How thick should lining be for natural conception?

[friendlyBadger]

Hi

I had a recent non-fertility related transvaginal ultrasound. My uterus apparently looked really healthy but my lining was 6.4mm at 2DPO. My periods are usually as follows:
Day 1: light flow (quite brown sludgey)
Day 2: heavy bright red flow
Day 3: medium flow (red)
Day 4: light
Day 5: light brown watery

Google tells me that this could be too thin to conceive? I've been trying to conceive for 7 months using SMEP with no whiff of a BFP or even a faint line and I'm starting to get worried. I've also been temping to confirm ovulation.

My blood tests came back normal also so unsure if it's hormone related?
day 3 - oestrogen: 164, LH: 4.5, FSH: 7.6
day 21 - progesterone: 48

Online when it mentions 7mm as being the minimum for uterine lining for IVF, it isn't clear what the minimum is for natural conception. Does anyone know if it's the same for natural conception? Also, should the lining be 7mm by the time of implantation? or by the time of ovulation? Also, should the lining continue to increase from ovulation until implantation or does it decrease due to progesterone?

Thanks so much :)

Forgot to mention that my 2 most recent periods have been super light for some reason. Ultrasound was before these 2 periods so worried that the lining would be even thinner now :(

I can't help with the thickness but my periods were less than 24 hours and could've got away for most if not all without using anything and we have a little boy so just to say that a short or light period doesn't necessarily mean anything 🤞🏻 for you x

thanks so much @firsttimemummy321! that's so reassuring

Hi OP, I'm pregnant now but when TTC for several months I also had so many worries about my lining being too thin so I wanted to share some of that with you to hopefully help you! My periods sounded just like yours (sometimes they would stop and start too) and I had an external ultrasound scan which showed a 6mm lining at 10dpo. This really worried me!
Was your scan external? If so I have realised they can't measure lining very accurately that way. So it may well have been thicker!
To be sure, I booked a private scan (internal) to measure lining and look at follicles and she said lining was between about 8mm and had a 'perfect triple layer appearance' which is apparently the most important sign of a healthy lining. Hopefully that reassures you. I found that scan so reassuring! I had no kind of special heavy period that month either (I did keep an eye out - it was light as always)

I read a lot about thickening the lining etc and learnt that it's all about Estrogen (rather than progesterone -which I had previously thought) and the run up to your ovulation is when it builds rapidly. I made sure I did loads of walking around this time to improve blood flow and also had acupuncture. Not sure if these things necessarily made any difference but they definitely made me feel like I was 'doing something'. To be fair - acupuncture was unavailable until after the 8mm lining month (due to covid) so it was all down to walking (or was was never actually thin in the first place maybe!)

Overall I think I was worried for nothing. I really hope it happens for you soon!!

Thanks SO much Blossomhalo, I really appreciate your message.

When during your cycle was your lining 8mm?

My scan was internal but they also said it had a perfect triple layer appearance so that's great to know that that's one of the main things :)

I made the original post on the second day of my period this month and was so worried as it seemed sooo light for my second day but it ended up developing into one of the heaviest periods I think I've ever had! I drank beetroot juice everyday for a month which apparently thins your blood and promotes blood flow so feeling much more positive about my lining :)

I've also recently started acupuncture and am walking lots so fingers crossed it's all making a difference!

Sorry for such a delayed reply, I just saw this.
It was 8DPO when I had the 8mm lining.
I have a 12 day luteal phase too, so not too far from my period being due.

That's great news that you have had a bit of a heavier flow (well for reassurance at least)

I really hope all goes well for you