Assertion: birth control's hormone | /r/CapableOf | cancel out pituitary hormones
Facets:
Source sentences:
text: They also knew that if the egg becomes fertilized and attaches itself to the lining of her uterus (the beginning of pregnancy), still another hormone cancels out the pituitary hormones and prevents ovulation, keeping her ovary from secreting more eggs during the nine months that the fertilized egg is growing into an infant.