Читать книгу Getting Pregnant For Dummies - Sharon Perkins - Страница 38

Most women have two ovaries, which contain the most important accessory of all — eggs! How many eggs? Less every year, since every day of your life, eggs are lost through atresia, which means that they die off because they’re not being stimulated to mature. For example:

 Before birth, a girl fetus’s ovaries contain around 6 to 7 million eggs. The production of eggs stops when the fetus is near five months.

 A newborn baby girl’s ovaries contain about 2 to 3 million eggs.

 By puberty, only 300,000 to 400,000 eggs remain.

 Every month, 500 to 1,000 eggs are recruited from the resting pool and start down the path to maturity where they are capable of creating a normal embryo. This path takes over five months, and many eggs are killed by the ovary along the way. When a woman starts her period only about 20 to 30 remain, and in the next two weeks only one will emerge as the best egg. This egg is the one that is ovulated.

 By a woman’s late 30s, only 25,000 or so eggs remain.

 By age 50, only 1,000 or so eggs remain, and many are chromosomally abnormal because of the impact of aging on egg quality.