Egg quality: what affects it and what you can do
By the MyBabyBridge editorial team · · Last reviewed · 2 min read
Egg quality is one of the most important factors in whether a pregnancy happens and continues. This post explains what "egg quality" means, why it changes with age, and what is and is not within your control.
What "egg quality" means
A high-quality egg is mainly one with the correct number of chromosomes. Before ovulation, an immature egg (oocyte) goes through a special cell division called meiosis, which halves its chromosomes from 46 to 23. The sperm adds another 23, giving the embryo 46. If errors occur during meiosis, the egg can end up with too many or too few chromosomes. This is called aneuploidy.
Why this matters for pregnancy
Not every fertilized egg becomes a baby. Embryos with the wrong number of chromosomes often do not implant or end in miscarriage. ACOG notes that early pregnancy loss happens in about 10 of 100 known pregnancies, and that about half of early miscarriages occur because the embryo has an abnormal number of chromosomes.
Age is the biggest factor
People are born with all the eggs they will ever have. With age, both the number and the quality of eggs decline, and the share of eggs with chromosome errors rises. MedlinePlus notes that IVF live birth rates depend on factors such as the mother's age.
Can egg quality be improved?
There is no proven way to reverse age-related decline in egg quality. Some researchers are studying whether supporting the egg's mitochondria (its energy-producing structures) with supplements such as CoQ10 helps, but a meta-analysis of randomized trials found no difference in live birth rates, so this remains unproven. Talk with your doctor before taking any supplement.
What you can do
- Follow general prepregnancy advice from ACOG: a healthy diet, a prenatal vitamin with folic acid, regular exercise, a healthy weight, and no tobacco, alcohol, or drugs.
- Don't wait too long to get help. ACOG recommends an evaluation after 1 year of trying, or after 6 months if you are older than 35.
- If you want children later, ask a doctor about options such as egg freezing, which work best at younger ages.