Conception is a complicated process that depends upon many factors. They include the production of healthy sperm by the man and healthy eggs by the woman; unblocked fallopian tubes that allow the sperm to reach the egg; the sperm’s ability to fertilize the egg when they meet; the ability of the fertilized egg (embryo) to become implanted in the woman’s uterus; and sufficient embryo quality.
Finally, for the pregnancy to continue to full term, the embryo must be healthy and the woman’s hormonal environment adequate for its development. When just one of these factors is impaired, infertility can result.