In about nine months, or two hundred and seventy days from the time of conception, labor commences, terminating in the birth of the child. The child may be born, however, as early as the seventh month, and yet live, and in some cases nine months and a half may elapse before the birth of the child. In the latter case, labor is more difficult on account of the increased size of the child. But delivery earlier or later than two hundred and seventy days, is an exception to the general rule, and is attended with more or less danger to the mother or child.

During pregnancy, the female is liable to numerous troublesome affections, some of which we shall now enumerate.