Some men’s semen contains very few sperm or even no sperm at all (azoospermia). There are two types of azoospermia: obstructive and non-obstructive. To obtain sperm directly, two surgical procedures can be utilized: TESA (testicular sperm aspiration) and MESA (microsurgical epididymal sperm aspiration). TESA involves placing a needle through the skin of the scrotum and simply sucking out the fluid inside the testicle. MESA uses an operating microscopy to locate the tubules of the epididymis precisely, so that large numbers of sperm can be extracted. Then, specialized micromanipulation tools and inverted microscopes are used to carefully inject the sperm into egg. After three to five days, the embryo can be placed into the mother’s uterus.