Physiology of Puerperium

Physiology of Puerperium

Involution of the uterus

Definition: the uterus returns to its normal site, tone & position of non pregnant state Mechanism:

·                 Ischemia: After the birth of the baby & placenta, the uterine muscle & blood vessels contracts so the blood circulation decreases. /A localized anemia/

·                 Autolysis: muscle fibers are digested by proteolytic enzyme, waste product then pass in to the blood stream and are eliminated by the kidneys.

·                 Lining of the uterus is cast off and is replaced first by granular tissue and then by endometrium.

Progress of change in the uterus after delivery

Lochia- discharge from the uterus during puerperium.Reaction of lochia is alkaline which favors growth of organisms

Amount – varies with each woman

Odour- heavy and unpleasant but not offensive

The lochia undergo sequential change as involution progresses. 

Lochia Rubra – Red in colour last 1-4 days consists ofblood, chorion, decidua, amniotic fluid, lanugo, vernix caseosa and meconium.

Lochia serosa – purple, lasts 5-9 days contains lessblood more serum as well as leukocytes & organisms.

Lochia alba – creamish pale discharge lasts 9-12 days N:B: It is important that midwife/nurse realize the danger ofretained products which is indicated persistent red lochia .

Changes in other body system

Urinary tract – Physiological changes which occurred duringpregnancy are reversed. The urinary tract is revived from pressure of delivery.

Alimentary canal:- Heart burn improves due to hormonal fall and released pressure on the sphincter. Constipation presents for few days; painful perineum inhibits defecation.

Circulatory system:- blood volume decreases to pregravidlevel & blood regains its normal viscosity. Muscle tone of blood vessel improves cardiac out put returns to normal and blood pressure returns to its usual level. The action takes place with in the 1^st 24-48hrs after the birth of the baby.

Respiratory system- full ventilation because lungs are nolonger compressed by the enlarged uterus.

Endocrine system – Oxytocin – is secreted by posteriorpituitary gland and acts up on uterine muscles & upon breast tissue. It continuous to act upon uterine muscle fibers that maintaining their contractions reducing the placental site & presenting hemorrhage. In women who choose to breast feed their babies, the sucking of the infant stimulates further secretion of oxytocin and this aids the continuing involution of the uterus and expulsion of milk. After the placenta is expelled the circulatory level of human chorionic gonadotrophin, HLP, estrogen and progesterone fall rapidly and this brings about a number of physiological changes.

Musculoskeletal system:-The softened pelvic joints andligaments of pregnancy gradually return to normal over a period of about 3 months. The abdominal and pelvic floor muscles gradually regain their tone with the assistance of postnatal exercise.

Psychological state:- emotional liability /sucing of mood/ isvery common during the early days of the puerperium. After delivery most women experience of mood elation but a few days later they may be depressed and tearful. It is probably a reaction to the physical and mental stress of child birth.