Module 4

Module 4—From Fertilization to Birth

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Most people love babies. Images of babies are used to sell everything from diapers to cars.

 

Between conception and birth, a period of approximately 40 weeks, the fertilized egg divides, differentiates, and specializes to form a complex multicellular organism. The fertilized egg begins its journey down the Fallopian tube and undergoes many changes before implanting in the uterus. In the first eight weeks of development and differentiation, many factors can have impacts on the embryo. Many support structures are formed to facilitate the embryo’s development. From fertilization all the way through until birth, different hormones regulate and control the progression of prenatal development. Environmental factors can also affect the developing embryo and fetus. Reproductive technologies can be used to enhance or reduce reproductive potential, but there are often societal issues related to the use of these technologies.

 

Dividing the prenatal development and parturition events into different periods or stages is a way to gauge normal progress. That being said, it is important to remember that not all development and labour will follow the exact time frames given. These events progress at slightly different rates in each woman and in each individual pregnancy; no two pregnancies are exactly alike. However, it is important that you understand the overall progress and relative time periods described. Many factors and technologies can prevent or assist in prenatal development and observation.

 

In this module you will continue to help three couples, Jane and John, Olga and Karl, and Maria and José, who have come to you for help with their infertility problems. Throughout the module, further issues will come to light and decisions will need to be made by the couples in order for them to achieve their goal of having children.

 

Throughout the module you will explore the following focusing questions:

• What are the sequences of events and hormone controls that occur throughout fertilization and embryonic development?
  
  
• What major tissues and organs arise from the ectoderm, mesoderm, and endoderm?
  
  
• How are twins formed?
  
  
• What are the major events of each trimester?
  
  
• What is the significance of the first trimester?
  
  
• What is the significance of the effects of teratogens on embryonic and fetal development?
  
  
• What triggers the birthing process, and what are its stages?
  
  
• What controls lactation?
  
  
• What technologies are used to assist fertilization, to monitor development, and to facilitate parturition?

You have been introduced to the focusing questions for this module. Each lesson will restate these focusing questions to guide your study. To help you organize the concepts of this module, and to provide you with a potential aid for review, you may choose to download the Module 4 Concept Organizer. Fill in this concept organizer with the ideas that you master as you work through each lesson, or prepare the organizer when you have completed Module 4. You can use keywords, point form, or any amount of detail that meets your needs. You may choose to work from the file on your computer, print the document and work from the paper copy, or copy the outline onto a large sheet of poster paper. After you have prepared your concept organizer, you may wish to check your work with the concept organizer provided in the Module Summary. The concept organizer provided outlines some of the key topics that you should include in each lesson of your concept organizer. This is a great tool to review and use for study purposes, but using this organizer is completely your choice.

 

The Module Assessment for Module 4 involves completing a table outlining the genetic, hormonal, and environmental effects on embryonic and fetal development.

 

Throughout Module 4 you will continue to work toward the Unit B Assessment on the fertility case study involving three couples struggling with infertility. You may choose to recall the requirements of the Unit B Assessment by reading “A Fertility Case Study.” Keep in mind what you have discovered about the couples so far from your work in Module 3 and what treatment options you have already provided. Add to your information as you work through Module 4. You will need this information to complete the Unit B Assessment.

 

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