Pregnancy in women with Chronic Kidney Disease Stage 5 (chronic renal failure)

Key points

• Pregnancy in women with Chronic Kidney Disease (CKD) Stage 5 is associated with poor fetal outcomes and an increased incidence of maternal complications.
• Dialysis strategies for the management of this group of women are continually developing; however the effects on both mother and fetus of changes in dialysis dose are not well defined.
• This study will collect information about the incidence, management and outcomes of pregnancy in women with CKD Stage 5 in the UK.

Surveillance Period

February 2012 - January 2014

Background

Current advice given to women pre-pregnancy with CKD Stage 5 is to delay conception until they receive a renal transplant, which is associated with restored fertility and improved pregnancy outcomes. Women ineligible for prospective transplantation are counselled regarding high rates of fetal loss, severe preterm delivery, fetal growth restriction and small for gestational age infants and maternal complications including pre-eclampsia. Dialysis strategies are continually developing, however more intensive dialysis regimes are likely to be associated with treatment related complications (e.g. infection, fluid volume shifts) which may have consequences for both mother and fetus. Furthermore, the dialysis dose (urea clearance) has not yet been shown to be predictive of fetal outcome^[1][2].

More information is needed about the intrauterine effects and neonatal consequences of changes in dialysis dose. This project will collect information about pregnancy outcomes amongst current women with CKD Stage 5 during pregnancy in the UK and assess the role of dialysis regimens and other factors in the outcomes of women and their infants. Outcomes will be compared with women with renal transplants matched for age, parity and ethnicity. This information is important to inform future management and counselling of these women; in particular to provide a direct comparison of pregnancy outcomes between different forms of renal replacement therapy i.e. dialysis and transplantation.

Objectives

To use the UK Obstetric Surveillance System to describe the epidemiology, management and outcomes of pregnancy in women with CKD Stage 5 in the UK.

Research questions

• What is the current incidence of women who proceed with pregnancy beyond booking / 12 weeks gestation with CKD Stage 5?
• What is the pregnancy outcome of women with CKD Stage 5?
• What is the pregnancy outcome of women who require institution of dialysis treatment during their pregnancy compared with women who conceive on dialysis?
• What are the changes in haemodialysis regimes for women when they become pregnant?
• What are the pregnancy outcomes of women requiring dialysis during pregnancy?
• What are the differences in pregnancy outcomes between women with CKD Stage 5 and women with renal transplants?

Case definition

Any pregnant woman identified as having CKD Stage 5 prior to, or during their pregnancy.

This would usually include any pregnant woman in one of the following groups:

• A woman with an estimated glomerular filtration rate (eGFR) <15mls/min/1.73m²pre-pregnancy
• A woman receiving peritoneal or haemodialysis at conception
• A woman with a serum creatinine >300umol/l pre-pregnancy
• A woman with a serum creatinine >250umol/l on two or more occasions during pregnancy
• A woman commenced on peritoneal or haemodialysis to treat chronic kidney disease during pregnancy

Funding

This study is funded by the Lauren Page Charity

Ethics committee approval

This study has been approved by the NRES Committee East of England -Hertfordshire (study ref 11/EE/0456)

Investigators

Catherine Nelson-Piercy (Principal Investigator), St Thomas' Hospital, London.

Kate Bramham, Maternal and Fetal Research Unit, King's College London.

Download the Data Collection Form (DCF)

UKOSS Stage 5 Chronic Kidney Disease Form