Subchorionic hematoma and implantation: can better understanding the former help improve the latter?

Programmed cycles carry a higher risk of subchorionic hematoma formation. the most notable difference between natural and programmed cycles is the presence or absence of a corpus luteum. Relaxin and vascular endothelial growth factor are both produced by the corpus luteum and are therefore lacking in programmed cycles. Further, the absence of a corpus luteum has been implicated in the development of obstetric complications such as preeclampsia and postpartum hemorrhage in the setting of programmed cycles. Other potential predisposing factors are obesity, hypertension, and/or use of aspirin or other anticoagulants.