Nowadays it is more and more common for women to decide on a pregnancy later in life. It happens so due to social and cultural changes related to, among others, education, career, financial stability or simply meeting the right person to start up a family with. Sadly, often the deciding actor is also the struggle of previous unsuccessful fertility treatments over the course of many years.
But although social preferences in the world might be changing, the woman’s fertility isn’t. The fact that women choose the path of motherhood later on, does have its serious implications and consequences. It is difficult to synchronise the body with modern lifestyle as it is the age of a woman that plays the most important role in conception. Oocyte quality and quantity are known to diminish with age, making it less probable for a woman to conceive and then carry a child to term. And if a woman of advanced maternal age does get pregnant, there is a significantly higher risk of adverse pregnancy outcomes such as, e.g., pre-eclampsia, low birth rate, congenital birth defects and chromosomal anomalies.
Advanced Maternal Age (AMA) is generally defined as the age above 35 years. However, because of the mentioned social and cultural changes, the upper limit for AMA is more and more often determined as the age of 40. Additionally, thanks to the access to assisted reproductive technology (ART) and IVF, there have also been new definitions created – Very Advanced Maternal Age (VAMA) and Extremely Advanced Maternal Age (EAMA), describing women delivering at the age of 45-49 and even over 50.
Women are born with a limited number of eggs and over time, the quality and quantity of these eggs (the so-called ovarian reserve) decrease. On average, during the fourth month of fetal development, females have between 6 to 7 million oocytes. A rapid loss of eggs is experienced at birth, when the total number decreases to between 1 to 2 million (and is classed as 100% of woman’s oocytes). When a girl reaches her first menstruation takes place, the number of oocytes drops to around 300,000 – 400,000. This further reduces to 180,000 at the age of 30, and then again to 45,000 around the 40-year mark. As a woman heads towards the menopause, the number of her eggs is continuously diminishing.