-in-context
Inflammation and Fertility: The System Nobody Checked. https://fabfertile.com/blogs/learn/inflammation-and-fertility
Before You Choose Donor Eggs: A Functional Fertility Assessment. https://fabfertile.com/blogs/learn/before-donor-eggs-functional-fertility-assessment
About the Host
I'm Sarah Clark, founder of Fab Fertile and host of Get Pregnant Naturally, a podcast with over one million downloads. My functional fertility team works with couples navigating low AMH and failed IVF, reviewing functional lab results, gut microbiome, food sensitivity, vaginal microbiome, nutrigenomics, HTMA, DUTCH, toxin testing, and bloodwork alongside nervous system work, to help identify patterns that may not have been considered. We work alongside your medical team, not instead of them.
By Sarah Clark, founder of Fab Fertile, host of Get Pregnant Naturally (1M+ downloads), and author of Fabulously Fertile. Last reviewed June 2026.
References:
Secondary Infertility. Cleveland Clinic. 2023. Up to 11% of US couples, roughly equal split between female, male, and shared or unknown causes.
Understanding Secondary Male Infertility. University of Utah Health. 2024. About one-third of secondary infertility cases involve a male factor.
Postpartum Thyroiditis. American Thyroid Association. Occurs in approximately 5 to 10% of women in the US, higher risk with positive thyroid antibodies, about 20% of those who become hypothyroid remain so.
Prevalence of postpartum anaemia and iron deficiency by serum ferritin, soluble transferrin receptor and total body iron. British Journal of Nutrition. 2022. Iron deficiency by serum ferritin about 39% at 14 weeks postpartum.
Iron supplementation in postpartum women. World Health Organization, e-Library of Evidence for Nutrition Actions. Postpartum anaemia affects 10 to 30% of women in high-income countries.
