Chapter 4 homepage que es la anoxia

Thus far we have emphasized the protracted physical and psychological stress experienced by the mother in labor. The experience of the fetus during labor is also highly stressful, even under the best of conditions. Throughout all phases of labor the fetus remains dependent upon supplies of oxygen from the umbilical cord, the lifeline between the placenta and the fetus which allows for exchange of nutrients and waste products between the mother and baby. The umbilical cord, like the fetus, is being subjected to enormous pressure. The cord must maintain this oxygen supply as it trails alongside the infant through the birth canal.


The fetus can safely withstand temporary interruptions in its oxygen supply (e.G., during contractions) but prolonged deprivation of oxygen (greater than 2-3 minutes) will result in a state of fetal distress.Que es la anoxia prolonged fetal distress can cause varying degrees of damage to the central nervous system and, in extreme cases, death of the fetus.

Barbara looked forward to the heather’s birth only as relief from the misery of pregnancy. She paid as little attention as possible to her pregnancy and never went to see a doctor. She kept up her usual pattern of frequent alcoholic binges and occasional use of cocaine during the pregnancy. She had unprotected sex with numerous men without a thought of the possibility of disease.

She did not know when the the baby was due, but she sensed that is wouldn’t be for another month or two. Then suddenly she felt the first contractions. Her fear and intense pain brought her to a hospital emergency room.Que es la anoxia the doctor guessed that she was only about 35-36 weeks pregnant, but it appeared that labor had begun. He tried delay the labor, but he was not very hopeful. The good news was that tests showed the fetus was holding its own, at least for the moment. The bad news was that barbara had alcohol on her breath and a defensive attitude. That told the doctor everything he needed to know: this baby was at risk, the situation could degenerate rather quickly.

Despite the efforts to slow the labor, barbara continued to dilate, although very slowly. So the doctor changed strategy and decided to speed up the labor by breaking barbara’s bag of waters. That did not work either. He gave her a drug by IV drip that strengthened the contractions but they soon became extraordinarily painful.Que es la anoxia he withheld pain medication, due to the alcohol content of barbara’s blood and her generally weak physical condition.

After 15 hours in labor, barbara was fully dilated and heather began to descend, but very slowly. Then the doctor’s worst fears all came at once. Barbara’s contractions became intensely painful, the IV drip was slowed, the contractions weakened, heather stopped her descent, and her heartbeat slowed dramatically. The doctor told barbara that was concerned about the babies briefing and that he would have to some things to get the fetus out quickly. Whatever,: barbara snapped. Just knock me out and get it over with.

Struggling to hold back his anger, the doctor decided that the situation required the use of forceps.Que es la anoxia an epidural was administered, an episiotomy performed, and the blades of the forceps were inserted and locked. Heather was then gently, but firmly pulled from her mother’s uterus. She weighed just over 5 pounds.

Heather’s heartbeat was slow and irregular, her body was blue, and she was having difficulty breathing. She was rushed to the intensive care unit where emergency measure were taken to assist her breathing. Within a few hours a nurse came in to tell barbara that heather’s heartbeat had become normal and that she she finally breathing on her own. Barbara showed no response to the good news and expressed no desire to see her baby in the intensive care nursery.

Causes of fetal distress

There are many sources of fetal distress.Que es la anoxia rather than move into the usual head-down position for birth, one in thirty babies will assume the breech position, with the head up and the buttocks or feet or both down against the cervix. If the fetus is in a breech position or has not dropped when the bag of waters breaks, a portion of the umbilical cord may enter the vagina before the fetus, a condition called prolapse or prolapsed cord. When the fetus begins to descend through the vagina, it will pinch the cord, thus stopping the flow of oxygen. This situation is a serious medical emergency that requires rapid intervention. An insufficient supply of oxygen can also result from the decreased efficiency of the placenta late in pregnancy, or from premature detachment of the placenta during labor.Que es la anoxia when the baby is starved of oxygen, this is called anoxia. Anoxia causes brain damage and is the primary cause of cerebral palsy, a severe disturbance of the motor control center in the brain. Because the window for serious brain damage is a matter of minutes, an emergency cesarean delivery may be unavoidable.

Fetal distress can also result from rh blood incompatibility or rh-disease.

The rh factor in the blood of the mother and father can be either positive (present) or negative (absent). Most people are rh positive. The problem is when the mother is rh negative, the father is rh positive, and the fetus is rh positive. Under some circumstances, the mother will become sensitized resulting in the production of antibodies that can place the fetus at risk.Que es la anoxia the first time that this incompatibility occurs, the fetus will not be harmed. But if the mother becomes pregnant again with a rh negative fetus, the antibodies will attack the baby’s blood cells. Fortunately, when this condition is detected at the birth of the first child, the mother can be treated to prevent future problems. Electronic monitoring of mother and fetus

Electronic monitoring includes the use of both external and internal devices to monitor the fetal heart rate and the strength and duration of mother’s contractions. Electronic fetal monitoring or EFM can be accomplished through ultrasound sensors placed on the mother’s abdomen or by attaching a sensor to the scalp of the baby as it moves down the birth canal.Que es la anoxia

Electronic monitoring also includes monitoring the strength and duration of mother’s contractions. This may be accomplished through an external ultrasound sensor placed on the mother’s abdomen or by internally by placing a highly sensitive tube in the uterus next to the baby’s head.

The primary purpose of EFM is to identify fetal distress. The physician may compare the fetal heart rate in the non-stress state (without contraction) to the result of a contraction stress test to determine if the baby is experiencing fetal distress.

External monitoring of mother and fetus are accomplished by placing two belts across the mother’s belly, one for measuring the mother’s contractions and the other for measuring fetal heart rate.Que es la anoxia the sensors transmit data to recording and display devices that provide a steady stream of data to the physician.

In general, internal monitoring of the fetus and the mother’s contractions are more accurate than external monitoring. As invaluable as EFM is, these procedures also carry some risks of their own. Internal monitoring may require breaking the fetal membrane (if it is not already broken) which results in increased likelihood of infection to both the mother and the baby. This is of particular concern if the mother has an active vaginal infection such as herpes. The monitoring devices are also quite intrusive and/or confining and may have negative psychological effects on the mother. Finally, universal clear-cut criteria for medical intervention have not been established due to the highly complex nature of EFM data.Que es la anoxia fetal blood sampling

A second technique for monitoring the state of the fetus is fetal blood sampling. In the earliest version, a sample of blood is taken from a small cut in the scalp of the fetus and analyzed for oxygen and carbon dioxide levels and other indices of distress. The procedure can only be accomplished if the mother is sufficiently dilated and the amniotic sac has ruptured. The blood sampled from the scalp provides a more accurate diagnosis of fetal distress than EFM does.

Fetal blood sampling can also be conducted during the pregnancy to diagnose genetic disorders, check for various diseases and infection, and to check oxygen levels using percutaneous umbilical cord blood sampling ( PUBS) (also known as cordentocesis ) PUBS involves inserting a long, thin needle into the mother’s abdomen (guided by ultrasound) and then into the umbilical cord of the fetus to extract a small sample of blood.Que es la anoxia the fetal cells extracted by this procedure allow for a much faster DNA analysis as compared to amniocentesis or CVS. The blood obtained allows for detailed study of multiple diseases (e.G., anemia) and infections. PUBS can also be used to transfuse blood and/or medication to the fetus. However, the procedure brings with it considerable risk of infection and bleeding to the fetus and is therefore only used when the survival of the fetus is determined to be in jeopardy.