The Risk of Advanced Maternal Age: Causes and Overview

Abstract

Since 1980, the progress of modern society has greatly affected the fertility of women. In recent years, there has been an increase in the number of (AMA) among non-pregnant and older mothers-that is, women with childbearing age greater than or equal to 35 years of age, especially at the senior level in both developed and developing countries. Over the past few decades, the age structure of the world's reproductive population has changed dramatically. In China, the age structure of childbearing population keeps changing. The fertility rate of women aged 35 to 39 was 8.65% in 2004 and 17.04% ten years later. By 2016, the rate of late pregnancy was about 31% [1-3]. In Europe, the probability of chromosomal abnormalities increases with the age of the mother. In 2016, the Chinese government liberalized the "two-child policy" and gradually replaced the "one-child policy". The new policy encourages couples to have two or more children, which may lead to more pregnant woman [4]. AMA has gradually become an important social and clinical issue. At present, the proportion of women who have delayed their childbearing age to 35 years old has increased signifi cantly, especially in Western countries. At present, the delay in childbearing age may be related to a variety of factors, such as female education level and career goals, effective contraceptive strategies, lack of support for parental social incentives, and a widely disseminated misconception that assisted reproductive technology can compensate for infertility that naturally decreases with age [3]. The older the parents are pregnant, the higher the risk of illness in their offspring [5]. There is a large body of research and data confi rming a negative correlation between maternal age and child health at birth. The live birth rate of AMA is lower than that of young women conceived through natural or assisted reproductive technology. To some extent, the decrease of fertility is due to the increase of ovary aneuploidy, which leads to the decrease of embryo quality and abortion [6,7]. However, the biochemical mechanism of aging affecting ovary and embryo quality remains to be clarifi ed. The reasons for the decline of ovarian reserve in AMA are considered to be energy production disorders, cell cycle checkpoints, and meiotic