The jury of matrons was a form of special jury at English common law, usually used to resolve legal disputes over whether or not a party to a legal action was pregnant.
The civil jury of matrons was used to determine whether a recently widowed woman was pregnant with what was presumed to be her late husband’s child. Such a pregnancy could delay or prevent the late husband’s property from passing to his father or brother, if he died without male heirs. Civil matrons juries were composed of twelve knights and twelve matrons, summoned by a writ de ventre inspiciendo ("to inspect the belly"). Civil juries of matrons appear to have largely died out by the turn of the 19th century and became obsolete with the Married Women's Property Act 1882.
In the criminal context, women convicted of capital crimes were permitted to plead that they were 'quick with child' (that is, the motions of the foetus could be felt), and to have this claim tested by a group of six women. If the woman was found to be quick with child then she was reprieved until the next hanging time. Criminal juries of matrons were customarily drawn from the women observing the proceedings.
The use of matrons’ juries in a criminal context was documented as early as 1387, in language which suggests that it was already a customary procedure. By the sixteenth century, women who successfully pleaded their belly, as the practice was colloquially known, were frequently either pardoned or granted a lesser sentence, such as penal transportation. With the decline of capital offenses and the rise of a more sophisticated medical understanding of pregnancy, the practice was increasingly regarded as obsolete, and was generally regarded as archaic and ridiculed in the press on the rare occasions it was employed in the 19th century.
A jury of matrons was employed at least once in the twentieth century, by Ada Annie Williams, who was sentenced to death in December 1914 for the murder of her four-year-old son, but received a reprieve until delivery on account of her pregnancy and subsequently had her sentence commuted. The common law was superseded by the Sentence of Death (Expectant Mothers) Act 1931, which was itself repealed by the Crime and Disorder Act 1998 along with numerous other statutes relating to the death penalty.