Pregnancy Outcome After Transferring Genetically Tested Embryos vs. Non-Tested Embryos

Abstract

Abstract

Background:  Assisted reproductive technology (ART) has revolutionized fertility treatments, offering many couples a chance at pregnancy who might otherwise have difficulty conceiving. One of the critical factors for ART success is the selection of viable embryos for transfer. Preimplantation genetic testing for aneuploidy (PGT-A) has emerged as a widely used method to enhance embryo selection, improve pregnancy outcomes, and reduce the risk of miscarriage. (2). By identifying chromosomally normal (euploid) embryos, PGT-A aims to increase implantation rates and overall IVF efficiency (3).

Aim:  This article aims to provide a comprehensive comparison of pregnancy outcomes between genetically tested (PGT-A) and non-tested embryos. Specifically, it examines implantation rates, miscarriage rates, live birth rates, and time to pregnancy, we seek to determine the clinical value of PGT-A and its role in optimizing ART outcomes

Design: Retrospective,  comparative study

Materials and methods: A total of 225 patients were included in this study, all of whom were under the age of 35. The study population included recipients, advanced maternal age patients, as well as patients with a history of recurrent miscarriages.

All donors and young patients  underwent ovarian stimulation with GnRH-antagonist protocol, The ovulation trigger was administered when 20% of follicles reached 18 mm. Aspiration was performed 35 hours after the ovulation trigger was administered followed  embryo transfer as part of their IVF treatment. The resulting blastocysts underwent preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing(NGS). Pregnancy outcomes were assessed by biochemical indicators, miscarriages, and live births.

The patients were divided into two groups - PGT-A Group (First Group): 110 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A). Non-PGT-A Group (Second Group): 115 patients who did not undergo genetic testing of embryos.

Results: A total of 116 embryos were transferred in the PGT-A group, single embryos were transferred to 104 patient and six patients requesting the transfer of two blastocysts. In this group, 59 pregnancies were achieved (53.6%). Among them, 4 pregnancies resulted in miscarriage at 6–7 weeks of gestation (6.8%), and 2 were biochemical pregnancies (3.4%), where pregnancy was detected only by hCG levels in the blood. Ultimately, 53 pregnancies continued to delivery (89.8% of pregnancies, 48.2% of all transfers), with live births occurring between 38 and 40 weeks of gestation.

In the non-PGT-A group, 220 embryos were transferred, with an average of 1.91 embryos per patient, leading to 41 pregnancies (35.7%). In this group, 7 pregnancies miscarried at 6 weeks (17.1%), 2 patients experienced late miscarriage at 14–16 weeks (4.9%), and one fetus out of them  (2.4%) was diagnosed with a chromosomal abnormality. The remaining 32 patients delivered healthy babies at 37–40 weeks of gestation (78% of pregnancies, 27.8% of all transfers).

Conclusion: PGT-A offers a significant advantage by selecting euploid embryos in improving pregnancy outcomes and reducing miscarriage rates(3). However, its routine use should be tailored to patient-specific factors. Further large-scale studies are needed to optimize patient selection criteria for PGT-A, ensuring its application is both cost-effective and beneficial for intended parents(4).