Twin Babies - Causes, Types, Diagnosis and Preventions - Health Education - DesiMD Healthcare - India

Understanding the Birth of Twin Babies

Dr.Surya Rao Poodipeddi profile Authored by Dr.Surya Rao Poodipeddi on 24 Sep 2014 - 10:43.

There is a difference between multiple pregnancy and multiple deliveries. Multiple pregnancies denote more than one fetus in the womb, which obviously means that the expectant mother may deliver more than one infant at the time of delivery.

Multiple deliveries on the other hand denote the number of deliveries the mother had during her reproductive age. For example if the woman has not given birth to a child at all she is known as nulliparous. If she has conceived for the first time we term it as primigravida. If more than two children are born to her she is called multigravida and if there are 10 or more children she is called a grandmal.

Multiple pregnancy:

When the pregnancy has more than one fetus in the womb regardless of her status of motherhood, usually a primigravid, it is called multiple pregnancy.

The exact reason for multiple pregnancies is not known and is always by chance. However, the probability increases in families with history of multiple pregnancies.

It’s a common occurrence these days in cases where assisted fertility procedures are used as in cases of IVF (In Vitro Fertilization. Statistics reveals that multiple pregnancies are more common in older mothers than in younger mothers. In some cases certain medications cause release of more eggs, which may increase the chances for multiple pregnancies.


In cases where assisted fertility methods are used in infertile ladies for whatever reason, there are chances for twins or triplets because two or three fertilized ova are implanted in the uterus to make sure that one ovum gets implanted, may lead to implantation of more than one fertilized ovum resulting in twins or triplets. Such assisted methods like IVF procedures account for a slightly higher incidence of twin pregnancies.

Types of pregnancies:

In majority of cases we normally encounter with twin pregnancy. However a pair of twins need not necessarily be normal twins depending on several factors.

Siamese or conjoined twins is an example of a departure from normal twins where there is incomplete splitting of the fertilized egg during pregnancy leading to incomplete separation of each fetus and the pair of twins so born are attached to each other at various levels like at the head, chest, stomach or hips.

This type of twins is called conjoined twins, the first ever being in Siamese mother hence commonly called Siamese twins. This information would help mothers to understand and appreciate such a possibility. However, modern improvements in this field can make it possible to successfully separate the babies as two individual babies, though such a procedure involves more expenditure besides the skill of the surgeon.

Normal pair of twins: Even in normal twins there are varieties, which every mother should know for a better understanding and knowledge about such verities. The two main types of twins are known as identical and fraternal or non-identical. Identical twins are formed when one fertilized egg splits into two at some time during the course of early pregnancy. Fraternal twins are born when two separate sperm fertilize two separate eggs. Identical twins share the same amniotic sac but have separate placentas whereas fraternal twins develop in two separate amniotic sacs with separate placentas.

Identical twins: This type of twins is born when the fertilized egg splits into two distinct entities in the early stage of cell division. The genetic material and DNA is shared by the twins and have the same genotype and phenotype which means that they not only have the same genetic make up but also look similar in looks. Identical twins are always of the same sex either male or female babies depending on the chromosomal influence.

Mirror Twins: This is a variation of identical twins and as the name implies the twins are the mirror images of each other. This variation is extremely rare. When present such twins have their organs placed on the opposite sides. For example one twin will have the heart on the right side (dextrocardia) and will be opposite handed to the other twin, meaning one twin will be a right-hander and the other a left-hander.

Fraternal Twins: as already explained, this type of twins occurs most commonly and they don’t look alike. This is because they are formed when two different sperm fertilize two separate eggs. They only share the space in the uterus but may not share the looks or same sex.


The easiest way to diagnose twin pregnancy is through ultrasonography, which reveals presence of two amniotic sacs and separate placentas. The mother will invariably notice a larger abdomen than is usual for a single baby and an ultrasonography settles the diagnosis.

Any multiple pregnancy might have its own risks which include:

  • Preterm birth: Multiple births usually occur before full term and invariable need a caesarian section to deliver the babies.
  • The growthof the babies may be slower because they have to share the available nutrients from the mother.
  • Possibility of birth defects is more in multiple births than in single babies.
  • Usually the babies are anemic.
  • There may be too much of amniotic fluid.
  • There may becomplications in the umbilical cord or placenta.
  • One of the fetuses may die in twins and one or more maydie in multiple pregnancies like quadruplets and quintuplets.

The mother too may face certain problems when there are multiple pregnancies like:

  • Excessive weight.
  • Conditions like hyperemesis gravidarum resulting in excessive vomiting thanis the case in a single baby.
  • Chances of gestational diabetes are more common in multiple pregnancies.

Most mothers with multiple pregnancies may have:

  • Toxemia of pregnancy requiring either deliberate evisceration of one or more fetuses to save the mother’s life or immediate caesarian operationprematurely to save the mother/babies or both.
  • Postpartum hemorrhage (bleeding afterdelivery)

Precautions for multiple pregnancies:

  • She may need more rest than normal pregnancy.
  • Extra precautions become necessary during pregnancy since the chances for preterm delivery are more than in normal delivery. Since the babies tend to be smaller than single babies frequent monitoring of the fetuses health with in the womb must be done.
  • The mother needs dietary modifications since she has to feed more than one baby with in the womb.
  • A preplanned decision whether the babies will be delivered vaginally or through acaesarian section has to be taken.
  • Any slightest change noticed by the mother must be informed to the attending obstetrician.

Having said this, the mother must exercise great care and focus more attention on each baby, in her attempts tonurse them.

*Disclaimer: This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.