Research Issues: Life Before Birth

The First Month

Fertilization (conception), the union of the sperm cell from the father with the ovum from the mother takes place and a new life begins. The new cell is called a zygote, and marks the beginning of the embryonic stage of development. Each parent donates 23 chromosomes to form the genetic blueprint (DNA) for the new human being. The zygote soon begins to divide and the cells begin the process of change, or differentiation, which will result in the formation of the tissues and organs of the developing life.

By the third week, the foundations of the brain, spinal cord and nervous system have been established, and the heart has begun to beat. By the fourth week, the backbone and muscles are forming. Arms, legs, eyes and ears have begun to show, but the embryo is small - about the size of an apple seed.

The Second Month

At about five weeks, the beginnings of fingers can be detected and the eyes begin to darken. Brain waves can be recorded at about six weeks. The appearance of the embryo is gradually becoming more recognizable as a developing baby. At seven weeks, the first spontaneous movements begin. The eyelids soon seal over until the seventh month. At eight weeks, the developing life is a little more than an inch and is called a fetus, the Latin word which means "offspring" or "young one". The stomach and kidneys have begun to function and the fetal child responds to touch.

The Third Month

Between nine and ten weeks, fingerprints can be seen forming and the developing baby will curve her finger around an object placed in its hand. By eleven weeks, the fetal child can swallow and squint and wrinkle its forehead. She is about two inches long, and muscle movements are becoming more coordinated. By the end of the third month, the baby wakes and sleeps, and is energetically moving. She opens and closes her mouth, turns her head, curls her toes and breathes the surrounding amniotic fluid.

The Fourth and Fifth Months

The sex of the child can be determined visually early in the fourth month. At about the end of the fourth month, the fetus is about 8 -10 inches long and weighs a half a pound or more. The unborn child can hear her mother's voice, heartbeat, and other sounds. The mother may begin to feel movement at about this time. By the end of the fifth month, the developing child is about 12 inches long.

The Sixth through Ninth Month

During the remainder of the pregnancy the child increases is dramatically in size. If born prematurely, and given proper care, the baby has a good chance of surviving. The skin begins to thicken in the eighth month, with a layer of stored fat for insulation and nourishment. By the end of the ninth month, the baby weighs about six to nine pounds and is ready for life outside the womb.

- adapted from "The First Nine Months", Focus on the Family

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