Spontaneous abortion in the first trimester of pregnancy

Spontaneous abortions in the first trimester of gravidity represent a clinically significant problem that can affect up to 15% of recognized pregnancies. The causes of early pregnancy loss are very heterogeneous and include genetic, environmental and immunological factors. Although the pathologist's main task is to exclude molar pregnancy, in some cases conventional histological examination can also contribute to the elucidation of the cause of miscarriage and the management of subsequent pregnancies, especially in the case of lesions with a high risk of recurrence that may lead to habitual abortion.

Combination of immunohistochemistry and ploidy analysis to assist histopathological diagnosis of molar diseases

Background:

Differential diagnosis between hydropic abortion, partial mole and complete mole is still a challenge for pathologists but really important for patient management.

Material and Method:

In this study, we have evaluated 111 products of conception from the first trimester. Histological analysis was made according to the main diagnostic histopathological features described in the literature and the cases were categorized in hydropic abortus (HA), partial mole (PM) and complete mole (CM). Immunohistochemistry was performed using monoclonal antibody against p57^kip protein a putative paternally imprinted inhibitor gene and DNA ploidy was analysed in all cases by image cytometry.

Results:

All 23 HAs presented a diploid DNA content and were p57^kip2 positive. From the 28 CMs, 12 cases (43%) were diploid and 16 cases (57%) were tetraploid but no expression of p57^kip2 was found with positive internal controls. From the 60 PMs, 58 cases were positive for p57^kip2 expression and 53 cases (88%) were triploid, 6 cases (10%) tetraploid and 1 case (2%) diploid.

Conclusion:

This study on 111 cases of early pregnancies confirms the usefulness of immunohistochemistry and cytometry but demonstrates the importance of the combination of both techniques to assist histology for the best reliable diagnosis.