Morphologic and histopathologic characteristics of placentas from twin pregnancies spontaneously conceived and from reduced and nonreduced assisted reproductive technologies.

OBJECTIVE

To prospectively evaluate morphologic and histopathologic characteristics of placentas from twin pregnancies obtained by assisted reproductive technologies (ART) and non-ART and to evaluate the influence of previous fetal reduction on placental features.

STUDY DESIGN

Fifty-five placentas from consecutive deliveries of ART-obtained and 50 placentas from consecutive deliveries of non-ART-conceived twin pregnancies were investigated by one pathologist, who was blinded to specimen origins. The patients' demographic and clinical data were also recorded.

RESULTS

The mean maternal and gestational ages were similar in both groups. ART-obtained pregnancies were associated with an increased incidence of pregnancy complications and lower mean birth weight. Placentas from ART-obtained pregnancies were mostly of the dichorionic type and were thinner, weighed less and had more infarctions as compared to non-ART-conceived pregnancies. Placental characteristics of reduced ART-obtained twin pregnancies were comparable to those of nonreduced ones. The second twin's placenta in all groups weighed less and had a higher incidence of anomalous umbilical cord insertion.

CONCLUSION

Placentas from ART-obtained twin pregnancies appear to have more pathologic features as compared to those of non-ART-conceived ones. Fetal reduction does not significantly affect the remaining placentas.