Embryo development speeds and gender

[Mctm123]

When I went through my last cycle, during the development stage, 7 eggs were fertilised and between day 1-3 I only had 1 embryo that developed fast (resulting in my little boy) the others were slow to develop and on day 3 they said they didn’t look symmetrical, not doing what they would like etc but then when I got there on day 5 all of them had gone to top quality blastocysts!

So regarding gender - I’m interested to know if the slow developing ones could be girls. Has anyone had this before where embryos that looked poor made a fast turnaround to day 5s?

I can't know for sure but I transferred a day 5 5BA which was a really fast fresh one with a frozen day 6 3BB - I had boy/girl twins and as my little girl twin always measured a week or more behind doctors are pretty confidant she was the day 6.

Amongst my friends I'd say those that transferred hatching day 5 blastocysts the majority but by no means all - had boys

I think there has been a few studies which shows that day 4 or 5 hatching blastocysts tend to be more likely to be boys and slower ones are girls.

I have a couple of frozen embryos left - a day 5 5AA and a day 5 2BB - I'd like to do one more transfer and I'm wondering which to go with as in the back of mind one is more likely to be a boy and the other girl - although I know nothing 100%

@shrugitoffonemoretime hi just wondered if you went ahead with the next transfer? I am considering doing another round. My embryos are graded 5AB/3BC/4CB and as I have 2 boys already would be nice to have a girl but obviously they are all a blessing and I would be grateful for a happy, healthy baby of course

I was wondering about this too, I've heard similar about slow developing ones being more likely to be girls, but I've no idea if it's true or one of those urban myths.

My partner would like a girl although I'm not fussed one way or the other.

Do they let you say which one you want to be transferred? Could you ask for a day 6 over a day 5 for example? Or do they just do the one they think looks best?

Hello! Unfortunately I never got to transfer my remaining embryos! my marriage broke down about a month after my post - turns out my now ex husband hadn't bonded with the twins and never expected IVF to actually work (after 5 rounds and £40k) and didn't want to parent full time 😳! Me the and kiddos are better off though!

@vardaverde

I got to choose which embryos I wanted - I did have to really stand my ground though - they weren't actually what the clinic wanted to transfer but I just had this "feeling" and I wanted to work backwards in terms of quality so my twins are actually lower graded than what I still have frozen! I told them since I was paying all the bills then I had a right to choose 😂

If you are after a girl I'd probably take a punt on the day 6 x

@vardaverde ill let you know as I’ve asked the question today. They did say they will take into consideration if I have any other requests rather than choosing the top quality one. I’ve said would I be able to chose the 3BC first for example.

@shrugitoffonemoretime really sorry to hear about your marriage, he sounds awful but I’m glad you’ve come out the other side and feeling better off. That must have been a lot to go through with twins also…you sound a super strong, fantastic mum. That’s a good shout what you said to tell them if you’re paying you get to chose!! I’ll use that one if it comes to it 😂 I too have a ‘feeling’ and I am drawn to the 3BC I’m not sure why. They are all day 5s however not day 6s. But something is telling me to use that one even though it’s officially ‘poor’ quality x

I had a FET of a day 3 frozen embryo. On test day my HCG was only 60 (they wanted anything over 50 but I was still worried). Anyway that little day 3 turned into my daughter so I have since wondered if there is actually something to the theory of girl embryos being a bit slower

Maybe bucking the trend here. My second egg collection was a freeze-all, with 3 embryos frozen. The 'best' embryo transferred first resulted in my daughter. I'm pregnant again with second embryo transfer, but don't know what we're having (I feel its another girl though) but will let you know! Can't remember grading as I tried to ignore that, as felt it wasn't helpful mentally.

There is some statistics though I'm sure that IVF is slightly more likely to result in a boy. I think there are several factors to this, including how sperm is selected for ICSI etc but part of it might be about 'boy' embryos being graded higher and transferred first.

BUT in both pregnancies, my babies have always measured ahead of dates at ultrasounds. My DD is tall and slim though and always has been.

In our case, the theory of slower embryos being girls holds (although I don't know about the difference in quality). We had 3 embryos from our second round, all the same grade 4BB, 2 from Day 5 and 1 from Day 6. The first Day 1 fresh transfer is my son, the second Day 1 FET was a BFN, and I'm now pregnant with the Day 6 after an FET and she's a girl.

I asked our clinic if we could transfer the Day 6 before the Day 5 - I had heard of Day 6s being girls but it was mainly because the Day 6 embryo was top quality at Day 3 whereas the Day 5 one was not, so I figured it might be more likely to work - but they said no because success rates are higher for those frozen earlier 🤷🏻‍♀️ We were self-funded with the NHS.
@Mctm123 what did your clinic say?

Just to chip in, but our second baby (lower graded embryo) is a boy 😆

Just a quick update on this. I used my 3BC in November and it failed. Went again for another transfer yesterday and planned to use the 5AB but to my complete shock, it didn’t survive the thaw!! So moved on to our lowest grade 4CB.

Frantically searching for success stories from 4CBs as this is our last go

It was the other way around for me, my best quality, quick growing embryos were my girls and my slow grower one that we thought we were going to miscarry was my boy. Same went for natural conception, I seemed to have miscarried my boys, only know from testing, but my stronger ones that stuck around were girls. I have alot more girls the boys.