Abruptio placentae in cynomolgus macaques (Macaca fascicularis): male bias

Abstract

Background: Abruptio placentae is a serious problem with a high rate of maternal and fetal mortality and documented sexual dimorphism in reoccurrence. Macaca fascicularis is a well-described reproductive model; however, there are no data available regarding sexual dimorphism in abruptio placentae in these species.

Methods: A retrospective study of pathology and medical records in a large colony of M. fascicularis was performed. Placental specimens were analyzed.

Results: The incidence of placenta abruptio in the colony was 15.7/1000 births. In the abruptio placentae group, male fetuses had lower placental disk length and increased femur length compared with female fetuses. The feto-pacental ratio and fetal weight were lower in the male fetuses in the abruption group compared with those in the stillbirth group without abruption placentae.

Conclusion: This is the first documentation of male bias in placental and fetal development in abruptio placentae in non-human primates.

Keywords: complications; non-human primate; placenta; pregnancy; sexual dimorphism.

Figure 1

A: Second trimester stillborn fetus (F) and placenta (P). B: Third trimester stillborn fetus (F) and placenta (P) with a large retroplacental hematoma (arrow). C: Bi-discoid placenta. D: One-disc placenta. Note areas of hemorrhage (arrow).

Figure 2

Representative photomicrographs of the placentas from Macaca fascicularis diagnosed with placenta abruptio. A: Collapse of the intervillous space (*), villous congestion (arrow) and increased number of syncytial knots (arrowheads). B: Placental infarct (***) with inflammatory cell infiltrates (##) and dystrophic calcification (arrowhead). C and D: Retroplacental hematoma (***), decidua (D) and inflammatory cell infiltrates (##). E: Intraplacental hematoma (IH) with entrapped villous necrosis (N). F: Extensive dystrophic calcification (arrowheads) and intervillous fibrinoid deposition (pink homogenous material).