Egg freezing is a medical procedure designed to preserve a woman’s fertility for future reproductive use. It involves extracting, freezing, and storing unfertilized eggs. This process offers individuals the flexibility to delay childbearing for personal or medical reasons. When ready for conception, these cryopreserved eggs can be thawed, fertilized in a laboratory, and transferred to the uterus as embryos to achieve pregnancy.
Why Age 34 Matters for Egg Freezing
Female fertility naturally declines with age due to decreasing egg quantity and quality. Women are born with a finite number of eggs, and this reserve diminishes over time, accelerating after the mid-30s. For example, the fertility rate for women aged 34–35 is about 14% less than for those aged 30–31. By age 37, the egg supply decreases more rapidly, and by 43, most eggs may be chromosomally abnormal, impacting pregnancy success.
Older eggs are more prone to genetic abnormalities, which can reduce conception chances and increase miscarriage risk. Age 34 is a notable point for egg freezing because, while egg quality is still favorable, the accelerated decline in both quantity and quality is impending. Freezing eggs at this age preserves higher viability, maximizing future pregnancy success.
Key Factors Influencing Egg Freezing Recommendations
Medical professionals consider individual factors when advising on egg freezing, which directly influence the recommended number of eggs to store. Diagnostic assessments provide insights into an individual’s potential egg yield per cycle. Ovarian reserve testing, which assesses both the quantity and quality of remaining eggs, is a primary component.
Key tests include Anti-Müllerian Hormone (AMH) levels and Antral Follicle Count (AFC). AMH, a hormone produced by ovarian follicles, indicates a greater number of remaining eggs. AFC uses a transvaginal ultrasound to count fluid-filled sacs in the ovaries that contain immature eggs, estimating the number of eggs that may be retrieved. These tests help predict ovarian response to stimulation and likely egg collection, but not directly pregnancy success.
Recommended Number of Eggs to Freeze at Age 34
For a 34-year-old, the recommended number of eggs to freeze aims for a reasonable probability of a future live birth. While individual circumstances and ovarian response vary, research provides general guidelines. Freezing enough eggs is important because not every egg leads to a successful pregnancy.
Studies indicate that for women aged 30-34, freezing over 18 eggs provides an 80% or higher chance of a live birth. Freezing 20 mature eggs at age 34 may offer a 90% chance for at least one live birth. Freezing 30 mature eggs could increase this to 97%. To achieve a 95% chance of a baby from frozen eggs, a woman aged 35 or less might need to freeze 30 eggs. These numbers maximize success likelihood given the natural attrition of eggs throughout freezing, thawing, and fertilization.
Understanding Success Rates with Frozen Eggs
The journey from frozen egg to live birth involves several stages. The age eggs are frozen primarily determines their quality and overall success. Modern flash-freezing techniques, known as vitrification, result in high thaw survival rates for eggs, typically 90% to 95%. After thawing, eggs are fertilized, usually via intracytoplasmic sperm injection (ICSI), where a single sperm is injected into each egg.
Fertilization rates for thawed eggs are comparable to fresh eggs, often 70-75%. Resulting embryos are cultured and monitored. The percentage of embryos progressing to a late stage, like a blastocyst, can vary, with about 50% for a 34-year-old.
The live birth rate per thawed egg for women aged 30-34 is estimated around 7.0%. Overall, women under 38 who thaw 20 or more mature eggs have achieved a 70% live birth rate per patient.