Obstruction of the fallopian tubes

There is a possibility of an infection, suffered during or after the first birth, or other diseases such as endometriosis, which have led to the fallopian tubes before permeable, were blocked and prevent the passage of sperm.

Detection.
In these cases, practice a histerosalpingografía, which is to introduce a contrast to see if the tubes are clogged. Also, the gynecologist may do a laparoscopy, making a tiny cut in the area under the navel and inserting a general anestecia optics that allows you to view internal organs. Through the vagina, it becomes a liquid reach the uterus of color to see if it goes through the tubes and reach the abdominal cavity.

By laparoscopy can also be detected endometriosis, a disease quite common cause of infertility, which causes an abnormal growth (misplaced) of the mucosa that covers the inside of the uterus and can affect, among other bodies, tubes and ovaries.

Treatment.
At present, many doctors are not in favor of intervening surgically desobstruir the tubes and to advise women to undergo in vitro fertilization treatment, as the operation involves risks and causes costs and time, while only succeeds pregnancy at no more than 25 to 35 percent of patients operated. In vitro fertilization offers similar results, but does not require general anesthesia or intervention, so that the expenses and time are reduced, and postoperative discomfort disappear.

Babies probeta

28 years ago who was born the famous Louise Brown, metaphorically called the first "test tube girl" in the history of mankind.
Today it is estimated that there are already more than three million children in the world born through assisted reproduction techniques, as announced at the annual conference of the European Society of Human Reproduction and Embryology held in Prague.

From the first practice of in vitro fertilization 1978, development has led a formidable scientific advancement and improvement in the way that people can be designed.

These techniques which, as everyone knows, are complicated and a relative effectiveness depending on the case, have allowed many families who could not produce offspring have been able to see fulfilled their aspirations to be fathers and mothers.

After tuning pioneer in artificial fertilization of an ovum by a sperm to treat female infertility, in the nineties was an important new step with the microinjection of sperm in the oocytes, which provides the possibility of alleviating male sterility.

All these developments have also allowed to know much better the causes of infertility, a problem that now concerns, according to recent studies, one of every six couples.

Today we know that, the well-known physiological reasons, we must also consider factors linked to human behavior, such as smoking, overweight and stress, among others.

These three billion human beings who literally owe the existence of scientific research and its technological applications allow us to reflect on attitudes with which the company provides and assimilates the advancement of scientific knowledge.

Just go to hemerotecas and see what they said and how they are valued in some cases in 1978 birth of Louise Brown or what was said a few years earlier when Christiaan Barnard in 1967 won the first heart transplant.
So it is good that our relativicemos inevitable tendency to allude to the myth of Frankenstein, even today that open new avenues for intervention on our own evolution.

There is no doubt that we have to give the necessary ethical filters and a strong ability to criticize the possibilities that we are giving ourselves, but always think in those three million people that would not exist if we had not taken the step of accepting , With conditions, which gives us the scientific knowledge.

If not they ask the parents of those three billion human beings who know what life is like. Or easier yet: themselves!

Which is the largest twin brother?

What is it? The first born? Does the first in shape?
Much has been said about that first birth is the lowest and the highest last. None of that is true. For the law, the first born, is undoubtedly the largest. Simple question of logic. In biology, everything is possible.

In the case of identical twins, generated from a single fertilized egg, both biologically-be-equal in age, and that his life began simultaneously.

If these are simple twins, the product of fertilization of two different eggs by two different sperm, there is-to-date any possibility of knowing if the fertilization was simultaneous or deferred.

And in the case of in vitro fertilization?
Even if, as in the case particularísimo of in vitro fertilization, we know exactly the time at which each egg was inseminated and the time at which each embryo was transferred to the interior of the uterus, we will never know which is which at the time of birth. That figure could only be made known whether a biopsy for genetic study of the embryo before transferring to the uterus, something-for now-is only possible in very limited. Most countries where technically feasible, the laws are very strict regarding the possibility of the so-called "pre-implantational biopsy of embryos.

Almost science fiction. Hence, not to discuss more: the first birth is the largest, but in reality was the ultimate gesture.

Strategies animal mating

The main occasions for cooperation animal are GALANTE, the copulation and breeding. The variety of responses to the need to work originates various mating strategies.

These strategies are as follows. First mention monogamy, which is the union in which both are involved throughout the reproductive process, for example, in the case of most birds. Then there's polygamy, where one male was aparea with several females, as do orangutans, gorillas, sea lions and Ornitorrinco. And lastly, polyandry, where a female is paired several males, for example, quail or female chimpanzee. In the latter case sends biology, since the female is fertile only every seven years, so it accepts be mounted by all males in the group, she makes sure that fertilization and not wasted an opportunity so valuable over time.

In each case, the strategy that best guarantees the reproduction which is extracted the nature and prevailing for each species.

Returning to monogamy, it is important to spell out that there has been a balance between conflicting interests. This happens because they raise new beings is so expensive that requires the collaboration of two members to carry it out, as in many birds. Another source suggests that when the couple is known, facilitates the reproduction, what happens, for example, long-lived species like the orca, where factors such as memory. In mammals, the female is enough alone to breastfeed for farming, so the marriage is often merely seasonal: lasts little more than the sexual encounter.

When the time comes to mating, there are a number of general characteristics. Most of the fish, for example, makes an external fertilization, in which the male and female get together during the time of reproduction. The female releases the eggs and the water with their male sperm. Species such as the hippocampus or mullet actual real parents are responsible, because males are responsible for hatching eggs. The first, on a specific bag, while the mullet in the mouth takes about eight days.

Although amphibians are coupled, its external fertilization is because the male has no penis. They mounted the female until they deposited eggs, a process that can be extended several days, and watering them with his sperm.

In birds, the male usually placed over the female, join sewers (only holes, which serve both for the sperm to excrement) and transferred semen to the female genital organs. The watercraft (such as ducks, geese, swans, and others), the male has developed a small penis hidden that excels in sexual intercourse.

Almost all male reptiles have penis: the crocodile and turtle male is similar to that of mammals, lizards and snakes look but one that actually are two, if only part of the side that tap. This turns upside down and is fixed to the female. They, store sperm and use it at intervals until several months or even years later.

In mammals, it is usual that the male to female mountain behind, do some pelvic movements, ejaculation and withdraw.