of conception has no effect on miscarriage rates, low birth weight, or preterm delivery. Destruction of fertilized eggs Luc Bovens has suggested that unprotected intercourse in the infertile periods of the menstrual cycle may still result in conceptions, but create zygotes incapable of implanting. Bovens maintains that, if one defines abortion to include any destruction of fertilized eggs, then the use of the rhythm method probably results in a large number of abortions. References Fertility awareness Calendars