Identifying twins on ultrasound: when is it possible?

Recognizing twins in the ultrasound: From this point in time it is possible

If two egg cells mature in your body at the same time, it is possible that both have been fertilized. The result is twins. The first signs of a twin pregnancy  are often early and rapid weight gain and a significantly larger uterus, which can only be recognized by a gynecologist or midwife. One of the surest signs that you are expecting twins is two heartbeats on an ultrasound.

• As a rule, twins are discovered during the first ultrasound scan, which is around the sixth week of pregnancyhe follows. In this early phase of pregnancy, however, it is more common for one embryo to be rejected in order to preserve the other. This happens, for example, when there is an insufficient supply of nutrients.
• If you have had a fertility treatment , such as artificial insemination , and you have had several egg cells implanted, a twin pregnancy is often discovered at the first check-up appointment after the treatment. This is usually the case in the fourth to fifth week of pregnancy .

Detect identical or fraternal twins on ultrasound

With fertility treatment, you can assume that your babies are fraternal. After all, two or more eggs were also fertilized.  

Whether the twins are identical or fraternal can best be seen on an ultrasound between the eighth and twelfth week of pregnancy . Identical twins can clearly be seen on ultrasound that they share an embryonic envelope. In the case of dizygotic twins , on the other hand, you can see that each embryo claims its own shell.

After the 16th week of pregnancy , it becomes almost impossible for a gynecologist to determine the babies’ egg identity. The reason: From then on, the embryonic envelope is too close to the inner wall of the uterus. The borders are therefore no longer clearly recognizable.