Glossary P

In the psychological context, perinatal grief refers to the profound sense of loss experienced by parents due to the death of a baby during pregnancy, childbirth, or shortly after birth. It includes complex emotions such as sadness, guilt, and anger. This often requires specialized psychological support, and individuals in need should explore mental health care in Chicago or any other city for coping and healing.

Perinatal hypoxia refers to an oxygen deprivation during labor and delivery which is an obstetrical complication that may be especially important in neurological development.
Period of the embryo refers to the second phase of prenatal development, lasting from the 3rd to the 8th prenatal week, during which the major organs and anatomical structures take shape.

Period of the fetus refers to the longest period of prenatal development that extends from the 9th until the 38th week after conception.

Period of the zygote refers to the first phase of prenatal development that lasts from conception until the developing organism becomes firmly attached to the wall of the uterus.
Periodic Limb Movement Disorder refers to a disorder charaterized by repeated involuntary movement of the legs and sometimes arms during sleep. (Please see Periodic Limb Movements in Sleep or PLMS)
Periodic Limb Movements in Sleep or PLMS refers to a sleeping disorder in which the patient's arms or legs jerk during sleep, causing brief arousals. (see also Periodic limb movement disorder)

Periodicity pitch refers to the constancy of a complex tone’s pitch when the fundamental frequency and other lower harmonics are eliminated. (Please see also Effect of the missing fundamental)