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1135924 tn?1268878271

Fraternal twins one sac is much much smaller than the other!

So I had my 6-7 week ultrasound a week ago. Two sacs with two heartbeats, but you could barely see the second sac. What are the chances if we saw a heartbeat with both that both will survive? Could one sac just be behind the other and that is why it is hard to see the second easily?
I have uploaded the photo of my ultrasound pic
13 Responses
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Avatar universal
Hi everyone, I'm also interested in how everything's going for you all.
I had a scan at 7w3d. Twin A measured 8.7mm (6w5d) and Twin B measured 7.4mm (6w3d), but twin B's sac was about half the size of the other and i've been told to be prepared that I might loose twin B. I wont get another US til 14 weeks. I'm currently 9weeks now and the wait and worry is driving me mad. Oh! and they're fraternal.
Helpful - 1
Avatar universal
Oh, and it turned out that they were actually identical, not non identical as initially thought x.
Helpful - 0
Avatar universal
I posted on here 5 years ago and noticed at the time that we never found out the end of peoples stories, which was what I desperately needed at the time. So here's how my story went.....after a dreadful pregnancy filled with fortnightly, then weekly, then twice weekly scans I delivered twins at 30 weeks as it was no longer safe for them to live with me. Weighing 2lb7 and 3lb11, they lived in the neonatal unit for 12 weeks before they were finally well enough to come home. They are now 4&1/2 and although one is still so much smaller than the other, and will always remain that way, they are both so very healthy considering. The initial worry was TTTS, fortunately that didn't develop. Turned out the problem was poor bloodflow from me to baby. I know there are still a few negative points to the story, but it all turned out well in the end which is all we had ever hoped for. Stay positive xx
Helpful - 0
Avatar universal
At 5 weeks I knew there were 2 sacs but only one heartbeat was detectable. Today I went for another ultrasound.  There were 2 heartbeats but dr said that twin b is not likely to survive until next u/s because it's considerably smaller and it probably had some chromosomal issues. I'm happy twin a is thriving but sad about the potential loss of twin b.  could twin b's chances of survival improve and grow into a healthy baby?  
Helpful - 0
Avatar universal
Hi I found out at 8 weeks im carrying twins..im now 14 weeks and went for my scan on the 10th twin 1 is quite abit smaller than twin 2..my consultant says not to worry as it may just be the pattern they both follow all the way through but I cant help but worry im bk for another scan in 3 weeks anyone else had the same problem at 14 weeks? X
Helpful - 0
Avatar universal
Hello ladies i am hoping to get a answer back but im not 7 weeks prego and have had the same issuse with baby b"s sac being smaller then baby a"s  it is indeed like one of you ladies said baby b have like no space it seems and baby a has a swiming pool well they both have strong healthy heart beats and im hoping for the best trying to stay pos  but they did say there could be a chance baby b stops growing   i would like to know the out come of some of your twins THANKS
Helpful - 0
Avatar universal
Hi.  I know the odds of getting a reply to this is slim sonce this thread is almost a year old but I just thought it was worth a shot. Smilies 18 what was the outcome of your pregnancy?  I just had an ultrasound and my images look very similar to yours.  I am before heartbeat stage though.  JUst wondering what my chances of keeping 2nd twin is.  Doctor says 60%.  Trying to stay positive
Helpful - 0
1488488 tn?1288184523
Just wondering how your twins are? I am in the same situation with my sacs being 2 diffrent sizes, I wasnt worried, just thinking that the bigger sac is probably a girl and the smaller sac being my lil boy lol
Helpful - 0
1135924 tn?1268878271
My last ultrasound was on the 16th. They both had grown especially the smaller one, even though they are still different sizes. I have another ultrasound on April 6th then a level 2 ultrasound on the 15th to a specialist that will do a careful examination of the two of them. My OB never said anything about losing one of them but she still seemed a little cautious, that is why I have been going and doing ultrasounds every 2 weeks, and now it is 3 weeks, and then going to a specialist to make sure they are both doing good. It just seems weird that the second one hardly has space in the sac not much fluid around it while the first one has this huge swimming pool (lol). Being that I am 11 weeks I am a lot less worried now. I just can't wait though for my April 15th appt.
I hope everything is okay with your two. Please keep me updated on how your doing too. I honestly think that once the heartbeats are seen like I saw on mine and you on yours everything should be good ;)
Helpful - 0
1263041 tn?1269909032
Just wondering how things have been going for you? I am in the same situation right now: 9 weeks with twins (both have great heartbeats though) and one sac is not even half the size of the other, although the babies themselves are only measuring about 4 mm difference. My OB told me there is a 50% chance of losing at least the smaller one and possibly both. This is our third pregnancy; the other 2 ended in early miscarriages so we are hoping and praying that our twins both make it!
Helpful - 0
1135924 tn?1268878271
thank you both for your responses, makes me feel better to know that!
Helpful - 0
878702 tn?1315099521
Two heart beats means they both would survive. Take rest and Good Luck
Helpful - 0
847328 tn?1289783114
Our doctor told us if you see a heartbeat, that we had a 80% chance that they both would survive.  Good Luck and keep us posted!!
Helpful - 0

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