What Are The Chances Of Having Twins?

Throughout history, across all cultures, people have been fascinated with twins. In addition to interest in the close emotional ties and biological similarities that twins may share, reports of special twin languages and twin extrasensory perception (ESP) help people to explore ideas of what it means to be human. How similar or different are they to each other? How important are genes and environment for development? Because identical twins share all of their genes, it is the environment—rather than genetics—that accounts for any differences between them.

Monozygotic twins: Monozygotic twins are also known as identical twins. These twins start their life as one egg which is fertilized by one sperm and latter splits into two eggs much earlier in the gestational period. These are very rare and have no link to heredity. But studies reveal that only one of four conceptions of twins is identical. Therefore, it seems likely that any differences between twins will have to be caused by environment rather than by genetics.

What would it be like to have a twin? This is a question people often ponder. People often say that they see someone that resembles someone they already know. It is almost like dejavu. "Twin" comes from the German word "twine" meaning "two together" (Nagy 1). Most people automatically think of two people who look just alike when they hear the word "twin". However, there is a lot more to twins than just looking alike. Twins are the most common type of multiple births. Many think there are only two types of twins, identical and fraternal; they often leave out conjoined twins. Twins are very unique and fascinating individuals because of their similarities biologically, physically, and psychologically.

Twins, share a bond that no parent, child or sibling relationship can ever compare. There are two main types of twins, and these include: monozygotic (identical) twins and dizygotic (fraternal) twins, and they are compared by their emotional, behavioural, and cognitive similarities. (Robert Plomin, 1997). According to Social Issues Referencing, 2007, whereas Identical twins are formed from a single (mono) zygote and are genetic “carbon copies”, fraternal twins develop from two (di) separate zygotes, as a result of two eggs being fertilized by two sperms independently. (Social Issues Referencing, 2007, para. 8)

There are a number of possible types of these births. These include thoracopagus, the most common, affecting 35% of all conjoined twin births, where the chest wall is shared, and often the heart. Pygopagus is another type, occurring in 19% of all cases, where the twins are joined at the buttocks. Two significantly less occurring patterns are ischiopagus, 6%, connected at the tailbone, and craniopagus, 2%, with a fused skull. Some other commonly occuring types include cephalopagus, with the upper torso and back of the cranium fused, and dicephalus, having two heads and necks connected to one body. Cephalopagus and craniopagus twins are rarely operated on, because the brain is such a delicate organ on which to operate, especially when shared brain tissue is involved. Other types include parapagus, a lateral fusion of the lower half of the body, and omphalopagus, joined frontally at the midsection. Finally there is parasitic twinning, where one twin is dependant upon the other for life, and often one is misformed, lacking organs or fully formed parts (www.twinstuff.com).

It is the popular saying that identical twins share much more than superficial physical characteristics that seems obvious and glaring both in nature and traits. Formed from a single egg that divides at an early point in gestation, identical twins have what may be the most intimate of all possible human relationships. They often are attracted to the way of life like same careers, enjoy the same style and type of music and same sports, like or dislike the same foods, pursue the same interests academically and recreationally, and find themselves aroused by similar emotional stimuli.

This nation's double birthrate struck thirty three. 9 baby twins per 1, 000 births inside 2014, upward coming from thirty three. 7 baby twins per 1, 000 births inside 2013, according to the record in the Focuses pertaining to Sickness Manage along with Deterrence.

For years I have been fascinated by that mysterious quirk of nature called twins. In my family, there are several sets of identical twins, and I have always concentrated on their similarities. I did not realize that identical twins also have many differences. My identical twin cousins, Sue and Heidi, appear to be perfect mirror images. They love to dress alike. They can feel each other's pain. They sound alike and can complete each other's sentences. But upon taking a closer look, I have found that they are as different as day and night. Aside from Sue and Heidi's outward characteristics, they possess several distinguishing traits that allow them to be viewed as two separate, independent

Chapter three made me understand more on things coming towards twins. Growing up I always thought that being a twin you always had to look alike or you had to be the same sex. I hardly understood why some of them weren’t the same sex or didn’t look alike. While reading chapter three I finally understood how genes work when it comes towards twins. Monozygotic twins is one zygote where two small babies are growing together. That’s what makes monozygotic twins identical because the two babies are growing in the same zygote. It will be very rare when two or three monozygotic decides to separate and make “monozygotic quadruplets or octuplets” which means it makes more set of twins. The second main point is dizygotic twins, where the zygote will split into two and the babies will grow into two different zygotes.

Twins can be either monozygotic or dizygotic. Monozygotic or identical twins develop from one zygote, which splits and forms two embryos. They are natural clones of each other and are genetically identical. There are three types of monozygotic twins that can form, that depends on early development in the fertilized ovum or embryo splits. The first type of monozygotic twins have separate amnions and chorions. About one-third of identical twins separate before the trophoblast forms on the fifth day. The second type of identical twins that share one chorion and one amnion. This type of split happens about one percent in monozygotic twins, because the tissue splits after these structures are already developed. The third type of twins that are monozygotic, share a chorion and a different amnion. This type of split occurs in about two-thirds of identical twins. Identical twins occur in about thirty percent of births in the world, although not all twins survive long enough to be born. Dizygotic or fraternal twins occur when two sperm fertilize two separate eggs. This usually occurs when two eggs are released from the ovaries and are fertilized. Dizygotic twins normally run in females in the

• Multiple births: Generally, in women who use IVF to establish a live birth, about 63% are single babies, 32% are twins, and 5% are triplets or more.

"Though conjoined twins are common in humans, wild birds, reptiles, amphibians, fish, and domestic and laboratory animals, the fetal abnormality is extremely

On ultrasound there is a live dichorionic/diamniotic twin gestation. Both twins are cephalic. Fetal biometry is symmetric and consistent

I observed a set of dizygotic or fraternal twins, Antonio and James, that had walked in, which were both males. I noticed that they were attached to their mother, which I had considered “normal” when thinking back to when my 15 year old daughter was that age. Even

There are risks associated with these types of ART. The use of any ovulation induction therapy can cause a woman’s ovary to swell up to 10 times its normal size (Cowley and Springen, 1997). It is also possible for up to 40 eggs, as opposed to the normal one, to be released in one cycle (Cowley and Springen, 1997). This results in a much higher risk for the conception of a multiple fetus pregnancy. There is a 5%-10% chance of a multiple pregnancy with the use of clomiphene (Jacobs, 2004). This is significantly higher than the 1% rate of occurrence of twins in unassisted pregnancies (Dr. Joseph F. Smith Medical Library, 2003). In about 1 out of 5 pregnancies achieved using FSH injection therapy the result is a multiple birth (Brown, 2001). In an attempt to avoid the conception of these multiple fetus pregnancies, it is suggested that the physicians monitor the number of eggs