Lifespan Overview

*This essay was done in collaboration with other classmates during a Lifespan, Growth, and Development Psychology class. I hope that it can give you some insight into the different stages of fetal development.

Prenatal Development

The prenatal stage of development is the most critical stage during pregnancy which determines the overall structure for the rest of an individuals lifespan. Factors of development that can be influenced by prenatal care can affect the baby’s developmental patterns for life in negative ways, such as birth defects, or in positive ways, such as intelligence. Topics of development that should be considered  in the process include Physical Development, Heritable Genetics and Partner Selection, the Maternal Role and Role of Support Systems, and Changes in the Human Body during Fetal Development.

Physical Development

Prenatal Development is the process in which an embryo or fetus gestates during pregnancy from fertilization until birth.  Prenatal development occurs in three stages: germinal, embryonic, and fetal. (Human Development 75)  During the three stages, fertilization by which sperm and ovum combine creates a zygote and then duplicates itself again and again by cell division to produce all the cells that make up a baby.  The phenomenal process of replication is called mitosis, which insures each newly formed cell has the same DNA structure as all the others.  (Human Development 54)  All the biological information needed to aid the zygote’s development into a baby happens at conception. (Human Development 55)  “The germinal stage occurs within the first two weeks of conception, characterized by rapid cell division, blastocyst formation, and implantation in the wall of the uterus.” (Human Development 75)  After the germinal stage, the single cell zygote matures into an embryo and then a fetus.  By weeks two through eight, the zygote has matured into the embryonic stage developing at a faster rate.  Within the first month, growth is rapid than any other time, the heart beats 65 times a minute, and it has the beginnings of the brain, kidneys, liver, and digestive tract. (Human Development 76)  The embryo is the most sensitive to damage from environmental exposures because the major organs of the body have not been created.  By the end of the second month, the embryo matures into a fetus.  The fetus grows close to twenty times its length in the embryonic stage and the precursors of all major organs of the body have been created.  Facial parts are clearly developed.  Arms have hands and fingers and legs have knees, ankles, and toes. Also, bones start to develop.  By the end of the third month, sex can easily be determined and organ systems are functioning.  The fetus now can move a variety of ways, sucking sensation develops, and mother may feel fetus kicking during the fourth month.  Becoming more active, weighing about one pound, and developing a sense of personality usually are dominant about the fifth month.  Eyebrows and eyelashes develop as well as fine hairs on the head.  In the sixth month, growth starts to slow down, eyes are functional, and the fetus can hear.  During the seventh and eighth month, reflex patterns have fully developed, it can cry, breath, and swallow normally.  Survival rate is high and position of head is down.  At full term pregnancy, the fetus is born weighing about seven and half pounds and learns quickly to adapt to the environment.

Heritable Genetics and Partner Selection

            A gene is a tiny, invisible unit containing information (DNA) that guides how the body forms and functions. Each individual inherits tens of thousands of genes from each parent, arranged on 46 chromosomes (Birth Defects 548).1 Genes control all aspects of the body, how it works, and all its unique characteristics, including eye color and body size. In the case of birth defects, the genes also may determine abnormalities called genetic defects if they are faulty in some way. Genes are influenced by chemicals and radiation, but sometimes changes in the genes are unexplained accidents (Birth Defects 549).2 Hereditary birth defects are caused when a mistake is made as DNA divides and forms a template to transcribe copies (Birth Defects and Brain Development 218).3 Disruptions in DNA structure through gene-environment interactions can cause disease or deformities called genetic defects (Importance of gene-environment interactions 409).4 Types of genetic defects from their family are Cleft lip and palate, Clubfoot, Spina bifida, Water on the brain (Hydrocephalus), neural tube defects, high cholesterol, Diabetes mellitus, heart defects and some forms of cancer (Congenital Abnormalities 634).5 The interactions between genes and environmental factors in the etiology of genetic defects affect pathological processes that contribute to the development of complex genetic defects. Maternal smoking causes TGFA and NOS3 genes to promote oral clefts and folate intake causes folate pathway genes to reduce neural tube defects (Importance of gene-environment interactions 411-413).6 Abnormal fetal growth by genetic defects threatens a healthy pregnancy and the long-term health of the offspring, which causes  financial, physical, psychological and social suffering (The Genetics of Birth Timing 493).7 Taking folic acid supplements before and during pregnancy reduces the risks of brain or spinal cord defects. Genetic counseling and screening tests like Alpha-fetoprotein test, Ultrasound, Amniocentesis, Chorionic villus sampling (CVS) are also helpful (Birth Defects 548).8 Partner selection has been a topic of extensive and systematic study by evolutionary psychologists. Evolution is concerned not simply with the numbers of offspring an individual produces in a lifetime, but with the numbers of those offspring that successfully reach adulthood and reproduce in their turn. To reproduce offspring successfully, choosing an appropriate partner and investing appropriately in the offspring that result are important, which is why men and women select their partner (Human evolutionary psychology 93).9 Thus, marriage or relationship searchers seek the best partner possible given their own qualifications (e.g., physical attractiveness or earnings) and constraints (e.g., children from a previous relationship). Men value physical attractiveness and youth in a partner more than women because attractiveness and youth are cues that suggest a woman’s reproductive value. Women value in men characteristics such as dependability, good earning capacity, ambition, a career-oriented mentality, and high socioeconomic status, which indicates cues of successful resource acquisition. Therefore, humans do not differ from other animals in that their mate choices are guided by cues to reproductive investment aimed at survival advantages of the offspring (Effect of Humor 67-77).10 Men are more willing than women to engage in sexual relations in the absence of emotional involvement and marital potential and are more likely to seek sexual relations with a number of partners for the sake of variety. Compared to women, men are more likely to seek out and engage in low-investment sexual relations, whereas women tend to seek emotional involvement. Sexual access thus becomes a bargaining chip that, consciously or unconsciously, women trade for emotional and material investment, whereas men trade investment for female sexuality and beauty (Effects of Potential Partners’ Costume 371).11 This evolutionary explanation of sex differences does not deny the importance of social, psychological, and historical factors; rather, evolutionary explanations offer a different but complementary type of analysis and focus on ultimate causes.

Maternal Role in Development and Role of Support Systems

In order to ensure the health of the mother and the development of the baby it is necessary for the mother to obtain a nutritious diet, take certain precautions that will not affect the fetus, and have a support system as well. It is important for the mother to take in enough nutrients in order to feed herself and her fetus. Since the development and well-being of the unborn baby greatly depends on what the mother eats, it is also beneficial for the baby if the mother takes vitamins (such as folic acid) which are vital in a pregnant woman’s diet. Good nutrition also depends on the mothers’ socioeconomic status because if the mother is not in a good financial position, she may not be able to afford good quality of nutrition or medical care necessary for the fetus. It is also important for the mother to take certain precautions when pregnant. Since everything the mother consumes will eventually reach the fetus, she should not consume drugs or alcohol, and she should not be around environmental hazards either because these factors can cause birth defects. Pregnant women should also stay active in order to maintain a healthy state, but should avoid doing too much exercise because it can be dangerous for the fetus. During pregnancy the mother should be considerate when taking medical drugs and any other kinds of drugs should be avoided so as to prevent damage to the fetus. Prenatal alcohol exposure is the most common cause of mental retardation and the leading preventable cause of birth defects in the United States (Papalia, Olds and Feldman 83). Exposure to alcohol can cause Fetal Alcohol Syndrome (FAS) in newborns, which can lead to devastating effects and learning disabilities. Pregnant women should also be aware that there are environmental hazards such as air pollution or radiation that can harm the baby. Having a support system is equally as important as taking careful considerations during pregnancy and eating healthy. During pregnancy, the most important thing is having support; any type of assistance from the family or partner facilitates the mother’s life and the baby. Maternal well-being during pregnancy can improve if the mother has some kind of encouragement. The prenatal environment of the baby is practically the mother’s body so the mother should be aware of everything that can affect or help the baby.

Changes in the Human Body during Fetal Development

Not only does the fetus have an impact on the mother, but the mother also has an impact on the fetus. The mother goes through many changes due to the developmental process of the fetus. The body is prompted to change in order to provide a suitable environment for the fetus while it is “growing,” to prepare for childbirth and nurturing. The body adapts to this by chemical changes such as increasing estrogen and progesterone, which may cause a decrease in energy levels. These control the menstrual cycle and may cause it to stop, a common indicator of pregnancy. Other hormones become active such as, Human Chorionic Gonadotropin (HCG), also called the “pregnancy hormone.” The process also puts other stressors on the mother’s body such as needing to “eat for two” and allow it to carry around extra weight. The body also accommodates for breastfeeding by generating milk in the breasts which increase in size during pregnancy. Pregnant women will feel sore in their breasts and their uterus will push against the bladder causing frequent urination. Many women also experience morning sickness and nausea. Blood pressure will change during these months, causing dizziness and lethargy. The expecting mother will feel better adjusted to the hormone changes by the second trimester. About this time is when the mother experiences movement from the baby in the abdomen. Other symptoms that come with this time during the pregnancy include leg cramps or heartburn caused by the pressure of the uterus growing by the stomach. These symptoms will increase as the pregnancy approaches the due date and the woman may feel more tired, irritable and uncomfortable, and perhaps may become in need of more assistance. Feet and ankles may swell because of pressure on the blood vessels and may produce varicose veins. During the last few months, the pregnant woman may also experience Braxton Hicks contractions, which last no longer than 30 seconds (Pagewise). If the mothers body fails to accommodate an environment for the developing fetus, the fetus could be born early, have low birth weight or die.

In Conclusion,  important topics mentioned such as Physical Development, Heritable Genetics and Partner Selection, the Maternal Role and Role of Support Systems, and Changes in the Human Body during Fetal Development, should be considered when assessing the outcomes of prenatal development. With increased awareness and education on this subject, we are preparing to deal with possible complications and outcomes of prenatal care. From the long term perspective, this understanding should also increase the quality of life for both the child and the caregiver for the following years of parenting and child rearing as well as precautionary measures to consider during the process of pregnancy.

Works Cited

Papalia, Olds, and Feldman. Human Development. Published by McGraw-Hill. 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2009. All rights reserved. (pg.82-88)

Pagewise, Inc. “How Your Body Changes During Pregnancy.” © 2002 Pagewise http://www.essortment.com/all/pregnancychange_rdwf.htm.

1, 2. Karen Ericson and Teresa G. Olde. “Birth Defects.” The Gale Encyclopedia of Medicine. Vol. 1. 3rd. Detroit: Gale, 2006. p548-549.

  1. Miranda Herbert Ferrara. “Birth Defects and Brain Development.” Human Disease and Conditions. Vol. 1. 2nded. Charles Scribner’s Sons, 2010. p218-219.
  2. H Zhu, S Kartiko and RH Finnell. “Importance of gene-environment interactions in the etiology of selected birth defects.” Clinical Genetics. 2009: 75: p409-423.
  3. Margot I. Van Allen. “Congenital Abnormalities.” McGraw-Hill Encyclopedia of Science & Technology. Vol. 4. 10thed. New York: McGraw-Hill, 2007. p634-636.
  4. H Zhu, S Kartiko and RH Finnell. “Importance of gene-environment interactions in the etiology of selected birth defects.” Clinical Genetics. 2009: 75: p409-423.
  5. BP Chaudhari and LJ Muglia. “The Genetics of Birth Timing : Insights into a Fundamental Component of Human Development.” Clinical Genetics. 2008: 74: p493-501.
  6. Karen Ericson and Teresa G. Olde. “Birth Defects.” The Gale Encyclopedia of Medicine. Vol. 1. 3rd. Detroit: Gale, 2006. p550-551.
  1. Louise Barrett, Robin Dunbar, and John Lycett. “chapter 5 ; Mate choice and Sexual selection.” human evolutionary psychology, Princeton : Princeton University Press, c2002. P93.
  2. ELIZABETH McGEE, MARK SHEVLIN. “Effect of Humor on Interpersonal Attraction and Mate Selection.” The Journal of Psychology, 2009. 143(1), p67-77.
  1. Townsend, John Marshall, Levy, Gary D. “Effects of Potential Partners’ Costume and Physical Attractiveness on Sexuality and Partner Selection .” Journal of Psychology, 00223980, Jul90, Vol. 124, Issue 4. P371-372.

Papalia, Olds, and Feldman. Human Development. Published by McGraw-Hill. 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2009. All rights reserved. (pg.54-76)

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