managing-high-risk-pregnancies

# Managing High-Risk Pregnancies

Guides management of preeclampsia, fetal growth restriction, preterm labor, and other high-risk conditions with evidence-based monitoring protocols and delivery timing per ACOG and SMFM guidelines.

## Why This Skill Exists

Approximately 6–8% of pregnancies in the United States are classified as high-risk, requiring increased surveillance and often multidisciplinary co-management with Maternal-Fetal Medicine (MFM). Hypertensive disorders of pregnancy complicate 5–10% of pregnancies and remain a leading cause of maternal mortality worldwide. ACOG Practice Bulletin No. 222 (Gestational Hypertension and Preeclampsia) and SMFM guidance on antenatal surveillance define specific monitoring intervals, laboratory thresholds, and delivery timing criteria that must be followed precisely.

Failure to escalate care, missing laboratory trends, or delivering too early or too late results in preventable morbidity. This skill structures the management of common high-risk conditions with precise criteria, surveillance schedules, and delivery timing algorithms.

---

## Checkpoint A: Pre-Draft Intake (Mandatory)

1. **High-risk condition(s)** — preeclampsia, chronic HTN, FGR, preterm labor, placenta previa, short cervix, multiple gestation, other? (Default: extract from problem list)
2. **Gestational age** — current GA and EDD? (Default: from prenatal record)
3. **Baseline blood pressures** — first-trimester BP for comparison? (Default: from initial OB visit)
4. **Laboratory trends** — most recent CBC, CMP, uric acid, LDH, urine protein? (Default: pull from lab results)
5. **Ultrasound data** — EFW, AFI, Doppler studies, cervical length? (Default: from most recent US)
6. **Antenatal testing schedule** — NST, BPP, or modified BPP frequency? (Default: determine from condition)
7. **Medications** — antihypertensives, aspirin, 17-OHP, magnesium, betamethasone, tocolytics? (Default: from medication list)
8. **MFM involvement** — co-managed or referred? (Default: confirm from chart)

### Documents to Request

- MFM consultation notes
- Serial blood pressure logs
- Laboratory trend data (minimum: CBC, CMP, LDH, uric acid, protein/creatinine ratio or 24-hour urine)
- Ultrasound reports (growth, Doppler, cervical length, amniotic fluid)
- Antenatal testing results (NST, BPP)
- Medication administration records
- Prior obstetric records (history of preeclampsia, preterm birth, FGR)

---

## Step 1: Classify Hypertensive Disorders of Pregnancy

Per ACOG Practice Bulletin No. 222:

| Diagnosis | Criteria |
|---|---|
| **Chronic HTN** | BP ≥ 140/90 before 20 weeks or pre-existing diagnosis |
| **Gestational HTN** | BP ≥ 140/90 after 20 weeks without proteinuria or severe features |
| **Preeclampsia without severe features** | BP ≥ 140/90 after 20 weeks + proteinuria (≥ 300 mg/24 hr or P/C ratio ≥ 0.3) OR other end-organ criteria |
| **Preeclampsia with severe features** | Any of: BP ≥ 160/110 on two occasions 4 hrs apart, platelets < 100K, creatinine > 1.1 or doubling, liver transaminases ≥ 2× ULN, pulmonary edema, new-onset headache unresponsive to medication, visual disturbances |
| **HELLP syndrome** | Hemolysis (LDH ≥ 600, schistocytes, bilirubin ≥ 1.2), Elevated Liver enzymes (AST/ALT ≥ 2× ULN), Low Platelets (< 100K) |
| **Eclampsia** | Preeclampsia + new-onset seizures |
| **Superimposed preeclampsia** | Chronic HTN + new proteinuria or sudden worsening / new severe features after 20 weeks |

---

## Step 2: Manage Preeclampsia by Severity

### Without Severe Features
- Weekly BP monitoring and symptom assessment
- Weekly labs: CBC, CMP, LDH (begin at diagnosis)
- Twice-weekly NST or modified BPP starting at diagnosis
- Growth ultrasound every 3–4 weeks
- Delivery at **37 + 0 weeks** (ACOG recommendation)

### With Severe Features
- **< 34 weeks:** Consider expectant management at a tertiary center IF maternal/fetal status stable
  - Betamethasone for fetal lung maturity (12 mg IM × 2 doses, 24 hours apart)
  - Magnesium sulfate for seizure prophylaxis and neuroprotection
  - Continuous FHR monitoring
  - Labs q 6–12 hours
  - Deliver if worsening despite management
- **34 + 0 to 36 + 6 weeks:** Deliver after betamethasone administration (if not previously given)
- **≥ 37 weeks:** Deliver — do not delay
- **Eclampsia or HELLP at any GA:** Stabilize and deliver regardless of gestational age

### Antihypertensive Therapy (Acute Severe HTN: BP ≥ 160/110)
Treat within **30–60 minutes** per ACOG Committee Opinion No. 767:

| Agent | Protocol |
|---|---|
| Labetalol IV | 20 mg → 40 mg → 80 mg (q10 min) |
| Hydralazine IV | 5 mg → 10 mg (q20 min) |
| Nifedipine PO | 10 mg → 20 mg (q20 min) |

---

## Step 3: Manage Fetal Growth Restriction (FGR)

Per SMFM guidance, classify FGR and determine surveillance:

| FGR Classification | Criteria | Surveillance |
|---|---|---|
| EFW < 10th percentile, normal Doppler | Isolated small for GA | Growth US q 3–4 weeks, weekly NST starting 32 weeks |
| EFW < 10th percentile, elevated UA S/D ratio | FGR with abnormal Doppler | Growth US q 2–3 weeks, twice-weekly NST, weekly Doppler |
| EFW < 3rd percentile | Severe FGR | Growth US q 2 weeks, twice-weekly BPP, serial Doppler |
| Absent end-diastolic flow in UA | — | Consider admission, daily BPP, deliver by 34 weeks |
| Reversed end-diastolic flow in UA | — | Admit, continuous monitoring, betamethasone, deliver by 32 weeks or sooner if deteriorating |

Delivery timing:
- Isolated FGR: 37–38 weeks
- FGR with abnormal Doppler: 34–37 weeks (based on severity)
- Absent/reversed end-diastolic flow: 32–34 weeks (with steroids)

---

## Step 4: Manage Preterm Labor and Short Cervix

**Short cervix (< 25 mm on transvaginal US before 24 weeks):**
- Vaginal progesterone 200 mg nightly (singleton with no prior PTB)
- Cerclage consideration (singleton with prior PTB and progressive shortening)
- Serial cervical length measurements q 2 weeks from 16–24 weeks in high-risk patients

**Active preterm labor (23 + 0 to 33 + 6 weeks):**
- Betamethasone 12 mg IM × 2 doses, 24 hours apart
- Tocolysis for 48 hours to complete steroid course (nifedipine or indomethacin < 32 weeks)
- Magnesium sulfate for neuroprotection if < 32 weeks (4 g bolus + 1 g/hr)
- GBS prophylaxis if status positive or unknown
- Transfer to facility with appropriate NICU level

---

## Step 5: Apply ACOG Delivery Timing Table

| Condition | Recommended Delivery GA |
|---|---|
| Uncomplicated pregnancy | 39 + 0 to 40 + 6 |
| Gestational HTN | 37 + 0 (or upon diagnosis if ≥ 37 wks) |
| Preeclampsia without severe features | 37 + 0 |
| Preeclampsia with severe features | 34 + 0 (after steroids if possible) |
| Chronic HTN (controlled) | 38 + 0 to 39 + 0 |
| Chronic HTN (poorly controlled) | 36 + 0 to 37 + 0 |
| GDM — diet-controlled | 39 + 0 to 40 + 6 |
| GDM — medication-controlled | 39 + 0 |
| Pre-gestational DM (well-controlled) | 37 + 0 to 39 + 0 |
| FGR (isolated, normal Doppler) | 37 + 0 to 38 + 0 |
| Dichorionic-diamniotic twins | 38 + 0 |
| Monochorionic-diamniotic twins | 36 + 0 |
| Prior classical cesarean | 36 + 0 to 37 + 0 |
| Placenta previa | 36 + 0 to 37 + 0 |

---

## Checkpoint B: Post-Draft Alignment (Mandatory)

1. **Is the high-risk condition correctly classified** per ACOG diagnostic criteria?
2. **Does the surveillance plan match** the condition and gestational age?
3. **Are laboratory trends documented** with interpretation (improving, stable, worsening)?
4. **Is delivery timing specified** and consistent with ACOG recommendations?
5. **Are all medications documented** with indication, dose, route, and timing?

---

## Quality Audit

- [ ] Each high-risk condition is named with ACOG-consistent diagnostic criteria
- [ ] Blood pressure classification follows ACOG thresholds (≥ 140/90 and ≥ 160/110)
- [ ] Preeclampsia severity is classified and documented with supporting lab values
- [ ] Acute severe hypertension treatment documented with agent, dose, and time
- [ ] Magnesium sulfate indication, loading dose, and maintenance documented
- [ ] Betamethasone administration documented with dates and times of both doses
- [ ] Antenatal testing schedule documented (NST/BPP frequency)
- [ ] Growth ultrasound interval documented and appropriate for condition
- [ ] Umbilical artery Doppler results documented for FGR cases
- [ ] Delivery timing plan stated with GA and supporting rationale
- [ ] MFM consultation documented with recommendations
- [ ] Tocolytic therapy documented with drug, dose, duration, and contraindications checked
- [ ] Neonatal team notification documented for anticipated preterm delivery

---

## Guidelines

1. **Apply ACOG diagnostic thresholds precisely** — do not round blood pressures or paraphrase laboratory criteria.
2. **Trend, do not snapshot** — a single lab value is less important than the trajectory across serial measurements.
3. **Document the reasoning for delivery timing** — state the condition, the ACOG-recommended window, and why the chosen GA was selected.
4. **Escalate proactively** — if any severe feature is present, document the decision pathway even if expectant management is pursued.
5. **Distinguish chronic from gestational** — the onset before or after 20 weeks is the defining criterion and must be documented.
6. **Track steroid and magnesium exposure** — document both doses of betamethasone with times, and magnesium start/stop times.
7. **Use standardized Doppler terminology** — normal, elevated S/D ratio, absent end-diastolic flow (AEDF), reversed end-diastolic flow (REDF).