The Role of hCG in Thawed Embryo Transfer

Inclusion Criteria

• Female adult expecting to receive transfer of a thawed embryo.
• At least one available frozen blastocyst of transferrable quality.
• Non-menopausal female with at least one antral follicle.
• Use of pre-implantation genetic testing (PGT), embryos derived from donor oocytes and/or donor sperm, a gestational carrier, and history of prior transfer(s) regardless of outcome are allowed.
• Subsequent embryo transfers after failed transfers under this study are allowed, but not after a transfer that has resulted in ongoing pregnancy at ten weeks gestation under this study.

Exclusion Criteria

• Minors (age\<18 years).
• Use of embryo(s) frozen at another center.
• Patient insistent on transfer of two embryos.
• Patient or partner unable to provide informed consent in English.
• Patient already enrolled in any other research study for her embryo transfer.
• History of anti-phospholipid syndrome or any other indication for use of Lovenox in pregnancy.
• Patient for whom the physician assesses this protocol is inappropriate or unsafe.