Underactive Thyroid Who Has Just Found Out She Is Pregnant — Free SCA Practice Case
Woman with an underactive thyroid who has just found out she is pregnant
Station Timer
Golden Minute
Initial Introduction
•Introduce yourself
•Ask an open question — "How can I help you today?"
•Listen — don't interrupt
•Catch early cues
Data Gathering
History, ICE & Diagnosis
Clinical Management
Diagnosis, Plan & Decisions
Safety Net
Follow-up & Close
Five cases are free: a live 12-minute consultation with an AI patient each, marked, and no card.
Materials for Candidate
Please review before starting the consultation
Full Name
Beatriz Santos
Age
32 years
Consultation Type
TelephoneAge
32
Situation
Telephone Consultation. Same day call.
Reason for Encounter
"I did a pregnancy test this morning and it's positive. I take a thyroid tablet every day and I need to know what to do about it."
Medical Records
- ●PMH: Autoimmune hypothyroidism for seven years. No other conditions.
- ●Medications: Levothyroxine 100 micrograms once daily, unchanged for three years. Combined pill stopped five months ago. No folic acid prescribed.
- ●Allergies: NKDA.
- ●Social: Non smoker. BMI 22.
Recent Notes
- ●Thyroid review, 3 months ago: TSH 1.6 mU/L (reference 0.4 to 4.0), free T4 15 pmol/L (reference 11 to 22).
Patient Script
For the friend playing the patient role
Character Overview: You are Beatriz Santos, a 32 year old manager of a high street bakery, ringing from your sofa after your shift (half past five to half past one). You speak quickly when you are anxious. You live with your husband Tiago. This is your first pregnancy.
You came off the pill about five months ago and said you would "see what happens". Your period is a week late and a test this morning was positive straight away. You are about five weeks, over the moon and terrified. Only Tiago knows.
You have had an underactive thyroid for seven years and take one tablet a day, almost never missing one. Your yearly blood check three months ago was "all fine" and you have never seen a hospital specialist. Your older sister Mariana has an underactive thyroid too and sees one. When she was pregnant two years ago she told you she was made to double her tablets.
You took your usual tablet this morning before the test. When it was positive you rang Mariana, who said to double yours straight away, so you took a second one. That is two today, and unless told otherwise you plan to carry on with two every morning. Afterwards you read online that too much thyroid hormone can be harmful too, and you are frightened you have hurt the baby. You do not know your sister's dose. You are polite, eager for a clear answer, and will follow it once it is explained.
Opening Sentence: "Hello, doctor, sorry to bother you. I did a pregnancy test this morning and it's positive, and I take a thyroid tablet every day. My sister told me to double it now I'm pregnant, so I've taken two today, but I'm worried I've done something to the baby by taking too much."
History if Asked (Data Gathering Phase)
- ●How far along she is: "About five weeks. My last period started five weeks ago, so I'm a week late. My cycle's always twenty eight days, regular as clockwork."
- ●Whether it was planned: "Sort of. We came off the pill five months ago and said we'd see what happens. We're really happy, just frightened of doing something wrong."
- ●Pain, bleeding or discharge: "No bleeding at all, no pain, no discharge."
- ●Sickness: "A little bit queasy first thing the last couple of days, but I haven't been sick. I kept both tablets down fine."
- ●Her thyroid history: "Underactive since I was twenty five. I was exhausted and freezing. They said it was my own body attacking the thyroid." No surgery or radioactive iodine, and she has never seen a hospital doctor about it.
- ●Her dose and last blood test: "It's 100, unchanged for about three years, twenty eight a month on repeat. The nurse did my yearly bloods three months ago, said it was perfect and to come back in a year."
- ●What she has taken today, and her plan (if asked how many tablets, or what she plans to do about the dose): "My normal one first thing, then another after the test, so two today, that's 200. I was going to take two every morning from now on, for the whole pregnancy, like Mariana." No extra tablets at any other time.
- ●Her sister (if asked): "Mariana's two years older and sees a hospital specialist. She told me they made her double her tablets in pregnancy, and her little boy's fine. I don't know her dose, only that she said 'double it'."
- ●How she takes it: "Every morning as soon as I'm up, with a big glass of water. My first coffee is about six and breakfast is half past eight. I hardly ever miss one."
- ●Other tablets, vitamins and supplements (only if asked about vitamins, supplements or anything over the counter): "Oh, yes, a supermarket multivitamin. I take it with my thyroid tablet and the same glass of water, so I only have to remember once." If asked what is in it: "Iron and calcium and zinc and lots of vitamins."
- ●Folic acid (only if asked): "No, I haven't started that. I know I should have."
- ●How she has been feeling lately: "Fine, really. A bit more tired in the last couple of weeks, which I put down to the early starts."
Ideas, Concerns, Expectations
Gating note: Beyond her opening sentence, Beatriz does not raise any of these herself. Each part comes out only when the doctor asks what she thinks, what is worrying her, or what she was hoping for.
- ●Ideas: Because her sister was told to double, she believes the same applies to her, and that more thyroid hormone is better for the baby. She had not thought you could take too much until she read it online. "Mariana said double it as soon as you know, and her little boy's perfect, so I thought that's just what you do."
- ●Concerns: Above all, that the extra tablet has harmed the baby. "I'd never forgive myself if something went wrong because of something I did. I read that too much can be bad as well. Have I hurt the baby?" She does not know whether to carry on with two or go back to one.
- ●Expectations: She wants to know whether she has harmed the baby and exactly what to take from tomorrow. "I just want someone to tell me exactly what to do."
If Asked: Medical History and Medications
Gating note: Beatriz answers each of these plainly when the doctor asks about it.
- ●Other health problems: "Nothing else. I've never had anything wrong apart from the thyroid."
- ●Medicines: "Just the thyroid tablet. Paracetamol now and then." She mentions the multivitamin only if asked about vitamins or supplements. No indigestion remedies. No allergies.
- ●Previous pregnancies and contraception: "No, this is my first." She was on the combined pill for years, nothing since.
- ●Family history: No thyroid problems except Mariana, no baby with spina bifida.
- ●Smoking, alcohol and caffeine: Never smoked. Wine at weekends, none since the test. Two or three coffees a day.
Social History and Lifestyle Impact
- ●Work: On her feet in a hot kitchen and shop from half past five until half past one. Nobody at work knows and she wants it kept that way until the twelve week scan.
- ●Home: Tiago knows and is thrilled.
- ●Privacy: "I don't want it all over the shop floor. Does anyone at the surgery or the hospital tell my work?"
If Asked: Associated Symptoms
Gating note: Beatriz answers these briefly and naturally, in one or two sentences.
- ●Negatives: No cold intolerance, dry skin, hair changes, weight change or bowel change. No palpitations, shakiness, sweating or racing heart, including since the second tablet. No neck lump or trouble swallowing. No headaches, dizziness or fever. Sleeping okay, happy but anxious. Passing urine a bit more often, no burning.
Responses to Management (The Negotiation Phase)
- ●If the doctor says she should not carry on with two tablets a day, explains why too much is not better, or says the extra tablet is unlikely to have harmed the baby:
- ●Reaction: Without a reason, doubtful: "But Mariana doubled and her baby is fine. Is she wrong?" Told her sister's dose may be set from her own blood tests, and that too much is no better than too little: "So I could have taken too much? What would that do?" Told to stop them to make up for it: "But I need them, don't I?" She settles if told one extra tablet is very unlikely to have caused harm: "So it's carrying on with two every day that's the problem, not today?"
- ●If the doctor says she will need a bit more than usual, gives a pattern, or says to wait for results:
- ●Reaction: "So I do need more? Is that all, two tablets on two days? Mariana said double." She accepts once told it is a smaller increase, matched to blood tests. Given a pattern, she asks which days, whether today counts as one, and whether she needs a new prescription, as she only gets twenty eight a month. Told to wait for results first: "So just one a day till then?" She accepts what she is told.
- ●If the doctor wants a blood test, a specialist opinion or to tell the midwife:
- ●Reaction: "Do I need to come in? I start at half past five tomorrow." She can go this afternoon or after her shift tomorrow. On a hospital doctor: "Is something wrong with the baby?" She settles if told it is a routine extra check for anyone on thyroid tablets. On the midwife: "I thought you weren't supposed to tell anyone until after the twelve week scan." She is reassured that early booking is usual and confidential.
- ●If the doctor asks about the multivitamin, or suggests folic acid and vitamin D instead:
- ●Reaction: "Oh, I take them together. Is that a problem?" Once it is explained: "How far apart do they need to be?" Offered folic acid and vitamin D alone: "Is that enough?" On folic acid: "Have I missed the important bit?" An honest, calibrated answer reassures her and she agrees to start today.
- ●If the doctor asks how she feels, mentions her sister, or suggests she should have checked first:
- ●Reaction: She opens up: "Will the baby be alright? Will it have a thyroid problem like me?" On her sister: "I only did what Mariana said. I panicked and wanted to do the best thing." Told she should have checked first, she is defensive and tearful: "I rang as soon as I got worried." She softens if told she has called at the right time and that this can be put right.
- ●If the doctor gives safety netting, asks her to examine herself, or explains the birth:
- ●Reaction: Vague netting such as "come back if there's a problem": "What sort of problem? Would a bit of spotting count?" Specific netting: "Okay. Can you say that again? I'll write it down." Asked to repeat the new routine, she does so correctly in her own words. She declines an examination: "I wouldn't know what I was feeling." After the birth: "Do I go back to one a day? Can I breastfeed?"
Mark Scheme
Domain 1: Data Gathering and Diagnosis
Domain 2: Clinical Management and Medical Complexity
Domain 3: Relating to Others
Clinical Learning Points
The Core Dilemma and the Model Plan
- ●Beatriz has well controlled autoimmune hypothyroidism on levothyroxine 100 micrograms daily and is about five weeks pregnant. On her sister's advice to "double" her tablets she has taken two today and plans two a day. She does need more levothyroxine, but not double, and she fears the extra tablet has harmed the baby.
- ●Model plan: tell her not to stop and not to keep doubling; explain that one extra tablet is very unlikely to have harmed the baby; raise the dose by about 25 to 30% now, without waiting for results or specialist advice; urgent thyroid function tests; specialist input; tell maternity services; fix the multivitamin timing; start folic acid; give specific safety netting and a named follow up.
- ●No examination is needed. A candidate who tries to examine her remotely gains nothing.
Why Thyroid Hormone Matters, and Why Too Little and Too Much Both Count
- ●In early pregnancy the baby depends on the mother's thyroid hormone. The British Thyroid Foundation (BTF) explains that women usually need higher doses of levothyroxine in pregnancy, especially in the first 20 weeks.
- ●NICE Clinical Knowledge Summaries (CKS, hypothyroidism, revised November 2024) say the dose must be adjusted as early as possible to reduce obstetric and neonatal complications. The BNF states that insufficient or excessive maternal thyroid hormone can harm the fetus, and RCOG Green-top Guideline 76 (April 2025) says the same of inadequate and excessive treatment, and of delay in starting or adjusting it.
- ●Keep the harm calibrated both ways: the aim is prompt correction, not alarm.
The Dose Decision on the Day
- ●Model answer, and the only route that passes: increase the dose now, by about 25 to 30%, without waiting for blood results or specialist advice. RCOG Green-top Guideline 76 advises women to increase the dose themselves as soon as the test is positive, by doubling it on two days each week (BTF summary). For her that is two tablets on two days a week, about 29% more. An NB Medical summary gives an extra 25 micrograms daily as the equivalent at doses up to 100 micrograms.
- ●CKS quotes 25 to 30% from as early as 4 to 6 weeks, and 25 to 50% in overt hypothyroidism, and the BTF patient leaflet gives 25 to 50 micrograms daily, so up to about 50% is also supported.
- ●CKS advises discussing dose changes urgently with an endocrinologist; that runs alongside the increase, not instead of it, and the tests and specialist advice then fine tune the dose.
- ●Today's two tablets can count as one of the two double days, with one more this week. This is a practical reading of that regimen, not a quoted rule.
- ●Not acceptable: keeping her on 100 micrograms until results or specialist advice come back, even for a day or two; leaving the dose to the booking appointment or next routine review; telling her to carry on with two tablets every day (a 100% increase); or telling her to skip tablets to make up for today.
- ●Her repeat is 28 tablets a month, so amend it for the higher dose. NICE NG145 does not cover thyroid disease in pregnancy.
The Extra Tablet and Her Sister's Advice
- ●The BTF and RCOG advice is itself a double dose on two days each week, so Mariana's "double" may be a shortened version of that. Do not criticise her.
- ●The emc summary of product characteristics for levothyroxine tablets (revised August 2023) says that in most overdoses there are no features, and gives 10 mg in an adult as the amount at which charcoal and a free T4 test are advised. One extra 100 microgram tablet is 0.1 mg. The half life is about a week, and signs of excess can take up to 5 days to appear.
- ●No guideline quantifies the risk from one extra tablet in pregnancy, so the wording should be calibrated: very unlikely to have harmed the baby, the blood tests will show where she stands, and the real concern is carrying on at double every day, because excess thyroid hormone can also harm the baby (BNF).
- ●Advise her to report a racing heart, tremor or sweating if it develops.
Thyroid Function Tests and Monitoring
- ●CKS advises checking thyroid function tests immediately once pregnancy is confirmed, read against pregnancy reference ranges because first trimester TSH runs lower. The BNF says to check when pregnancy is diagnosed, at booking, in the second and third trimesters and after delivery, with more frequent checks after any dose change.
- ●The BTF summary of RCOG Green-top Guideline 76 gives TSH and free T4 every 4 to 6 weeks until 20 weeks and again at 28 weeks. The mark scheme does not depend on the interval.
- ●Her antibodies are already known to be positive, so repeating them adds nothing. The BNF advises asking about biotin containing supplements, which can interfere with thyroid assays.
Specialist and Maternity Input
- ●CKS advises referring pregnant women with hypothyroidism to an endocrinologist and discussing dose changes urgently with one while awaiting review. Local routes vary (endocrinology, obstetric medicine, advice and guidance). The principle is that specialist input is set in motion during the call.
- ●NICE NG201 says antenatal care can begin by self referral or referral from a GP, with a first midwife booking by 10+0 weeks. If contact is later than 9+0 weeks the appointment should be offered within 2 weeks if possible.
- ●Telling maternity services at once means her condition and monitoring plan are recorded from the start. If the practice does not send the referral, tell her how to self refer. Her care is confidential, and neither the practice nor maternity services will tell her employer.
Taking Levothyroxine Well, Folic Acid and Vitamin D
- ●The BNF advises taking levothyroxine 30 to 60 minutes before breakfast, caffeine or other medicines. Beatriz does this well. The problem is the multivitamin with iron and calcium swallowed with the tablet.
- ●CKS advises separating levothyroxine from iron salts by at least 2 hours and from calcium carbonate or antacids by at least 4 hours. A combined product is safest at least 4 hours away. Folic acid and vitamin D alone do not interact, so replacing the multivitamin with those removes the problem.
- ●The NHS advises 400 micrograms of folic acid daily for the first 12 weeks, and starting at five weeks is still worthwhile. The 5 mg dose is for a neural tube defect history, diabetes, a BMI of 30 or more, sickle cell disease or thalassaemia, or certain epilepsy and HIV medicines. Hypothyroidism alone is not on the list and her BMI is 22, so 400 micrograms is the model, though offering 5 mg is not a fail.
- ●The NHS advises 10 micrograms of vitamin D daily. Avoid supplements containing vitamin A (retinol) and cod liver oil.
Early Pregnancy Safety Netting
- ●At five weeks the warning signs are vaginal bleeding, lower abdominal or pelvic pain (especially on one side) and shoulder tip pain. These need same day contact with the practice or the local early pregnancy assessment service.
- ●Collapse, sudden intense pain, or heavy bleeding with faintness needs 999 or A&E (NICE NG126; NHS advice).
- ●Thyroid specific triggers: repeated vomiting that stops her keeping the tablet down needs same day contact, because the dose will not be reliably absorbed. A racing heart, tremor or sweating should be reported.
- ●Tell her exactly when she will hear about her results and to ring if she has not heard.
After the Birth, and Talking to a Frightened Patient
- ●After the birth she returns to her pre pregnancy dose (the BTF summary of RCOG advice says 2 weeks after delivery), with thyroid tests around the 6 week check. The BNF states that the amount in breast milk is too small to affect newborn thyroid tests, so she can breastfeed. Every baby has a heel prick test that screens for an underactive thyroid.
- ●Lead with a clear answer (do not keep doubling, do not stop), then give the reason. Treat her wish to help the baby as sensible and her sister's advice as well meant. Do not make her feel reckless; she rang within hours of the test.
- ●Give the plan in words she can repeat: which days, how many tablets, when she will be phoned.
Common Mistakes in This Station
- ●Agreeing she should carry on with two tablets every day, or telling her to stop or skip tablets to make up for the extra one.
- ●Keeping her on the usual dose until blood results or specialist advice come back, or leaving the thyroid check until the booking appointment.
- ●Saying the extra tablet has certainly harmed the baby, or giving no answer to her fear.
- ●Never asking how many tablets she has taken, or about vitamins and supplements, so the multivitamin with iron and calcium taken with the levothyroxine is missed.
- ●Forgetting folic acid, or spending the call on contraception.
- ●Leaving without a route into maternity services, giving generic safety netting, or criticising her sister.
Mapped to the RCGP curriculum topic: Maternity and Reproductive Health.
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