1) Period 2) Period of time 3) Time period 
the period or state of confinement after labour.
the period of adjustment after childbirth during which the mother`s reproductive system returns to its normal prepregnant state. It generally lasts ... [1 related articles]
The period of about six weeks which follows immediately after the birth of a child.
<obstetrics> The period or state of confinement after labour. ... (18 Nov 1997) ... 
(pu″әr-pēr´e-әm) the period from the end of the third stage of labor until involution of the uterus is complete, usually lasting between 3 and 6 weeks.
The span of time from the end of delivery until the uterus
Type: Term Pronunciation: pyū-er-pē′rē-ŭm, -ē-ă Definitions: 1. Period from the termination of labor to complete involution of the uterus, usually defined as 42 days.
Puerperium: The time immediately after the delivery of a baby. (In Latin a 'puerpera' is a woman in childbirth since 'puer' means child and 'parere' means to give birth.) Puerperal fever is childbirth (or childbed) fever due to an infection usually of the placental site within the uterus. If that infection involves the bloodstream, it constitutes p...
The postpartum recovery period after the birth of a baby, whether it be by vaginal birth or cesarean birth. The timeframe is usually the first 4 to 6 weeks after the birth in which a woman's body returns to its normal physical state.
[n] - time period following childbirth when the mother`s uterus shrinks and the other functional and anatomic changes of pregnancy are resolved
puerperium (singular), puerperia (plural) 1. Period from the termination of labor to complete involution of the uterus, usually defined as 42 days. 2. Time of childbearing; labor in childbirth. 3. The period immediately after childbirth when the womb is returning to its normal size, lasting approximately six weeks.
the time period after childbirth (about 6 weeks) during which a woman's body returns to its normal physical state 
noun time period following childbirth when the mother`s uterus shrinks and the other functional and anatomic changes of pregnancy are resolved; `a perinatologist cared for her during the puerperium`
the four-week period following childbirth.
The span of time from the end of delivery until the uterus returns to its prepregnancy state, usually about six weeks.