NICE vs RCOG: Management of Pre-eclampsia (2025)

Introduction

Pre-eclampsia is a multisystem disorder unique to pregnancy, characterised by new-onset hypertension and proteinuria or other maternal organ dysfunction after 20 weeks of gestation. In the UK, two major bodies provide guidance for its management: the National Institute for Health and Care Excellence (NICE) and the Royal College of Obstetricians and Gynaecologists (RCOG). The NICE guideline NG133 (Hypertension in pregnancy: diagnosis and management) and the RCOG Green-top Guideline No. 67 (Management of Severe Pre-eclampsia/Eclampsia) are the primary reference documents. While complementary, they have distinct scopes and emphases. This comparison aims to delineate the key similarities and differences to aid clinicians in practical, day-to-day decision-making.

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Key Distinction in Scope: NICE provides a comprehensive pathway covering screening, diagnosis, and management of non-severe and severe pre-eclampsia. In contrast, the RCOG guideline focuses specifically on the inpatient management of severe, early-onset, and complicated pre-eclampsia, offering more detailed guidance for these high-acuity scenarios.

Diagnosis and Assessment

NICE Guideline NG133

• Diagnostic Criteria: Diagnoses pre-eclampsia in a woman with gestational hypertension (BP ≥140/90 mmHg) AND either:
  • Proteinuria (urine protein:creatinine ratio ≥30 mg/mmol or ≥300 mg/24hr).
  • Or evidence of maternal organ dysfunction (e.g., renal insufficiency, liver involvement, neurological complications, haematological abnormalities, uteroplacental dysfunction).
• Risk Assessment: Emphasises using the Fetal Medicine Foundation (FMF) first-trimester screening algorithm to identify women at high risk for prophylactic aspirin (150mg daily from 12 weeks until birth).
• Monitoring: Provides clear schedules for antenatal BP and urinalysis monitoring based on risk level.

RCOG Green-top Guideline No. 67

• Diagnostic Criteria: Aligns with NICE but places greater emphasis on the features of severe pre-eclampsia from the outset. These include severe hypertension (BP ≥160/110 mmHg), symptoms (e.g., severe headache, epigastric pain), and significant biochemical/haematological derangements.
• Assessment Focus: Concentrates on the intensive and frequent monitoring required for a woman with severe disease, including 4-hourly vital signs, daily bloods (FBC, U&E, LFTs), and strict fluid balance.

Practical Takeaway: Use NICE for the initial diagnostic framework and risk identification. Use RCOG's detailed criteria to swiftly identify and stratify the severity of disease in a woman already diagnosed, guiding admission and monitoring intensity.

Treatment and Management

Pharmacological Treatment

• Antihypertensive Therapy (Both): Both guidelines recommend treating hypertension to reduce the risk of stroke.
  • NICE: Recommends treatment for non-severe hypertension (BP ≥140/90 mmHg) with labetalol as first-line, followed by nifedipine MR or methyldopa. Target BP is <135/85 mmHg.
  • RCOG (for severe hypertension): Mandates urgent treatment for BP ≥160/110 mmHg. Also recommends labetalol first-line but provides more detailed protocols for acute hypertensive crises, including IV labetalol and hydralazine.
• Magnesium Sulphate:
  • NICE: Recommends for the prevention and treatment of eclampsia in women with severe pre-eclampsia, particularly if birth is planned within 24 hours.
  RCOG: Provides a more expansive and proactive indication. It recommends magnesium sulphate for all women with severe pre-eclampsia, irrespective of the planned timing of birth, for seizure prophylaxis. It offers a detailed loading and maintenance infusion regimen.

Timing of Birth

• NICE: Offers a structured timeline:
  • For pre-eclampsia before 34 weeks: Consider expectant management with corticosteroids for fetal lung maturation, balancing maternal and fetal condition.
  • At 34 to 36+6 weeks: Discuss planned birth after corticosteroids.
  • At 37 weeks or more: Offer planned birth within 24-48 hours.
• RCOG: Focuses on the management of severe, early-onset pre-eclampsia (<34 weeks). It provides nuanced guidance on the criteria for expectant management (e.g., stable maternal condition, reassuring fetal status) and the strict inpatient monitoring required during this period. The decision for delivery is based on predefined "maternal or fetal triggers".

Practical Takeaway: NICE provides the general schedule for delivery. RCOG is the essential guide for managing the complex decision-making and monitoring involved in delaying birth for a severely preterm pre-eclamptic patient.

Special Situations

HELLP Syndrome

• NICE: Briefly covers HELLP syndrome as a severe complication, advising urgent senior review and birth.
RCOG: Provides comprehensive guidance, including differential diagnosis, specific management of coagulopathy and thrombocytopenia, and the need for multidisciplinary care involving haematology and critical care.

Eclampsia

• Both guidelines stress immediate treatment with magnesium sulphate. RCOG offers a more detailed step-by-step resuscitation and management protocol for the acute event.

Postpartum Management

• NICE: States that women with pre-eclampsia should be monitored for at least 72 hours postpartum and for up to 2 weeks after transfer to community care. Antihypertensive treatment should be continued and weaned as appropriate.
• RCOG: Highlights that 44% of eclamptic seizures occur postpartum and recommends continuing magnesium sulphate for 24 hours post-birth in women who required it. It also emphasises the importance of postnatal review to discuss future cardiovascular risk.

Practical Clinical Flow: A Synergistic Approach

In practice, the guidelines are used together. A typical flow for a clinician might be:

1. Antenatal Screening & Initial Diagnosis (NICE-led): Use FMF algorithm for aspirin prophylaxis. Investigate new hypertension after 20 weeks using NICE diagnostic criteria.
2. Severity Stratification (RCOG-led): If pre-eclampsia is diagnosed, immediately apply RCOG criteria to determine severity. The presence of any severe feature (BP ≥160/110, symptoms, significant biochemical upset) mandates immediate admission.
3. Inpatient Management (RCOG-led): For severe disease, follow RCOG's intensive monitoring protocol, initiate magnesium sulphate for seizure prophylaxis, and treat severe hypertension aggressively.
4. Timing of Birth (NICE framework, RCOG nuance): Use NICE's gestational age timeline as a basis. For women <34 weeks, use RCOG's detailed guidance on expectant management and delivery triggers.
5. Postpartum Care (Combined): Continue vigilant monitoring as per NICE. Adhere to RCOG's specific advice on postpartum magnesium sulphate duration and long-term follow-up.

Frequently Asked Questions (FAQs)

1. Which guideline takes precedence in an emergency?

Answer: The RCOG guideline is specifically written for the management of severe, life-threatening disease. In an acute situation (e.g., severe hypertension, neurological symptoms), the more detailed and aggressive RCOG protocols for crisis management should be followed.

2. A woman at 32+0 weeks has a BP of 150/100 mmHg with no proteinuria but deranged LFTs. Is this severe pre-eclampsia?

Answer: Yes. According to both guidelines, evidence of maternal organ dysfunction (in this case, liver involvement) fulfils the diagnostic criteria for pre-eclampsia, even without proteinuria. The deranged LFTs and gestational age make this a case of severe, early-onset pre-eclampsia, requiring management as per the RCOG guideline.

3. For how long should magnesium sulphate be continued postpartum?

Answer: This is a key difference. NICE does not specify a fixed duration. RCOG explicitly recommends continuing the infusion for 24 hours after birth (or after the last seizure), whichever is later, due to the high risk of postpartum seizures.

4. When should we consider expectant management at <34 weeks?

Answer: This is detailed in the RCOG guideline. It can be considered if the mother is stable (BP controlled on oral medication, no deteriorating organ dysfunction, no uncontrollable symptoms) and the fetus is reassuring. This must be conducted in a tertiary centre with continuous intensive monitoring.

5. What is the key difference in the use of magnesium sulphate?

Answer: NICE suggests it "should be considered" for seizure prophylaxis, often linked to imminent birth. RCOG recommends it more definitively for all women with severe pre-eclampsia as a standard of care, regardless of the immediate delivery plan.

Source Links

• NICE Guideline NG133 (Hypertension in pregnancy: diagnosis and management)
  Last updated: June 2023 (Review by 2025).
  URL: NICE NG133
• RCOG Green-top Guideline No. 67 (Management of Severe Pre-eclampsia/Eclampsia)
  Last updated: May 2022 (Review date: 2025).
  URL: RCOG Green-top Guideline No. 67