When you see those two lines disappear at a follow-up ultrasound, or when the bleeding starts, and you already know what it means, the questions come fast. What did I do wrong? Is something broken inside me? Will this happen again? After experiencing multiple miscarriages myself — a chemical pregnancy and a blighted ovum, both layered on top of a long infertility journey — I can tell you the self-doubt comes in hard and doesn't leave.
"Are miscarriages genetic?" is one of the most common things women search for after a loss, and I understand why. We want a reason. We want something we can point to, test for, and fix. The honest answer is genuinely complicated, which is both validating and frustrating.
If you're grieving a loss right now, Rescripted has additional resources on miscarriage and pregnancy loss that may help you feel less alone.
First, how common are miscarriages really?
While it doesn't make it any less heartbreaking, miscarriage is, unfortunately, extraordinarily common. According to the American College of Obstetricians and Gynecologists (ACOG), early pregnancy loss occurs in 10% of all clinically recognized pregnancies, but when you factor in very early losses — the ones that happen before a pregnancy is even confirmed — the true rate may be closer to 26%.
Recurrent pregnancy loss, newly defined by the ASRM as two or more miscarriages, affects approximately 2-5% of women of reproductive age. And about 50% of the time no clear cause is ever identified. That means half the women who go through recurrent loss are told, essentially, "we don't know why." If you've heard those words, I want you to know the absence of an answer is not the absence of your pain being real.
In a Rescripted survey of roughly 2,600 respondents, 69.2% said miscarriage risk was their top pregnancy health concern. That number tells you everything about how much fear and grief surround this experience.
Are miscarriages genetic?
Yes, genetics plays a significant role in miscarriage, but not always in the way people assume. When most of us ask "Is this genetic?" we're really asking two different questions, and it helps to separate them.
The first question is about the embryo itself: Did a chromosomal abnormality in that specific pregnancy cause the loss? The second is about inheritance: is there something in my genes, or my partner's genes, or my family history, that makes me more likely to miscarry?
Roughly 50-60% of first-trimester miscarriages are caused by chromosomal abnormalities in the embryo. The majority of these are random events that occur during fertilization or early cell division; they are not inherited. In other words, most early pregnancy losses are biological accidents, not a reflection of either parent's health or genetics.
Miscarriage due to genetics in the embryo
During fertilization, the egg and sperm each contribute 23 chromosomes. Sometimes the resulting embryo ends up with too many or too few — a condition called aneuploidy. When this happens, the embryo usually can't develop normally, and the pregnancy ends.
Trisomy, where an embryo has three copies of a chromosome instead of two, is the most common type. A review of chromosomal analyses in first-trimester losses found that trisomy 16 is the most frequent chromosomal abnormality identified in pregnancy loss, making it the single most common trisomy among miscarried pregnancies.
It's important to know that these events are sporadic; they happen by chance. They are not something you passed down or could have prevented.
That said, maternal age is a significant and well-documented factor. The risk of chromosomal abnormalities in embryos increases after 35 and rises significantly after 40, as eggs that have been stored longer are more likely to undergo errors during cell division.
After my own losses, the explanation that "it was likely a chromosomal abnormality" was meant to be reassuring, and in some ways, it was. But it also felt like being told the answer was that there was no answer, just bad luck.
The gene that causes miscarriages — is there one?
There isn't a single gene that "causes" miscarriage, but research has identified significant associations between recurrent miscarriage and dozens of maternal genetic polymorphisms across multiple genes, spanning several biological systems:
Blood clotting (thrombophilia): Inherited clotting disorders can impair blood flow to the placenta. Factor V Leiden is the most common inherited thrombophilia, present in 3–5% of the general population and found in significantly higher rates among women with recurrent loss.
Immune regulation: Genes affecting how the immune system tolerates a pregnancy may influence whether the body sustains or rejects an embryo.
Uterine receptivity: Genetic variations can affect the uterine lining's ability to support implantation and early development.
Thrombophilia, specifically factor V Leiden and other clotting mutations, can create microscopic clots in placental blood vessels, starving the pregnancy of nutrients and oxygen. Women with this mutation are two to three times more likely to have multiple (recurrent) miscarriages. If you've experienced recurrent loss, testing for inherited clotting disorders is reasonable and something to discuss with your provider.
It's also worth mentioning that gene mutations can arise spontaneously in a pregnancy rather than being inherited, which is another reason family history doesn't always tell the full story.
Can having miscarriages be genetic, as in, inherited from your mother?
While the research here is still emerging, a large intergenerational cohort analysis of 31,565 mother-daughter pairs found a statistically significant association between a mother's history of miscarriage and her daughter's risk of experiencing pregnancy loss. Other obstetric conditions — preeclampsia, preterm birth, endometriosis, PCOS — show similar intergenerational patterns, and miscarriage may share some of the same underlying pathways involving immune function, vascular health, and hormonal regulation.
This doesn't mean miscarriage is destined or inevitable if your mother experienced it. It means there may be inherited predispositions worth knowing about and bringing up proactively with your provider.
When I think about my own family history, I realize how much I don't know. My mother's generation, and certainly my grandmother's, didn't talk about pregnancy loss the way we're beginning to now. The silence wasn't because it didn't happen; it was because the culture didn't make space for it.
Are miscarriages inherited through the father's side, too?
Yes, paternal factors matter more than has historically been acknowledged.
Sperm DNA fragmentation, actual breaks in the DNA strand of sperm, has been associated with recurrent pregnancy loss in multiple studies. And chromosomal rearrangements in either parent, particularly balanced translocations (where chromosomal material is rearranged but no genetic information is missing), are an identifiable cause of a portion of recurrent miscarriage cases that can be detected through parental karyotyping.
Questions Women Are Asking
Pregnancy loss has historically been treated as a "woman's issue." But it's a reproductive issue, and the full picture includes both partners.
What causes miscarriage beyond genetics?
Genetics is a major piece, but not the only one. This matters especially for readers whose losses were chromosomally normal and who are still searching for answers.
Other established causes include:
Uterine structural abnormalities (present in an estimated 7-28% of women with recurrent loss), including septate uterus, fibroids, and polyps
Thyroid dysfunction, both hypo- and hyperthyroidism
Antiphospholipid syndrome, an autoimmune condition that increases clotting
Uncontrolled diabetes
And then there's the toughest category: unknown. In roughly half of recurrent miscarriage cases, thorough evaluation reveals no clear explanation.
How is the genetic cause of a miscarriage identified?
If you're wondering what testing looks like, here are the main tools available.
Chromosomal analysis of the products of conception (POC): Per the updated 2026 ASRM guidelines — the first revision to RPL guidance since 2012 — genetic evaluation of miscarriage tissue is now recommended for all patients experiencing RPL, starting with the second loss. This is a meaningful shift from previous guidelines, which treated POC testing as optional.
Parental karyotyping: A blood test that maps both partners' chromosomes to identify balanced translocations or other structural rearrangements. Typically recommended after two or more losses.
Thrombophilia panel: Blood testing for inherited clotting disorders like Factor V Leiden and prothrombin gene mutation.
Genetic counseling: A resource for couples who've had recurrent loss and want help interpreting results, understanding risks, and making decisions about future pregnancies.
One important note: not all providers proactively offer these tests after a single loss. Many follow the traditional guideline of waiting until two or three miscarriages before investigating. If you want answers sooner, advocating for yourself is valid and appropriate.
What about PGT, preimplantation genetic testing?
For those pursuing IVF, preimplantation genetic testing for aneuploidy (PGT-A) screens embryos for chromosomal abnormalities before transfer, reducing the risk of miscarriage from chromosomal causes, but it's not a guarantee. The biopsy samples only a few cells from the trophectoderm (the outer layer that will become the placenta), not the cells that will actually become the fetus. That means results can occasionally be misleading. On top of that, new spontaneous chromosomal mutations can arise after the biopsy that PGT-A wouldn't catch. For these reasons, current recommendations include genetic testing on the products of conception even after a loss of a PGT-A-normal embryo.
During my own IVF journey, PGT gave me valuable information before the transfer, not after the loss. It didn't eliminate the anxiety, but it gave me something to hold onto that felt like agency in a process that had taken so much of it away.
What to do if you think miscarriage runs in your family
If any of this resonated, here are concrete steps:
Talk to your OB or a reproductive endocrinologist. Bring up family history explicitly (it may not be asked about routinely).
Consider genetic counseling, especially before trying to conceive again after recurrent loss.
Ask about testing: parental karyotyping, thrombophilia panel, thyroid function, and uterine imaging. Know what's available.
Remember that predisposition is not destiny. Having a genetic risk factor means you and your provider can monitor more closely and potentially intervene, not that future pregnancies will end the same way.
You didn't cause this
If you've replayed every cup of coffee, every stressful day at work, every moment you should have rested more, eaten differently, worried less, know that I've done the same thing.
But the vast majority of pregnancy losses, even recurrent ones, are not caused by anything the mother did. They are biological events — often chromosomal, often random, often unexplained. Your body didn't fail you. A cell divided unevenly. A blood vessel formed incorrectly. Something deeply microscopic went sideways in a process so complex it's remarkable it works at all.
If a friend sat across from me right now and told me she'd just lost a pregnancy, I would tell her: this is not your fault. It was never your fault. And you're allowed to grieve without earning it through explanation.
