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  • Writer's pictureKirsten McLennan

My thin endometrium lining

“Five per cent of women under 40 have thin linings…it’s difficult to treat and we rarely know the cause”.

I still remember the day our IVF specialist uttered those words. The problem was: we were onto our third fertility specialist and knee deep in IVF.

So how did we get here?

Up to that point, all I knew about the endometrium lining was it had to measure at least 6mm to transfer in Australia (8mm in most countries). But it was after three consecutive cancelled transfers and a few worrying remarks from our sonographers, “Oh dear, your lining’s looking a bit thin”, I started to research it. And wow did I find out a lot!

What was the first thing I learned?

The lining is crucial to falling pregnant and sustaining a pregnancy. It’s considered one of the stars of the female reproductive system and plays a key role during pregnancy. As the wallpaper of the uterus, it becomes thicker with pregnancy so it’s ready to receive an embryo and support the placenta.

An optimum lining is 10-12mm at transfer. On our cancelled cycles, my lining measured late 4mm’s. On the transfers that went ahead, it was 5.5-6mm. But with a lining around 6mm, it’s extremely difficult to conceive.

As one of our specialists put it, “You need healthy and rich soil for a plant to grow”

One research study I read found with a lining of 6-7mm, the pregnancy rate (not birth rate) was only 7.4 per cent. For women with a lining over 7mm, it was more than triple, 30.8 per cent. Another study showed that with a lining of 6mm, of 35 embryo transfers conducted, only two babies were delivered.

For most women, it’s hard to treat but one of the few known causes is lack of estrogen. On one cycle, I took about 10 estrogen pills a day (I wish I were exaggerating). I also tried acupuncture to help nourish my blood and thicken my lining. What felt like millions of tiny needles were placed into my body. I looked like a porcupine. But to my surprise, I found it quite relaxing.

My lining increased, but not enough

On day 22 of this cycle, our nurse told us we would have to cancel the transfer. There were so many tears that day. I was exhausted. For 22 days I had tried everything, and it still wasn’t enough. I had barely moved the dial. My lining had started at 3mm and 22 days later, it was only 4.7mm. Most linings start at 3mm at the end of your period and increase 1-2mm a day, with many women reaching 10-12mm by their transfer day (usually day 16-20).

It was on our last cancelled cycle I finally took matters into my own hands. On this cycle, my lining had remained stubbornly low and at my final scan, five days before our transfer, it was only measuring around 5.5mm.

I wasn’t confident, but our specialist encouraged us to push ahead as it was, “close enough”. Only, I had read that with people with lining issues, it’s not uncommon for the lining to fluctuate. I asked for an ultrasound the day before the transfer. Not being standard practice, she reluctantly agreed. It was at this scan we learned my lining had gone back down and was barely reaching 5mm. The cycle was abruptly cancelled.

As the failed and cancelled cycles started to build up, we changed to our third specialist

At our first appointment, he hit us with the hard truth: thin linings are rare, usually genetic, and often difficult to fix. And while he confirmed everything I had already read, when he said the words out loud, it felt confronting.

He went on to tell us that as we had already tried the popular treatment solution – Estrogen therapy, aspirin, acupuncture, and Clexane injections – it didn’t leave us with many options.

It was then he told us surrogacy was our, “best chance of success”.

We didn’t know too much about surrogacy then, but it seemed overwhelming and I knew in my heart I wasn’t ready to give up on being pregnant myself. Accepting our decision, he made another suggestion: a stem cell procedure. The procedure would help invigorate my blood flow and nourish my lining. It would either work or it wouldn’t. One day off work and minimal recovery time. It was worth a try.

It worked. For this treatment cycle, my lining reached 6.5mm

We transferred in a Grade A Pre-implantation Genetic Screening (PGS) embryo and I became pregnant. I still remember so clearly the day we got our positive result, the high was enormous. But the next day, dread set in. I was petrified of something going wrong. The lining measurement haunted me. Yes, it was enough to transfer, but it wasn’t the ‘ideal’ thickness.

At our first scan at 7.5 weeks, we had the devastating news our baby was measuring too small and the heartbeat was too slow. Two days later at our follow up scan, the baby had passed. We were heartbroken.

A couple of weeks after my D&C procedure, our specialist called with the biopsy results. The baby was genetically normal. The baby was perfect. The baby was a girl. I wish I hadn’t found out the gender as it was impossible not to imagine how life would have been like with a baby girl. But above all else, it was yet another confirmation that the issue was me. Each egg collection, the specialist would retrieve an above average number of eggs for my age. When they tested them for chromosome abnormalities using PGS, most tested normal.

So, it wasn’t the embryos that were the problem. It was the carrier. It was me

As we had fallen pregnant though, we decided to try one last time. It didn’t work of course. I’m was not sure what we’re thinking. I suppose we weren’t ready yet to close that door. You always hold out hope.

But the day we received the negative result, I knew I had had enough. Something snapped in me that day and I knew that I never wanted to try and get pregnant ever again. Ryan agreed 100 per cent.

It took us a couple of years to fall pregnant with surrogacy but on 5 July 2019, our beautiful son Spencer John Wilson was born.

But if I had my time over, I wish I had been more proactive with my treatment. A thin endometrium lining is a key cause of preventing pregnancy and it’s easy to diagnose. And yet, it took us years of treatment before we knew this.

Reflecting back, I now know how crucial it is to do your research; be informed; arm yourself with knowledge; and talk to others who are also going through fertility treatment.


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