Multiple Births Essay Research Paper Multiple Births

Multiple Births Essay, Research Paper

Multiple Births

Multiple births are rare in humans with twins as being the most common form

of this event. Multiple births can arise in many different combinations of ways

but the probability of giving birth to more than one child remains fairly

constant when compared to the entire human race. The chances of multiple births

can also vary from race and genetic background. Scientist and researchers do

not know what the exact cause of these variations is but many of them feel that

it is caused by hormone differences between different racial groups and/or the

difference in social class.

The prenatal and infant mortality is much higher in multiple pregnancies

than in pregnancies that only involves one child. The danger of premature birth

also increased with the higher number of offspring that are involved. In many

multiple births, not all of the children survived to childhood or were born dead.

Through the advances in technology, the survival rate of infants born in a

multiple pregnancy has increased. The first quintuplets, five babies born in a

single pregnancy, to survive in medical history were the Dionne quintuplets.

The use of drugs that treat female sterility, or fertility drugs, may

increase the chances of giving birth to multiple children. These drugs cause

the ovaries to release an egg once a month but in some cases they release more

than one egg, sometimes releasing several at a time, increasing the chances of a

multiple birth. The drug clomiphene citrate is one of the most widely taken

fertility drug and has resulted in the birth of twins about once in every twelve

births, much greater than the chances of the birth of natural twins.

Twins are the most common form of a multiple pregnancy. About one in

eighty-seven births result in the birth of twins. Twins can be fraternal, also

known as dizygotic twins, or identical, also called monozygotic twins, with the

birth of identical twins being the rarest, occurring about four times in every

thousand births, about one-forth as often as the birth of fraternal twins. This

ratio of the birth of twins to the total number of births remains fairly

constant but the birth of fraternal twins can alter greatly. Fraternal twins

are most common among black African followed by people of European origin.

Asian races originating from the orient are the least likely to give birth to

fraternal twins.

The birth of twins can occur in two different ways, the fertilization of

a single egg or the fertilization of two eggs. In the case of dizygotic twins,

the woman’s ovaries release two eggs about the same time instead of one, with

each being fertilized by the male’s sperm, fraternal twins begin to develop.

The two zygotes develop differently, each having a different genetic coding.

They can be both boys, both girls, or a single boy and a single girl. Because

each embryo develops on its own from different genetic characteristics,

dizygotic twins resemble family characteristics as do brother and sister.

The birth of monozygotic twins takes place much differently than do the

births of fraternal twins. Identical twins originate from a single egg,

fertilized similarly to that of a single pregnancy. A change transpires early

in the pregnancy that causes the development of identical twins. The change

from a single birth to the birth of monozygotic twins occurs when the zygote

ruptures into two separate structures. These two parts begin to develop into

individual fetuses, sharing a similar genetic code and developing in a similar

manner. Identical twins are of the same sex, resemble each other very closely,

and have similar fingerprints and blood types.

Scientists also believe that Siamese twins, also known as conjoined

twins, develop in a similar fashion as do monozygotic twins. Siamese twins are

identical twins with the difference that the zygote did not divide completely

during their development. Such twins are usually joined at the hip, chest,

abdomen, buttocks, or head. With current monitoring equipment, conjoined twins

can be detected maturing in the mother and during birth a Cesarean section is

sometimes needed to deliver the children safely. Separation of the twins

sometimes leads to the death of one or both of the twins. This births are a

rare event, occurring only about once in every fifty-thousand births.

Other forms of multiple births such as triplets, quadruplets and

quintuplets, occur very similarly to the birth of twins. Births of triplets are

rarer than the birth of twins, occurring approximately once in every seven-

thousand nine-hundred births. The birth of triplets can occur in a combination

of ways. If the zygote divides into three separate structures in the early

stages of development, identical twins will be born. If a two cells are

fertilized and one divides into two structures as in monozygotic twins, the

birth of a pair of identical twins will be born along with a single infant. If

the ovaries release three eggs, which are then fertilized, then the birth of

fraternal triplets will occur.

The same level of combinations can be observed in the development of

quadruplets, quintuplets, and the very rare occasion of a pregnancy of six

children. The birth of quadruplets only takes place once in every seven-hundred

and five thousand births and quintuplets are born once in every eight million

births. The birth of six infants is so rare that accurate statistics cannot be

made while compared to the total amount of births around the world. In all of

these forms of multiple pregnancies, the process is very similar. If the

woman’s ovaries release four or five eggs then the birth of quadruplets or

quintuplets will arise. If the cell divides into four of five structures will

then cause the pregnancy of identical quadruplets or quintuplets. These and

numerous other combinations can occur as the number of infants involved


Multiple pregnancies are a rare occasion, one of the factors for the

incomplete statistics of the birth of a six child pregnancy. The number of

infants born in multiple births, as well as larger births consisting of six or

more children, are also increasing due to the use of fertility drugs. This

widespread use is forcing researchers not to accept any multiple births that

were endorsed by drugs as part of the general statistics. Some aspects of

multiple births are still not clear to scientist. The difference between the

probabilities of multiple pregnancies of women of different races is just one of

these problems. More about multiple births has been learned over the ages but

more is still to be learned and tested by scientists.


ДОБАВИТЬ КОММЕНТАРИЙ  [можно без регистрации]
перед публикацией все комментарии рассматриваются модератором сайта - спам опубликован не будет

Ваше имя:


Хотите опубликовать свою статью или создать цикл из статей и лекций?
Это очень просто – нужна только регистрация на сайте.

opyright © 2015-2018. All rigths reserved.