Life example: Mr. Zhang is an infertile patient. That day, he had a semen lab test as prescribed by his doctor. When he got the semen test sheet, he saw that the result of the report stated that the sperm concentration was 1×106/ml (1 million per ml). Mr. Zhang had some prior knowledge of assisted reproduction, and after reading this figure, he was secretly glad and even complacent: although his sperm did not reach the normal standard, he still had so many sperm after all, so he should not have much problem to have offspring with only one sperm, or at least he could achieve the purpose of fertility through second-generation IVF, right? With the continuous advancement of assisted human reproduction technology (ART for short), more and more infertile couples are gaining offspring. In particular, the propaganda that “if you have one sperm, you can solve your fertility problem” has greatly encouraged infertility patients and doctors. Indeed, with intracytoplasmic sperm injection (ICSI for short, commonly known as second-generation IVF), the discovery of just one sperm has the potential to successfully fertilize an egg and result in a pregnancy. After all, an egg needs only one sperm to be fertilized, and each person is the product of the union of one egg and one sperm. Therefore, infertile patients like Mr. Zhang, there is indeed a good hope that fertility can be achieved in some way. However, there should be absolutely no blind optimism. 1 million sperm is far from normal fertility needs: The minimum range of normal reference values for sperm concentration in healthy men set by the World Health Organization is 20 x 106/ml (20 million per ml). In fact, this indicator used to be 60×106/ml 20 years ago. The sperm concentration of healthy fertile men is mostly in the range of (60 to 150) × 106/ml, which means an average of 100 million sperm per milliliter. In addition, even healthy couples do not always get pregnant in the first month after cohabitation, and the natural pregnancy rate is about 25% per month. Then, for an infertile patient with only 1/100th of the normal number of sperm, the probability of natural pregnancy is very small. This is exactly the reason why Mr. Zhang suffered from infertility. It is also easy to “fall through the cracks” with second-generation IVF: Self-aware patients like Mr. Zhang may consider second-generation IVF technology to solve their fertility problems, thinking that it will be foolproof. In fact, this is not true. First of all, the success rate of IVF is definitely not 100%. Secondly, patients who choose to undergo IVF may encounter various troubles, for example, not being able to get sperm within the critical time frame for insemination – this can cause patients to suffer a great loss and in some cases, have to give up this treatment. Why does this happen? In fact, sperm are so tiny that they need to be magnified hundreds of times to be seen as very small sperm. When analyzing semen, the lab technician can see hundreds or more sperm within each high magnification microscope of normal male semen. In contrast, similar to Mr. Zhang’s case of 1 million sperm per milliliter, only one sperm can be seen under the microscope, and this sperm is not necessarily a good sperm with motility; in addition, there is no guarantee that sperm can be found in every field of view (it is not uncommon that no sperm can be seen). If the patient is not in good health, or if there is a problem with the sperm retrieval process, this can result in an embarrassing situation where no sperm can be found under the microscope. Let’s say you put 1 million fish in the ocean, can you still find them? It was also found that when the sperm concentration is less than 0.2×106/ml (200,000 per ml), it is difficult to find the sperm even in the case of centrifugation. It is best to be prepared: As the saying goes, one must be prepared for the future. For patients with particularly low sperm counts, it is best to prepare a little in advance. Consider first a period of medication to improve sperm. Although the majority of patients still have difficulty achieving a natural pregnancy, taking medication can increase the concentration of some sperm and at least reduce the chance of “stepping out” when doing IVF. Moreover, the outcome of second-generation IVF treatment should be better, or at least less harmful, with improved semen quality. In addition, after getting the sperm, the good sperm can be frozen in advance for the second generation of IVF technology, which can also avoid “stepping out of the box”, although this microscopic sperm freezing technology is not yet commonly carried out, but only in some medical institutions. If sperm is not available during IVF II treatment and the patient is not considering direct sperm retrieval (puncture or biopsy of the epididymis or testicles), one can also consider freezing the eggs in case sperm is subsequently found for IVF II.