Fetal stage

Definition

The fetal stage is the final phase of prenatal development that occurs from the ninth week of gestation until birth. During this stage, significant growth and maturation of the fetus take place, including the development of all major organ systems, increasing body size, and the acquisition of functions necessary for survival outside the womb.

5 Must Know Facts For Your Next Test

1. The fetal stage begins at about nine weeks of gestation, marking a transition from the embryonic stage, where basic structures form, to a focus on growth and functional development.
2. By the end of the fetal stage, typically around 38-40 weeks of gestation, the fetus has usually reached a weight of 5.5 to 8.8 pounds and measures about 18-22 inches long.
3. During this stage, organs continue to mature; for instance, lungs develop surfactant to aid in breathing after birth.
4. Fetal movements, or 'quickening', typically begin around 18-20 weeks and are important for assessing fetal health and development.
5. The fetal brain undergoes rapid development during this period, with neurons forming and synapses developing in preparation for postnatal life.

Review Questions

• What are some key developments that occur during the fetal stage that distinguish it from earlier stages of prenatal development?
  • During the fetal stage, significant growth occurs as the fetus develops major organs and systems necessary for life outside the womb. Unlike earlier stages where structures are initially formed, this phase focuses on maturation and increasing complexity. For example, the lungs develop surfactant to ensure proper breathing after birth, and brain development accelerates with neuron formation and synapse connections.
• How does fetal movement serve as an indicator of fetal health during pregnancy?
  • Fetal movement, often referred to as 'quickening', is an important indicator of fetal health and wellbeing. Typically felt between 18-20 weeks of gestation, these movements signal that the nervous system is developing appropriately. Changes in the pattern or intensity of these movements can alert healthcare providers to potential issues with fetal health, prompting further evaluation or monitoring.
• Evaluate how environmental factors during the fetal stage can impact long-term health outcomes after birth.
  • Environmental factors such as maternal nutrition, exposure to toxins, or stress levels during the fetal stage can significantly influence long-term health outcomes. For instance, inadequate nutrition can lead to low birth weight or developmental delays, while exposure to harmful substances like alcohol or drugs can result in conditions like Fetal Alcohol Spectrum Disorders. Understanding these impacts emphasizes the importance of a healthy maternal environment throughout pregnancy for optimal fetal development.

Related terms

embryonic stage: The embryonic stage is the period of development from fertilization until the end of the eighth week, where foundational structures and organs begin to form.

gestation: Gestation is the process of carrying or being carried in the womb between conception and birth, encompassing all stages of prenatal development.

neonatal period: The neonatal period refers to the first 28 days after birth, a crucial time for adaptation to life outside the womb.