Academic Illuminations II: Menstruation During Pregnancy

The Problem

The Shafi'i school states that a pregnant woman can menstruate. (This is relevant to Islamic law because menstruating women have special rulings associated with prayer and fasting.) Medically, menstruation is the shedding of the uterine lining, which would negate pregnancy. Initially, I thought I had found a solution to this puzzle, and that is to distinguish between legal menstruation and medical menstruation. The distinction is real: the minimum age for menstruation in the Shafi'i school is approximately nine lunar years of age. If a girl were to precociously menstruate before this age (and there are documented cases of this happening), it would not be considered legal menstruation, and the Islamic rulings related to menstruating women would not apply to her. Legal menstruation, according the Shafi'i school, is any blood that appears in a girl of age that: lasts for 24 hours or more when combined; lasts no more than 15 days; and is preceded by at least 15 days of purity. Thus, the bloody show that pregnant women experience in late pregnancy might very well be considered legal menstruation if it fulfills these conditions, or so I thought.

Two problems emerge with the above approach. First of all, the definition of menstruation in legal texts usually indicates that it is damu jibillah, or "naturally occuring blood"; i.e. not due to illness or some other external factor. Secondly, Shafi'i jurists have issued the fatwa that, if a reliable doctor tells a woman her bleeding is not due to menstruation, then the rules of menstruation do not apply to her. Given then that the distinction between legal and medical menstruation doesn't seem to go beyond the minimal legal age for menstruation, the puzzle remained.

The Illumination

As almost everyone with some background in Islamic Law knows, Islamic legal texts do not only attempt to answer common, day-to-day questions, but also the rare, and even theoretical. We are truly indebted to them for doing so, for what was theoretical during their time (such as a person being able to traverse large areas of the earth in an instant) is looking very likely during our time. The scenario of a pregnant woman menstruating becomes a realistic possibility when you consider that some women have the rare condition of two uteruses. It is therefore possible for a woman to menstruate through one while being pregnant in another. Beyond this, it is also possible for an anatomically normal woman very early in her pregnancy to experience a regular menstrual cycle, such as when a woman becomes pregnant close to the start of her menstrual cycle. (Don't believe me? See this and this.)