During the pregnancy so many questions are filled in the mother's mind. These questions are quite natural in every gynecologist appointment but no one can’t explain all the questions with that level of patience.

Here we are going to answer some questions which every mother has to know, and are very curious about.

Twin baby scan

How do doctors check if it's a twin baby or not?

From the first week to till the last week doctors use different types of ultrasound scans at different stages to monitor the baby's overall growth and development. Each scan has a different purpose depending on the stage of pregnancy. Among them TIFFA or anomaly scan is one of the important ultrasound scans. It is useful to monitor the overall development of the baby in the mother womb, but when there are two babies, the examination involves an additional level of assessment and careful evaluation of each baby individually.     

How Doctors examine the twin baby in tiffa scan? 

During the tiffa scan the doctor primarily checks for the foetus. Foetus nothing but (an unborn human or animal baby in the womb.)the doctor checks for how many active foetus are growing in the mother’s womb. 

One developing fetus → it may be a single pregnancy.

Two developing fetuses → it indicates a twin pregnancy.

Cardiac activity →position of both babies→ Examines the placenta/placentas→ Checks the amniotic sacs.

Cardiac activity:
After successful identification of the twin baby, the doctor examines each baby individually and the primary examination is done for cardiac; doctor checks for each baby heart beat.

position of both babies: After successful completion of cardiac examination the doctor checks the position of both babies in the mother womb here the crucial thing is to know the name called cervix. The cervix is the lower, narrow part of the uterus (womb) that connects to the top of the vagina. It is roughly 3 to 4 centimeters (1.2 to 1.6 inches) long and acts as a doorway between the vagina and the inside of the uterus. 

Baby positions:

Head-down – the head is facing toward the lower part of the uterus.

Breech position – the baby's bottom or feet are facing downward.

Transverse position – the baby is lying sideways across the uterus.

Oblique position – the baby is positioned at an angle.

Here the position of the baby doesn’t mean the baby will remain in the same position till the delivery, because the baby moves frequently in the mother’s womb.  

Examines the placenta/placentas:

The placenta can usually be called as

(Mavi). In some twin pregnancy cases each baby has its own. Placenta is nothing but the temporary organ   baby through the umbilical cord; It gives the baby food and oxygen, takes away waste, and makes important hormones.

When both Two Babies have shared Two Placentas each one has its own it can be called “Dichorionic Twin Pregnancy.”

When two babies share only one placenta it can be called “Monochorionic Twin Pregnancy.”

Checks the amniotic sacs:

After complete checkup of the placenta doctor examines the membrane arrangement to determine how many amniotic sacs are present.

Amniotic sac is a kind of a thin, tough, transparent pair of membranes (the inner amnion and outer chorion) inside the uterus that surrounds, protects, and supports a developing fetus during pregnancy; the Amniotic sac is filled  with the Amniotic fluid The amniotic fluid cushions the baby and protects the baby in the mother's womb.

Types of Amniotic sac’s:

MCDA - Monochorionic Diamniotic 

The “Monochorionic Diamniotic” means when the twins are identical twins who share one placenta but live in two separate amniotic sacs. In simple terms the babies share one placenta, but each baby has its own separate amniotic sac. 

MCMA - Monochorionic Monoamniotic

The “Monochorionic Monoamniotic” means when the twins are identical twins who share one common placenta and one single amniotic sac without a dividing membrane. It accounts for about 1% of all twin pregnancies, so it requires specialist assessment and closer monitoring.

Conclusion: 

Every twin pregnancy is different, which is why we need to be very careful and regular checkup is very crucial when carrying a twin baby. Tiffa Scan or anomaly scan helps doctors to examine the both twin babies' development and growth.

About the Doctor

Dr. Naren Satya

Consultant Radiologist

Naren Ultrasound and Fetal Medicine Center, Visakhapatnam