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# ⭐ **AMNIOTIC FLUID – COMPLETE MASTER REFERENCE**

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## **1. What is Amniotic Fluid?**

Amniotic fluid (AF) is the **protective liquid** within the amniotic sac that surrounds the fetus.

### **Functions**

* Cushioning → prevents trauma
* Allows fetal movement → musculoskeletal development
* Prevents cord compression
* Maintains temperature
* Enables lung development → fetal breathing movements
* Prevents adhesions of membranes
* Facilitates exchange of nutrients, water, biochemical products

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## **2. Sources of Amniotic Fluid (Based on Gestation Age)**

### **First Trimester**

* **Amnion + maternal plasma transudate**
* Chorionic membrane diffusion

### **Second Trimester**

* **Fetal urine (major source)**
* Fetal lung secretions
* Transmembranous & intramembranous pathways
* Fetal swallowing regulates AF volume

### **Third Trimester**

* **Fetal urine = 700–900 mL/day**
* Fetal swallowing = AF removal
* The balance determines AFV

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# ⭐ **3. Colors of Amniotic Fluid & Their Clinical Meaning**

| **Color** | **Meaning / Cause** |
| ------------------ | ---------------------------------------------------- |
| **Clear** | Normal |
| **Greenish** | *Meconium-stained fluid* → fetal distress, post-term |
| **Yellow** | *Hemolysis* (Rh isoimmunization), bilirubin |
| **Dark brown** | *Old meconium*, fetal demise |
| **Red / bloody** | Placental abruption, vasa previa rupture |
| **Straw-colored** | Chorioamnionitis sometimes |
| **Golden-colored** | Severe hemolytic disease |
| **Milky white** | Vernix |

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# ⭐ **4. Assessments of Amniotic Fluid**

## **4.1 AFI (Amniotic Fluid Index)**

Sum of vertical pockets in 4 quadrants.

| **AFI Value** | **Interpretation** |
| ------------- | ------------------ |
| **< 5 cm** | Oligohydramnios |
| **5 – 8 cm** | Borderline low |
| **8 – 24 cm** | Normal |
| **> 24 cm** | Polyhydramnios |

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## **4.2 Single Deepest Vertical Pocket (SDVP)**

* **< 2 cm** = Oligohydramnios
* **2–8 cm** = Normal
* **> 8 cm** = Polyhydramnios

**Preferred in multiple pregnancies.**

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# ⭐ **5. AMNIOTIC FLUID DISORDERS**

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# **A. Oligohydramnios**

### **Definition**

* **AFI < 5 cm**
* **SDVP < 2 cm**

### **Causes**

#### *Fetal*

* Renal agenesis (Potter sequence)
* PCKD
* Posterior urethral valves

#### *Placental*

* Uteroplacental insufficiency
* Preeclampsia
* Post-term pregnancy

#### *Maternal*

* ACE inhibitors
* NSAIDs
* Dehydration

#### *Others*

* **PPROM** (most common in third trimester)

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### **Investigations**

* USG → AFI/SDVP
* Doppler → Placental insufficiency
* Anomaly scan → Renal system
* NST / BPP for fetal well-being
* Check maternal BP, proteinuria

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### **Management**

**Depends on Cause + GA:**

#### **1. < 34 weeks**

* Hydration (oral + IV)
* Stop ACE-I / NSAIDs
* Doppler surveillance
* For PPROM → antibiotics + steroids
* Expectant management

#### **2. 34–37 weeks**

* If stable, close monitoring
* Consider induction if fetal distress or severe oligohydramnios

#### **3. ≥ 37 weeks**

* **Induction of labor**

#### **Intrapartum**

* **Amnioinfusion** for recurrent variable decelerations

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# **B. Polyhydramnios**

### **Definition**

* AFI > 24 cm
* SDVP > 8 cm

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### **Causes**

#### Fetal:

* Anencephaly / Open NTD
* Esophageal atresia
* Duodenal atresia (“double bubble”)
* High-output cardiac failure
* Twin–twin transfusion syndrome (TTTS)

#### Maternal:

* Diabetes mellitus
* Rh isoimmunization

#### Placental:

* Chorioangioma

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### **Investigations**

* USG → AFI, anomalies
* Glucose challenge test
* Doppler if fetal anemia suspected
* TORCH IgM if infection suspected

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### **Management**

#### **Mild (Most common)**

* Observation
* Serial USG

#### **Moderate–Severe**

* **Indomethacin 25 mg q6h** (ONLY < 32 weeks)
* **Amnioreduction**
* Treat underlying cause
* Control maternal diabetes
* TTTS → fetoscopic laser ablation

#### **Delivery**

* Indications:

* Fetal compromise
* Maternal distress
* Severe polyhydramnios

Risk of **cord prolapse**, **malpresentation**.

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# 🔥 **NOW — 30 HIGH-YIELD CASE SCENARIOS WITH MANAGEMENT**

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# ⭐ **Case Scenarios 1–10: Oligohydramnios**

### **Case 1**

A 32-week G2P1 mother with severe preeclampsia has AFI = 3 cm. Doppler shows high resistance in umbilical artery.

**Diagnosis:** Placental insufficiency–related oligohydramnios
**Management:**

* Admit
* Steroids
* Daily NST
* Deliver if absent/reversed EDF

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### **Case 2**

28 weeks, PPROM, AFI 2 cm.

**Management:**

* Antibiotics
* Steroids
* Expectant management
* Deliver if chorioamnionitis or fetal distress

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### **Case 3**

38 weeks, AFI 4 cm, NST reactive.

**Management:**

* Induce labor (term oligohydramnios)

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### **Case 4**

22-week anomaly scan → Bilateral renal agenesis, absent bladder filling, severe oligohydramnios.

**Likely diagnosis:** Potter sequence
**Management:**

* Counsel → incompatible with life
* Option for termination

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### **Case 5**

41-week post-term pregnancy, AFI = 4 cm.

Management: Induction due to placental insufficiency

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### **Case 6**

G1 mother on ACE inhibitors (enalapril). AFI 3 cm.

Management:

* STOP ACE-I immediately
* Hydration
* Monitor AFI

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### **Case 7**

Pregnant woman with dehydration from vomiting; AFI 5 → 8 cm after hydration.

Management: Rehydration therapy

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### **Case 8**

Intrapartum oligohydramnios with recurrent variable decelerations.

Management: **Amnioinfusion**

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### **Case 9**

PPROM + fever + foul-smelling discharge. AFI 2 cm.

Diagnosis: Chorioamnionitis
Management: Immediate delivery + IV antibiotics

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### **Case 10**

32 weeks → IUGR + AFI 3 + BPP 4/10.

Management: Deliver (non-reassuring fetal status)

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# ⭐ **Case Scenarios 11–20: Polyhydramnios**

### **Case 11**

GDM mother, AFI = 28 cm, fetus large for gestational age.

Management:

* Control sugars
* NST / BPP surveillance
* Deliver at term

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### **Case 12**

20 weeks, AFI 32 cm, USG shows absent stomach bubble.

Diagnosis: Esophageal atresia
Management:

* Refer to fetal medicine
* Counsel
* Plan postnatal surgery

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### **Case 13**

34 weeks, severe polyhydramnios + maternal dyspnea.

Management:

* Therapeutic amnioreduction
* Rule out anomalies

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### **Case 14**

28 weeks, AFI 35 cm, monochorionic twins with discordant growth.

Diagnosis: TTTS
Management: Fetoscopic laser ablation

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### **Case 15**

20-week fetus with anencephaly + polyhydramnios.

Management: Discuss termination options

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### **Case 16**

Rh isoimmunization → MCA PSV high → fetal anemia + polyhydramnios.

Management: Intrauterine transfusion

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### **Case 17**

UTI in pregnancy + mild polyhydramnios.

Management: Treat infection; repeat scan

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### **Case 18**

Chorioangioma on placenta + polyhydramnios.

Management: Monitor + possible laser coagulation

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### **Case 19**

35 weeks → fetal hydrops + AFI 30 cm.

Management: Investigate cause (Rh, infection) + possible early delivery

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### **Case 20**

32-week mother with severe reflux due to polyhydramnios.

Management: Amnioreduction + symptomatic therapy

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# ⭐ **Case Scenarios 21–30: Mixed, Advanced, Exam-Level**

### **Case 21**

Severe IUGR + oligohydramnios + absent diastolic flow.

Action: Immediate delivery ( > 32 weeks )

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### **Case 22**

Pregnancy with lupus nephritis flare → oligohydramnios.

Management: Treat maternal disease + surveillance

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### **Case 23**

Polyhydramnios after uncontrolled diabetes, AFI improved after insulin optimization.

Interpretation: Reversible cause

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### **Case 24**

Borderline AFI (6 cm) and reduced fetal movement.

Management: NST + repeat AFI in 24 hours

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### **Case 25**

Post-amniocentesis fluid leakage → oligohydramnios.

Management: Expectant + hydration

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### **Case 26**

36 weeks, breech + polyhydramnios.

Risk: Cord prolapse
Management: Elective C-section

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### **Case 27**

Term pregnancy + thick meconium-stained fluid.

Interpretation: Fetal distress
Management: Continuous FHR monitoring; prepare for neonatal resuscitation

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### **Case 28**

Fetus has duodenal atresia ("double bubble") + AFI 30.

Management: Delivery at tertiary center + neonatal surgery

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### **Case 29**

AFI normal earlier; now sudden drop to AFI 3.

Rule out: PPROM
Test: Nitrazine/ferning/IGFBP-1

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### **Case 30**

Suspected polyhydramnios, but SDVP = 6 cm (normal).

Interpretation: AFI misleading; SDVP more accurate

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