Impact of the Presence of the Corpus Luteum on Pregnancies Obtained Through Frozen Embryo Transfer(FET)

Impact of the Presence of the Corpus Luteum on Pregnancies Obtained Through Frozen Embryo Transfer(FET): a Prospective Randomized Controlled Study

In pregnancies achieved through programmed frozen embryo transfer cycle (PC-FET) and modified natural frozen embryo transfer (mNC-FET), to determine whether there are differences in endothelial and placental function, maternal cardiovascular function, fetal growth and fetal cardiovascular and cerebral programming and to assess whether there is an association between these differences and the plasma concentrations of the main secretion products of the Corpus Luteum (CL) with vasoactive and angiogenic action.

Inclusion Criteria:

• Female patients 18- 37 years old (both included) at the time of oocyte retrieval and less than 41 years of age at the time of embryo transfer.
• Regular menstrual cycles between 24 and 35 days.
• Availability of cryopreserved blastocysts from own gametes
• Indication for single embryo transfer.
• Patients who will be included in the LUTI study are candidates for either of the two procedures under study, and will have no contraindications for either procedure.

Exclusion Criteria:

• Recurrent pregnancy loss (3 or more).
• Recurrent implantation failure in previous IVF treatments (3 or more unsuccessful embryo transfers). .
• Diagnosis of polycystic ovarian syndrome, diabetes mellitus, chronic arterial hypertension, maternal heart disease and autoimmune diseases (Systemic Lupus Erythematosus (SLE) or Antiphospholipid syndrome (APS)).
• Active treatment with aspirin, heparin or other anticoagulant therapy, antihypertensives or other drugs used to treat circulation or coagulation disorders .
• Indication for PGT (Preimplantation Genetic Testing).
• Multiple pregnancy.