The Transition From Blastomere to Trophectoderm Biopsy: Comparing Two PGS Strategies

Study Overview
=================
Brief Summary
-----------------
Shortly after the implementation of Comprehensive Chromosome Screening (CCS) techniques for Preimplantation Genetic Screening (PGS) came the transition in biopsy timing. Trophectoderm biopsy is meant to overcome the limitations of cleavage stage biopsy and single cell analysis.

Detailed Description
-----------------
The investigators have recently introduced this new approach and a frozen-thawed policy of euploid blastocysts is routinely performed. This is a single centre retrospective study in patients undergoing a PGS cycle. The aim of the study is to assess the results obtained in a PGS programme after the implementation of a new biopsy timing and transfer policy. Results obtained in PGS cycles with blastocyst biopsy and frozen-thawed embryo transfer were analysed in comparison to cycles with cleavage stage biopsy and fresh blastocyst transfer.

Official Title
-----------------
The Transition From Blastomere to Trophectoderm Biopsy: Comparing Two PGS Strategies

Conditions
-----------------
Infertility, Preimplantation Genetic Screening

Intervention / Treatment
-----------------
* Procedure: Cleavage stage biopsy group
* Procedure: Trophectoderm biopsy group


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Own gametes PGS for: advanced maternal age, repeated implantation failure, recurrent miscarriages, severe male factor, and previous affected pregnancies Exclusion Criteria: PGS cycles with gamete donation Altered karyotypes Combined Preimplantation genetic diagnosis (PGD)+PGS cycles

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cleavage stage biopsy group<br>Patients undergoing a PGS cycle with single blastomere biopsy on day 3 and analysis using comparative genomic hybridation bacterial artificial chromosome (BAC) arrays (aCGH) If euploid blastocysts were available, patients underwent fresh blastocyst transfer on day 5. | Procedure: Cleavage stage biopsy group<br>* intracytoplasmatic sperm injection (ICSI)- (Invitro Fertilization)IVF Time lapse embryo culture Cleavage stage biopsy aCGH analysis Fresh euploid embryo transfer<br>|
| Trophectoderm biopsy group<br>Patients undergoing a PGS cycle with blastocyst biopsy on day 5-7 and analysis using comparative genomic hybridation bacterial artificial chromosome (BAC) arrays (aCGH). If euploid blastocysts were available, patients underwent frozen-thawed blastocyst transfer. | Procedure: Trophectoderm biopsy group<br>* ICSI-IVF Time lapse embryo culture Day 3 zona pellucida opening Trophectoderm biopsy aCGH analysis Frozen-thawed euploid embryo transfer<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ongoing clinical pregnancy rate | Clinical pregnancy confirmed by ultrasound | 20 weeks after embryo transfer | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implantation Rate | Embryos implanted confirmed by ultrasound | 6 weeks after embryo transfer | 
| Number of available euploid blastocysts per cycle | Transferable or vitrified euploid blastocysts | Up to 15 days after embryo biopsy | 
| Miscarriage Rate |  | Until 20 weeks after embryo transfer |