Cervical length fluctuating from 23mm to 36 mm — confused

Hi! I’m 18 weeks, with a history of conisation, and my CL measurements have been:
12w: 37 mm
16w: 23-25 mm
Started vaginal progesterone (200 mg)
Next day: 30-35 mm
17w: 35-36 mm

My doctor thinks the 23–25 mm measurements may have been transient/measurement-related (she mentioned urinating/temporary spasm) and is reassured by the later measurements.
I’m struggling because I feel like I’m just waiting for something bad to happen. Could 25 mm have simply been an early sign of shortening despite the later normal measurements?

Also, I find it hard to believe progesterone could make such a difference after just one day. My doctor said I could stop it based on the current measurements, but I’m tempted to continue for peace of mind.

I’ll be measured again this week (18w) and on my 2nd trimester scan (20w).

Would you follow your doctor’s advice or continue progesterone for reassurance? Has anyone experienced this kind of CL fluctuation?

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u/drihgy — 2 days ago
▲ 4 r/CautiousBB+1 crossposts

Looking for positive pregnancy stories after a cone biopsy

Hi everyone,
I’m currently 14w pregnant with my first baby and looking for some reassurance.
About 3 years ago, I had one cone biopsy for CIN2 (tissue height about ~12mm?). So far my pregnancy has been going well, and my cervical length was 37 mm at 11–12 weeks. My OB is monitoring my cervix because of my history.
I keep reading stories about cervical insufficiency and preterm birth after conization, and it’s making me quite anxious.

I’d love to hear from anyone who:
had a cone biopsy before pregnancy,
had cervical length monitoring,
and went on to have a healthy pregnancy (with or without a cerclage).
Did your cervix stay stable? If it shortened, when did it happen and how was it managed?

I’m hoping to hear some positive experiences because it’s easy to find the scary stories online.

Thank you!♥️

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u/drihgy — 24 days ago