*Could gender prediction be wrong? Also the foetal age?*

[serene73]

Hello there lovelies*

I'm expecting my first baby at somepoint in the next year I was just wondering if anyone could shed any light on the following two things:

1. The foetal age: I was away in Spain for a two month period and came back to the UK on one night only to see my partner on my birthday.

The first day of my last period was 21st April.

I saw my partner on 20th May, meaning that 20th May was the date of conception.

By my calculations I am 14 weeks and 5 days (from conception).

However last tuesday (23rd August), I was told I was 16 weeks and 4 days, meaning that by this week I would be 17 weeks and 5 days.

Do I go from the date of conception???... Its all so confusing! Seems like some very strange maths going on...! Surely foetal development starts from conception? Why do a lot of sites say you were pregnant before you even did the deed?

also 2. I was told the gender at the last scan (which by my calculations would have been at 13 weeks and 4 days - am I wrong??)... He said that it looked feminine to him, he wasn't completely 100% sure, but it looked like a girl. No lines were pointed out. This was a private scan. Its just that I was 100% in myself that it was a boy, at 3 weeks pregnant I had a sober and fully conscious 'vision' in which a young boy appeared who looked like my partner and screamed 'Mummy' and hit me on the head (I had wanted to get rid of the pregnancy before I had this vision). Also every dream I've had has involved a boy... I felt I was meant to keep it as I had 'met' it and upon hearing that it was a girl I broke down and have felt a bit disillusioned since. The night after the scan I had a dream in which I was told that the scan was wrong and it upset me even more when I woke up. I would be fine with a girl, would still love it, would just like to know if gender predictions can be wrong??

Any help would be appreciated! *****

[Brisen]

The most common way for calculating your due date is to use the date of you last menstrual period, so that's why the sites and whatnot will say you're pregnant before conception.  You are generally two weeks behind what the Dr. will tell you.  So if they're saying you are 17 weeks 5 days, that is 15 weeks 5 days from ovulation/conception.  On average.  If you didn't conceive two weeks after your last period, there will be more variation.  

But the date you had sex isn't necessarily the conception date; sperm can hang around waiting for the egg for a few days.  I've heard up to a week.  Doctors assume that the date given by the scan is more accurate because it is based on development as well as size, but there is still wiggle room.

That's my layman's understanding, anyway.

[Brisen]

Oh, and about gender -- http://www.baby2see.com/gender/external_genitals.html is an interesting read about that.  If you were 16 weeks and 4 days (so, gestational age = 14w4d) at the scan, there is a reasonable chance it was accurate.  By 20 weeks, it's much more accurate, though they do the anatomy scan usually between 18 - 22 weeks, and I think it's still fairly reliable even if you're in at 18 weeks. 

[bluedaisy]

There is always a possibility that the gender is a mistake - it doesn't happen often, but it does happen and I think the earlier the scan, the more likely to be mistaken.

We were living in Tanzania when we had a 21 week u/s with our dd and we were told 95% she was a boy!!  We found out at 27 weeks that she was definitely a girl!  Of course, our situation was a little different because we were in Tanzania where the equipment wasn't completely up to date and it's not common for people to find out the sex ahead of time.

I would say it's unlikely that the u/s is wrong, but it is a possibility.  Will you be having another one?

[1love4ever]

Use a due date calculator online, and you can select date of conception or of last period and it will tell you  how far along you are.  Predicting the gender thru ultrasound can always be wrong, especially when its done that early!  I had a friend who was 20 weeks when she was told she was having a girl.  It came out a boy!  Lol.   And yes ultrasounds can also be incorrect about predicting your due date as well, and about estimating the weight of the baby, etc.