PLACENTA PREVIA 359 



and leucocytes give the discharge a creamy white appearance, it 

 is called the lochia alba. 



Placenta previa. Wherever the ovum attaches itself the de- 

 cidua serotina develops to form the maternal part of the placenta. 

 Should the implantation of the ovum be so low as to encroach 

 upon the internal os, it causes a placenta previa. 



Ectopic Gestation. If an impregnated ovum begins to develop at any point 

 outside the uterus this constitutes an extra-uterine or ectopic gestation. Men- 

 struation ceases as in a normal pregnancy and a decidua vera begins to form, 

 but is often shed at two or three months. Very infrequently the develop- 

 ment of the ovum and fetus goes on to term, when delivery must be by abdom- 

 inal section, but the usual course is rupture of the containing part and inter- 

 nal hemorrhage, necessitating an operation of emergency. 



In all extra-uterine or ectopic pregnancies the descriptive name is derived 

 from the abnormal location, as tubal, ovarian, etc., etc. 



The child-bearing age begins at puberty or the time of develop- 

 ment of the generative organs and the establishment of ovulation 

 and menstruation. It continues until the climacteric or menopause 

 which marks the cessation of menstruation. 



