NURS 2866 Ch. 18 - Maternal Physiologic Changes

What is involution in the postpartum uterus?

Involution is the process by which the uterus returns to its non-pregnant state. It begins immediately after delivery with the contraction of uterine muscles.

Where is the uterus located immediately after delivery?

After delivery, the uterus can be palpated through the abdomen and should be at or slightly above the umbilicus, positioned midline.

How does the fundus change postpartum?

The fundus (top of the uterus) descends approximately 1–2 cm every 24 hours.

Where should the fundus be on postpartum day 3?

On postpartum day 3, the fundus should be about 3 cm below the umbilicus.

When is the uterus no longer palpable abdominally postpartum?

By 2 weeks postpartum, the uterus should no longer be palpable abdominally.

What is subinvolution?

Subinvolution refers to the failure of the uterus to return to its non-pregnant state. This is often caused by retained placental fragments or infection.

How is hemostasis maintained postpartum?

Hemostasis postpartum is maintained primarily by uterine contractions, rather than by clotting and platelet aggregation as in other body systems.

What hormone enhances and coordinates uterine contractions?

Oxytocin, released from the pituitary gland, enhances and coordinates uterine contractions.

What medication supports uterine involution after delivery?

Pitocin (synthetic oxytocin) may be given IV or IM after delivery to support involution.

How does breastfeeding affect uterine contractions postpartum?

Breastfeeding stimulates oxytocin release and helps with uterine contractions, often referred to as afterpains.

What is lochia?

Lochia is uterine discharge after birth.

Describe lochia rubra.

Lochia rubra is bright red, contains small clots, and lasts about 3–4 days.

Describe lochia serosa.

Lochia serosa is pinkish or brownish discharge that lasts around 10-14 days. 

Describe lochia alba.

Lochia alba is yellow or white discharge that lasts from 2 to 6 weeks.

What is the amount of lochia in the first 2 hours postpartum?

The amount of lochia is typically equivalent to a heavy menstrual period and should gradually decrease over time.

How does the cervix change immediately postpartum?

The cervix remains soft immediately postpartum and stays partially dilated.

What happens to the cervix as it starts to close postpartum?

The cervix gradually lengthens, thickens, and firms as it starts to close.

Does the cervix return to a completely closed state postpartum?

The cervix usually does not return to a completely closed state; a slight opening typically remains.

What are common conditions of the vagina and perineum postpartum?

Edema is common after delivery, particularly if the patient had a laceration or episiotomy. Hemorrhoids may also be present postpartum.

What happens to placental hormones after delivery?

After delivery of the placenta, there is a dramatic decrease in hormones such as estrogen and progesterone.

How does the hormonal shift postpartum affect fluid loss?

This hormonal shift contributes to diuresis (fluid loss) of the extra fluid retained during pregnancy.

What happens to hCG levels postpartum?

hCG (human chorionic gonadotropin) declines but can be detectable in blood for 3–4 weeks postpartum.

How do prolactin levels change postpartum?

Prolactin levels increase as progesterone drops.

How do prolactin levels behave in breastfeeding women postpartum?

In breastfeeding women, prolactin levels peak during the first month postpartum and remain elevated with frequent and sustained breastfeeding.

How do prolactin levels behave in non-breastfeeding women postpartum?

In non-breastfeeding women, prolactin levels return to pre-pregnancy range within 3 weeks.

When can ovulation occur postpartum in non-breastfeeding women?

Ovulation may occur as early as 27 days postpartum in non-breastfeeding women, with the average range around 7–9 weeks.

What causes diuresis within 12 hours of birth?

Diuresis is due to decreased estrogen levels, removal of increased venous pressure in the lower extremities, and loss of pregnancy-induced blood volume.

How much urine output is common postpartum in the first 2–3 days?

Urine output of 3000 mL or more per day is common for the first 2–3 days postpartum.

What changes occur in the breasts of breastfeeding mothers postpartum?

In the first 24 hours postpartum, there are minimal changes. Colostrum, a clear to yellowish fluid, is present initially. Breasts become fuller and heavier as colostrum transitions to mature milk within 72–96 hours.

What changes occur in the breasts of non-breastfeeding mothers postpartum?

Breasts may become nodular. Prolactin levels drop rapidly. Nipple stimulation should be avoided to prevent initiation of milk production.

How does pregnancy affect blood volume?

Pregnancy induces hypervolemia, increasing blood volume by 40–50% to prepare for blood loss during delivery.

What is the expected blood loss for vaginal birth?

300–500 mL.

What is the expected blood loss for cesarean section?

500–1000 mL.

How does plasma volume change postpartum?

Plasma volume decreases further due to diuresis in the first few days postpartum.

How does cardiac output change after birth?

Cardiac output increases immediately after birth and returns to pre-labor values within 1 hour.

When does cardiac output return to pre-pregnancy levels postpartum?

By 2 weeks postpartum, cardiac output continues to decrease and returns to pre-pregnancy levels by 6–8 weeks.

What changes occur in heart rate postpartum?

Heart rate may be elevated initially; bradycardia (40–50 bpm) is common in the early postpartum period.

What changes occur in temperature postpartum?

A slight increase (up to 100.4°F/38°C) during the first 24 hours is normal. A low-grade fever is not necessarily indicative of infection during this time.

How do hematocrit levels change postpartum?

Hematocrit drops for the first 3–4 days, then begins to rise.

What happens to WBC counts postpartum?

Leukocytosis is normal during labor and postpartum, with WBC counts potentially reaching up to 30,000/mm³. Therefore, WBC count may not be a reliable marker for infection postpartum.

How does the immune system change postpartum?

During pregnancy, the immune system is mildly suppressed. It gradually returns to normal postpartum.

What might patients with autoimmune disorders experience postpartum?

Patients may experience flare-ups due to immune system rebound and should be educated to expect possible symptom recurrence.