IN THEORY, THE PROCESS OF CHILDBIRTH is relatively simple. The neck cervix, of the mother's uterus, which is tightly closed during pregnan relaxes and widens (dilates). The uterus muscles begin to tense and short in waves called contractions, which become more frequent powerful. This stage is called labour- aptly named, since it is hard work for mother and baby. Gradually the contractions push the bab through the dilated cervix and along the vagina to the outside world This is stage two, delivery. It is followed by stage three, afterbirth, when the placenta emerges. In practice, childbirth experiences vary. Sometimes the labour is slow, or the baby becomes stuck. Methods used to help" the birth have ranged from the ineffectual to the barbaric. The surge Caesarean delivery is named after Roman Emperor Julius Caesar (100-44 supposedly born this way. In the past it was usually carried out if the mot died. Only this century have mother and baby had a reasonable chance. The medical speciality of childbirth is obstetrics, from the Latin obstare. This means to "stand opposite referring to the midwife who stood near the mother, and helped her through the event.