Unit 3: Lesson 2: Prenatal Development

Lesson 2: Prenatal Development

Lesson 2: Prenatal Development

A human fetus

Prenatal development occurs after fertilizing a human egg and before a baby is delivered separately from the baby's mother. Although the question of when life begins is highly controversial, it is clear that a significant amount of development occurs in the womb and significantly influences lifespan development. Considering the prenatal period as part of the developmental process can help us learn more about related factors that may influence later health and development.

The physical development of many babies goes smoothly in the womb. They grow and develop typically and emerge from the womb without significant health problems. In part, this is because the mother's womb acts as a form of protection for the developing fetus. However, some environmental issues can create health and developmental problems for fetuses.

A teratogen is any substance or agent that interferes with the normal development of a fetus in the womb. Examples of teratogens include drugs (prescription and nonprescription), pollutants, infectious diseases, maternal malnutrition, and so on. When considering teratogens, health science professionals note that several factors influence whether a teratogen will impact prenatal health and development; these factors include the dose or amount of the substance to which the fetus is exposed, the length of time that the fetus is revealed, and the genetic vulnerability of the individual fetus. The damage that any teratogen creates can also be related to the age of the fetus. For example, a teratogen may prohibit a fertilized egg from attaching to the uterine wall in the early days after fertilization. During the embryonic period, teratogens may create developmental issues with body organs.

Maternal nutrition is a teratogen that will influence the development and health of a fetus. Fetuses rely on their hosts for adequate nutrition to develop generally within the womb. This can include the total number of calories the mother consumes and the specific nutrients, minerals, and other substances. For example, folic acid is often identified as an essential vitamin for pregnant women. This is because a deficit in folic acid during pregnancy can lead to neural tube defects, such as spina bifida, for the baby.
Another example is the consumption of fish during pregnancy. Fish can be a great addition to a healthy diet, but many fish contain high levels of mercury that may cause developmental issues for a fetus. Mercury can damage he brain and the nervous system, particularly during the embryonic stage when these tissues are formed.

At the end of the prenatal stage, a baby is born. Aspects of the delivery can also influence the health and wellness of the newborn infant. During the delivery, the baby is under a great deal of stress, although the baby secretes both adrenaline and noradrenaline for protection. If the delivery takes too long, there is a risk that the baby will be deprived of oxygen, which can lead to brain damage. As soon as the baby is born, health science professionals assess the baby's health using the Apgar Scale, which rates the baby's heart rate, muscle tone, skin color, and so on. It is used to help identify infants at a higher risk of problems due to the stress of the delivery and to evaluate them for other health concerns.

Infancy

When a child is born, they have a few qualities that we associate with humans, such as walking or talking. Thus, the infant must begin developing the skills and characteristics we associate with most adults. Although this will be a long development process, it is underway even among infant children. Some of this development happens quickly, and within an infant's first year, most will begin sitting, crawling, standing, or even walking.

Physical development is one aspect that infants will experience at a rapid pace. Before the baby is born, physical growth occurs more at the top of the body than at the bottom. The head is proportionally larger at birth than other body parts. As the infant develops, development occurs from the top/head down in what is known as the cephalocaudal pattern. For example, infants typically learn to hold their heads up and then control their torsos to reach for toys, learn to sit up, and finally, know how to stand and walk. Development in infants also follows the proximodistal pattern, where growth and development start at the body's core and move to the extremities. Babies generally learn to control their torsos and arms before using individual fingers, for example. Infants also experience growth in their length/height and weight during their first year. For instance, babies usually double their birth weight by the time they are four months old and roughly triple their birth weight by the time they are one year old. Most infants also grow about one inch per month during the first year.

Brain development is another crucial aspect during the infant's first year. At birth, the baby has billions of nerve cells. These nerve cells or neurons are involved in information processing in the brain, and they communicate with each other to help us understand and interact with the world. As infants develop and experience the world around them, these neurons create connections or pathways with each other. Connections are maintained and strengthened, while those unused are replaced or left to disappear. This type of development is one reason infants must be protected from falling, shaking, or other head injuries. Shaken baby syndrome is one condition that health science professionals may need to treat; it occurs when a baby is shaken, and it results in hemorrhaging and swelling that can cause brain damage or even death. Another health concern in infancy is Sudden Infant Death Syndrome (SIDS). SIDS is a condition in which the infant stops breathing and dies for no apparent reason. About 3,000 infants die from SIDS in the United States each year, and the risks are most significant for babies between one and three months of age. Over the past several decades, doctors have recommended that babies sleep on their backs, which seems to reduce the incidence of SIDS.