Prenatal Development January 1,2017

Start of the Period of the Zygote

2017 BCE

The single-cell human embryo that results from the joining of the sperm and joining together

End of the Period of the Zygote

2017 BCE

Replication of the male and female DNA and the alignment of chromosomes in preparation for the first cell division through mitosis

Start of the Period of the Embryo

2017 BCE

Means “growing within” and refers to the “human offspring in the first eight weeks following fertilization"

End of the Period of the Embryo

2017 BCE

The human embryo has grown from a single cell into the nearly 1 billion cells which form over 4,000 distinct structures.

Start of the Period of the Fetus

2017 BCE

The head is nearly half of the fetus' mass. Its eyelids are closed during this period and do not open again until around the 7th month of development in the womb. The ears begin to take their final shape and tooth buds appear.

End of the Period of the Fetus

2017 BCE

It may have a full head of hair and its fingernails and toenails may extend past the ends of its fingers and toes. During this time, the fetus can gain as much as half a pound of weight every week.

Start of the First Trimester

2017 BCE

Conception occurs around week 3.Weeks 5 or 6 the women suspects pregnancy.Weeks 6-10 is a period of development in which most of the major systems of the body begin to form.

Start of the Third Trimester

2017 BCE

Many women feel contractions during this time, which is just the uterus's labor preparation.You will be slowing down as your belly gets larger, your ligaments loosen and you gain weight. After week 30 or 32, it is not uncommon to gain a pound a week until birth. The vast majority of women give birth between week 38 and week 40.

Start of Second Trimester

Feb 8, 2017

Begins week 13. You may experience clumsiness, forgetfulness and the occasional discomfort (swollen feet, hot flashes, back pain) as your body changes and your belly grows.