Vol.15 No.3

From Fertilization to Full-Term
By Agatha Thrash, M.D.

About one day before conception, a woman has ovulated one ovum (female sex cell) that travels down one of her Fallopian tubes toward the uterus.

One spermatozoon out of hundreds of millions will penetrate the outside layer of the ovum and fertilize it.

A zygote, as the fertilized egg is called, is immediately formed, half of its 46 chromosomes coming from the egg, and the other half from the sperm. It has a new and unique DNA (genetic) composition.

This is the point at which a new life begins—the mysterious transition from living human cells in the form of ovum and sperm, to a living human person.

About five days after conception, the fertilized ovum has divided many times and is now called a blastocyst.

Twelve days after conception, the blastocyst is fully attached to the lining of the uterus.

This is the event that most of the pro-choice groups define as the start of pregnancy. At this point or shortly after, a home pregnancy test kit may reliably detect pregnancy.

At two weeks it is now called an embryo, and is continuing its progression to becoming a mature person.

At three weeks the embryo is about 1/12 of an inch, the size of a pencil point.

At four weeks the embryo is 1/5 inches long. It looks something like a comma; its head is definitely detectable, along with a lower section.

At five weeks tiny arm and leg buds have formed, and hands with webs between the fingers appear.

At six weeks, the embryo has filled out its lower section to become the body. The face definitely resembles a human being.

At two months its brain begins to become identifiable.

At ten weeks it is now called a fetus, and its gender is plain.

At three months the fetus is about 3 inches long, and weighs about an ounce.

Over 90% of abortions are performed between ten weeks and three months.

At four months (16 weeks) it is 8 inches long, and weighs half a pound. Movements can be felt; its heartbeat can usually be heard with a stethoscope.

Abortions are still available to the mother.

At five months, it is almost 12 inches long and weighs about a pound. There is hair on its head, movements can be felt easily.

Abortions are usually unavailable at this age, except under very unusual circumstances. The lungs of the fetus may be developed to the point where it would have a chance to live on its own outside of the mother, with very special care.

At six months, or about 26 weeks, it is 14 inches long, weighs almost two pounds, and the lungs and bronchioles continue to develop. The process of linking up the brain’s nerve cells is rapidly progressing. Elementary brain waves are detected. There is evidence that the fetus can feel pain. Almost everyone agrees that the baby is now conscious.

Most states outlaw abortions at this stage, except under very unusual circumstances.

At seven months the baby is 16 inches, and weighs about 3 pounds. Regular brain waves similar to those of adults are now produced.

The eight-month baby is about 18 inches long and weighs about 5 pounds.

The full-term baby measures about 20 inches in length; the average weight is about 7 pounds.