Regarding the causes and risk factors of primary postpartum hemorrhage, all of the following are established risk factors EXCEPT:

Explanation

## Risk Factors for Primary Postpartum Hemorrhage ### Established Risk Factors (Options 0, 2, 3) **Option 0: Prolonged second stage of labor** - Prolonged second stage (>2 hours in nullipara, >1 hour in multipara) increases uterine exhaustion - Results in inadequate uterine contraction and increased bleeding - Associated with increased use of instrumental delivery, which itself increases PPH risk - [cite:Park 26e Ch 25] **Option 2: Placental abruption** - Placental abruption causes massive PPH due to: - Direct loss of fetal blood from placental site - Coagulopathy (DIC) from release of thromboplastin - Uterine atony from placental irritation - One of the most important causes of severe PPH - [cite:Park 26e Ch 25] **Option 3: Multiparity (parity ≥5)** - Grand multiparity (≥5 previous deliveries) is a well-established risk factor - Mechanism: Uterine muscle becomes atonic with repeated pregnancies - Increased risk of abnormal placentation (accreta, previa) - [cite:Park 26e Ch 25] ### NOT an Established Risk Factor (Option 1) — THE ANSWER **Maternal age >35 years: NOT a direct risk factor** **Key Point:** While advanced maternal age (≥35 years) is associated with increased obstetric complications overall (gestational diabetes, preeclampsia, chromosomal abnormalities), it is **NOT an independent risk factor for primary PPH**. The increased PPH risk seen in older women is secondary to comorbidities (hypertension, diabetes) and placental pathology, not age itself. **High-Yield:** - Young maternal age (<20 years) and very advanced age (>40 years) may carry some risk, but age 35 is not a cutoff for PPH risk - This is a common distractor because advanced age is a risk factor for many obstetric complications - [cite:Park 26e Ch 25] **Clinical Pearl:** The "4 T's" mnemonic for major causes of PPH: - **T**one (uterine atony) — 70% of cases - **T**rauma (cervical/vaginal lacerations, uterine rupture) — 20% - **T**issue (retained products of conception, placental fragments) — 5% - **T**hrombosis (coagulopathy, DIC) — 5% ### Risk Factors for Primary PPH — Summary Table | Category | Risk Factors | | --- | --- | | **Uterine factors** | Multiparity (≥5), prolonged labor, uterine overdistension (polyhydramnios, multiple gestation), fibroids | | **Placental factors** | Abruption, previa, accreta, retained placenta | | **Delivery factors** | Instrumental delivery, cesarean section, episiotomy | | **Maternal factors** | Anemia, coagulopathy, preeclampsia, chorioamnionitis | | **NOT independent factors** | Maternal age 35 years (unless with comorbidities) | **Warning:** Do not confuse "advanced maternal age" (a risk factor for chromosomal abnormalities and gestational complications) with "PPH risk." Age alone does not increase PPH; underlying conditions do.