Key learning points
- Immunisation is an effective public health measure for preventing disease and stopping the spread of disease from person to person – and this includes from mother to child
- The immunisation schedule in the UK has become increasingly complex. Midwives should ensure they keep up to date with the current programme
- Vaccination is a safe and effective way of making sure pregnant women are protected from the serious consequences of disease which can be exacerbated by pregnancy
Midwives are in an ideal position to discuss and promote immunisation with women and families throughout pregnancy and during the immediate postnatal period. They need to know where to access the most recent information on vaccines including the rationale for their use, in the online version of the Green Book.2
The World Health Organization (WHO) has recognised the value of vaccination in protecting against infectious diseases. It is second only to clean water in its overall contribution to global health.3
Midwives have always been involved in providing advice on immunisation, educating parents about what vaccines are available and recommended for their babies.
It has always been important to use these opportunities during pregnancy to make sure women get the best advice for the future health of their babies. It has only been in the last few years that providing the actual vaccines has been part of routine antenatal screening.5
The schedule in the UK routinely includes vaccines to protect against 19 different infections. The schedule changes as new vaccines are developed and understanding evolves about how they can affect the burden of disease at different stages of life. The schedule is updated regularly and is available from the Public Health England (PHE) website.4 Midwives need to know where to find information and where they can recommend parents look. The box at the end gives resources.
Infection in pregnancy
Pregnancy causes changes to the normal immune response, which may result in an altered susceptibility for the woman and foetus, with a greater risk of serious outcomes from certain infections.6
Women and midwives may well have anxieties about actively immunising during pregnancy because of the potential teratogenic effects of vaccines to the foetus.
The majority of vaccines will not have been actively tested on pregnant women because of the potential for risk and the information available from the manufacturers will advise caution in pregnancy because of the lack of available safety information and not because of any proven risk.
As a response to these issues, the WHO Global Advisory Committee for Vaccine Safety (GACVS) has reviewed and evaluated the evidence on vaccines given in pregnancy. It considered evidence from studies where vaccines were given intentionally as a result of a particular threat and also on post-vaccination surveillance studies where vaccines had been given inadvertently. The review, published in 2014, discussed the risks and benefits of vaccination in certain situations and for particular infections. The report showed no evidence of adverse pregnancy outcomes from vaccination with inactivated vaccines and therefore, where it is appropriate, vaccination should be available in pregnancy. The report also concluded that although there is a theoretical risk to the foetus in using live vaccines, there is a substantial body of literature describing their safety.7
Vaccination in pregnancy works first to protect the mother. Some infections, for example influenza, are known to cause more serious disease and complications in pregnancy.
The foetus can also be affected by the teratogenic effects of the mother getting an infection. The infant will also benefit from the passive immunity acquired from giving the mother vaccines in pregnancy and boosting the antibodies that cross the placenta and provide protection in the first few months.
The benefits of vaccination are always assessed in relation to the specific threat caused by the disease in comparison to perceived risks, and the feasibility of ensuring the vaccine is available to all pregnant women. PHE publishes a useful leaflet on pregnancy and vaccination.8
Specific vaccines recommended in pregnancy
Influenza
Influenza is more likely to cause severe illness in pregnant women than in those who are not pregnant. The reason for this is thought to be the normal physiological changes that occur during pregnancy; altered heart rate, oxygen consumption and immune response.
The vaccine is offered during the flu season (October to February) to help protect the woman from infection. It can be given at any stage of pregnancy. The vaccine helps protect against influenza and its complications, including maternal pneumonia, premature birth, low birth weight and, in rare cases, maternal mortality.
Influenza can also be serious for neonates and passive immunity from vaccinating women also protects the infant.9,10
Pertussis
There has been an increase in pertussis infections in many countries. Waning immunity from the vaccine and natural infection mean that boosting of immunity is required for lasting protection. The disease can be fatal, particularly in babies too young to be protected by the primary immunisation schedule. Maternal vaccination boosts the maternal antibodies that cross the placenta and provide protection to the baby for the first few months. The vaccine is offered in the second trimester from 16 weeks of pregnancy. In practice, the foetal anomaly scan at 20 weeks provides an ideal opportunity, although the vaccine can be given after this and midwives should always check the vaccine has been offered.11
Screening for MMR status
The measles, mumps and rubella (MMR) vaccine was introduced into the UK in 1988. Rubella is normally a mild illness but can cause serious complications such as terminations and congenital rubella syndrome if women contract the disease in the early stages of pregnancy. The vaccine is very effective, with one dose providing protection in 95% to 100% of cases. Infections in the UK are now very rare since the introduction of universal vaccination. Those most at risk are women born overseas and particularly those from rubella endemic countries. Ideally, women should be asked about their vaccination history during the antenatal period to check they have had the recommended two doses of vaccine pre-conception. MMR is a live vaccine and is not recommended during pregnancy, but women should be reminded to go to their GP surgery postpartum and have missing doses to protect them in future pregnancies from rubella.
Hepatitis screening and vaccination
All babies born after August 2017 in the UK receive hepatitis B vaccine as part of a hexavalent vaccine that also includes diphtheria, tetanus, polio, pertussis and Hib. It is given to infants at two, three and four months of age.12
Antenatal policy for pregnant women includes screening women for the presence of hepatitis B infection. The infants of infectious women are at risk of acquiring infection at the time of delivery and should be started on a course of hepatitis B vaccine at birth. Susceptible infants should receive a monovalent hepatitis B vaccine at birth and also at one month; this is in addition to the vaccine they receive as part of the routine injection at two, three and four months.
Hepatitis B vaccine is very effective and can protect these infants from contracting chronic hepatitis B in 90% of cases. They should also have a dose of vaccine with their 12-month injections, alongside a blood test to check they have not become infected. Midwives are in an ideal position to make sure that the importance of this vaccine is explained to the woman and her family and that this information is passed on the GP surgery and health visiting teams to make sure the course is completed.
References
1 PHE. Health matters: giving every child the best start in life. 2016
2 PHE. Immunisation against infectious diseases (The Green Book) gov.uk/government/collections/immunisation-against-infectious-disease-the-green-book
3 Andre F, Booy R, Bock H et al. Vaccination greatly reduces disease, disability, death and inequity. WHO Bulletin worldwide 2008 who.int/bulletin/volumes/86/2/07-040089/en/#R47%23R47
4 PHE. Current Immunisation schedule gov.uk/government/publications/the-complete-routine-immunisation-schedule
5 NHS. Screening programmes Continuing Professional Development for Screening, resource cards 2016 cpd.screening.nhs.uk/resource-cards
6 Jamieson D, Theiler R, Rasmussen S. Emerging infections and pregnancy. Emerging Infectious Diseases Journal 2006;12:1638-43
7 WHO GAVS. Safety of Immunization during Pregnancy: A review of the evidence 2014 who.int/vaccine_safety/publications/safety_pregnancy_nov2014.pdf
8 PHE. Pregnancy and how to protect your baby 2017 gov.uk/government/publications/pregnancy-how-to-help-protect-you-and-your-baby
9 RCOG. Influenza vaccination in pregnancy 2014 rcog.org.uk/en/guidelines-research-services/guidelines/influenza-vaccination-in-pregnancy/
10 PHE. Influenza vaccination in pregnancy guidance for health care professionals 2014 gov.uk/government/publications/influenza-vaccination-in-pregnancy-advice-for-healthcare-professionals
11 PHE. Vaccination against pertussis whooping cough for pregnant women 2016 gov.uk/government/publications/vaccination-against-pertussis-whooping-cough-for-pregnant-women
12 PHE. Hexavalent combination vaccination programme 2017 gov.uk/government/publications/hexavalent-combination-vaccine-programme-guidance
13 Oxford Vaccine Group. Vaccines in development: Respiratory Syncytial Virus (RSV) and Group B streptococcus 2016 ovg.ox.ac.uk/vaccines-in-development
Resources
