Module 4 Lesson 3 - 3

Comparison of Embryonic and Fetal Developments

The main difference between the embryonic and fetal development periods relate to the type of development of the organism. The embryonic period is a time of morphogenesis when the organs are formed. During the fetal period the organs continue to develop.

Fetal Development. © Jun 2, 2015 Stephen E. Wisecarver. OpenStax is licensed under a Creative Commons Attribution License 4.0 license.  Access for free at https://cnx.org/contents/cuddklxQ@1/4-3-Stages-of-Development-SW

Watch and Listen

View the following video clips to gain a better understanding of the events of fetal development.

Thought Lab - Folic Acid and Neural Tube Defects 

1. As mentioned earlier, ensuring proper nutrition (consuming adequate nutrients, vitamins, and minerals) is as important as avoiding harmful teratogens when pregnant. Answer the following analysis questions; then, check your work to see how well you understand the need for folic acid.
   
   
   1. What is a neural tube defect?
      
   2. What is the daily recommended dose of folic acid for women who are planning to become pregnant?
      
   3. When should women start taking folic acid supplement?
      
   4. Can adequate amounts of folic acid be obtained from food?
      
   5. What complications are associated with having a baby with neural tube defect?
      


Check your work.

Answers to Analysis Questions, page 524 of textbook


1. Taking folic acid supplement lowers the risk of having babies with neural tube defects. Neural tube defects occur in 1 in 750 babies born in Canada. These defects occur when neural tubes fail to close properly during the third and fourth weeks of pregnancy. Two most common types of neural tube defects are spina bifida, which affects the spine, and anencephaly, which affects the brain.
   


2. The recommended daily amount of folic acid for women who could become pregnant is 0.4 mg daily prior to conception. It is not recommended to consume more than 1 mg of folic acid per day.
   
   
3. The recommendation is that women have an adequate intake of folic acid from 1 month prior to conception and for 3 months after conception.
   
   
4. Dietary intake of folic acid is inadequate to prevent NTDs; women are unlikely to reach the recommended intake of folic acid without vitamin supplements.
   
   
5. Complications related to incidents of NTDs such as spina bifida include hydrocephalus, paralysis, abnormalities of the hips, and bowel and bladder problems. Other problems such as tendonitis, learning disabilities, and social disorders are common as the child develops lacking folic acid.
   
   

Going Beyond

Think about these questions concerning fetal development. (You are not required to submit answers to these questions.)

1. Why are most women who wish to become pregnant informed to take a prenatal vitamin supplement?
   
   
2. Many teen pregnancies occur every year in Canada. Do you see a possible problem with some teenage dietary habits and teenage pregnancy?
   
   
3. Do you know of any common household substances that pregnant mothers should avoid?
   
   
4. Why should pregnant women not change cat litter boxes for cats that live indoors and outdoors?

Many complications can affect prenatal development. One of the most common developmental problems is premature birth in which fetal development does not come to full-term. If you are interested, research premature birth to answer some or all the questions presented below.

1. How small can a baby be and still survive outside the womb?
   
   
2. What are some of the complications for babies born early?
   
   
3. How are preemies (babies born prematurely) cared for immediately following birth and for a few weeks after birth?
   
   
4. What is 'kangaroo care' for preemies?
   
   
5. What residual complications to premature birth can carry into later childhood or adulthood?