Missed abortion 12th week of pregnancy despite good development, possible causes and diagnosis

Hello,

I would like a professional assessment of my pregnancy loss and whether further investigations are advisable.

MY BACKGROUND:

I (32 years old)

10 years of trying to conceive with ex-husband (42)

3 negative IVF/ICSI treatments (2018, 2019) embryos always severely delayed (e.g. day 5 only beginning morula)

3 natural early cleavages 2019, 2020 (biochemically only lasted a few days, HCG always very low)

Immunology 2019: plasma cells 0, uNK 137/mm², T4/T8 slightly elevated, still thyroid antibodies at the time

Hashimoto's, well controlled for years, no antibodies for three years (TSH ~0.8)

Coagulation and genetics unremarkable, only PAI-1 4G/5G heterozygous and 844 A>G polymorphism genotype AG heterozygous, which according to my information is classified as clinically unremarkable.

My husband had a poor spermiogram, with DNA fragmentation.

Until then a hysteroscopy

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PREGNANCY WITH MY NEW PARTNER (35):

I became pregnant with my new partner 2025 within 3-4 months.

Everything had developed on time up to the 10th week of pregnancy.
The only noticeable thing was that the amniotic cavity was very elongated.

In the 10th week of pregnancy I had heavy periods, was hospitalized for 3 days, took more progesterone and bed rest. )My progesterone was never measured, but I still took Utrogest from ES+17 as a precaution):

The amniotic cavity became round again

The baby continued to grow normally

Heartbeat strong

No further bleeding

In the 12th week of pregnancy, the baby was unusually quiet during the ultrasound.
One week later, a cardiac arrest was detected (presumably shortly after the ultrasound in the 12th week of pregnancy).

RELEVANT INTERVENTIONS TO DATE:

A total of 3 hysteroscopies at different facilities in 2018, 2019

Two laparoscopies in 2019

Recently scraping (suction curettage)

I have read that multiple intrauterine interventions can increase the risk of chronic endometritis (plasma cells).

MY QUESTIONS TO YOU:

1. can a missed miscarriage after 12 weeks gestation be caused by chronic endometritis - or is this unlikely at this stage?

2. would you recommend a repeat biopsy for plasma cells after 3 hysteroscopies and a scraping - or only if there are symptoms?

3. are there any other useful examinations that I should initiate before a new pregnancy if everything (coagulation, genetics, immunology, hormone status, thyroid, plasma cells, uNK) was already unremarkable in 2019?

4. can the elongated shape of the amniotic cavity at the beginning be an indication of an unfavorable implantation that later led to an abortion?

5. in your experience, is there a connection between the heavy bleeding in the 10th week of pregnancy and the later cardiac arrest - or is it usually more likely that the embryo aborts in the 12th/13th week of pregnancy due to genetic causes?

I have not been to a fertility clinic since 2019.

Thank you for your time and expertise.

OK, thank you very much. I have to say that I haven't been to a fertility clinic for 6 years because I put my desire to have children on hold with my ex-husband and the biochemical pregnancies and the fact that I only got pregnant three times in all those years were probably due to his bad sperm. As I said, the embryos that were transferred to me at the time were always further behind in their development than they should have been. I got pregnant very quickly with my new partner. That's why I no longer want to go to a fertility clinic. From the 7th week of pregnancy you also leave this clinic. They wouldn't have done anything in the last pregnancy either. I was already in the 12th week of pregnancy.