Spontaneous abortions can be classified further as sporadic or recurrent. By definition, an incomplete abortion is the partial expulsion of the products of conception before the 20th week of gestation. The timing of miscarriage suggests the pathophysiology of a spontaneous abortion. Anatomic factors usually are associated with second-trimester pregnancy loss. Surveillance data for pregnancy-related deaths from 1987 through 1990 demonstrate more deaths due to ectopic pregnancy and spontaneous and induced abortion among African American women than among Caucasian women.
Age primarily affects the oocyte.
When oocytes from young women are used to create embryos for transfer to older recipients, implantation and pregnancy rates mimic those seen in younger women. The number of miscarriages and chromosomal anomalies decreases, suggesting that the uterus is not responsible for poor outcomes in women of advanced reproductive age. Although classified as different entities, incomplete and inevitable miscarriages present in a similar clinical fashion and have similar treatment. An inevitable abortion involves continuous and progressive dilation of the cervix without expulsion of the products of conception before the 20th week of gestation. An average pad absorbs approximately 20-30 mL of blood.