Explaining the hepatitis B exposed-neonate pathway — OSCE

Candidate instructions (8-minute station)

You are the paediatric registrar in the postnatal ward. A mother who is known to be hepatitis B surface-antigen positive (found on her routine antenatal screening) has just delivered a healthy term baby boy by normal vaginal delivery. The baby is well, feeding, and afebrile. The midwife has asked you to come and talk to the parents because the baby is due to receive the hepatitis B vaccine and the hepatitis B immunoglobulin injection, and the parents — who were told during the pregnancy that the mother carries hepatitis B — are anxious and have questions. They do not understand why the baby needs "two injections for an infection he doesn't have", whether the baby is already infected, whether they can breastfeed, and whether this will affect a future pregnancy. [4]

Your tasks are: [6]

1. Explain in plain language what hepatitis B is, how it is passed from mother to baby at birth, and why the birth-dose vaccine and immunoglobulin within the first day are so important to the baby. [4] [6]
2. Explain what chronic hepatitis B means — that it is usually silent in childhood but can cause liver problems decades later — and why preventing it now changes the baby's whole future. [6]
3. Address the parents' questions about breastfeeding, whether the baby is already infected, and what the follow-up blood test at nine to twelve months will tell them. [4]
4. Explain how a future pregnancy would be protected — maternal antiviral tablets (tenofovir) in the third trimester for a mother with a high viral load, alongside the same birth-dose bundle. [4]

You are not expected to give exact doses to the parents; explain the plan in plain language and confirm that any decision is made by the neonatal team with the parents' consent. [6]

Examiner prompt to the actor (father)

"She's been told she carries hepatitis B, but she's never been sick a day in her life — so what does it even mean? And the baby's perfect, he's feeding, he's not jaundiced — why does he need two injections right now for something he hasn't got? Are you saying he's already infected? And she really wants to breastfeed — is that safe? And what about next time, if we have another baby?" [4]

Marking domains

• Frame and explanation (3): explains in plain, non-judgemental language that hepatitis B is a virus carried in the blood that can pass to the baby during the birth, that most carriers feel entirely well, and that the vaccine plus immunoglobulin given now work together — the vaccine builds the baby's own immunity while the immunoglobulin gives immediate protection during the gap — to prevent the baby from becoming a carrier. [4] [6]
• Chronic hepatitis B and why prevention matters (3): explains that if a newborn catches hepatitis B the body often does not clear it, so the baby can carry it silently for life, and that over decades that can lead to liver scarring or liver cancer; explains that preventing the infection now with the two injections gives the baby the best chance of never carrying the virus. [6]
• Breastfeeding and follow-up testing (2): confirms that breastfeeding is safe and encouraged once the baby has had the immunoglobulin and vaccine; explains that a blood test at around nine to twelve months will tell them whether the baby is protected (has made antibody) or has become a carrier — and that the baby is watched in the meantime. [4]
• Future pregnancy and reassurance (2): explains that for a future pregnancy, if the mother's viral load is high, she would be offered an antiviral tablet (tenofovir) in the last part of pregnancy to lower the virus, alongside the same birth-dose injections for the baby; addresses the father's questions without defensiveness and avoids blame or speculation about how the infection was acquired. [4] [1]

Model answer — the explanatory script

"Thank you for asking me in, and congratulations on your son — he's doing really well. I can see you've got some worries about the hepatitis B and the injections, so let me explain what it is and why we're acting now, because the two are connected." [4]

"Hepatitis B is a virus that lives in the blood and is carried by a lot of people who feel completely well — your partner has never been sick from it, and that's very common. The thing about hepatitis B is that it can pass to a baby during the birth, as the baby passes through. Now, here's the key point: if a newborn catches it, their body very often doesn't clear it — they carry it for life. And carrying it silently for decades can, later in adult life, lead to liver scarring or even liver cancer. So the reason we act in the first day of life is to stop your son from ever carrying the virus." [6]

"The way we do that is with two injections, and they work as a team. The first is the hepatitis B vaccine — that teaches your son's own immune system to fight the virus off, but it takes a few weeks to build up. The second is the hepatitis B immunoglobulin — that's a ready-made antibody, an immediate shield, that protects him during those first few weeks while the vaccine is getting to work. Together they prevent the vast majority of babies from becoming carriers. That's why both, now, in the first day — ideally within twelve hours — matter so much. He's not infected yet that we know of; we're preventing the infection taking hold." [4] [6]

"Now, your questions. Breastfeeding — yes, it's safe and we encourage it, once he's had the immunoglobulin and the vaccine. Is he already infected? We don't assume so — we'll check with a blood test at around nine to twelve months, which tells us whether he's made his own protective antibody, meaning he's protected, or whether he's carrying the virus. In the meantime he's watched and immunised on the normal schedule, and he can feed and grow like any baby. We'd rather give the injections and find at nine months he's protected than miss the window." [4]

"And for a next baby — because I know you'll be thinking about it — there's a clear pathway. If your partner's viral load — the amount of virus in her blood — is high, she would be offered an antiviral tablet called tenofovir in the last part of the pregnancy, which lowers the virus and makes it much less likely to pass across. Then the same two injections are given to the baby at birth. Together that gives the next baby the best possible protection. Your obstetric team will plan all of this with you for next time. None of this is anyone's fault — hepatitis B is common, and our job is simply to protect your son and any future children." [4] [1]