A 28-year-old primigravida at 32 weeks of gestation presents to the antenatal clinic with a complaint of decreased fetal movements over the past 3 days. On examination, the fundal height is 28 cm (less than expected for gestational age). Doppler ultrasound shows an estimated fetal weight of 1400 g (10th percentile for 32 weeks), normal amniotic fluid volume, and umbilical artery pulsatility index (PI) at 90th percentile. Maternal serology is negative for infections. What is the most appropriate next step in management?

Explanation

## Clinical Assessment of IUGR This patient has **asymmetric IUGR** (low weight relative to gestational age with normal amniotic fluid) with **preserved diastolic flow** on Doppler (PI at 90th percentile indicates absent or minimal diastolic flow abnormality—borderline but not severely abnormal). ### Doppler Interpretation | Doppler Finding | Umbilical Artery PI | Clinical Significance | Management | |---|---|---|---| | Normal | <95th percentile | Low risk | Standard antenatal care | | Elevated | 95th–99th percentile | Borderline; monitor closely | Twice-weekly NST + repeat Doppler in 3–5 days | | Absent/Reversed | >99th percentile or absent diastolic flow | High risk; severe placental insufficiency | Admit; consider delivery if <34 weeks with corticosteroids | **Key Point:** At 32 weeks with preserved diastolic flow (PI at 90th percentile), the fetus is at **intermediate risk**. The standard approach is **expectant management with intensive surveillance** rather than immediate delivery, which carries significant neonatal morbidity. ### Management Algorithm for IUGR at 32 Weeks ```mermaid flowchart TD A[IUGR at 32 weeks]:::outcome --> B{Umbilical artery Doppler?}:::decision B -->|Normal/Elevated PI| C[Admit for surveillance]:::action B -->|Absent diastolic flow| D[Deliver after steroids]:::urgent C --> E[Twice-daily NST]:::action C --> F[Repeat Doppler in 3–5 days]:::action E --> G{Abnormal NST or worsening Doppler?}:::decision G -->|Yes| H[Deliver immediately]:::urgent G -->|No| I[Continue monitoring until 34 weeks]:::action I --> J[Deliver at 34 weeks]:::action ``` **Clinical Pearl:** The threshold for delivery in IUGR shifts based on gestational age and Doppler findings. At 32 weeks with **borderline Doppler**, the risk of neonatal complications from prematurity (respiratory distress, intraventricular hemorrhage) often exceeds the risk of intrauterine compromise; hence, expectant management with close monitoring is preferred. **High-Yield:** The **Delphi consensus** and **RCOG guidelines** recommend: - Borderline/elevated PI at <34 weeks: admit for twice-weekly NST + repeat Doppler every 3–5 days - Absent/reversed diastolic flow: administer corticosteroids and deliver within 24–48 hours - Delivery target: 34 weeks for uncomplicated IUGR with preserved Doppler **Tip:** Do not discharge a patient with suspected IUGR and decreased fetal movements—this requires admission and intensive fetal assessment. Betamethasone is indicated only if delivery is planned within 7 days.