xeric
06-14-2007, 12:17 PM
In humans, the process during which a developing embryo grows within the woman's womb. It begins at conception and ends at birth, and the normal length is 40 weeks, or around nine months.
Menstruation usually stops on conception. About one in five pregnancies fails, but most of these failures occur very early on, so the woman may notice only that her period is late. After the second month, the breasts become tender, and the areas round the nipples become darker. Enlargement of the uterus can be felt at about the end of the third month, and after this the abdomen enlarges progressively. Fetal movement can be felt at about 18 weeks; a heartbeat may be heard during the sixth month. Pregnancy in animals is called gestation.
Occasionally the fertilized egg implants not in the womb but in the Fallopian tube (the tube between the ovary and the uterus), leading to an ectopic (‘out of place’) pregnancy. This will cause the woman severe abdominal pain and vaginal bleeding. If the growing fetus ruptures the tube, life-threatening shock may ensue. Toxaemia is characterized by rising blood pressure and, if left untreated, can result in convulsions leading to coma.
According to 1996 World Health Organization (WHO) figures, 585,000 women die annually from pregnancy-related causes; 99% of these deaths occur in developing countries. The highest rate of maternal death is in Sierra Leone with 1,800 deaths per 100,000 live births, compared with an average of 27 for industrialized countries.
Menstruation usually stops on conception. About one in five pregnancies fails, but most of these failures occur very early on, so the woman may notice only that her period is late. After the second month, the breasts become tender, and the areas round the nipples become darker. Enlargement of the uterus can be felt at about the end of the third month, and after this the abdomen enlarges progressively. Fetal movement can be felt at about 18 weeks; a heartbeat may be heard during the sixth month. Pregnancy in animals is called gestation.
Occasionally the fertilized egg implants not in the womb but in the Fallopian tube (the tube between the ovary and the uterus), leading to an ectopic (‘out of place’) pregnancy. This will cause the woman severe abdominal pain and vaginal bleeding. If the growing fetus ruptures the tube, life-threatening shock may ensue. Toxaemia is characterized by rising blood pressure and, if left untreated, can result in convulsions leading to coma.
According to 1996 World Health Organization (WHO) figures, 585,000 women die annually from pregnancy-related causes; 99% of these deaths occur in developing countries. The highest rate of maternal death is in Sierra Leone with 1,800 deaths per 100,000 live births, compared with an average of 27 for industrialized countries.