Multiple gestations can be confirmed perfectly by fourteen weeks into the pregnancy. It is important to be confirmed because doctors can manage regular follow-up so that adverse events can be detected timely. After conceiving, it is important to be approved that you have multiple embryos inside your womb. Doctors can identify it by using transvaginal ultrasound to determine the fetuses' zygosity.

If you have two amniotic sacs one baby, it may be called disappearing twin syndrome. It may be possible that during an early ultrasound scan, doctors detect two gestational sacs, but later on, they can hear only one fetal heartbeat, and the second sac has disappeared.  

Multiple gestation pregnancy:

According to the experts, multiple gestations that share placentas are likely to the highest risk of complications including twin-twin transfusion syndrome (TTTS) for Mo/Di and umbilical cord complications for Mo/Mo. 

 Twin-Twin Transfusion Syndrome occurs when one twin shares blood with the other that may result in the donor getting too little blood and the receiver receiving too much. 

There are rare chances of Mo/Mo pregnancy but it is very risky and requires frequent ultrasound monitoring and a cesarean section birth.

Ten weeks before of Gestations:

When you are pregnant with more than one baby, doctors can detect  Amnionicity and Chorionicity. 

Amnionicity: 

Amnionicity can be referred to as the number of membranes that enclose fetuses in multiple pregnancies. When more than one fetuses share only one amnion, they share an amniotic sac. 

Chorionicity:

When multiple chorionic membranes enclose the fetuses in multiple pregnancies, known as Chorionicity.

Physicians can use transvaginal ultrasound to determine Chorionicity so that they can detect a number of gestational sacs, yolk sacs, and amniotic sacs within the chorionic cavity. 

There is a correlation between the number of gestational sacs and fetal heartbeats. 

Gestational sacs develop a chorion and placenta. If doctors detect a single gestational sac with two heartbeats, it is a clear indication of monochorionic twin pregnancy. If they are two in number, they indicate a dichorionic pregnancy. 

You can consider this method to detect Chorionicity before ten weeks gestation accurately. 

Although, it has become an argument in the reproductive medicine community. Usually, if two yolk sacs are detected, the pregnancy is considered diamniotic. And if the yolk sac is single, doctors can recommend repeating the ultrasound later in the first trimester because it is not a definite condition to determine that it is a  monoamniotic pregnancy. 

Transvaginal ultrasound is preferred as the first choice for conducting an amnion evaluation as the intertwin membrane is very thin. Multiple amniotic sacs within a gestational sac determine Amnionicity in a monochorionic pregnancy. If the doctors find it difficult to visualize the membrane, they can change the angle of insonation to get visibility. If still, they fail to reveal new information, they will recommend repeated ultrasound scans necessarily. 

It is important to consult a maternal-fetal medicine specialist if you have multiple pregnancies so that complications can be detected earlier and treatment can reach you timely.

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