Module 4 Fertilization to Birth

2.4.2 page 3

Reflect on the Big Picture

It is an awesome and exciting path to be on when a couple wanting children discovers they are pregnant. However, many expecting couples choose to wait until the pregnancy is at least three months along, the end of the first trimester, before they announce the news. This also corresponds to the completion of embryonic development and the first months of fetal development.

Most miscarriages happen within the first 13 weeks of a pregnancy, and most of these miscarriages are lost due to chromosomal abnormalities, which prevent normal embryonic and fetal development. Therefore, many couples wait to inform their friends and family they are pregnant until this time period has passed. This saves the discomfort of answering the many questions of “how is the pregnancy going” when the baby is lost.

Jane and John had their pregnancy confirmed and were also able to get past the first 13 weeks with no complications. Since Jane and John knew that they wanted to conceive, Jane was watching her nutritional requirements and her exposure to any harmful substances. They are thrilled to be able to add to their family and follow their baby’s fetal development.

Going Beyond

There are so many complications that can affect prenatal development. One of the most common developmental problems is premature birth, in which fetal development does not come to full term. Research premature birth to answer some or all of 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 that are born early?
3. How are premies cared for immediately following birth, and then a few weeks after birth?
4. What is ‘kangaroo care’ for premies?
5. Are there any residual complications to premature birth that can carry over into later childhood or adulthood?

Module 4: Lesson 2 Assignment

Submit your Module 4: Lesson 2 Assignment to your teacher.

Lesson Summary

Prenatal development is divided into three trimesters and two development periods. Embryonic development begins at fertilization and ends after about the eighth week of pregnancy. Fetal development begins at the ninth week and continues until birth. Both embryonic and fetal development occur within the first trimester. The first trimester is the time when developing embryo and fetus is most vulnerable to improper nutritional requirements and exposure to harmful teratogenic agents, as this is the time when the most sensitive embryonic development is taking place. The fetal period consists of significant development events that are related to the progressing months of pregnancy. Most of the time spent in the fetal period results in further development of the organ systems. The understanding of the ‘significant developmental events’ during pregnancy helps doctors and parents to follow the development of maturing fetus to term.

Refer to Table 15.2 on page 521 of the textbook for a review of the major events, by month, in prenatal development.