Final answer:
Quickening is the subjective sign of pregnancy reported by the client, typically felt between weeks 16 and 20 due to discernible fetal movements.
Step-by-step explanation:
The sensation of feeling the baby move, described by the client, is known as quickening. This is a subjective sign of pregnancy, typically experienced between weeks 16 and 20, as the fetal movements become more discernible. These sensations occur because the fetus has grown and its limb movements are more powerful, but still restricted within the womb. The developing fetus is usually in the fetal position at this stage, with arms crossed and legs bent and covered with vernix caseosa and lanugo to protect and moisturize the skin.