Protective hand cradling an embryo in IVF with DNA helix in background

IVF Breakthrough: Is Partial Zona Dissection the Key to Higher Pregnancy Rates?

Theo Raines in Health & Wellness August 2025 • 4 min read.

"Explore how a refined mechanical technique in preimplantation genetic diagnosis (PGD) could significantly improve your chances of a successful IVF outcome."

For couples undergoing in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD), the journey can be filled with hope and anticipation, but also with questions about the best techniques to maximize success. PGD allows for the screening of embryos for genetic abnormalities before implantation, increasing the chances of a healthy pregnancy. But what methods are used to access the cells needed for testing, and how do these methods impact the embryo's viability and the overall success of IVF?

Traditionally, accessing embryonic cells for PGD involves either chemical methods, using an acidified solution to 'drill' through the zona pellucida (the outer shell of the embryo), or mechanical methods, where a small opening is carefully created. Each approach has its proponents, but concerns exist regarding the potential harmful effects of chemicals on delicate embryos, as well as the skill required for precise mechanical manipulation.

Now, new research sheds light on a potentially superior mechanical technique: Partial Zona Dissection (PZD). This refined approach focuses on carefully creating a small slit in the zona pellucida to extract a cell, and it is showing promising results in terms of embryo development and pregnancy rates. Let's delve into the study and explore the benefits of PZD.

Partial Zona Dissection (PZD): A Gentler Approach to Embryo Biopsy?

Protective hand cradling an embryo in IVF with DNA helix in background

The study, published in the journal Clinical and Experimental Reproductive Medicine, compared the outcomes of PGD using two different methods: zona drilling with acidified Tyrode's solution (chemical ZD) and Partial Zona Dissection (PZD). Researchers retrospectively analyzed 85 PGD cycles from 71 couples, evaluating blastocyst formation, hatching rates, clinical pregnancy rates, ongoing pregnancy rates, implantation rates, and fetal gender ratios.

The results indicated a significant advantage for PZD. Specifically, the PZD group demonstrated:

Higher clinical pregnancy rates (40.7% vs. 15.4%)
Higher ongoing pregnancy rates (35.6% vs. 11.5%)
Higher implantation rates (18.1% vs. 5.7%)
Improved blastocyst formation and hatching rates in non-transferred embryos

These findings suggest that the mechanical PZD method may offer a less invasive and more effective means of accessing embryonic cells for PGD, leading to better embryo development and increased chances of a successful pregnancy. The study authors also noted that while the chemical ZD method was used during a different period than the PZD method, the consistent culture environment and experienced technician minimized potential biases, highlighting the potential superiority of PZD.

Implications for Your IVF Journey

For couples considering IVF with PGD, these findings offer valuable insights. While zona drilling with acidified Tyrode's solution remains a viable option, Partial Zona Dissection presents a promising alternative with potentially improved outcomes. Discussing the latest research and techniques with your fertility specialist is crucial in determining the best approach for your individual circumstances.

It's important to remember that IVF success depends on many factors, including patient age, embryo quality, and the expertise of the clinical team. However, by staying informed about innovative techniques like PZD, you can actively participate in optimizing your chances of a successful outcome.

While this study provides compelling evidence for the benefits of PZD, further prospective research is needed to confirm these findings and explore the long-term effects of different biopsy methods. As the field of reproductive medicine continues to advance, staying informed and proactive will empower you to make the best decisions for your fertility journey.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.5653/cerm.2012.39.3.118, Alternate LINK

Title: Outcomes Of Preimplantation Genetic Diagnosis Using Either Zona Drilling With Acidified Tyrode'S Solution Or Partial Zona Dissection

Subject: Reproductive Medicine

Journal: Clinical and Experimental Reproductive Medicine

Publisher: The Korean Society for Reproductive Medicine

Authors: Hyun Jung Kim, Chung Hyon Kim, Soo Min Lee, Seung Ah Choe, Joong Yeup Lee, Byung Chul Jee, Doyeong Hwang, Ki Chul Kim

Published: 2012-01-01

Everything You Need To Know

What is Partial Zona Dissection (PZD) in the context of IVF?

In the context of in vitro fertilization (IVF), Partial Zona Dissection (PZD) is a refined mechanical technique used in preimplantation genetic diagnosis (PGD). It involves creating a small slit in the zona pellucida, the outer shell of the embryo, to access cells for genetic testing. This method aims to minimize harm to the developing embryo, offering a gentler approach compared to chemical methods.

Why is Partial Zona Dissection (PZD) important?

Partial Zona Dissection (PZD) is significant because it enhances embryo development and boosts pregnancy rates in IVF. The study showed that couples using PZD had significantly higher clinical pregnancy rates (40.7% vs. 15.4%), ongoing pregnancy rates (35.6% vs. 11.5%), and implantation rates (18.1% vs. 5.7%) compared to those using chemical methods like zona drilling with acidified Tyrode's solution. This advantage stems from the less invasive nature of PZD, leading to better embryo viability.

What are the implications of using Partial Zona Dissection (PZD) for couples undergoing IVF?

The implications of using Partial Zona Dissection (PZD) in IVF are substantial. Couples undergoing IVF with preimplantation genetic diagnosis (PGD) may experience improved outcomes. The research indicates a shift towards mechanical methods such as PZD, which are gentler on the embryos, improving blastocyst formation, hatching rates, and overall pregnancy success. These findings provide valuable information for couples, highlighting the importance of discussing the latest techniques, like PZD, with their fertility specialists to optimize their IVF journey.

What is the role of Preimplantation Genetic Diagnosis (PGD) in IVF?

Preimplantation genetic diagnosis (PGD) is a crucial step in IVF for couples seeking to screen embryos for genetic abnormalities before implantation. This process increases the chances of a healthy pregnancy. PGD involves accessing embryonic cells, which can be done through methods such as chemical zona drilling or the mechanical technique of Partial Zona Dissection (PZD). The chosen method impacts the embryo's health and the overall success of IVF.

What are the differences between zona drilling with acidified Tyrode's solution and Partial Zona Dissection (PZD)?

Zona drilling with acidified Tyrode's solution is a chemical method used to access embryonic cells for preimplantation genetic diagnosis (PGD). This method involves using an acidified solution to create an opening in the zona pellucida. However, this approach may potentially harm the developing embryos. The study compared this method to the mechanical technique called Partial Zona Dissection (PZD) and found that PZD led to significantly better outcomes in terms of pregnancy success rates, emphasizing the importance of choosing the method which ensures embryo viability.