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Pulmonary Vascular Disease

Research questions

  • What is the current incidence of Eisenmenger's syndrome and pulmonary hypertension in pregnancy in the UK?
  • How are Eisenmenger's syndrome and pulmonary hypertension in pregnancy managed in the UK?
  • What are the prognostic features associated with Eisenmenger's syndrome and pulmonary hypertension in pregnancy?
  • What are the outcomes of Eisenmenger's syndrome and pulmonary hypertension in pregnancy for both mother and infant?


Pre-existence or gestational occurrence of pulmonary vascular disease, including Eisenmenger's syndrome, primary and secondary pulmonary hypertension, is one of the rare conditions widely considered to pose an extreme risk of maternal death[1]. Four of the nine maternal deaths in women with congenital heart disease reported in the UK in the last triennium were associated with pulmonary vascular disease[2]; since 1991 there have been 22 maternal deaths in the UK associated with this condition[2]. Eisenmenger's syndrome is estimated to carry a maternal mortality rate of 40% per pregnancy[2], with an infant mortality rate of 10-15%[1]. A systematic review of the literature in 1998 suggested that the maternal mortality rate had remained unchanged over the previous 20 years[1]. However, the authors of this review recognise that there may be inherent biases in published reports of pregnancy in women with pulmonary vascular disease in pregnancy and call for more information from detailed prospective case series in order to differentiate the risks of pregnancy and eventually provide an optimal plan of management. Cases in the UK were collected prospectively on a voluntary basis by the UK Registry of High Risk Obstetric Anaesthesia[3], however, problems with ascertainment caused the register to cease to collect all data. This prospective study through UKOSS will provide an appropriate national case series with good ascertainment and allow a comprehensive study of the epidemiology and current management of Eisenmenger's syndrome and pulmonary hypertension.

Case Definition

EITHER Pulmonary hypertension: defined as 1) a mean (not systolic) pulmonary artery pressure equal to or greater than 25mmHg at rest or 30 mmHg on exercise in the absence of a left-to-right shunt or 2) a pulmonary artery systolic pressure greater than 36mmHg[4]. Pulmonary hypertension may be primary (no cause identified) or secondary (known cause identified, for example, vasculitis, connective tissue disease, chronic pulmonary thromboembolism, sickle cell disease, drug use),

OR Eisenmenger's syndrome: defined as pulmonary hypertension secondary to an uncorrected left-to-right shunt from a ventricular septal defect, atrial septal defect or patent ductus arteriosus[5].

Study Size

The study will run initially for five years. The study will aim to collect data on 40 cases (based on an estimated incidence of 1 in 90,000 births).

Download the Data Collection Form (DCF)

UKOSS Pulmonary Vascular Disease Form


  1. a, b, c Weiss BM, Zemp L, Seifert B, Hess OM. Outcome of pulmonary vascular disease in pregnancy: a systematic overview from 1978 through 1996. J Am Coll Cardiol 1998; 31(7):1650-7.
  2. a, b, c de Swiet M, Nelson-Piercy C. Cardiac Disease. London: RCOG, 2004: 137-50.
  3. ^ Dob DP, Yentis SM. UK registry of high-risk obstetric anaesthesia: report on cardiorespiratory disease. Int J Obstet Anesth 2001; 10(4):267-72.
  4. ^ Thorne S, Nelson-Piercy C, MacGregor A, Gibbs S, de Swiet M, Guillebaud J. Pregnancy and contraception in heart disease and pulmonary arterial hypertension: Recommendations from an expert working group. Heart 2005; In press.
  5. ^ Yentis SM, Steer PJ, Plaat F. Eisenmenger's syndrome in pregnancy: maternal and fetal mortality in the 1990s. Br J Obstet Gynaecol 1998; 105(8):921-2.

Updated: Tuesday, 17 January 2023 18:31 (v5)