Products of conception

by Jason Wasserman MD PhD FRCPC
September 12, 2024

The term products of conception refers to the tissues that result from a pregnancy, including the embryo or fetus, placenta, and membranes. These tissues are typically found in the uterus and support the development of the embryo or fetus during pregnancy.

When does a pathologist examine products of conception?

Products of conception are examined by a pathologist when pregnancy-related tissue is removed from the uterus, either after a miscarriage, elective abortion, or during a surgical procedure like dilation and curettage (D&C). Examination of these tissues is often requested to confirm the presence of pregnancy-related tissue, identify potential complications, or determine the cause of pregnancy loss.

Why is the examination of products of conception important?

The examination of products of conception is important because it allows pathologists to:

• Confirm pregnancy: In some cases, it may be necessary to confirm that pregnancy tissue has been completely removed, especially after miscarriage or abortion.
• Identify abnormalities: Pathologists can detect any abnormalities in the pregnancy-related tissue, which may provide insight into potential causes of miscarriage or other pregnancy complications.
• Ensure proper treatment: Examining products of conception ensures that no abnormal tissue remains in the uterus, which could lead to complications such as infection or ongoing bleeding.

What medical conditions can be identified by examining products of conception?

Pathologists can identify several medical conditions by examining products of conception, including:

• Incomplete miscarriage: When some pregnancy-related tissue remains in the uterus after a miscarriage, which may require further treatment.
• Molar pregnancy (hydatidiform mole): A rare abnormal growth of pregnancy-related tissue that can lead to complications and, in some cases, cancer.
• Ectopic pregnancy: A pregnancy that develops outside the uterus, often in a fallopian tube, may be diagnosed if the pathologist does not find any normal pregnancy-related tissue in the uterus.
• Chromosomal abnormalities: Sometimes, genetic abnormalities in the fetal tissue may be identified, which could explain the cause of miscarriage.
• Placenta accreta/percreta: These are conditions where the placenta abnormally attaches too deeply into the uterine wall (accreta) or even through the wall and into surrounding organs (percreta). These conditions can lead to complications during pregnancy or delivery.

What are the microscopic features of products of conception?

When pathologists examine products of conception under the microscope, they look for several key features, including:

• Villi: These are finger-like projections that make up the placenta and help transfer nutrients from the mother to the developing embryo or fetus. Normal villi have a well-organized structure, while abnormal villi may appear enlarged or misshapen.
• Trophoblastic cells: These cells are responsible for forming the placenta and may show abnormal growth patterns in conditions like molar pregnancy.
• Fetal tissue: If the pregnancy was further along, pathologists may also identify embryonic or fetal tissue, such as organs or bones.
• Implantation site: This is the area where the pregnancy attached to the uterine wall. Pathologists may see changes in this site, such as inflammation or scarring, which could provide clues about pregnancy complications.

These microscopic features help pathologists confirm the presence of pregnancy tissue and identify any abnormalities that may have contributed to pregnancy loss or complications.