Clinical Research Directory

Inclusion Criteria: 1. Signed informed consent 2. Female patient undergoing programmed frozen embryo transfer using exogenous estrogen and progesterone, with exogenous progesterone administered via a combination of vaginal progesterone (Endometrin®) (2-3 times daily) and intermittent progesterone-in-oil (PIO) (every 3rd day) according to standard protocol. Protocols involving other formulations of vaginal progesterone (e.g. Crinone®, Prometrium®, will also be included). 3. Planned transfer one 1 euploid embryo. Recruited patients will have at least 1 euploid embryo available for transfer. 4. Standard eligibility criteria to undergo frozen embryo transfer at Shady Grove Fertility. 5. 18 years and older Exclusion Criteria: 1. Age less than 18 years or greater than 51 years 2. Planned intervention based on serum progesterone concentration measured any time after initiation of intramuscular or vaginal progesterone. 3. Uterine cavity abnormality that has not been surgically corrected. 4. Any medical or surgical contraindication to undergoing programmed frozen embryo transfer or pregnancy. 5. Planned use of embryos cryopreserved by slow-freeze, prior to blastocyst stage, or other than PGT-A normal. 6. Currently breast feeding, pregnancy, or having a contraindication to pregnancy. 7. Participation in any experimental drug study within 60 days prior to screening.