HELLP Syndrome

Key points

• There has been no comprehensive study of the risk factors for HELLP syndrome
• There is debate about the optimal management of women who develop the syndrome prior to 34 weeks of gestation when the maternal and fetal status is reassuring and there is some controversy regarding risk factors for adverse outcome.
• This study will estimate the incidence of HELLP syndrome in the UK and will investigate and quantify the associated risk factors, management and outcomes and will also explore whether any factors are associated with poor outcomes.

Surveillance Period

June 2011-May 2012

Background

HELLP syndrome is a serious complication of pregnancy characterised by haemolysis, elevated liver enzymes and a low platelet count^[1]. Incidence estimates vary from 0.5 to 7.6 per 1000 deliveries^[2][3]and between 8% and 24% of cases with severe preeclampsia/eclampsia^[3][4]. Although there have been reports that women with HELLP syndrome are more likely to be older, of white ethnicity and multiparous^[5][6][7] and the majority, although not all, have signs of preeclampsia^[7][8], there has been no comprehensive study of the risk factors for this complication.

There is a consensus that prompt delivery is indicated when HELLP syndrome develops after 34 weeks of gestation or when fetal or maternal conditions deteriorate. However, there is debate about the optimal management of women who develop the syndrome prior to 34 weeks of gestation when the maternal and fetal status is reassuring. There is also some controversy regarding risk factors for adverse outcome. This study aims to estimate the incidence of HELLP syndrome in the UK, to investigate and quantify the associated risk factors, management and outcomes and to explore whether any factors are associated with poor outcomes.

Case definition

All pregnant women identified as having HELLP syndrome defined as new onset of the following:

Elevated liver enzymes, defined as:

Serum aspartate aminotransferase (AST) ?70 U/L

OR

Gamma-glutamyltransferase (?-GT) ?70 U/L

OR

Alanine aminotransferase (ALT) ?70 U/L

AND

Low platelets, defined as platelet count < 100 x10⁹/l.

AND

EITHER

Haemolysis, defined by abnormal peripheral blood smear or serum lactate dehydrogenase (LDH) levels ?600 U/L or total bilirubin ?20.5 µmol/l

OR

Hypertension, defined as a systolic blood pressure ? 140 mmHg or a diastolic blood pressure ? 90 mmHg

OR

Proteinuria, defined as 1+ (0.3 g/l) or more on dipstick testing, a protein:creatinine ratio of 30 mg/mmol or more on a random sample, or a urine protein excretion of 300 mg or more per 24 hours

Research questions

• What is the incidence of HELLP syndrome in the UK?
• What are the risk factors for HELLP syndrome?
• How is HELLP syndrome managed in the UK?
• What are the outcomes for mother and infant?
• Are there any factors that are associated with poor outcomes?

Investigators

Kate Fitzpatrick, Marian Knight, Jenny Kurinczuk, Peter Brocklehurst, Maria Quigley, NPEU;

Sue Sellers, United Bristol Hospitals NHS Trust; Mervi Jokinnen, RCM;

Shona Golightly, CMACE; Gwyneth Lewis, Department of Health;

James Walker, NPSA; Alison Burton, Oxfordshire PCT; Jenny Furniss, Lay representative.

Funding

This study has been funded by the National Institute for Health Research as part of the new UK National Maternal Near-miss Surveillance Programme (UKNeS).

Ethics committee approval

This study has been approved by the North London REC1 (Study Reference Number 10/H0717/20)

Download the Data Collection Form (DCF)

UKOSS HELLP Syndrome Case Form

UKOSS HELLP Syndrome Control Form