Anti-Ro & Anti-La antibodies : Guideline for the management of babies born to mothers with systemic lupus erythematosus (SLE) and other autoimmune disorders

exp date isn't null, but text field is

Objectives

Guideline for the management of babies born to mothers with systemic lupus erythematosus (SLE) and other autoimmune disorders.

This document is applicable to all medical, nursing and midwifery staff caring for the newborn in hospital or community.   It is intended as a guide to the management of babies born to mothers with anti-Ro or anti-La antibodies. Note that some babies may develop neonatal lupus without a diagnosis having been made in the mother.  The guideline should be used with reference to the relevant pharmacy monographs.

1. Introduction

Systemic lupus erythematosus (SLE) is a chronic inflammatory multisystem disease. Most women with SLE have normal fertility, but they are at higher risk of pregnancy complications including hypertension, preterm labour, thrombosis and postpartum haemorrhage.  There is a higher incidence of miscarriage and fetal loss especially in women with co-existing antiphospholipid syndrome (presence of lupus anticoagulant and anticardiolipin antibodies).

Neonatal lupus — Neonatal lupus is a passively acquired autoimmune disease that occurs in about 2 percent of babies born to mothers with anti-Ro/SSA and/or anti-La/SSB antibodies. It is caused by passage across the placenta after about the 20th week of pregnancy of anti-Ro/SSA and/or anti-La/SSB antibodies to intracellular ribonucleoproteins. Antibody levels are reported by the lab in GG&C. Approximately 50% of women who give birth to a baby with the neonatal lupus syndrome do not have a diagnosis of lupus or any other autoimmune disease (eg Sjögren’s syndrome) at the time of their pregnancy despite the presence of anti-Ro/SSA or anti-La/SSB antibodies. Around half of these mothers will go on to develop autoimmune disease, and they should all therefore be referred to a rheumatologist for assessment postnatally.

Signs of neonatal lupus include a red, raised rash on the scalp and around the eyes. The rash almost always resolves by six to eight months of age following clearance of the maternal antibodies and the majority (90 percent) of these infants do not subsequently develop lupus.

Infants may also demonstrate transient abnormalities of liver function and generalised or selective reduction in cellular blood components, e.g., anaemia, reduced white cell count and/or thrombocytopenia.

The most common cardiac manifestation of neonatal lupus is complete heart block, which occurs in approximately 2 percent of newborns whose mothers have anti-Ro/SSA or anti-La/SSB antibodies. Complete heart block may rarely be associated with cardiomyopathy secondary to endocardial fibroelastosis (EFE), and is irreversible.

Women with known anti-Ro/SSA or anti-La/SSB antibodies will undergo weekly monitoring of the fetal heart rate using Doptone, starting from 18 weeks of pregnancy. Four weekly ultrasound scans will be undertaken from 20 weeks of gestation onwards, aiming to detect fetal heart block at an early stage to allow monitoring of fetal cardiac function and alert the neonatal/cardiology team to the potential need for a pacemaker after birth.

There is at present no proven treatment for fetal heart block prior to birth. There have been reported cases of reduction in the degree of heart block and reversion to sinus rhythm after maternal steroid therapy but dexamethasone is not recommended as prophylaxis to prevent fetal congenital heart block (1). Neither has intravenous immunoglobulin been established as an effective preventative treatment (2). A ventricular heart rate of <55 beats per minute, reduced left ventricular function, hydrops, presentation earlier in pregnancy and reduced cardiac function are risk factors for fetal and neonatal death. Antenatal treatment with an alpha-sympathomimetic drug is not routinely employed due to the risks to the maternal health (3,4).

If a mother gives birth to a baby with neonatal lupus, her risk of having a child with neonatal lupus in a subsequent pregnancy is 16-18%. Several maternal therapies have been trialled in a bid to prevent CHB in a further pregnancy, however evidence is lacking.

2. Management of the asymptomatic baby

Cord bloods:

FBC and differential WBC

Clinical examination soon after birth – if heart rate > 80 beats per minute and baby clinically stable, he/she should remain with mum.

ECG prior to discharge.
The ECG should be discussed with a neonatal consultant prior to baby’s discharge.

Feeding advice:

Breastfeeding is recommended for most women with SLE as there is no increased risk of neonatal lupus related to breastfeeding. Note that most medications enter breast milk to some extent:

  • Diclofenac or ibuprofen can be used, but aspirin should be avoided.
  • If NSAIDs are not tolerated, dihydrocodeine may be used with caution as higher doses may lead to drowsiness, or rarely, respiratory depression. 
  • Prednisolone can be taken in low doses up to 40 mg/day.
  • Chloroquine, hydroxychloroquine and heparin appear to be safe while breastfeeding.
  • Azathioprine and cyclosporine enter breast milk in very low concentrations and their continued use can be considered on a case by case basis. This should have been discussed with mother prior to delivery and a plan documented in the handheld records and/or maternal Badger.
  • Cyclophosphamide and methotrexate should be avoided during breastfeeding.

Follow up – out patient clinic 2-3 weeks. The family should be advised to contact the neonatal unit for earlier review if baby develops a rash, or if there are any other concerns.

Advice should be given to parents to avoid the baby being exposed to direct sunlight (complete (i.e. Factor 50 or greater) sunblock plus a hat).

3. Management of the symptomatic baby

3.1 Congenital heart block

As noted above, the congenital heart block associated with neonatal lupus is considered a form of passively acquired autoimmune disease in which maternal autoantibodies to Ro (SS-A) and La (SS-B) cross the placenta and injure the previously normal fetal heart. While the non-cardiac manifestations of neonatal lupus are generally transient, and resolve with clearance of maternal antibodies from the infant's circulation at several months of age, damage to the conduction system and myocardial disease are irreversible.

Neonatal lupus is usually diagnosed in the presence of a slow heart rate discovered in a fetus or newborn in the absence of associated structural cardiac abnormalities. In utero, the peak onset of the diagnosis of bradycardia is between 18 and 24 weeks of gestation, corresponding to about six weeks after effective placental transport of maternal IgG antibodies begins. The precise mechanism is unknown. The degree of heart block may vary from first degree to third degree block, but most cases diagnosed in utero present with at least second degree or more advanced block. There is a high mortality rate, particularly in fetuses diagnosed with hydrops. Of all cases that are recognised with congenital heart block, the majority will have a pacemaker placed before reaching adulthood.

Babies identified to have a slow heart rate (<80 bpm) should be transferred  to the neonatal unit for a baseline ECG  to confirm the rhythm and a 24 hour ECG recording should be undertaken. The baby should be discussed with paediatric cardiology on-call team prior to transfer to the postnatal ward, to allow outpatient follow up to be arranged. Infants with a mean heart rate < 55 bpm, or any other abnormal cardiac findings should admitted urgently to the NICU, discussed with the on-call neonatology consultant and referred to cardiology as soon as possible. Even with a heart rate of < 55bpm, most neonates will be asymptomatic but if there are signs of low cardiac output, an intravenous infusion of isoprenaline may help to increase the heart rate temporarily before a pacemaker is inserted. Isoprenaline may be sourced from NICU at RHC.

3.2 Pancytopenia

Pancytopenia is rare but isolated thrombocytopenia more common. Most cases will resolve spontaneously over 4 – 6 months with disappearance of maternal antibody; treatment of severe thrombocytopenia or pancytopenia will be symptomatic. Intravenous immunoglobulin may be helpful. Significant abnormalities of the blood count should be discussed with a consultant.

All babies with blood dyscrasia or skin rash should be referred to rheumatology

References
  1. Friedman DM, Duncanson LJ, Glickstein J, Buyon JP. A review of congenital heart block. Images Paediatr Cardiol 2003;5:36–48.
  2. Pisoni CN, Brucato A, Ruffatti A et a. Failure of intravenous immunoglobulin to prevent congenital heart block. Findings of a multicenter, prospective observational study. Arthritis Rheum 2010;62:1147-52.
  3. Friedman DM, Kim MY, Copel JA, Davis C et al. for the PRIDE Investigators Utility of Cardiac Monitoring in Fetuses at Risk for Congenital Heart Block The PR Interval and Dexamethasone Evaluation (PRIDE) Prospective Study. Circulation 2008;117:485-493.
  4. Hutter D, Silverman ED, Jaeggi ET. The benefits of transplacental treatment of isolated congenital complete heart block associated with maternal anti-Ro ⁄ SSA antibodies: A review Scandinavian Journal of Immunology 2010;72:235–241
Editorial Information

Last reviewed: 23 October 2019

Next review: 01 October 2022

Author(s): Dr Helen Mactier, Neonatal Consultant; Dr Janet Gardner-Medwin, Consultant Paediatric Rheumatologist; Dr Ann Duncan, Consultant Obstetrician

Co-Author(s): Other persons consulted: Dr Karen McLeod Consultant Paediatric Cardiologist; Dr Lindsey Hunter, Consultant Paediatric Cardiologist; Dr Janet Brennand, Consultant Obstetrician; Peter Mulholland, Neonatal Pharmacist

Approved By: West of Scotland Neonatology Managed Clinical Network