Pregnancy Childbirth 08

I did erase all the copied part that had absolutely no sense here. I want you to follow the rules... Okay?--Pierre.brawand 24 janvier 2009 à 14:24 (MET)

What is pregnancy?

For human beings, pregnancy occurs amongst the female, taking place precisely in the uterus. It is the state of carrying one or more embryos that will eventually develop into a foetus, during a period of nine months. This period starts at conception and ends at the point of delivery.

There is not a HUMAN RACE. You should use either "For humans", or "For human beings", ok?--Pierre.brawand 24 janvier 2009 à 14:24 (MET)

How does pregnancy occur?

Pregnancy takes place after fertilization, which usually occurs in the the fallopian tube, near the uterus. The sperm cells travel up the cervix and into the uterus in search of the egg. Once in the uterus, the uterus contracts and helps the sperm enter into the fallopian tubes, which are situated above. Conception takes place when the egg and a sperm cell come into contact to form a zygot. Pregnancy occurs by the implantation of the embryo (which is at this stage a ball of rapidly multiplying cells called the blastocyst) into the uterus about three or four days after fertilization.The embryo attaches itself to the uterine wall ( which is also called the uterine lining) and will then develop and grow inside the uterus for a period of nine months (about 266 days) and during this time, various changes occur in the mother's body in order to accomodate the growing fetus.

you could briefly mention how the embryo is generated: fertilization of two gametes to create a zygote, and then the cleavage state that generates the embryo.--Pierre.brawand 24 janvier 2009 à 14:24 (MET) Pregnancy is divided into three trimesters, each of which lasting about three months each. These trimesters help us to monitor not only the growth of the baby and the mother but also the changes occuring inside the mother's body. Although complications such as miscarriages can occur, the foetus usually grows healthily during pregnancy, recieving its nutrients from it's mother and growing in a safe and comfortable environnement which is the uterus.

the monitoring is performed not only on the embryo/fetus, but also on the mother...--Pierre.brawand 24 janvier 2009 à 14:24 (MET)

What are the different stages of pregnancy?

First trimester

The first trimester includes fertilization and implantation. During this period, the most important changes concerning both the fetus and the mother occur. The mother may experience problems such as excessive vomiting, weight gain, heartburn, dizziness and tiredness due to these changes. Nausea and vomitting are usually very common and are probably the first symptoms of pregnancy the mother will experience. These changes experienced by the mother is due to the growth of the embryo, which by about the eighth week of pregnancy, would have a developping brain, tiny arms and legs and even a heartbeat. This means that from the eighth week, an altrasound of the embryo can be taken. By week twelve, almost all the fetus' limbs are developed. It is possible to find out at this stage if the fetus will be a boy or a girl because it's sexual organs would have started developing. At the end of the trimester, which usually lasts for about thirteen weeks, the mother will stop experiencing vomiting and nausea and her energy levels will go back to normal but she will start experiencing headaches due to the greater pumping of blood by her enlarged heart.

The first trimester of pregnancy lasts for about 14 weeks. At the beggining, it's an embryo 'till about 5 weeks of life and it looks like any other vertebrate embryo. (see annexe 1)

After 9 weeks de organs begin to devellop and the embryo has now a human form and is called a fetus. The fetus measures about 5.5 cm long. At the end of the trimester it looks like a mini human and we can now know it's sex by doing an ultrasound exam ( see annexe 2 & 3)

Second trimester

The main changes consisting the fetus's development during the second and third trimesters involve the fetus's change of size and general improvement of the human features.

The annexe 4 shows a fetus at 14 weeks, 2 weeks into the second trimester. The fetus is now about 6 cm long.

At week twenty (annexe 5), well into the second trimester, the fetus now weighs about half a kilogram, and has the developed face of an infant. Its arms, legs, fingers and toes have now lengthened. By this time, the fetus's heartbeat can be detected with a stethoscope, and the fetus is usually quite active which is why the mother may often feel her baby move. The fetus can now bend forward into the fetal position, with its head bent against its knees, because of the limited space in the uterus. By the end of the second trimester, the fetus's eyes have opened fully and it's teeth have formed.

Third trimester

The third trimester starts at week twenty eight and ends at week forty-one. It is a time of rapid growth as the fetus gains the strenght it will need to survive outside the protective environment of the uterus. The fetus's activity decreases at this stage because it is in the process of fully occupying all the available space. The uterus, in turn, eventually expands as the fetus grows, so as to accommodate the fetus's bigger size. During this time, the mother's abdominal organs compress and they are displaced causing her to urinate frequently, have digestive blockages and experience strain in her back muscles. At this stage of pregnancy, it is very important for the mother to eat regularly because of the fetus' rapid growth. Its muscles and lungs (the fetus's respiratory system will develop so that the baby can practise breathing) are under development and it's head is growing bigger to accommodate it's rapidly developing brain. It can now blink its eyes (which now have lashes), and With its eyesight developing, it may be able to see the light that penetrates the mother's womb. The fetus gains the ability to maintain its own temperature, it also loses a lot of its hair, except on its head. This trimester, the baby needs about 250 milligrams of calcium each day to strengthen its hardening bones. This is why it is very important for the mother to eat well, mainly calcium based products.

The mother also experiences, during this period, some uncomfortable symptoms. She will experience some swelling on her feet and ankles and also on her eyelids. Her uterus will expand beneath her diaphragm, the muscle just below the lungs, and this is likely to cause her to easily run out of breath. She is also likely to experience what is called the Braxton Hicks contractions. These contractions are nothing compared to the real thing. They're just warm-ups for the real thing which is why they're painless and come and go unpredictably. True labor contractions get longer, stronger and closer together. Another obvious symptom of pregnancy is the mother's weight gain. This is due to the baby's own weight but the placenta, the amniotic fluid, much larger breasts and uterus, extra fat stores, and increased blood and fluid volume also contribute to this weight gain.

Babies born prematurely-as early as 24 weeks- may survive, but they require special medical care after birth. Different techniques of childbitrh will be seen later.

The fetus usually rotates so that its head points down towards the cervix. If it doesn't, the process of birth can be much more difficult. The mothers' abdominal organs may be squashed, causing frequent urination,digestive troubles,and back-aches. At birth (annexe 6) ,babies are about 50 cm in lenght and they weigh about 2.0-4.5 kg.

How is pregnancy monitored?

While pregnancy is a completely natural phenomenon, it however needs to be followed by health care professionals in order to discover the best possible outcome. The quality of such prenatal monitoring and delivery care greatly influences a child's growth and development. In the interest of reducing levels of perinatal and maternal mortality the pregnancy has to be followed by professionals how will use different techniques. One of those is the :

Electronic fetal monitoring (EFM):

The continuous monitoring of the baby during labour, either through transducers which are attached by belts to the mother’s abdomen, or by a scalp electrode which is inserted through the mother’s vagina and attached to the baby’s scalp.

During the early stages of pregnancy,the progress can be closely monitored with weekly blood tests and regular ultrasounds.

What are the possible complications during pregnancy?

There are some possible complications for the mother and for her baby which could occur during pregnancy.

After 4 or 5 weeks of pregnancy, there could be some repercussions on the spinal column of the mother. This is due to the keep of weight and the increase of volume of the uterus. This is why it is advised to a pragnant woman not to remain standing for a long time and to not carry too heavy expenses. Other small problems could occur during pragnancy like occasional and irregular contractions which are due to a dehydration.

But there are some other more serious complications like the ectopic pregnancy. It is when the fertilized egg isn't implanted in the uterine wall but in an another tissue. The egg can be implanted either in the Fallopian tube, or in cervix. Less frequently it can also be implanted in the ovaries or the abdomen. This abnormality is due to the enzymes which are produced by the fetus and allow it to developp itself in varied types of tissues. But further, great tissue damage can be caused to an embryo implanted elsewhere than in the uterus because of the non-sufficient supply of blood. The ectopic pregnancy is very dangerous for the mother and she has to abort.

What is childbirth?

Childbirth is the step that follows the period of nine months or 42 weeks of pregnency, when the developed fetus or baby is pushed out of the mother's uterus and into the outside world, along the birth canal. It happens normally spontaneously after the period of gestation, but if the pregnancy goes past 42 weeks, it could be stimulated artificially. Childbirth is actually a whole process that includes two main phases: labor and delivery. The latter are themselves divided into different stages.

How does childbirth occur?

To answer this question, the main phases which are labor and delivery are to be developed:

Labor is the whole process of birth occuring before the birth itself, which is called the delivery.

Labor usually begins after the breaking of the bag of waters: it breaks under the pressure of the baby going towards the cervix, and lets the amniotic fluid flows away the uterus (see the section "What are the functions of the bag of waters?"). Labor can last from few hours to 24 hours, and even more; it is in this phase that the mother feels intense pain because she is undergoing contractions. These are due to the periodic tightening and relaxing of the uterus, because it is getting ready to deliver the baby. As the delivery time approaches, the contractions intensify. Eventually the baby is expelled followed by the delivery of the placenta. To describe these phenomenons occuring during labor more in detail, it is necessary to mention that the labor phase is in fact divided into three stages:

First stage of labor

Dilation of the cervix (neck of the uterus that ends in the vagina) is the main part of this stage and the longest one, which is accompanied by contractions, and which lasts for about 14 hours during a first pregnancy, and for about eight hours during subsequent ones. This stage is divided into two phases, one is the latent (or early) labor, and the other one the active labor.

During the latent labor, that occurs first, the cervix opens or dilates to a width of about 4 centimeters, whereas at the end of the first stage it will open until 10 centimeters. While the cervix dilates progressively and slowly, the smouth muscles in the wall of the upper part of the uterus contract and thicken in order to expell the baby, causing periodic contractions, approximatively 30 seconds each at the beginning, and every ten minutes; the tightening of the muscles are stimulated by a hormone called oxytocin that the petuitary gland of the mother secrets increasingly in late pregnancy.

The pain the mother feels at these moments are tend to be mild, sometimes painless, but sometimes very painful too and the cervix may take a lot of time to dilate. Latent labor lasts from 6 to 12 hours, which is longer than the active labor because the process is slower. The mother is then encouraged to walk around, since it naturally stimulates the process, and she generally feels comfortable at this step.

Gradually the contractions become stronger, longer (40 to 60 seconds)and closer, i.e. the pauses between the periods of pain are shorter, then the cervix accelerates to dilate when its width reaches approximatively 4 centimeters: it is the beginning of the active labor, and indeed things go much faster in this phase. Whithin about 8 hours, the cervix opens from 4 to 10 centimeters, and as it has been said, the contractions appear more frequently with considerable pain. The cause is that the upper muscles really start to push down the baby by contracting firmly.

At this stage, the mother is advised to relax and to use some breathing exercises to bear the pain; alternatively, if asked, the doctor can give her medication or anesthetics.

When the cervix reaches an opening width of 8 centimeters and is on the way to 10 centimeters, a phase called the transition takes place, relating the first to the second stage of labor. The head of the baby starts to descend already along the cervix, making the mother feel an urge to push with her abdominal muscles.

(annexe 6)

Second stage of labor

The period from full dilatation of the cervix to delivery of the infant is called the explusion stage. Strong uterine contractions, lasting about 1 minute each, occur every 2-3 mitues, and the mother feels an increasing urge to push with her abdominal muscles. Within a period of 20 minutes to an hour or so, the infant is forced down and out of the uterus and vagina. Then a midwife cuts the umbelical cord after the baby has been delivered. The end of the cord remains for several weeks, then it dries out and falls off, leaving the belly button.

(annexe 7)

The final stage

The final stage is the delivery of the placenta ("afterbirth"), usually within 15 minutes after the birth of the baby.

(annexe 8)

Hormones continue to be important after the baby and placenta are delivered. But this state will vanish and the uterus will retun to its prepregnancy state after some times. The mother also starts to produce and secrete milk by the mammary glands in order to give nutrients and antibodies to the baby that will help protect the infant from infection.

How and why is labor sometimes induced?

The labor phase is sometimes induced, it is what we call "labor induction" and it means that labor is stimulated artificially or naturally, because in most of the cases the pregnancy has gone 2 weeks or more past the due date. The problem may be that the baby grows too much inside the body and the mother isn't able to carry it anymore; in addition, she won't have enough food for the baby from inside her. Other reasons could be that:

-The waters bag has broken but the mother hasn't any contractions;

-The mother has diabeties;

-She has high blood pressure;

-She's got an infection in her uterus;

-In the uterus, there isn't enough amniotic fluid around the baby.

-Both the baby and the mother has severe health problems.

The labor can be induced artificially or by natural ways.

How to Induce Labor artificially

There are a few different ways the labor can be medically induced. One common way is to use prostaglandin gel. This gel, which helps to soften the cervix, is applied to the back of the vagina. The gel alone may be enough to start labor, but it can also increase the risk of developing a fever, having diarrhea, cause fetal distress and possibly cause hemorrhage after birth.

Something with a bit less risk associated with it is having the water broken. However, to do this, the cervix needs to be dilated a few centimeters. Plus, some women find the procedure, which involves an instrument that resembles a large crochet hook, to be rather uncomfortable. While breaking the water can sometimes be enough to get labor going.

Another way may be an injection of oxytocin, a hormone that will start the contractions and help them to get strong and regular. Therefore tightening of the uterus and dilation of the cervix are induced.

Medical induction might take 2 or 3 days to work, however if it is the fist pregnancy it can take more time, and only then the mother is ready to deliver vaginally. There are some risks, such as the ineffectivness of the medicine or the "over" effeciency, i.e. the contractions become too strong obliging the mother taking pain medications. In both cases the doctor could stop the procedure and do cesarean section.

Natural Ways to Induce Labor

There are a number of home remedies for inducing labor naturally when the due date has past. But none of these remedies will start labor unless the vagina has already begun to dilate. However, some methods can help to tonify and soften the uterus.

1. Eat spicy foods or pineapple.

2. Go for a walk or march up some stairs. This is way to bring on labor because of the pressure of the baby's head pressing down on the cervix. At the very least, walking can help get the baby into a better position for labor.

3. Have sex. Sex can help by releasing a hormone, which causes the uterus to contract. Additionally, semen contains a substance, which will help soften the cervix.

4. Nipple stimulation. For those who find sex just too uncomfortable right now, nipple stimulation may be a better choice. It helps to bring on labor in much the same way sex does. However, this method may take a bit more effort than sex to start labor.

5. Stretching of the uterine opening membranes. This can be done by the doctor or midwife and has been found to increase the chances of labor starting within 48 hours.

6. Complementary therapies. Acupuncture, massage, teas, herbs and homeopathic remedies can be helpful when it comes to inducing labor.

References

still a lot a work to be done...--Pierre.brawand 24 janvier 2009 à 14:24 (MET)

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