Physiological Changes in Postpartum Patients (Chapter 21)

Post partum Period

The interval between the birth of the newborn and the return of the reproductive organs to their normal nonpregnant state.

AKA Puerperium or the fourth trimester of pregnancy.

How long does the postpartum period traditionally last?

6 to 12 weeks, though it may vary.

What is the involution process in the postpartum period?

The return of the uterus to a nonpregnant state after birth, progressing rapidly.

This process begins immediately after expulsion of the placenta with contraction of the uterine smooth muscle.

By 24 hours after birth, the uterus is about the same size as it was at 20 weeks of gestation.

How much does the fundus of the uterus descend every 24 hours during involution?

1 to 2 cm.

Where does the uterus lie 2 weeks after childbirth?

In the true pelvis.

What is subinvolution?

The failure of the uterus to return to a nonpregnant state, commonly caused by retained placental fragments and infection.

What role does oxytocin play in the postpartum period?

It strengthens and coordinates uterine contractions.

What are afterpains?

Painful contractions that occur after childbirth as the uterus contracts.

In first-time mothers uterine tone is good, the fundus generally remains firm, and the patient usually perceives only mild uterine cramping.

Periodic relaxation and vigorous contractions are

more common in subsequent pregnancies and may cause uncomfortable cramping which typically resolve in 3 to 7 days.

More noticeable after births in which the uterus was overdistended

Breastfeeding and exogenous oxytocic medication usually intensify these afterpains because both stimulate uterine contractions.

Placental Site

Immediately after the placenta and membranes are expelled, vascular constriction and thromboses reduce the placental site to an irregular nodular and elevated area.

Upward growth of the endometrium causes sloughing of necrotic tissue and prevents the scar formation characteristic of normal wound healing.

This unique healing process enables the endometrium to resume its usual cycle of changes and permit implantation and placentation in future pregnancies.

Endometrial regeneration is completed by postpartum day 16, except at the placental site.

Regeneration at the placental site usually is not complete

until 6 weeks after birth

What is lochia?

Vaginal discharge that occurs after childbirth, consisting of blood, mucus, and uterine tissue.

Lochia Rubra

Consists mainly of blood and decidual and trophoblastic

debris. The flow pales, becoming pink or brown (lochia serosa)

after 3 to 4 days.

Lochia Serosa

A pinkish-brown discharge lasting approximately 2 to 4 weeks

Lochia Alba

Whitish-yellow in colour because it contains primarily leukocytes and decidual cells; it may continue for another few weeks, although not all patients experience lochia alba.

What indicates non-lochial bleeding?

A gush of bloody discharge when the uterus is massaged, suggesting cervical or vaginal tears.

How does the cervix change after childbirth?

It is soft immediately after childbirth

It closes gradually and may appear bruised with small lacerations.

The external cervical os never regains its prepregnancy appearance; it is no longer shaped like a circle but appears as a jagged slit that is often described as a “fish mouth”

Lactation delays the production of cervical and other estrogen-influenced mucus and mucosal characteristics.

What changes occur in the vagina and perineum postpartum?

Estrogen deprivation leads to thinness of vaginal mucosa, dryness, and coital discomfort; lacerations or episiotomies heal within about 2 weeks.

Vaginal dryness is more prevalent among breastfeeding patients.

What is the effect of pregnancy on pelvic muscular support?

Supportive tissues of the pelvic floor are stretched and may take up to 6 months to regain tone.

What happens to the abdominal wall in the first 2 weeks postpartum?

It remains relaxed, giving the appearance of still being pregnant.

How long does it take for the abdominal wall to return to its pre-pregnancy state?

About 6 weeks.

Diastasis Recti Abdominis

The abdominal wall muscles separate

What hormonal changes occur in the postpartum endocrine system?

Placental hormones like estrogen and progesterone decrease; thyroid hormones return to pre-pregnant levels by 4 weeks.

What is the role of prolactin in postpartum women?

Prolactin levels increase, especially in breastfeeding mothers.

The persistence of elevated serum prolactin levels in breastfeeding patients appears to be responsible for suppressing ovulation.

Kidney Function postpartum

Returns to normal within 1 month after birth. About 6 weeks are required for the pregnancy induced hypotonia and dilation of the ureters and renal pelves to return to the nonpregnant state.

In a small percentage of patients, dilation of the urinary tract may persist for 3 months or longer, increasing the chances of developing a urinary tract infection

Postpartum Fluid Loss

Diueresis caused by decreased estrogen levels, removal of increased venous pressure in the lower extremities, and loss of the remaining pregnancy-induced increase in blood volume.

Aids the body in ridding itself of excess fluid.

Urine output of 3 000 mL or more each day during the first 2 to 3 days is common.

Profuse Diaphoresis especially at night for the first 2 to 3 days.

Accounts for weight loss of 2 to 3kg

What gastrointestinal changes are common after childbirth?

Appetite increases, and spontaneous bowel evacuation may be delayed for 2 to 3 days.

This delay can be explained by decreased muscle tone in the

intestines during labour and the immediate puerperium, prelabour diarrhea, and lack of food or dehydration during labour

What happens to breasts in breastfeeding mothers postpartum?

Colostrum is produced, and 'milk coming in' occurs between 72 to 96 hours after birth.

What is the experience of non-breastfeeding mothers regarding breast engorgement?

Engorgement occurs on the 3rd or 4th postpartum day and resolves spontaneously within 24 to 36 hours.

How does blood volume change after childbirth?

Blood volume decreases within a few days after birth.

Average blood loss for vaginal delivery

300ml to 500ml

Average bloodloss for CS

500ml to 1000ml

Physiological changes that protect postpartum patients in bloodloss

-Elimination of uteroplacental circulation reduces the size of

the maternal vascular bed by 10 to 15%

-Loss of placental endocrine function removes the stimulus for vasodilation

-Mobilization of extravascular water stored during pregnancy occurs.

By the third postpartum day, the plasma volume has been replenished as extravascular fluid returns to the intravascular space

What cardiovascular changes occur immediately postpartum?

Cardiac output remains increased for 48 hours after birth.

What happens to blood components postpartum?

Hematocrit and hemoglobin levels drop, while white blood cell count and coagulation factors may change.

Coagulation Factors

Clotting factors and fibrinogen are normally increased during pregnancy and remain elevated in the immediate puerperium. When combined with vessel damage and immobility, this hypercoagulable state causes an increased risk of thromboembolism, especially after Casarean birth.

Fibrinolytic activity also increases during the first few days after childbirth.

Factors I, II, VIII, IX, and X decrease to nonpregnant levels

within a few days.

Varicosities

Varicosities (varices) of the legs and around the anus (hemorrhoids) are common during pregnancy.

All varices, even the less common vulvar varices, regress (empty) rapidly immediately after childbirth.

Total or nearly total regression of varicosities is expected after childbirth.

What respiratory changes occur immediately postpartum?

There is an immediate decrease in intra-abdominal pressure, increasing chest wall compliance.

What neurological changes occur postpartum?

Pregnancy-induced neurological discomforts, such as carpal tunnel syndrome, typically abate after birth.

What musculoskeletal changes occur postpartum?

Joints stabilize completely by 6 to 8 weeks, and some women may notice a permanent increase in shoe size.

What integumentary changes occur postpartum?

Chloasma usually disappears, but hyperpigmentation of areolae and linea nigra may not regress completely.

How does the immune system change postpartum?

The mildly suppressed immune system during pregnancy gradually returns to the pre-pregnancy state, which can trigger autoimmune conditions.