• First trimester fetus within opened amniotic sac.
• Richly vascular placenta completely surrounds opening of sac.
• Chromosomal abnormalities including triploidy, trisomy (reported for every chromosome), monosmy X (Turner^s syndrome), among others.
• Problems with mainintaing implantation including antiphospholipid antibody syndrome
• Chromosomal abnormalities may result in fetal death with subsequent death of the placenta.
• Unknown what effect chromosomal abnormalities have on the placenta^s function.
• Antiphospholipid antibody syndrome is associated with abnormal decidual vascularization and thrombosis of decidual vessels with abruption.
• Ascending infection leads to membrane rupture and premature delivery.
• Anatomic cervical incompetence can also lead to miscarriage.
• Human pregnancy generates large numbers of spontaneous losses.
• Estimates of the percentages of conceptions that fail to reach term has increased with the advent of early detection methods.
• Greater than 25% of pregnancies end spontaneously.
• Current estimates are that approximately 50% of first trimester losses (by far the most common) are secondary to chromosomal abnormalities.
• Increasing spontaneous abortion rate with age.
• Some women are habitual aborters.
• Most women are not habitual aborters.
• An attempt to categorize the miscarriage as either secondary to chromosomal abnormalities or euploidy is useful in the management of women with recurrent losses.
• Aneuploid losses may repeat with advanced maternal age. Also will repeat if parent carries a balanced translocation (very rare).
• Euploid losses may repeat but intervention with aspirin and/or heparin may permit maintenance of a subsequent pregnancy to viability.
|General Gross Description|
• An empty sac or disorganized embryonic tissues (identified by microscopy) may be secondary to early fetal demise.
• Alternatively the fetus may be delivered within the amnionic sac followed by the placenta.
|General Micro Description|
• Findings vary with etiology of the loss.
• Common to all is an implantation site with acute hemorrhage and inflammation.
• Decidualized endometrium is generally sloughed as well.
• The villi may show infarct or intervillositis in cases associated with euploidy.
• The villi may show a complex villus outline, trophoblastic inclusions, and calcifications in aneuploid gestations.
• Histologic abnormalities can be demonstrated in the fetus.
• Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th ed. Philadelphia, W.B. Saunders, 1994, pp. 1078-9.