Jehovah's Witnesses ascribe to a belief system that requires abstaining from blood, including transfusions, but does not prohibit minimal contact such as exterior contact with menstrual blood or menstruating women. Personal beliefs and practices vary by the individual, but many couples that belong to the Jehovah's Witness religion abstain from sexual contact during a woman's menstrual period even though the act is considered a scriptural grey area.
The Old Testament book of Leviticus refers to menstruating women as unclean, forbidding contact of any kind with menstruating women, including sexual intercourse and contact with anything they sat on or laid on for a week surrounding menstruation. However, modern followers of the religion do not follow this scripture to the letter because it is not referenced in both the Old and New Testaments.
The religion's blood taboo does carry over to menstruation, leading encouraged use of hormonal birth control for women to suppress monthly periods.
The commonly-held Jehovah's Witnesses beliefs against ingesting or accepting blood into the body by transfusion, on the other hand, are stated in both sections of the Bible. The New Testament book of Acts expressly demands abstaining from blood. Because of this, abstaining from blood is cemented into the tenants of the religion while specific menstrual taboos are not.