Complications in the Third Stage of Labor

Core Concepts

The normal third stage and signs of placental separation

After the newborn is born, the uterus contracts firmly. This contraction shortens the uterine muscle fibers, which shears the placenta off the decidua. Classic signs that the placenta has separated (Calkins' signs) include: the uterus becomes globular and rises in the abdomen, the umbilical cord lengthens, and a small gush of blood appears. The placenta delivers by one of two mechanisms: the Schultze mechanism (center of the placenta separates first, so it folds like an umbrella and delivers shiny-side-down, with blood hidden behind it) or the Duncan mechanism (margins separate first, so it delivers edge-first, with more visible blood loss). Both are normal; the difference matters because Duncan delivers more visibly.

Uterine atony

Atony — failure of the uterus to contract firmly — is the most common cause of early postpartum hemorrhage. A soft, "boggy" uterus cannot clamp down on the open blood vessels at the placental site. Risk factors include uterine overdistention (large baby, twins, polyhydramnios), prolonged or rapid labor, grand multiparity, deep anesthesia, and retained products of conception. A full bladder is a classic contributor: a distended bladder pushes the uterus up and to the side and prevents it from contracting. The nurse's first-line response in most facilities includes fundal massage and bladder emptying, but specific actions, medications, and administration follow provider orders and institutional protocol. The key habit is repeated assessment: the fundus must stay firm and midline, and lochia within expected limits.

Retained placenta and retained products

Sometimes the placenta does not deliver within the expected time, or part of it stays behind. Retained placenta means the placenta has not been expelled; retained products of conception means fragments remain, which can cause late hemorrhage and infection weeks later. Abnormal placental adherence — the placenta accreta spectrum — can make separation partial or impossible and carries high bleeding risk; it is often identified before birth by ultrasound, but not always. Removing a retained placenta is a provider procedure (manual removal), often with analgesia or anesthesia; the nurse prepares the person, monitors for bleeding, and documents.

Lacerations and other sources of bleeding

Not all third-stage bleeding comes from the uterus. Lacerations of the cervix, vagina, or perineum — including extensions of an episiotomy — can bleed briskly. When the uterus is firm and midline but bleeding continues, the provider usually inspects the genital tract for lacerations. Distinguishing uterine from non-uterine bleeding is a core assessment skill: atony produces a boggy fundus with dark, trickling lochia, while laceration bleeding is often bright red and continuous despite a firm fundus.

Uterine inversion

Uterine inversion — the uterus turns inside out, with the fundus protruding into or through the cervix/vagina — is rare but dramatic: sudden severe pain, a visible or palpable mass, and shock out of proportion to visible blood loss. It is associated with strong traction on the cord before separation and with uterine atony. Inversion is an emergency that requires immediate provider response and often pain management and fluid resuscitation; the nurse's job is recognition, call for help, and support.

Uterine rupture and cord avulsion

A uterine rupture that begins earlier in labor can extend or become apparent in the third stage; the same signs apply (pain, bleeding, earlier fetal heart rate changes, loss of fundal height). Cord avulsion — the cord tears away from the placenta, usually from traction before separation — is less dangerous by itself but signals the placenta may have been manipulated too early; the provider will deliver the placenta manually.

Coagulopathies

Sometimes the problem is not a loose uterus but blood that will not clot — a coagulopathy such as disseminated intravascular coagulation (DIC). DIC is a secondary complication of other conditions: placental abruption, amniotic fluid embolism, prolonged retention of a dead fetus, or severe hemorrhage itself. Findings can include oozing from puncture sites, bleeding that does not clot, and petechiae. When bleeding continues despite a firm uterus and intact tissues, coagulopathy is on the differential — and it is a medical emergency.

Blood-loss measurement and early warning

Visual estimation of blood loss is notoriously inaccurate — clinicians consistently underestimate. Many facilities now use quantitative measurement (weighing and measuring collected blood) to track loss more objectively. Early warning signs: tachycardia, narrowing pulse pressure, pallor, dizziness, and delayed capillary refill often precede a drop in blood pressure. After any birth the nurse monitors fundus, lochia, vital signs, and perfusion frequently and documents trends.

Common Confusions