A 32-year-old G3P2 at 28 weeks of gestation attends her routine antenatal visit. Her blood pressure is 138/88 mmHg (baseline at first visit was 110/70 mmHg). She denies headache, visual disturbances, or epigastric pain. Urine dipstick shows 1+ proteinuria. Haemoglobin is 10.2 g/dL. What is the most appropriate immediate next step in management?

Explanation

## Hypertension in Pregnancy — Diagnosis and Risk Stratification at 28 Weeks ### Clinical Scenario Analysis This patient presents with: - **Elevated BP:** 138/88 mmHg (rise of ~28/18 mmHg from baseline) - **Proteinuria:** 1+ on dipstick - **Anaemia:** Hb 10.2 g/dL - **Absence of severe features:** No headache, visual disturbance, epigastric pain, or symptoms of preeclampsia - **Gestational age:** 28 weeks (viable, but early preterm) ### Diagnostic Criteria for Hypertensive Disorders in Pregnancy | Disorder | SBP/DBP Criteria | Proteinuria | Symptoms | |---|---|---|---| | **Gestational Hypertension** | ≥140/90 mmHg (new onset after 20 weeks) | Absent | None | | **Preeclampsia** | ≥140/90 mmHg OR rise ≥30/15 mmHg from baseline | ≥1+ on dipstick OR ≥0.3 g/24 hrs | May be absent (asymptomatic) | | **Severe Preeclampsia** | ≥160/110 mmHg | ≥3+ on dipstick OR ≥5 g/24 hrs | Headache, visual changes, epigastric pain, seizures | **Key Point:** This patient meets criteria for **preeclampsia** (BP rise + proteinuria at ≥20 weeks), but **NOT** severe preeclampsia (BP <160/110, no severe symptoms). The diagnosis is **presumptive** until 24-hour urine protein is quantified. ### Why Repeat BP + 24-Hour Urine Protein? **High-Yield:** The diagnosis of preeclampsia requires **confirmation** because: 1. **BP reproducibility:** A single elevated reading may reflect "white coat" hypertension. Repeat measurement after 15 minutes of rest in a calm environment is standard practice. 2. **Quantification of proteinuria:** Dipstick is qualitative and prone to false positives (dehydration, contamination, concentrated urine). 24-hour urine protein quantification is the gold standard. - Normal: <0.3 g/24 hrs - Preeclampsia: ≥0.3 g/24 hrs (or ≥1+ dipstick if 24-hr unavailable) - Severe: ≥5 g/24 hrs 3. **Risk stratification:** Once diagnosis is confirmed, management depends on: - Presence/absence of severe features - Fetal maturity (at 28 weeks, delivery is preterm; expectant management preferred if no severe features) - Maternal stability ### Assessment for Severe Preeclampsia **Clinical Pearl:** Severe preeclampsia features include: - **Maternal:** SBP ≥160 or DBP ≥110 mmHg, headache, visual disturbances, epigastric pain, pulmonary oedema, oliguria, thrombocytopenia, elevated LFTs, seizures (eclampsia) - **Fetal:** Oligohydramnios, FGR, abnormal Doppler, fetal distress This patient has **none** of these — she is asymptomatic with normal vital signs except BP. ### Why NOT Immediate Admission/Antihypertensives? **Warning:** Starting antihypertensive therapy without confirmed diagnosis is premature. Reasons: 1. BP may normalize after rest (white coat effect). 2. 24-hour urine protein may be <0.3 g/24 hrs, ruling out preeclampsia (gestational hypertension instead). 3. At 28 weeks without severe features, **expectant management** is preferred (allows fetal maturation). 4. Antihypertensives are indicated only if: - BP persistently ≥160/110 mmHg (risk of maternal complications), OR - Preeclampsia is confirmed + patient is symptomatic or has severe features ### Management Algorithm at 28 Weeks ```mermaid flowchart TD A[BP 138/88 + 1+ proteinuria at 28 weeks]:::outcome --> B[Repeat BP after rest<br/>24-hour urine protein]:::action B --> C{Confirmed<br/>preeclampsia?}:::decision C -->|No| D[Gestational HTN<br/>Observe, repeat BP weekly]:::action C -->|Yes| E{Severe features?}:::decision E -->|No| F[Expectant management<br/>Weekly BP, urine, FGR monitoring<br/>Corticosteroids for fetal lung maturity]:::action E -->|Yes| G[Admit, antihypertensives<br/>Consider delivery after 34 weeks<br/>or if maternal/fetal compromise]:::urgent ``` ### Anaemia Management The patient's Hb of 10.2 g/dL is mild anaemia. This should be addressed with iron supplementation but is **not** the immediate priority in the context of possible preeclampsia. **Mnemonic:** **CONFIRM** (for preeclampsia diagnosis at first suspicion): - **C**onfirm BP with repeat reading - **O**btain 24-hour urine protein - **N**ote severe features (headache, visual, epigastric pain) - **F**etal assessment (NST, ultrasound for FGR, oligohydramnios) - **I**nvestigate labs (CBC, LFTs, creatinine) if severe features present - **R**isk stratify (mild vs. severe preeclampsia) - **M**anage expectantly (if <34 weeks + no severe features) or deliver (if ≥34 weeks or severe features) ### Why This Is "Best Next Step" The patient is **stable** (no severe symptoms), **at a critical gestation** (28 weeks — preterm delivery carries neonatal risk), and **diagnostic confirmation is pending** (BP may normalize, urine protein may be <0.3 g/24 hrs). The immediate next step is **diagnostic confirmation** via repeat BP and 24-hour urine protein, which will guide all subsequent management decisions.