Quickening

In pregnancy terms, quickening is the moment in pregnancy when the pregnant woman starts to feel or perceive fetal movements in the uterus.

The first natural sensation of quickening may feel like a light tapping, or the fluttering of a butterfly. These sensations eventually become stronger and more regular as the pregnancy progresses. Sometimes, the first movements are mis-attributed to gas or hunger pangs.

A woman's uterine muscles, rather than her abdominal muscles, are first to sense fetal motion. Therefore, a woman's body weight usually does not have a substantial effect on when movements are initially perceived. Women who have already given birth have more relaxed uterine muscles that are consequently more sensitive to fetal motion, and for them fetal motion can sometimes be felt as early as 14 weeks.

Usually, quickening occurs naturally at about the middle of a pregnancy. A woman pregnant for the first time (i.e., a primigravida woman) typically feels fetal movements at about 18–20 weeks, whereas a woman who has been pregnant more than once (i.e., a multipara woman) will typically feel movements around 15–17 weeks.

The word "quick" "alive". Historically, quickening has sometimes been considered to be the beginning of the possession of "individual life" by the fetus. British legal scholar William Blackstone explained the subject of quickening in the eighteenth century, relative to feticide and abortion:

Life... begins in contemplation of law as soon as an infant is able to stir in the mother's womb. For if a woman is quick with child, and by a potion, or otherwise, killeth it in her womb; or if any one beat her, whereby the child dieth in her body, and she is delivered of a dead child; this, though not murder, was by the ancient law homicide or manslaughter. But at present it is not looked upon in quite so atrocious a light, though it remains a very heinous misdemeanor.

Nevertheless, quickening was only one of several standards that were used historically to determine when the right to life attaches to a fetus. According to the "ancient law" mentioned by Blackstone, another standard was formation of the fetus, which occurs weeks before quickening. Henry de Bracton explained the ancient law, about five hundred years before Blackstone:

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