Ovulation occurs when an egg is released from the ovary and enters the fallopian tube. Conception can take place at this point if a sperm cell penetrates the egg and fertilizes it.
The timing of this meeting between egg and sperm is crucial to allowing conception to take place. The egg remains alive for approximately 24 hours after ovulation. Sperm cells live for approximately 72 hours (although with optimal nutrition from cervical fluid this may be as much as five days). Therefore, fertilization is most likely to occur if marital relations occur a day or two before ovulation.
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