Other Free Encyclopedias » Social Issues Reference » Child Development Reference - Vol 6 » Prenatal Development - Ovum Or Germinal Stage, Embryo Stage, Fetal Stage, Prenatal Environmental Influences, Stress, Exercise - Conclusion

Prenatal Development - Prenatal Environmental Influences

mother birth fetus pregnancy

With increasingly sophisticated technology, the fetus has been studied and is considered to be an active agent in its own development. Many scientists believe that anything that affects the environment of the fetus can have an effect upon development beginning at conception and not at birth.

Environment does indeed begin to influence the individual as soon as he or she is conceived. As the zygote undergoes mitosis (cell division), the new cells themselves become part of the mother's environment, and through their particular physical and chemical influence they guide and control the development of further new cells. Different genes are activated or suppressed in each cell, so that while one group of cells is developing into brain tissue, another is giving rise to the heart, another to the lungs, and another to the skeletal system. Meanwhile, the lump of cells is surrounded by the larger environment of the mother's uterus, and this environment is surrounded by the mother and the world in which she lives.

The great majority of women have uncomplicated pregnancies and give birth to healthy babies, and for many years it was believed that the baby in the uterus was completely insulated from outside influences. Scientists now know that this is not entirely true. Environmental influences ranging from radioactivity and stress in the outside world to drugs, chemicals, hormones, and viruses in the mother's bloodstream can affect prenatal development.

Such threats affect the health of the fetus in several ways. This is because the body organs and parts develop at different speeds and go through definite phases. First they go through a phase of rapid multiplication in the number of cells. Then there is an increase in both the number of cells and in cell size. In the third and final phase of development, cell size continues to increase rapidly, but cell division slows down.

When a body part or organ system is growing most rapidly both in cell number and size, this is known as a critical period. If an environmental factor, such as a chemical or virus, interferes with growth during the critical period, development of that organ system will be permanently affected.

The effect of environmental influences varies, therefore, in accordance with the stage of prenatal development in which the environmental factor is encountered, as well as the intensity of the threat, as shown in Table 1.

During the first three months of pregnancy, tissues and important body systems develop in the embryo. Adverse influences during this period will affect the basic structure and form of the body and may have particularly serious effects on the nervous system. Physical development can be arrested and irreparable malformation may occur. For example, many women who took the once-available drug Thalidomide during the first three months of pregnancy gave birth to children with serious defects. When taken toward the end of pregnancy, however, the drug did not seem to have any negative effects.

Teratogens

The scientific study of congenital abnormalities caused by prenatal environmental influences is known as teratology (from the Greek word teras, meaning "marvel" or "monster"), and the environmental agents that produce abnormalities in the developing fetus are called teratogens.

Drugs

Chemicals (over-the-counter and prescribed pharmaceuticals as well as illegal substances) can cause a wide range of congenital abnormalities that account for about 10 percent of birth defects. The severity of the abnormality depends on the amount of the chemical the mother is exposed to, the developmental stage of the fetus, and the period of time over which the mother's exposure to the chemical takes place.

In terms of narcotics, women who are addicted to heroin, morphine, or methadone give birth to addicted babies. Soon after birth, the babies show symptoms of withdrawal, including tremors, convulsions, difficulty breathing, and intestinal disturbances.

Smoking and Nicotine

Cigarette smoking has already been shown to have dire consequences for the smoker, and it can be hazardous for the fetus and the newborn child. The results of studies of thousands of pregnancies in the United States and elsewhere, encompassing various ethnic, racial, and cultural groupings, indicate that the fetus and newborn are significantly affected by cigarette smoking during pregnancy.

Maternal smoking increases the risk of spontaneous abortions, bleeding during pregnancy, premature rupture of the amniotic sac, and fetal deaths and deaths of newborns. Women who smoke during pregnancy give birth to babies who are about one-half pound (225 grams) lighter (on the average) and smaller in all dimensions (for example, length and head circumference) than babies of nonsmokers, are born prematurely, and have other health problems.

Alcohol

The effects of alcohol are almost undisputed. Fetal alcohol syndrome (FAS), identified in 1973, is perhaps one of the best known and best documented outcomes of drinking, affecting approximately one out of every 750 births. And it is not just the heavy drinker who may place her fetus in danger. It has been found that women having one or more drinks daily were three times more likely to miscarry than women who had less than one drink daily.

FAS is a pattern of malformations in which the most serious effect is mental retardation. Other possible complications include permanent growth retardation, malformations of the face, brain damage, hyperactivity and learning disabilities, and heart defects.

Even if a child does not suffer from FAS, the effects of alcohol consumption can be significant. Although these children do not manifest the characteristics discussed above, they are at high risk for such problems of children of alcoholics as hyperactivity and learning disabilities. Results of research also indicate that moderate drinking can affect the later development of a child's intelligence as measured by IQ scores at age four.

The Mother

Since the mother's body is the chief element in the fetus' environment, the mother's physical condition can significantly affect the baby's development.

Among the maternal factors known to influence the fetus are disease, age, diet, reactions associated with a certain blood component, and prolonged stress.

Even a mother's knowledge of what is taking place in her body can be important. Some research has shown that mothers who consumed potentially teratogenic drugs during pregnancy had very little information about these drugs and even less information about their effect during pregnancy.

Diseases

Since the placenta cannot filter out extremely small disease carriers, such as viruses, children can be born with malaria, measles, chicken pox, mumps, syphilis, or other venereal diseases that have been transmitted from the mother.

Rubella is the most widespread of the viruses that have a teratogenic effect. If a pregnant woman contracts rubella in the first three months of pregnancy, she is likely to give birth to a child with a congenital abnormality such as heart disease, cataracts, deafness, or mental retardation. Interestingly, there is not a direct relationship between the severity of the disease in the mother and its effect on the fetus. For example, women who have had mild attacks of rubella have given birth to babies with severe abnormalities.

Although rubella might be the most widespread disease, acquired immunodeficiency syndrome (AIDS) is by far the most frightening and the one that has received the most publicity. The vast majority of children with AIDS contracted the disease sometime between early pregnancy and birth. The disease is usually transmitted from the mother through the uterus during pregnancy or is acquired by the off-spring at birth.

As of the early twenty-first century, there was not a cure for AIDS, and the majority of efforts at controlling the disease focused on education in an effort to get potential female AIDS victims to take the proper precautions and avoid sexual relationships with high-risk males, usually those involved with drugs. Significant progress was being made, especially concerning children.

Toxemia is a frightening condition that is potentially fatal for the mother and the fetus. It is characterized by high blood pressure, swelling, and weight gain due to a buildup of fluid in the body tissues, and the presence of protein in the mother's urine. In severe cases the woman may go into convulsions or coma, placing a tremendous strain on her, which is carried over to the fetus. Women with toxemia frequently give birth to premature babies or to babies smaller than average for their gestational age. Like many other types of blood-pressure disorders, however, toxemia can be treated through medication and diet.

Anoxia is a condition in which the brain of the baby does not receive enough oxygen to allow it to develop properly. Anoxia can cause certain forms of epilepsy, mental deficiency, cerebral palsy, and behavior disorders. If the amount of brain damage is not too severe, however, it may be possible to compensate for the disorder to some extent. Epilepsy can often be controlled with drugs, for instance, and many children with cerebral palsy can learn to control their affected muscles.

Age

Teenage mothers and those over thirty-five years of age have a higher risk of miscarriage, premature birth, and some birth defects than mothers in the prime childbearing years. Some of the reasons are fairly obvious. Very young mothers have not yet completed their own development, and the reproductive system may not be quite ready to function smoothly or effectively. In older women the reproductive system may be past its most efficient functioning.

In both cases, pregnancy puts an extra strain on a body that is not fully able to bear it. Furthermore, there is some reason to think that a woman's ova may deteriorate with age, leading to a greater risk of birth defects. Women have all their ova in partly developed form when they are born. So a woman who becomes pregnant at age thirty-seven, for example, is "using" an ovum that has been more or less exposed to thirty-seven years' worth of harmful chemicals, radiation, virus infections, and whatever else has happened to her body. This may explain why, for instance, Down syndrome is most common in children born to mothers over forty years of age.

It is quite possible that men's sperm may also be susceptible to chemicals and radiation effects over time. Furthermore, there may be genetic disorders that cause changes in sperm structure.

Diet and Physical Condition

Just as other aspects of physical health are important, so is the mother's diet. While physicians and researchers have long realized that pregnancy puts additional demands on the mother's body, they used to assume that the fetus' nutritional needs would be met first, even at the mother's expense.

The current opinion, however, is that the prenatal development of the fetus and its growth and development after birth are directly related to maternal diet. Women who follow nutritionally sound diets during pregnancy give birth to babies of normal or above-normal size. Their babies are less likely to contract bronchitis, pneumonia, or colds during early infancy and have better developed teeth and bones. The mothers have fewer complications during pregnancy and, on the average, spend less time in labor. The less time in labor, the easier the birth and the less stress the mother and child experience.

But if the mother's diet is low in certain vitamins and minerals when she is pregnant, the child may suffer from specific weaknesses. Insufficient iron may lead to anemia in the infant, and a low intake of calcium may cause poor bone formation. If there is an insufficient amount of protein in the mother's diet, the baby may be smaller than average and may suffer from mental retardation, with almost 20 percent fewer brain cells. Mothers who are also physically small (under 100 pounds [45 kilograms] in total body weight) are risky for pregnancy as well because of the stress that pregnancy can place on them.

The Rh Factor

The Rh-positive factor is an inherited genetically dominant trait in the blood that can result in a dangerous situation for the fetus. When blood containing the Rh factor (that is, Rh-positive blood) is introduced into blood without the Rh factor (Rh-negative blood), antibodies to combat the Rh factor are produced. If an Rh-negative woman mates with an Rh-positive man, the resulting child may have Rh-positive blood. Any small rupture in the capillaries of the placenta will release the Rh factor into the mother's bloodstream, causing her body to produce the antibodies needed to fight it. The antibodies in the mother's blood will then cross the placenta into the fetal bloodstream and attack its Rh-positive red blood cells, depriving the fetus of oxygen. The result may be a miscarriage, possible brain defects, or even death to the fetus or newborn child. Only in circumstances involving an Rh-negative mother and an Rh-positive child does this danger exist.

This condition in the child is called fetal erythroblastosis. Firstborn children are not threatened, because the mother's blood has not had time to produce a large amount of antibodies, but the risk increases with each pregnancy. In the past, erythroblastosis was always fatal, but now medical techniques can minimize the harmful effects of Rh incompatibility. After the birth of an Rh-positive child, the Rh-negative mother can be given an injection of the drug Rhogam to reduce the buildup of antibodies in her blood. If this is not done, future Rh-positive children will be endangered by the high antibody level. A doctor who suspects an Rh incompatibility between mother and fetus can measure her antibody level and induce labor if the antibody count becomes too high. Immediate and complete blood transfusions to the newborn infant can then eliminate the mother's antibodies from its blood. If the fetus is not yet mature enough to survive after birth, a blood transfusion may be possible in utero.

Prenatal Development - Stress [next] [back] Prenatal Development - Fetal Stage

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over 3 years ago

Prenatal Development - Prenatal Environmental Influences

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about 3 years ago

The development of a baby in preNatal Environment

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Prenatal Development - Prenatal Environmental Influences - Mother ...
The effect of environmental influences varies, therefore, in accordance with the stage of prenatal development,
Thanking you

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almost 7 years ago

the rh factor section doesn't mention any thing about the harm it can do to the mothers body. If it doesn't harm the mother it needs to be stated in the paragraphs somewhere.

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almost 2 years ago

great information that helps in my studies

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almost 3 years ago

In 1964 my mother was given amniocentesis and I was subsequently born via c-section a month premature. I was RH Positive, my older brother RH Positive. My mother was RH negative. My father recently told me that the Dr.s informed him and my mother that although i survived, having 6 full blood exchanges, I would encounter many medical problems as an adult.

I am now 46, and the past 9 years of my life have been wrought with multiple medical problems, including diverticulitis/ostomy, severe osteoporosis (with multiple broken bones), and now the osteoarthritis I've ignored is beginning to debilitate me. I've had to quit work.

I find NOTHING about the effects of such a traumatic birth, not being touched by human hands for over a month, all the blood loss/transfusions/exchanges... I don't know what happened when I was a baby.

I have always been an active woman, sports enthusiast, downhill skiing, biking, roller blading, etc... and I'm left with nothing but walking and bike riding.

I have two teenage daughters... and I worry about them. is there ANY RESEARCH STUDIES ON PRE RHOGAM babies and long term health effects? I can deal with the osteoarthritis... I can't deal with the fact I've been told I can never fall again. I'm only 46. I'm looking for a cure, but justification that I'm not crazy and maybe my father is correct that this was just 'fate'.

thank you for your time and I look forward to a reply, even if it isn't an answer. I'm at my wits end and will be a guinea pig if need be... this just makes no sense why my body would deteriorate, when I took such good care of it. (no smoking, no drinking, no fried foods...) I just don't get it.

Jennifer

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about 3 years ago

send the message

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over 3 years ago

thank you very much for the information you provided

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almost 3 years ago

Great information and out of respect to all (comments), I couldn't recomend neuroptimal neurofeedback to just about any walk of life enough, but especialy the immediate and surrounding environments, throughout the whole intergrated creation of a brand new life.Please look into it,its like nothing else.

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about 1 year ago

http://social.jrank.org/pages/515/Prenatal-Development-Prenatal-Environmental-Influences.html

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about 2 years ago

certainly, this information had been of great significant to my research,thanks lot.

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almost 3 years ago

pls, i need the effect of socio cultural factors on a foetus and growing child

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almost 2 years ago

Actually this information helped me much in studying prenatal development in my psychology course and contributed much in raising my course work points.BIG UP !!!!!!!!

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about 2 years ago

certainly, this information had been of great significant to my research,thanks lot.

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about 2 years ago

certainly, this information had been of great significant to my research,thanks lot.

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over 2 years ago

thanks for the goods work done,and am hoping also to publish abook of psychology to put on web,but still luck of financial suport

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over 2 years ago

this information has really been of much help in my research. thanks

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about 2 years ago

Certainly it contais great information.it helps my studies. thanks

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over 2 years ago

thanks for the goods work done,and am hoping also to publish abook of psychology to put on web,but still luck of financial suport

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over 1 year ago

Thank you... very comprehensive.

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over 1 year ago

Thank you... very comprehensive..

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over 1 year ago

It was quite useful to me when doing my work

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over 1 year ago

great ingormation that helps in my studies

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almost 2 years ago

The information given is very useful and good for my academic work. Thanks alot!

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about 2 years ago

certainly, this information had been of great significant to my research,thanks lot.

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about 2 years ago

certainly, this information had been of great significant to my research,thanks lot.

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about 2 years ago

Just fabulous .i have completed my research.THUMBS UP!!!

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about 2 years ago

Just fabulous .i have completed my research.THUMBS UP!!!

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about 2 years ago

Certainly it contais great information.it helps my studies. thanks

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about 2 years ago

Certainly it contais great information.it helps my studies. thanks

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over 2 years ago

Hello, i was doing some research on rubella. I was wondering if perhaps a male was exposed to the vaccination of german measels and shortly there after concieved if this too could cause birth defects? if anyone has any information that could help it would be greatly appreciated! im trying to do a research project on birth defects so i could use ANY information!

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over 2 years ago

Thank you for the useful information, but i have a question.I wish to know of educational implications that one can give to children affected during prenatal development.Such children with either physical or mental challenges?

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over 2 years ago

I would like to know how can the environment and children experiences affects brain development, considering the pre natal, positive and negatives affects.
Thank you

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3 months ago

This has been very helpful to me providing additional insight on my study. thanks very much.

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6 months ago

Mimi