Note: Williams Obstetrics is not available in the textbook library. The following is drawn from Creasy & Resnik's Maternal-Fetal Medicine and Tintinalli's Emergency Medicine, both authoritative references that cover postpartum hemorrhage with content largely overlapping what Williams Obstetrics presents.

Postpartum Hemorrhage (PPH)

Definition

• A 10% drop in hematocrit, OR
• A need for packed red blood cell transfusion, OR
• Volume loss generating symptoms of hypovolemia

Normal pregnancy increases plasma volume by 40% and RBC volume by 25% by end of the third trimester. This can mask early signs — the first sign may be only a mild rise in pulse rate, and up to 30% of total blood volume may be lost before blood pressure drops.

Classification

Causes — The "4 T's"

1. Tone (Uterine Atony) — ~70–80% of cases

• Preeclampsia
• Prolonged use of uterotonics or tocolytics
• Prolonged labor
• Multifetal gestation
• Fetal macrosomia
• Grand multiparity
• Retained placenta
• Uterine infection (chorioamnionitis)

2. Trauma — ~20% of cases

• Rare but carries high maternal and fetal mortality
• Primary risk factor: previous cesarean section
• Other risks: single-layer uterine closure, fetal weight >3,500 g, labor augmentation, bicornuate uterus, grand multiparity, connective tissue disorders
• Signs: persistent abdominal pain, severe vaginal bleeding, loss of fetal station, palpable uterine defect

• Rare but dramatic complication of the third stage of labor
• Related to fundal implantation of the placenta (occurs in only 10% of pregnancies but found in virtually all cases of acute puerperal inversion)
• The thin fundal myometrium invaginates as the placenta separates → uterus "delivers itself inside out"
• Vigorous fundal pressure or excessive cord traction may precipitate inversion
• Complete inversion: inverted fundus extends beyond the cervix (beefy-red mass at the introitus)
• Incomplete inversion: fundus has not extended beyond the external os — diagnosed by bimanual/visual exam; should be suspected when fundus cannot be palpated abdominally

3. Tissue (Retained Products) — ~10% of cases

4. Thrombin (Coagulopathy) — uncommon

Initial Resuscitation

• Monitor vital signs frequently
• Establish adequate IV lines promptly
• Begin fluid resuscitation (lactated Ringer solution)
• Prepare for blood transfusion
• In remote settings, non-pneumatic antishock garments + uterotonics reduce blood loss and increase maternal survival
• In extensive PPH, a central venous pressure line or Swan-Ganz catheter facilitates accurate cardiovascular monitoring and prevents errors of hydration/pulmonary edema

Management by Cause

Uterine Atony — Step-Up Approach

• Intrauterine balloon tamponade (large Foley catheter or Bakri balloon) — especially for low placental implantation site
• Uterine packing with sterile gauze (retrospective evidence supports use in atony)
• Selective pelvic vessel embolization — where facilities and personnel are available

1. Repair of any uterine lacerations
2. Uterine artery ligation (O'Leary technique)
3. Hypogastric (internal iliac) artery ligation — reduces blood pressure and flow through pelvic vessels; ample collateral circulation means no long-term consequences; subsequent pregnancies are possible
4. B-Lynch brace suture — compressive suture that closes uterine blood supply; uterus-conserving; confirmed effective in case series
5. Hayman technique — simpler variant of brace suturing
6. Peripartum hysterectomy — for most extreme, refractory cases

Retained Placenta / Placenta Accreta

• Manual removal or surgical curettage
• Severe cases may require emergency pelvic embolization, B-Lynch sutures, or peripartum hysterectomy

Uterine Inversion — Management

1. Immediate recognition
2. Summon anesthesiologist (general anesthesia may be needed)
3. Tocolysis to relax the uterus:
   • Magnesium sulfate
   • β-mimetic agents
   • Nitroglycerin
4. Johnson technique for manual reinversion: gentle but firm persistent pressure on the fundus, elevating it into the vagina and then abdomen (presumed to work via indirect traction on the round ligaments)
5. Authorities disagree on whether the placenta should be removed before reinversion — practically, the Johnson technique is easier without the placenta in place
6. If reinversion fails → laparotomy

Secondary Postpartum Hemorrhage (24 hours – 6 weeks)

• Failure of uterine lining to subinvolve at the former placental site
• Retained placental tissue
• Genital tract wounds
• Uterogenital infection