so what are these milestones based on?

tootlebug

th 34 week "biggie", 36 weeks, 28, 24, etc.  spontaneous conception, monitored or both?

im just curious...because it seems that every stinkin' day in utero makes a difference with twins.  so what if multiples are conceived spontaneously?  and the woman doesnt know when she ovulated?  they could be told that they are for example, 35 weeks based on u/s measurements when they are really 34w1d (or something, that's just an example) since babies measure "a week ahead" and "a week behind" all the time...that's actually my situation with my babies but i know when i conceived bc i was using OPKs/charting/being heavily monitored by the RE.  is this a dumb question?  probably.....am i pondering before getting dressed for the day?  yes....

ninjabridemom

I actually am not aware of differences in milestones based on type of conception...

 

My understanding is that the milestones come from baby's development.  As of 29 weeks, the viability increases.  As of 34, the lungs have started the develop.  They should be good to go around 36.  Etc.

tootlebug

i know but what im saying is, if the babies are conceived spontaneously....like by "just having sex" (geeze what would that be like?? : ) or whatever, no OPKs, no RE monitoring...the date may not be totally exact.  ie. someone could think they ovulated on day 14 but reall it was day 21 and they took a test a couple weeks later bc they were late and it was positive.  but they could have a larger baby via u/smeasurement and therefore have a due date that's a week ahead than it should be.  it's not a big deal, im just curious if there is any information about this.  i dont even know if i am articulating myself correctly.

llamagoat

Our twins were conceived spontaneously and when we went for a dating ultrasound found out they were a week behind what we had thought (and also found out there were two!) but when they gave us the new gestational age, we just assumed that as fact and have been using that for the due date, despite what we originally thought the gestational age was as first.

We thought the due date was June 9th and after the dating u/s it became June 16th and that's what we've been using ever since. 

OrangeSmoke

I think the milestones (just like the milestones when they are outside babies) are general guidelines.  So yes, most babies will smile by 2 months, but it doesn't mean that all of them smile exactly 2 months from the date they were born.

I think in utero milestones are the same.  So at 24 weeks, most babies born will have a chance at life.  But certainly there will babies that won't make it being born at 25 weeks and some babies that will born at 23 weeks (I know one personally!).

Hope that helped?!

 

ninjabridemom

Oh I see.

 

I guess LMP for spontaneous with corrections from the first ultrasound if necessary.  They moved me back a day based on the first ultrasound, lol, so I figure it's pretty accurate.  Date of conception for monitored stuff, I'd assume.

tootlebug

llamagoat:

Our twins were conceived spontaneously and when we went for a dating ultrasound found out they were a week behind what we had thought (and also found out there were two!) but when they gave us the new gestational age, we just assumed that as fact and have been using that for the due date, despite what we originally thought the gestational age was as first.

We thought the due date was June 9th and after the dating u/s it became June 16th and that's what we've been using ever since. 

...but what if they are just smaller babies?  like i said, im 34 1/2 weeks, and one of mine is measuring 35 1/2 weeks, the other 33 1/2 weeks.....but i know that im exactly 34w4d bc i was using OPKs/charting and being heavily monitored by the RE.  if i wasnt being monitored by the RE and conceived them spontaneously, would i be "35 1/2 weeks" because of the bigger baby?  or "33 1/2 weeks", because of the smaller baby.

Breezy8407

Ours were spontaneous, and I am pretty certain within about 3 days when they were conceived because I was charting.

My due date was originally 5/19 based on LMP. At one of our first ultrasounds, they decided that because of the size of the babies (or so I think), my due date should be adjusted a week to 5/11.  I was very regular in my cycles, so I was confused when they were saying the date of conception was off. I offered to bring in my charts to show them...oh well. I was happy to move up a week.

As of yesterday, my boy is measuring a week ahead (so would be two weeks ahead of my original date) and girl is measuring about right on for gestational age (so she would be a week ahead of original DD), so my conclusion is that I just have big babies...???

KDR1979

A 1st trimester ultrasound is the most accurate way to date a pregnancy. If that u/s changesYour due date by more than 5 days, the ultrasound due date becomes your official (will not change)Due date. After the 1st trimester, babies grow differently for a variety of reasons, but theirDue date will not change. 24 wks=viability, 50% chance of survival (but those that survive can have many issues)28 weeks = much higher survival rate34 weeks usually means lung maturity. Most babies still need nICU time, but they are Usually " feeders & growers" & don't need breathing help.

erniebufflo

My pregnancy and my twins were a total surprise. When I may have ovulated has never mattered because they start day 1 of your 40 weeks on day 1 of your last period. 

tootlebug

erniebufflo:

My pregnancy and my twins were a total surprise. When I may have ovulated has never mattered because they start day 1 of your 40 weeks on day 1 of your last period. 

um...no, that's not how it works.  that's how OBs try and date stuff in the beginning but that is not very accurate for some women. what if a woman ovulated on day 25 or 30 of her cycle instead of the infamous close to or around day 14? in fact, one of my best friends was told she was going to miscarry based on her LMP.  they said she should have been 8 1/2 weeks and she was only measuring 5 1/2 weeks.  (it was sac plus yolk sac, no hb yet on the ultrasound).  i was actually the one that calmed her down, bc i taught her how to chart and use OPKs and we knew that she didnt ovulate until day 40 (or around there) of that cycle. so we knew that she was really only 5 1/2 weeks.