Why do my miscarriages keep happening at the same week?

Is it normal for losses to happen at the same week each time?

It is common, and it does not by itself point to one cause. Most miscarriages happen in the first trimester, during a stretch of weeks when the embryo and the early placenta are developing quickly. When losses happen within that stretch more than once, they often land at a similar point.

A repeated week can feel like a message, and it deserves attention. But the same week can reflect very different causes:

• A chromosome error in the embryo, which often shows itself in the first trimester
• A structural issue in the uterus, such as a septum or a fibroid affecting the cavity
• A clotting problem such as antiphospholipid syndrome
• An untreated thyroid or blood sugar problem

A 2021 analysis in The Lancet estimated that 15.3 percent of recognized pregnancies end in miscarriage, and only a small share of women have more than one. That is why a pattern across two or more losses is worth evaluating rather than explaining away.

The week is a clue. The evaluation is how the clue gets read.

What usually causes a first-trimester loss?

The most common cause of a first-trimester loss is a chromosome error in the embryo. ASRM’s 2026 guidance states that 50 to 60 percent of first-trimester miscarriages are due to embryonic aneuploidy, meaning the embryo has too many or too few chromosomes.

These errors usually happen by chance as the egg or sperm forms, and they become more common as eggs age. A 2019 BMJ study found that miscarriage risk was about 10 percent for women aged 25 to 29 and rose to 53 percent at 45 and over, a rise that reflects, in large part, more frequent chromosome errors in older eggs.

A pregnancy with a significant chromosome error often cannot continue developing, which is one reason so many losses happen early.

Other causes are less common but important, because some are treatable:

• Uterine factors, such as a septum, polyps, or fibroids affecting the cavity
• Antiphospholipid syndrome
• Uncontrolled thyroid disease or diabetes

For many women, a single loss has a chromosomal explanation. With repeated losses, the possibilities widen.

What does it mean if a lost pregnancy had normal chromosomes?

A loss with normal chromosomes means the embryo’s genetic makeup is unlikely to explain it, so the evaluation turns to factors outside the embryo. ASRM’s 2026 guidance notes that in women with recurrent loss, a chromosomally normal loss is more likely than after a single loss, and the likelihood rises with the number of losses.

After a chromosomally normal loss, ASRM’s evaluation focuses on:

• The uterine cavity, through a saline ultrasound, hysteroscopy, or similar test
• TSH, with treatment if it is above 4 mIU/L or the lab’s upper limit
• Antiphospholipid antibodies after three or more losses or a blood clot
• HbA1c when diabetes risk factors are present

Testing for chronic endometritis and sperm DNA fragmentation may also be considered in selected cases.

A normal result can feel frustrating, because it removes the most common explanation. It is also useful. It tells you and your doctor where to look next, instead of leaving every possibility equally open.

What should I write down about each loss?

Write down the details that help a doctor see the pattern clearly and quickly. A one-page record of every pregnancy saves time in appointments and keeps important facts from getting lost between providers.

For each pregnancy, record:

• The date of the positive test and how the pregnancy was confirmed (blood test, urine test, or ultrasound)
• The week the loss happened or was diagnosed
• Whether a heartbeat was ever seen
• Any treatment beforehand, such as medication, stimulation, IUI, or IVF
• Whether the tissue was tested, and the result
• What you were told about why it happened

Add the tests you have had, with dates and actual values, and note anything you asked about that was never done.

ASRM’s 2026 guidance builds its evaluation around a woman’s specific history and risk factors. The clearer your history is on paper, the easier it is for your care team to apply that guidance to you rather than to an average patient.

How do I cope as that week gets closer in a new pregnancy?

Coping starts with expecting the fear rather than fighting it. Anxiety as a familiar week approaches is a common response after loss, not a sign that something is wrong with you or with the pregnancy.

The emotional weight of loss is well documented. A 2020 study by Farren and colleagues in the American Journal of Obstetrics and Gynecology found that one month after an early pregnancy loss, 29 percent of women met criteria for posttraumatic stress and 24 percent had moderate to severe anxiety. ASRM’s 2026 guidance calls psychological support an essential part of miscarriage care.

Things that can help as the week approaches:

• Ask your care team, before you need it, what support and check-ins are available in early pregnancy.
• Plan the days around that week gently, with fewer demands and people you trust nearby.
• Use short calming practices when fear spikes, such as a few slow breaths with a longer exhale.
• Consider a counselor who works with pregnancy after loss.

You do not have to feel calm to deserve support. You deserve it either way.