17 Sep, 2007
Pregnancy Course
Posted by: admin In: Uncategorized
Course :
Although pregnancy actually occurs about two weeks after a woman has her last period, for convenience, doctors always date a pregnancy from the first day of that last menstrual period. From this date, a pregnancy normally lasts for forty weeks, but it is not unusual for it to be one or two weeks shorter or longer than this.
The growth of the foetus is rapid to start with, but slows down as maturity approaches.
At 8 weeks of pregnancy the embryo is 2.5 cm. long and the nose, ears, fingers and toes are identifiable. Most of the internal organs form in the next four weeks, and by twelve weeks a 9 cm. long, perfectly formed miniature baby is present.
At 16 weeks, the baby is 18 cm. long, and the sex can be determined. The skin is bright red because it is transparent, and the blood can be seen through it.
The skin is the normal colour by 24 weeks, and the baby is 32 cm. long. This is the earliest that a baby has any chance of surviving outside the mother, but infants are at high risk if born before 32 weeks.
The miracle is completed when labour starts. The trigger for this is not accurately known, but a series of nervous and hormonal stimuli dilates the cervix that guards the opening into the womb, and starts the rhythmic contractions of the womb, that will bring another human being out into the world, who in due course, will start the cycle again.