Determination of twins...

buggles

For you moms of multiples:

At what point during gestation can one determine if you're carrying twins and is there a difference in determination depending on whether they are fraternal or identical?

And how and when can they determine whether they're fraternal or identical? 

I always wondered.

calmbride04

One of the big indications of fraternal twins at my u/s was the 2 seperate sacs and 2 placentas. That told us that, more than likely, 2 eggs dropped.

cands

The vast majority of people find out at their first ultrasound, so for me that was 6 weeks 2 days, but it varies based on when folks had their first ultrasound.  It's possible for one of the babies to be missed on an ultrasound, but it's relatively rare, and when it happens it's usually 5 week or 6 week ultrasounds.

Somethings that show identical or fraternal can be found on early ultrasounds (like identicals who share a sac), but other times it can't be determined until after birth. 

PianoPlayingSarah

B/c my girls were spontaneous and I had no major issues early on, I didn't have an u/s until 17 weeks - where they discovered triplets.  If I wasn't scheduled for an u/s that day, I'm sure my doctor would have put me in for one b/c I was huge for 17 weeks.

It was determined then that they were identical b/c all 3 shared a placenta and they were in one big sac with very thin membranes separating them.  The placenta was tested after birth and confirmed to be just 1 placenta.  Sometimes 2 placentas can fuse together and look like one.

Mrs.Babbsy

I found out at my 7w appointment. We saw both heartbeats in the same sac. Mine are identical.

 

MrsEABarton

I had an ultrasound at 5w6d and they saw two sacs and were also able to see where the two separate eggs had come from (can't remember the name, it's Latin though) - one of from each side, so I know I'll have fraternal.

7w4d

Andrea Isaacs

Since I didn't take fertility treatments, my dr. didn't have a reason to do an ultrasound until the big one.  So I was 18 weeks, going in to find out the sex of the "baby" and discovered we were having twin boys. 

ChiBride2007

I found out at 7w2d. My OB typically does an u/s at the first visit to date the pregnancy, rule out ectopic, etc.

sweater

We found out by accident around 14 wks during our doppler to the heartbeat. Sent in for an early u/s to confirm it and sure enough - twins!

My boys were mono amniotic - meaning they shared the same amnio sac in addition to gestational sac and placenta - so mine are considered identical without any tests. (they shared an amnio sac because my egg split too late and my ?body thought I was only having one baby)

When people say "sac" on here...they're usually referring to the gestational sac.

TYPICALLY - if there are two gestational sacs and placentas the twins are fraternal. If there is one gestational sac and placenta, they are identical.

But the only true way to know is if the twins have a DNA test after birth since crazy things like fusing placentas happen. ?

FaeryStarGazer

cands:

The vast majority of people find out at their first ultrasound, so for me that was 6 weeks 2 days, but it varies based on when folks had their first ultrasound.  It's possible for one of the babies to be missed on an ultrasound, but it's relatively rare, and when it happens it's usually 5 week or 6 week ultrasounds.

Somethings that show identical or fraternal can be found on early ultrasounds (like identicals who share a sac), but other times it can't be determined until after birth. 

Ditto this. Found out at 6w, when there were two very clear eyes (sacs) staring out of my uterus!  We didn't know until we bought a DNA test whether or not the girls were identical or fraternal (we totally thought they were fraternal until they were 11m old).

laurncui812.0

They were able to see two fetal poles at 6 weeks and determined they were identical at about 10 weeks when they saw one placenta but two sacs.

JustaKidAtHeart

Mine were missed at my first u/s (6w2d) and we found out at 11w at what turned into a big thing when the nurse couldnt hear a HB so I got an u/s that wasnt scheduled