In vitro fertilization (IVF) has brought new hope for many infertile couples, but many scientists point out that IVF entered clinical practice without undergoing rigorous safety testing and evaluation. Due to the desperate desire of infertile couples for new life, the technology quickly and widely entered clinical practice soon after the birth of the first IVF baby, Louise Brown, in 1978. However, there are still unanswered questions about whether IVF babies will develop abnormalities in intelligence and social skills when they reach adulthood, and whether they are at greater risk of various diseases than naturally conceived children.
Some medical experts note that there are many differences between IVF and natural conception. For example, in natural conception, only about 2,000 sperm enter the uterus after 20 billion sperm compete with each other, and only the strongest and fastest sperm can fertilize the egg. However, IVF techniques typically select sperm based on their external morphological characteristics, and any sperm with intact structure can be selected. The huge differences between natural selection and artificial selection may have implications for embryo formation and development, and further research is needed.
In addition to sperm selection, IVF embryos also spend 2-3 days in test tubes or culture dishes, exposed to more oxygen than in the uterus, and living in culture medium. The environment of test tubes or culture dishes clearly differs from that of the uterus, which may affect the gene expression of IVF babies. Whether this will bring benefits or harm to IVF babies remains unclear today.
Some scientists have noted differences in maze-solving performance between IVF mice and normal mice. Normal mice can memorize the maze route after a few attempts, while IVF mice are slower in learning and memory. It is reported that American scientists have also found about 10% differences in gene expression between IVF babies and normal people. Based on these findings, some experts suggest that, in the face of increasingly widespread IVF technology, it is urgent to establish a standardized follow-up mechanism for IVF babies and conduct follow-up studies on existing IVF babies to examine their development at different ages, growth levels, and comprehensive evaluation of their learning achievements and social roles in adulthood, as well as their disease risks in old age. Only by establishing a large-scale and reliable IVF database can the safety evaluation of IVF technology be improved.