Here’s a **comprehensive, structured, and clinically detailed overview** of **Post-term Pregnancy** and **Fetal Macrosomia**, integrating all relevant aspects — including definitions, pathophysiology, causes, features, investigations, complications, and management — suitable for both medical learning and reference. --- ## 🩺 **Post-term Pregnancy** ### 🔹 **Definition** * **Post-term pregnancy** (also called **prolonged pregnancy**) is defined as: > Pregnancy that extends **≥42 completed weeks (≥294 days)** from the first day of the **last menstrual period (LMP)**. * **Late-term pregnancy**: 41⁰–41⁶ weeks * **Post-term pregnancy**: ≥42⁰ weeks --- ### 🔹 **Pathophysiology** * Usually due to **inaccurate dating** or **true prolonged gestation**. * **Placental senescence** → ↓ placental perfusion & oxygen transfer → **chronic fetal hypoxia**. * **Amniotic fluid volume decreases (oligohydramnios)** → ↑ cord compression risk. * **Fetal overgrowth (macrosomia)** may occur due to continued growth beyond term. * **Meconium passage** due to fetal distress → meconium aspiration risk. --- ### 🔹 **Etiology / Risk Factors** | Maternal | Fetal | Placental | | ------------------------------------- | --------------- | ----------------------------------------- | | Primigravida | Male fetus | Placental sulfatase deficiency | | Family history of post-term pregnancy | Anencephaly | Anencephalic pregnancy (↓ fetal cortisol) | | Obesity | Genetic factors | Placental enzyme defects | | Prior post-term pregnancy | | | --- ### 🔹 **Clinical Features** * **History:** LMP >42 weeks, reduced fetal movements. * **Examination:** * Fundal height may plateau or decrease. * Reduced liquor (oligohydramnios). * Fetal heart rate abnormalities. * **Fetus:** Signs of postmaturity: * Dry, peeling skin * Long nails, scant vernix * Thin body, meconium staining --- ### 🔹 **Complications** #### Maternal: * Labor dystocia due to macrosomia * ↑ Cesarean section rate * Postpartum hemorrhage * Perineal trauma #### Fetal/Neonatal: * Stillbirth, perinatal mortality * Meconium aspiration syndrome * Hypoxia, acidosis * Shoulder dystocia * Neonatal hypoglycemia and seizures * Oligohydramnios-related cord compression --- ### 🔹 **Investigations** 1. **Accurate dating:** Early ultrasound confirmation. 2. **Antenatal surveillance after 41 weeks:** * **Non-stress test (NST)** * **Biophysical profile (BPP)** * **Doppler velocimetry** (umbilical artery) * **Amniotic fluid index (AFI)** – oligohydramnios = AFI <5 cm --- ### 🔹 **Management** #### **1. Prevention** * Early ultrasound dating (first trimester). * Avoid unnecessary post-dates by accurate menstrual history. #### **2. Expectant Management (41–42 weeks)** * Daily fetal movement count. * Twice-weekly NST, AFI/BPP. * Induction if **abnormal tests** or **oligohydramnios**. #### **3. Induction of Labor** * Recommended at **41 weeks** (to reduce perinatal mortality). * Use: * **Membrane sweeping** * **Cervical ripening**: Prostaglandin E2 (dinoprostone) or misoprostol. * **Oxytocin infusion** when cervix is favorable. * Continuous electronic fetal monitoring. #### **4. Delivery** * Vaginal preferred unless obstetric contraindication. * Cesarean if fetal distress, failed induction, or cephalopelvic disproportion. #### **5. Neonatal Care** * Resuscitation readiness. * Manage meconium aspiration, hypoglycemia. --- ## 👶 **Fetal Macrosomia** ### 🔹 **Definition** * **Birth weight ≥4,000–4,500 g** regardless of gestational age. * **Severe macrosomia:** >4,500 g * **Extreme:** >5,000 g --- ### 🔹 **Pathophysiology** * Excessive fetal growth due to **maternal–placental nutrient oversupply**, especially **glucose**. * **Insulin** acts as the main fetal growth promoter (anabolic hormone). --- ### 🔹 **Etiology / Risk Factors** | Maternal | Fetal | Genetic | | ------------------------------- | --------------------------- | --------------------- | | Diabetes mellitus (GDM, Type 2) | Male fetus | Familial tall stature | | Obesity | Beckwith–Wiedemann syndrome | Parental obesity | | Excessive weight gain | Post-term pregnancy | | | Multiparity | | | --- ### 🔹 **Clinical Features** * **Large symphysis–fundal height** (≥4 cm more than gestational age). * **Difficult palpation of fetal parts**. * **Ultrasound findings:** * Estimated fetal weight (EFW) >90th percentile. * Increased abdominal circumference. * **During labor:** prolonged/obstructed labor, shoulder dystocia. --- ### 🔹 **Complications** #### Maternal: * Prolonged labor, obstructed labor * Shoulder dystocia, perineal tears * Postpartum hemorrhage * Increased cesarean rate #### Fetal: * Shoulder dystocia, brachial plexus injury * Clavicle fracture * Birth asphyxia * Neonatal hypoglycemia * Increased perinatal morbidity --- ### 🔹 **Diagnosis** 1. **Clinical Estimation:** Fundal height, Leopold maneuvers. 2. **Ultrasound:** * EFW by Hadlock’s formula (BPD, AC, FL, HC). * EFW ≥4,000 g suggestive. --- ### 🔹 **Management** #### **Antenatal** * Control maternal diabetes, weight. * Serial growth scans. * Plan delivery at 38–39 weeks if diabetic mother with large fetus. #### **Intrapartum** * **Trial of labor** if EFW <4,500 g and no cephalopelvic disproportion. * **Elective cesarean** if: * EFW >4,500 g (diabetic) * EFW >5,000 g (non-diabetic) * Preparedness for **shoulder dystocia management**: * McRoberts maneuver, suprapubic pressure, internal rotation. #### **Postnatal** * Monitor neonatal **blood glucose**, trauma, and jaundice. --- ### 🔹 **Prevention** * Tight maternal glycemic control. * Weight management during pregnancy. * Early induction or cesarean if macrosomia predicted. --- ### 🔹 **Key Differences** | Feature | Post-term Pregnancy | Macrosomia | | ---------- | ------------------------ | ----------------------------------------- | | Definition | ≥42 weeks | ≥4–4.5 kg fetus | | Cause | Prolonged gestation | Maternal hyperglycemia, obesity | | Main risk | Placental aging, hypoxia | Shoulder dystocia, birth trauma | | Management | Induction at 41–42 wks | Mode of delivery decision based on weight | --- ### 🧩 **Tags** `post-term pregnancy, prolonged pregnancy, macrosomia, fetal overgrowth, induction of labor, obstetrics, perinatal care, gestational diabetes, fetal monitoring, shoulder dystocia, pregnancy complications, obstetric management` --- Would you like me to now create **20 case-based MCQs with answers and explanations (HTML, CSS & JS single file)** on this topic?