what is the phenomenon where in twin fetus share a placenta(smetimes called twin to twin perfusion)?
488515
Twin to twin transfusion is not to be confused with two babies sharing a placenta.  Identical twins share a placenta, and there are no health risks to mother or babies.\n\nTwin to twin transfusion is where instead of both twins sharing a placenta, one twin gets all the nutrients from the other twin.  It's a very serious condition, and if detected early enough in the pregnancy, women are often informed about abortion.  If it's not detected early enough, or if the mother doesn't wish to have an abortion, then the twin that gets the nutrition from the placenta may have a chance of survival.  The one who gets all the nutrition from its twin is likely malformed and underdeveloped, and is incredibly unlikely to survive at all.
320253
It would have to be when my sister lost her baby a couple of years ago.  The baby had a trisomy 18(an extra chormosome) that doesn't happen very often.  My sister carried her to full term and lost the baby after about 4 months, when they said she wouldn't live past 3 weeks.  She died in my sister's arms and that was very painful.
633332
Yes identical twins do have the same DNA. They came from the same egg so they have identical DNA.\n\nIdentical twins\nIdentical twins occur when a single egg is fertilized to form one zygote (monozygotic) which then divides into two separate embryos. The two embryos develop into fetuses sharing the same womb. Depending on the stage at which the zygote divides, identical twins may share the same amnion (in which case they are known as monoamniotic) or not (diamniotic). Diamniotic identical twins may share the same placenta (known as monochorionic) or not (dichorionic). All monoamniotic twins are monochorionic. Also note that any monochorionic or monoamniotic twins are identical twins. This condition does not occur in fraternal twins.\n\nThe later in pregnancy that twinning occurs, the more structures will be shared. Zygotes that twin at the earliest stages will be diamniotic and dichorionic ("di-di"). Twinning between 4 to 8 days after fertilization typically results in monochorionic-diamniotic ("mono-di") twins. Twinning between 8 to 12 days after fertilization will usually result in monochorionic-monoamniotic ("mono-mono") twins. Twinning after 12 days post-fertilization will typically result in conjoined twins.\n\nIn placental species, twins sharing the same amnion (or the same amnion and placenta/chorion) can cause complications in pregnancy. For example, the umbilical cords of monoamniotic twins can become entangled, reducing or interrupting the blood supply to the developing fetus. About 50% of mono-mono twins die from umbilical cord entanglement. Monochorionic twins, sharing one placenta, usually also share the placental blood supply. These twins may develop such that blood passes disproportionately from one twin to the other through connecting blood vessels within their shared placenta, leading to twin-to-twin transfusion syndrome.\n\nMonozygotic twins are genetically identical (unless there has been a mutation in development) and they are the same gender. (On extremely rare occasions, an original XXY zygote may form monozygotic boy/girl twins by dropping the Y chromosome for one twin and the extra X chromosome for the other.) Monozygotic twins generally look alike. Fine physical details such as fingerprints will differ. As they mature, identical twins often become less alike because of lifestyle choices or external influences.\n\nThe likelihood of a single fertilisation resulting in identical twins is not a hereditary trait.[citation needed] The exact cause for the splitting of a zygote or embryo is unknown.\n\nHuman identical twins can behave as differently as any other siblings (a matter of much interest to psychologists). They develop their own individual personalities, enabling them to be identified as individual persons. Many identical twins spend most of their time together (especially as children), so people often assume that they will behave alike just as they look alike; however, this is not the case. Twins are unique individuals that establish their own individual likes and dislikes. There are usually obvious signs of differences when the identical twins are observed separately or together.\n\nIdentical twins have identical DNA but differing environmental influences throughout their lives affect which genes are switched on or off. This is called epigenetic modification. A study of 80 pairs of human twins ranging in age from 3 to 74 showed that the youngest twins have relatively few epigenetic differences. The number of differences between identical twins increases with age. 50-year-old twins had over three times the epigenetic difference of 3-year-old twins. Twins who had spent their lives apart (such as those adopted by two different sets of parents at birth) had the greatest difference. (Fraga, et al., 2005).\n\nSome monozygotic twins are known as "mirror twins" or mirror image twins. These are identical twins with opposite features, that is, one may be right-handed a
725486
this is an answer to bball..you want an example?  lets see..plancental abrubtion which could cause bleeding to death...gestational diabetis which in some cases are very severe...pre eclamptic..yeah you can look that one up but its not pretty...and one I heard just on the news..the heart was outside the chest of the baby..as the baby deteriorated, the infection grew..and well you can imagine.  not every woman carries in the best of health.\n\n\n\nmy niece HAD to have an abortion while 5 months pregnant..I wont go into details but she was devestated...so no, Its not wrong in my eyes.
44227
While the baby or for this case the foetus is developing the it starts to use its receptive body mechanics. While this happens its when the determination of whether it will be a left handed or right handed occurs. \n\nThe foetus can think and explore its surrounding and even have the capability to detect the mothers voice vibrations. While the foetus moves around as in your case they become more close to one another to death since its depicted in their developing minds the early sence of oneness.\n\nGenerally the foetus as tiny as imagined at around 7-8 months all this happen. They even actually dream and yawn play listen and remember. This enables the brain complete the nervous connection and responce to stimulation.
18147
yes, its called a true hermaphradite, and it is due to a hormonal problem during development of the fetus.  rare.
112493
Predisposing factors\nThe cause of monozygotic twinning is unknown. Fewer than 20 families have been described with an inherited tendency towards monozygotic twinning (people in these families have nearly a 50% chance of delivering monozygotic twins). Some evidence suggests that the environment of the womb causes the zygote to split in most cases.\n\nDizygotic twin pregnancies are slightly more likely when the following factors are present in the woman:\n\nShe is of African descent \nBetween the age of 30 and 40 years \nGreater than average height and weight \nConception is soon after the cessation of oral contraceptives \nSeveral previous pregnancies. \nWomen undergoing certain fertility treatments may have a greater chance of multiple births. This can vary depending on what types of fertility treatments are used. With in vitro fertilisation (IVF), this is primarily due to the insertion of multiple embryos into the uterus. Some other treatments such as the drug Clomid can stimulate a woman to release multiple eggs, allowing the possibility of multiples. Many fertility treatments have no effect on the likelihood of multiple births.
551911
That is perfectly normal.   Check out this link  http://www.med.upenn.edu/fetus/gestage.html
308552
They are Fraternal Twins
561947
identical come from one egg that split when fertilized and fraternal come from 2 separate eggs. Identical are together in one 1 sack and share a placenta fraternal are in separate and each have a placenta-same with triplets and quints.\nThat's why identical triplet and Quints are SO rare.
230357
This is very serious.  It's called an ectopic pregnancy. If you know someone who has this, they should consult with their doctor at once.
189500
WHile they are fetuses and think about how nice the placent looks!....they start playing w/themselves when thay can reach it or accidentally reach it. When they are fetuses they have automatic erections which are just kind of a reflex. When they are two yrs old thay play with it because it gives them pleasure or kind of.
427713
You know this reminded me of a story, I know this guy who is very cool but not well liked, he scares others, well when someone was having a party and he did not get invited, he asked his friend who was in labor if he could have her placenta, and guess what he did with it, he went to the party and put the placenta at the bottom of the punch and that sat around and waited for others to realize what he did. Oh that was classic, so why dont you go anyway and create some madness, madness is much funner anyway.
51702
First, you have our sympathy on your loss.\nThe actual term is skin slip.\nSeveral factors are at work here.  Since the baby's death took place before birth, temperature in the womb would be relatively warm.  That, and the thinness of the skin would lead to rapid breakdown of the surface.  \nIt is unfortunate that this prevented you from viewing your child, but it is not something that could have been prevented.
722229
I am only a first year med student, but your topic interested me and I spent some time researching it.\n\nIt can also be called PNH (periventricular nodular heterotopia) or just PH. The most common form of the disease results from a mutation in a gene on the FLN-1 gene on the X chromosome.  What is odd is that it is a X-linked dominant mutation (most of what you hear with the X chromosome is recessive).  This means that either:\n\n-The mother of the child had it and passed it on\n-That a spontaneous mutation occured while the DNA of the egg was being copied.  (A baby girl who is born has already copied all the DNA for her future children, so it was nothing a mother could have affected through lifestyle)\n-A third option is that it is caused by something called "somatic mosaicism".  This is a difficult topic to explain.  It means that while the embryo was multipling and copying its DNA, a mutation occured in this gene just randomly.  Therefore every cell that comes afterward from this cell is also affected.  This means that if the mutation occured early, a lot of cells would be affected.  It it occured later in the embryo, less cells would be affected.  A 1999 article I read said that this was the generally accepted view on males with PH.   \nI also read that they generally see this disease in baby girls, because boys with the mutation rarely survive to term birth and are often miscarried.  Females have two X chromosomes and thus the other "normal" X chromosome must have some protective effect.  \nThe gene makes a protein that is important for the migration of neurons during embyrogenesis.  With this malfunctioning protein the neurons did not migrate properly during while in gestation (in the mother's womb).  \nI read a lot about epilepsy (seizures) being associated with PH (actually 80% according to two articles I read).\nI also read that the levels of mental retardation can be vary a lot (which is very much in line with the idea of somatic mosaicism = varying degrees of pathology depending on which types of cells have the mutation and which don't).  There are some reported to have no mental retardation.  \nI was not able to find any support groups for your son's condition which is critical for further information.  I would recommend that your son be seen by a pediatric neurologist if he has not seen on yet (though I would assume he has).\nFinally, I did find a web site that tries to confidentially try to link up families that have similar genetic conditions that there are no support groups for.  This issue is about Angelman's syndrome but if you go to the bottom of the "Links Line" there is a family with an 11 year old son with the condition that would like to talk to others.  There is a contact person at the bottom.\n\nhttp://www.geneticsupportcouncil.org.au/uploads/pdfs/Gene%20Advocate%20Edition%2026%20June%202004_364.pdf\n\nHope this all helps.  I am still an eager first year medical student and I have sympathy for your family since I have three daughters of my own.
197210
Either through the placenta or in the birth process when tissues are torn and the baby comes into contact with the mother's blood.
1083003
Fraternal twins occur when two eggs are fertilized. That is why fraternal twins often look nothing alike. They look like siblings but not like twins. This is often where you get twins that are a boy and a girl. I know a set of fraternal twins the girl has blue eyes and red hair the boy has brown hair and brown eyes. One looks like the dad and one looks like the mom.\n\nIdentical twins occur when the egg after fertilization splits into two halves. From this point on each half of the egg multiplies and divides until there are two identical embyos. These two babies will look very similar, sometimes identical.