Can A Twin Be Missed On Ultrasound & Twin Heartbeats: Are There Two
Can A Twin Be Missed On Ultrasound & Twin Heartbeats: Are There Two
My misdiagnosed twins are now 38 months, 3 weeks, and 6 days old.
Sonograms & my own true story
Is missing a twin on ultrasound humanly possible? Yes. It is probable? No. With advances in ultrasound technology it is getting easier to not only visualize babies inside of the womb at each stage of development, but to also see fetal development earlier than ever before. It’s only getting better and better and clearer and clearer.
Missing a second baby is becoming far more rare as time passes on. Years ago missing a twin even with ultrasound was a greater possibility early on in a pregnancy. And of course, before ultrasound twins were missed all of the time. Many women didn’t know until delivery day, like my great grandmother.
Putting all of that aside, I personally have had this occur, so this mistake can not be disregarded completely. Some women may simply feel like they are pregnant with twins and there’s only one baby showing on the ultrasound monitor. Maybe a woman is hoping for twins and is curious to find out the answer to this question badly.
Now, for women who are going through any kind of infertility treatment, and is receiving very early ultrasounds, it is possible for one baby to be too small to be picked up on ultrasound one particular week (for example weeks 5 or 6). Then a week later another baby or gestational sac only might pop up on the screen suddenly shocking you. This happened to me also.
With Mikayla I experienced Vanishing Twin Syndrome where at 5 and then 6 wks. 2 days there was only 1 sac. 1 week later there were two sacs and one baby present. Sometimes the sac ends up with another embryo inside of it and sometimes it does not. This can occur because implantation of two embryos (or more even) can occur at different times. (Even days apart from one another) helping to cause this phenomenon. Women who do not get an early sonogram may never know.
Here’s my picture from this experience. The second sac is smaller and did not develop.
The other way to miss a twin is not by being very early, though most often this will only happen when you still are quite early, is due to human error. Yes, even a doctor can make a mistake. I would guess it would be easier for a mistake to be made by a ultrasound technician, However, in my case it was a doctor with over 35 years of OB/GYN office AND hospital experience delivering babies. (Whacked but true.)
If this rare event was to happen to you, or anybody for that matter, obviously the earlier the easier the mistake could be made. It is highly unlikely that any doctor could miss a twin on ultrasound close to or beyond the first trimester of pregnancy. The baby or babies would be quite large on the screen and hard not to spot. Does this mean it has never happened? No, I am sure it has. But it would be extremely, extremely rare.
In my case, I had gone to a Reproductive Endocrinologist prior and knew it was twins already. I had seen two sacs and then two babies and heartbeats several times. Everything measured right on the money. Then when I traveled over to my first OB appt. at 7 wks and 6 days I thought I would surprise my OB, whom I was very close with, by letting him see the twins for himself. I got the big surprise instead. 1 baby!
Real photo of my twins turned singleton, soon to turn twins again.
When I fessed up and did tell him, ”No, I am having twins” as I looked on the screen and watched him measure only one baby. He assured me that I was pregnant with only a singleton. So this was quite a jarring shock. He further said that I must have experienced what I did years earlier..a second vanished twin experience. My head was saying differently through. One week earlier a heartbeat and same sized sac with baby? One week later..everything gone?
With Mikayla I saw the sac on ultrasound into the second trimester. Where did this go to so fast? He was so confident he didn’t even bother taking a second look around. If I hadn’t been to a reproductive doctor prior, I would never have known it was twins and would have been heavily shocked come my 12 week visit to say the very least.
At 9 weeks 3 days I got the ultrasound I demanded and there they were clear as day…two babies! He told me one must have been hiding behind the other or some crap, but I don’t know if he just felt like a dolt for making such a huge oversight. In the picture above it looks as if the photo of my one baby was taken zoomed in or something. He should have looked around a bit more, hey?
Longest week and 1/2 of my life, BUT….
Mama was right!
So, intuition can mean something. But if you are into your second trimester and the ultrasound is saying only one baby, you can pretty much trust that with 99.999% assurance. You can see my story and draw your own conclusions from it. I know I can’t be the only one, but again..it was early.
Now if you get an early ultrasound and one baby was missed, which I have proven can happen. And then you don’t get another scan until say your 20 week anatomy scan, that is when this can occur seemingly past the 1st trimester of pregnancy. But that would be because you didn’t have an earlier scan in between. That’d be a shocker, hey?
Fast facts about missing/ hiding twins
1. Vaginal ultrasounds are more precise in visualizing early, fetal development during the 1st 8 weeks of pregnancy. After that abdominal ultrasound is usually used as the fetus is large enough to see through the belly at this time. (My twin was still missed on vaginal.)
2. This is most likely to occur in VERY early ultrasounds. (1st two months.) Many women don’t get ultrasounds prior to 8 weeks. This is why sometimes vanished twins are not recognized or ever known about.
3. This is more likely to happen in identical twins where early on they can ‘shadow’ one another. Meaning one is hidden like the eclipse of a moon. This goes for the twins that are inside of the same sac together. Two sacs with two babies are harder to miss.
4. By the 2nd trimester (but the 20th week of pregnancy where an anatomy scan is performed if you didn’t get that 12 week scan) if they see one baby you are having one baby.
Clearly this ultrasound of mine shows twin heads together.
I believe this was at 14 weeks.
5. Because the uterus becomes more full and ‘chaotic’ with twins or more, and doctors aren’t usually looking for 3, 4, or 5 babies (unless you had treatments he or she is very much aware of) it is more possible to miss a higher order multiple for a time, than to miss a twin. Ex. a triplet, quadruplet, etc.
4. Dreams and personal thoughts about twins can not supersede the evidence. I had an intuition (and a hope) that I was carrying one baby only. HA on me 😆 . I had dreams I had quintuplets the other night. Not ever going to happen. Base your care on medical facts. Sometimes intuition is correct, and there may be something to be said for that. However, sonograms are most reliable.
5. Larger women are more likely to have a twin missed. Just as it is harder for a doppler to pick up a heartbeat or heartbeats on an overweight woman, and may happen later because of this. An ultrasound may not have as good of a picture to view your baby or babies as it is in a smaller-sized woman. (Though today’s equipment should be able to see things still quite clear.) It is just a slightly greater possibility in the earlier stages, most especially.
6. High beta numbers (if your levels have been checked because you are trying to conceive) CAN indicate multiples but is never a diagnosis. Women pregnant with multiples do typically have higher HCG beta test numbers than most but not all singleton mamas. A faster rate of doubling may even be a bigger clue. I know this happened to me, and to some others I knew. To read more about beta numbers and multiples click the pink link.
Showing faster & feeling more symptoms than a prior pregnancy. Does that mean anything?
1. Being larger with a second or third or more pregnancy is NOT an indicator of twins, though this can make many women suspect them. Most women notice being larger with a subsequent pregnancy with even just 1 baby in tow as the abs are usually less strong and more lax. And the uterus has been previously stretched out already. A woman is very likely to show sooner and even grow a bit larger in a second, third, and beyond pregnancy.
2. Do not base size alone and/or exacerbated pregnancy symptoms on meaning twins. Every pregnancy is very unique and very different. I felt better with my twins than with two of my singletons. You may have worse symptoms with multiples but also you may not.
3. If you have not had an ultrasound and your doctor notices that your fundal height is say 6 weeks ahead of where it should be, he will send you for an ultrasound as twins may be suspected in such a case.
4. Fundal height is a measurement of uterine growth usually using a measuring tape over your belly. A week or two over or under is not alarming, but if it’s measuring very large for dates compared to what it should be, this may raise eyebrows. It might be twins, extra amniotic fluid, or your due date might be off. A scan will figure this all out for you.
What about two heartbeats?
Sometimes a woman thinks she hears two heartbeats on a doppler, though they tell her she is carrying one baby via ultrasound. It is very easy for a woman to become confused about heartbeats. A woman’s own heartbeat can very easily be mistaken for a second baby to an untrained ear. A baby’s heartbeat in utero is about twice as fast as yours. Many women may not realize that.
Some dopplers also don’t have a heart beat number display which would make this harder to figure out on your own. (If you buy one..get that display!) Tracking twins down for two separate heartbeats is quite a challenge. I did do so early with my at home doppler but it’s tricky. I have a lot of pregnancy and doppler experience though.
Best money you can spend for peace of mind during pregnancy.
Mine I bought some time ago when they were far more expensive. I tracked down 3 of my babies as early as 8 and 1/2 weeks.
Twins have two distinct heartbeats in two different places in the abdomen that can be about 10 beats apart from one another but can also be very close in beat count. I tracked mine throughout pregnancy. One twins of mine was always just a bit higher. (5 to 10 beats. Sometimes a bit more than 10 at times.) She is in fact my more hyper twin. How funny? But both heartbeats were obviously way higher than my own.
In early pregnancy the beats grow increasingly faster, peaking at 9 weeks and then leveling out. 160-190 beats roughly per minute at this time. (Average 160-170, but my girls were always higher at this point in pregnancy. Is the myth true?)
Heartbeats by gestational age
When it is first visible on sonography ~ 6 weeks of gestation where is usually around 100 – 120 beats per minute (bpm).
This then increases progressively over the subsequent 2 – 3 weeks becoming
~ 110 bpm (mean) by 5 – 6 weeks
~ 170 bpm by 9 – 10 weeks
(My twins even got higher. I have a naturally high pulse rate though.)
This is followed by a decrease becoming on average.
~ 150 bpm by 14 weeks
~ 140 bpm by 20 weeks
~ 130 bpm by term
Although the healthy fetus the heart rate is usually regular, a beat-to-beat variation of approximately 5 – 15 beat per minute can be allowed.
The heart rate slows as you head into your 2nd trimester, however, it remains faster than our own all along. Also, the further along you get, the further apart these individual heartbeats could be heard, and the easier they can be recognized distinctly and uniquely. At first the babies are quite close to one another. It is more tricky, though through my vast experience everything became super obvious to me but can easily throw you.
Believing you hear two heartbeats when everything else is saying singleton..trust in your doctor.
You most definitely are not having twins.
You can bring it up and ask your doctor to check though.
If you have any doubts so bad that they are keeping you up at night, you can always request another ultrasound, which insurance may or may not pay for. Or you may opt for an ultrasound outside of your doctor’s office if they refuse you. This is what I was going to do if they didn’t take me in and see me before my 12 week scan.. which was when they had me written down as due back.
I did say I had cramping, so I told a white lie but I just knew he was not right. Oh, and I did have some cramping in early pregnancy so it wasn’t a complete lie. Remember though that I had evidence of twins FIRST.
Do do what you have to do to find peace within yourself.
In closing, whichever way the pendulum swings in your case, singleton or twins, I wish you a very happy and healthy pregnancy. I hope this helps to answer some of the pressing questions I know that many moms-to-be have.
The more experienced the doctor
Updated the ultrasound equipment
And the further along you get…
The more assured of your ‘diagnosis’ you should be.
If in doubt by all means check it out. Nothing is EVER impossible. I hope this article is helpful 😛 .
Good luck and best wishes with your outcome.