Ultrasound Sometimes Misses Twins in the Second Semester
A missed twin ultrasound in the second trimester can be quite stressful for the parents. Good stress and scary stress! If you were expecting just one baby and now have to suddenly prepare for two, it can be overwhelming. The best thing you can do is to begin to educate yourself on the incidence of twins. Letting family in on the lucky find will help you to feel supported. Seek a moms of twins support group. Every pregnant woman should be aware that the ultrasound sometimes misses twins, and to prevent any last minute surprises you should have regular ultrasounds and discuss with your doctor.
Uh Oh, Who's That Playing Peek-a-Boo? It's Baby Number Two
Single Heartbeat Occuring in One SacA key factor with the missed twin ultrasound second trimester is that there may be only a single heartbeat occurring in one sac. The doctor will then determine that you only have one baby. Babies can also hide behind each other, so you might not even notice that there is more than one during the second trimester scan, although a qualified technician should be able to pick this up. There is a slight chance that the heartbeats are also in perfect sync, and that both babies are lying in exactly the same position. You can try to manipulate movement when you go for an ultrasound during your second trimester so that you can see if this might be the case.
Vanishing Twin SyndromeAnother reason that the second trimester ultrasound can miss twinsis the fact that you may now only have one baby. This is called the "vanishing twin syndrome". It is fairly common if you had a scan before 10 weeks that confirmed a multiple pregnancy to find that only one fetus has developed. Basically for one reason or another only one embryo grew. It is believed that the undeveloped embryo has been absorbed by the remaining sac as it grows in the uterus. On very rare ocassions there is evidence later in the life of the child born that singular cells of a second twin continued to grow within the body of the developed fetus.
Ways to Prevent Missing a Twin in an UltrasoundIf you suspect a missed twin ultrasound second trimesteryou should make a plan to get another scan one or two weeks later. This should provide you with some relief. There are some other things that you can also look out for which may indicate a second embryo. This could be that you have grown more than normal for the number of weeks you are supposed to be pregnant. A blood test can measure your pregnancy hormone levels (HCG or human chorionic gonadotropin). If they are higher than normal, a twin pregnancy might be the cause.
Other people report feeling excessively lethargic right from the beginning of their pregnancy, and some are hungry all the time, even more so than normal for a pregnant woman. You could also have more severe morning sickness. These are all common pregnancy symptoms, but the more exaggerated they are, the more chance of a twin pregnancy.
While it is annoying and stressful, remember that people and equipment can be wrong. If you had a case of discovering a twin later in pregnancy, it could have been caused by a malfunction of the machine, failure to scan the entire uterus sufficiently, or simply because the babies were playing hide and seek with you!