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02.02 Prenatal Development and the Newborn
Prenatal Development
Prenatal development describes the period of time from a baby’s conception to the day parents welcome him or her into the world. This time period is full of remarkable changes that have a dramatic impact on an individual’s development later in life. Learning about the earliest developmental processes allows us to better understand the foundation upon which development throughout the lifespan is built.
Prenatal development occurs in three basic stages. The first two weeks after conception are called the germinal stage. The next six weeks of development are known as the embryonic stage. The remainder of prenatal development occurs in the fetal stage. Examine the cards below to learn more about these stages:
Prenatal Stages—Text Version
The Germinal Stage (Weeks 1 and 2)
The germinal stage begins when male sperm cell fertilizes the female egg.
Fertilized egg (known as a zygote) is formed.
Zygote (a fertilized egg cell) divides into two cells, and those cells continue to multiply.
Cell division continues at a rapid rate and develops into a blastocyst (structure during embryonic development that contains cells which create the embryo).
The blastocyst implants in the wall of the mother’s uterus.
The Embryonic Stage (Weeks 3 to 8)
Blastocyst becomes an embryo.
Approximately 22 days after conception, the early stages of spinal cord and brain are formed.
Around the fifth week, the head is formed and the heart is beating.
Around the sixth week, the arms and legs begin to appear.
By the eighth week, the embryo has formed nearly all basic organs and parts but is only about one inch in length.
The Fetal Stage (Weeks 9 to Birth)
Early body systems and structures such as the kidneys, liver, intestines, and brain are beginning to function.
Sex organs form.
Fetus continues to grow in both weight and length.
Around 18 weeks, fetal movement can be felt.
Around 19 weeks, fetus can hear.
Around 27
Prenatal Development
Prenatal development describes the period of time from a baby’s conception to the day parents welcome him or her into the world. This time period is full of remarkable changes that have a dramatic impact on an individual’s development later in life. Learning about the earliest developmental processes allows us to better understand the foundation upon which development throughout the lifespan is built.
Prenatal development occurs in three basic stages. The first two weeks after conception are called the germinal stage. The next six weeks of development are known as the embryonic stage. The remainder of prenatal development occurs in the fetal stage. Examine the cards below to learn more about these stages:
Prenatal Stages—Text Version
The Germinal Stage (Weeks 1 and 2)
The germinal stage begins when male sperm cell fertilizes the female egg.
Fertilized egg (known as a zygote) is formed.
Zygote (a fertilized egg cell) divides into two cells, and those cells continue to multiply.
Cell division continues at a rapid rate and develops into a blastocyst (structure during embryonic development that contains cells which create the embryo).
The blastocyst implants in the wall of the mother’s uterus.
The Embryonic Stage (Weeks 3 to 8)
Blastocyst becomes an embryo.
Approximately 22 days after conception, the early stages of spinal cord and brain are formed.
Around the fifth week, the head is formed and the heart is beating.
Around the sixth week, the arms and legs begin to appear.
By the eighth week, the embryo has formed nearly all basic organs and parts but is only about one inch in length.
The Fetal Stage (Weeks 9 to Birth)
Early body systems and structures such as the kidneys, liver, intestines, and brain are beginning to function.
Sex organs form.
Fetus continues to grow in both weight and length.
Around 18 weeks, fetal movement can be felt.
Around 19 weeks, fetus can hear.
Around 27