Obstetrics: Medical Problems

• Prescribing: Prescribing in Pregnancy and Breastfeeding
• Blood pressure: Hypertension in Pregnancy | Pre-eclampsia | HELLP Syndrome
• Metabolic and liver: Gestational Diabetes | Pre-existing Diabetes | Obstetric Cholestasis | Acute Fatty Liver of Pregnancy | Thyroid Disease in Pregnancy
• Blood: Anaemia in Pregnancy | VTE in Pregnancy | Rhesus Disease and Red Cell Antibodies
• Other conditions: Epilepsy in Pregnancy | Other Medical Conditions | Obesity in Pregnancy
• Infections: Group B Streptococcus | Chickenpox in Pregnancy | Rubella, CMV, Toxoplasma, Parvovirus and Listeria | HIV, Hepatitis B, Syphilis and Herpes
• Revision: Drug Reference Table | Spot the Diagnosis | Exam-style Scenarios | Key Points | Guidelines and Further Reading

🤰 Medical problems in pregnancy — pre-eclampsia, gestational diabetes, VTE and infection are common and can harm both mother and baby. In the UK, most maternal deaths are now from medical causes (heart disease, VTE, epilepsy, sepsis, mental health), not obstetric ones. Treat pregnant women as you would anyone else — don't withhold essential drugs or scans — but choose treatments safe for the baby, and involve the obstetric team early.
Your four questions for every patient: How many weeks pregnant is she? Is this a pregnancy-specific condition (pre-eclampsia, cholestasis, AFLP) or a pre-existing one? Is the treatment safe in pregnancy and breastfeeding? Does she need delivery planning?

Prescribing in Pregnancy and Breastfeeding

• Principles:
  • Use drugs only when the benefit outweighs the risk; prefer well-established drugs at the lowest effective dose.
  • The first trimester (especially 3–8 weeks — organ formation) carries the highest risk of malformations.
  • Don't stop essential medicines suddenly (antiepileptics, antidepressants, asthma inhalers) — the illness usually poses a greater risk.
  • Check the BNF and UKTIS (UK Teratology Information Service); "Best Use of Medicines in Pregnancy" (bumps) patient leaflets.

• Generally safe — paracetamol; penicillins, cephalosporins, erythromycin; labetalol, nifedipine, methyldopa; LMWH; insulin and metformin; levothyroxine; lamotrigine and levetiracetam; inhaled steroids and salbutamol; prednisolone; azathioprine; hydroxychloroquine; sertraline (most SSRIs).
• Breastfeeding — most drugs are compatible. Check the BNF or the UK Drugs in Lactation Advisory Service. Avoid, for example, amiodarone, lithium (specialist), cytotoxic drugs, high-dose aspirin, and codeine (risk of neonatal opioid toxicity in "ultra-rapid metabolisers").

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Hypertension in Pregnancy

• Prevention — aspirin 75–150 mg at night from 12 weeks until birth (NICE NG133) for women with:
  • One high-risk factor:
    • Hypertensive disease in a previous pregnancy.
    • Chronic kidney disease.
    • Autoimmune disease (SLE, antiphospholipid syndrome).
    • Type 1 or type 2 diabetes.
    • Chronic hypertension.
  • Two or more moderate-risk factors:
    • First pregnancy.
    • Age 40 or over.
    • Pregnancy interval over 10 years.
    • BMI 35 or more at booking.
    • Family history of pre-eclampsia.
    • Multiple pregnancy.
• Treatment — target BP 135/85 or below:
  • Labetalol first line (avoid in asthma).
  • Nifedipine (modified-release) second line, or first line if labetalol is unsuitable (e.g. Black African or Caribbean women — consider nifedipine first).
  • Methyldopa third line — stop within 2 days after birth (depression).
  • Chronic hypertension — switch ACE inhibitors, ARBs and thiazides (within 2 days of a positive test).
• Monitoring — BP and urine; bloods (FBC, U&E, LFTs) for pre-eclampsia; fetal growth scans.
• After birth:
  • Many need treatment for days to weeks.
  • Enalapril (and amlodipine or nifedipine) are suitable when breastfeeding; avoid diuretics if breastfeeding.
  • Review at 6–8 weeks; raised lifetime risk of hypertension, heart disease and stroke.

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Pre-eclampsia

• What it is: A placental disorder (poor early placental invasion) causing widespread blood vessel damage. Affects about 3–5% of pregnancies; the cure is delivery of the placenta.
• Definition (NICE) — new hypertension (140/90 or more) after 20 weeks with one or more of:
  • Proteinuria — urine protein:creatinine ratio 30 mg/mmol or more (or ACR 8 mg/mmol or more).
  • Kidney — creatinine 90 µmol/L or more.
  • Liver — raised transaminases (ALT or AST over 70), right upper quadrant or epigastric pain.
  • Neurological — eclampsia, confusion, severe headache, visual disturbance (scotomas, blindness), stroke, clonus.
  • Blood — low platelets (under 150), haemolysis, DIC.
  • Uteroplacental dysfunction — fetal growth restriction, abnormal Doppler, stillbirth.
• Symptoms to warn about — severe headache, blurred vision or flashing lights, pain under the ribs, vomiting, sudden swelling of the face, hands or feet.
• Tests:
  • PlGF-based tests (placental growth factor, or the sFlt-1/PlGF ratio) — help rule pre-eclampsia in or out between 20 and 36+6 weeks.
  • FBC, U&E, LFTs; urine PCR.
  • Fetal assessment — growth scan, umbilical artery Doppler, amniotic fluid, CTG.
• Management:
  • Admit if severe hypertension or any concerns; frequent BP checks; fluid balance (restrict to about 80 mL/hour in severe pre-eclampsia — risk of pulmonary oedema).
  • Antihypertensives — labetalol, nifedipine; IV labetalol or hydralazine for severe hypertension.
  • Magnesium sulfate — for severe pre-eclampsia (to prevent seizures) or eclampsia.
  • Corticosteroids if delivery is likely before 34+6 weeks.
  • Timing of birth:
    • Under 34 weeks — continue the pregnancy if stable (with steroids) unless there are indications for earlier delivery.
    • 34–36+6 weeks — usually continue with close monitoring if stable; deliver if concerns.
    • 37 weeks or more — deliver (within 24–48 hours).
    • Deliver at any gestation for: uncontrolled severe hypertension, worsening blood or liver tests, eclampsia, pulmonary oedema, abruption, or fetal compromise.
  • Vaginal birth is usually possible; epidural helps BP control.
• Complications:
  • Mother — eclampsia, stroke (intracranial haemorrhage), HELLP, pulmonary oedema, AKI, DIC, abruption, liver rupture, PRES (posterior reversible encephalopathy).
  • Baby — growth restriction, preterm birth, stillbirth.
• Can occur after birth — up to about 6 weeks (most in the first week).

⚠️ Safety Pearl: Headache, visual disturbance, epigastric pain or vomiting in the second half of pregnancy or after birth — check BP and urine straight away. Pre-eclampsia can be life-threatening even with "only moderately" raised BP.

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HELLP Syndrome

• What it is: A severe form of pre-eclampsia — Haemolysis, Elevated Liver enzymes, Low Platelets.
• Features:
  • Epigastric or right upper quadrant pain, nausea, vomiting, malaise — often mistaken for gastritis or gallstones.
  • BP may be only mildly raised; proteinuria may be absent.
  • Can occur after birth.
• Tests: Low platelets; raised ALT/AST; haemolysis (raised LDH, low haptoglobin, fragments on film, raised bilirubin); clotting.
• Complications: DIC, abruption, AKI, liver haematoma or rupture (shock, severe pain), pulmonary oedema.
• Management:
  • Stabilise and deliver — BP control, magnesium sulfate, correct clotting (platelets if very low, especially before caesarean or epidural).
  • Steroids for fetal lungs if preterm (only if delay is safe).
  • HDU care; usually improves within 48–72 hours after birth.
• Differentials — acute fatty liver of pregnancy, TTP, HUS, viral hepatitis.

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Gestational Diabetes

• What it is: High glucose first found in pregnancy, from placental hormones causing insulin resistance. Affects about 1 in 20 pregnancies.
• Risk factors (offer OGTT at 24–28 weeks — NICE NG3):
  • BMI over 30.
  • Previous baby weighing 4.5 kg or more.
  • Previous gestational diabetes — offer early testing (OGTT soon after booking, or self-monitoring), and again at 24–28 weeks if normal.
  • First-degree relative with diabetes.
  • Family origin with a high prevalence of diabetes (South Asian, Black Caribbean, Middle Eastern).
  • Also consider if glycosuria (2+ once or 1+ twice) or polyhydramnios or a large baby on scan.
• Diagnosis — 75 g oral glucose tolerance test:
  • Fasting glucose 5.6 mmol/L or more, or
  • 2-hour glucose 7.8 mmol/L or more.
• Glucose targets (self-monitoring):
  • Fasting — under 5.3 mmol/L.
  • 1 hour after meals — under 7.8, or 2 hours after meals — under 6.4.
  • On insulin — keep above 4.0.
• Treatment (step up):
  • Diet and exercise (dietitian; low glycaemic index; walking after meals).
  • Metformin if targets not met within 1–2 weeks.
  • Insulin (added or instead of metformin) if targets still not met, or if metformin isn't suitable.
  • Insulin straight away if fasting glucose is 7.0 or more at diagnosis; consider if 6.0–6.9 with complications (e.g. a large baby or polyhydramnios).
  • Glibenclamide if metformin is declined or not tolerated and insulin refused.
• Monitoring — growth scans (macrosomia, polyhydramnios).
• Birth — offer birth by 40+6 weeks (earlier if complications or on insulin per local policy).
• Risks:
  • Baby — macrosomia, shoulder dystocia, birth injury, polyhydramnios, stillbirth, neonatal hypoglycaemia, jaundice, breathing problems.
  • Mother — pre-eclampsia, caesarean; type 2 diabetes later (up to half within 10 years).
• After birth:
  • Stop glucose-lowering treatment straight after birth.
  • Baby — feed within 30–60 minutes; check glucose at 2–4 hours.
  • Mother — fasting glucose at 6–13 weeks (or HbA1c from 13 weeks); then HbA1c yearly; lifestyle advice; early testing next pregnancy.

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Pre-existing Diabetes

• Higher risks — miscarriage, congenital abnormalities (heart, neural tube — linked to high HbA1c), pre-eclampsia, stillbirth, macrosomia, preterm birth, neonatal hypoglycaemia.
• Before pregnancy:
  • HbA1c under 48 mmol/mol; avoid pregnancy if over 86.
  • Folic acid 5 mg.
  • Stop statins, ACE inhibitors and ARBs (at conception); switch non-insulin drugs except metformin.
  • Retinal and kidney assessment.
• In pregnancy:
  • Joint diabetes–antenatal clinic every 1–2 weeks.
  • Type 1 — offer continuous glucose monitoring (CGM); hybrid closed-loop systems. Watch for hypoglycaemia (worse in the first trimester) and DKA (can occur at lower glucose levels).
  • Aspirin from 12 weeks.
  • Retinal screening at booking and 28 weeks (and 16–20 weeks if retinopathy) — retinopathy can worsen.
  • Fetal heart scan; serial growth scans from 28 weeks.
  • Birth — between 37+0 and 38+6 weeks (earlier if complications); IV insulin–glucose (variable rate) during labour.
• After birth — reduce insulin to pre-pregnancy doses (risk of hypoglycaemia, especially when breastfeeding).
• See the Diabetes chapter.

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Obstetric Cholestasis

• Intrahepatic cholestasis of pregnancy (ICP) — reduced bile flow in the liver, usually in the third trimester; more common in South Asian women and with twins or IVF.
• Features:
  • Itching without a rash, especially of the palms and soles, often worse at night.
  • Dark urine, pale stools; jaundice is uncommon.
  • Skin may show scratch marks only.
• Diagnosis (RCOG 2022):
  • Raised serum bile acids — 19 µmol/L or more, with itching and no other cause.
  • LFTs often raised (ALT); exclude hepatitis, gallstones, pre-eclampsia, AFLP.
  • Normal range ALT is lower in pregnancy.
• Risks: Stillbirth (raised mainly when bile acids are 100 µmol/L or more), preterm birth, meconium-stained fluid.
• Management:
  • Monitor bile acids and LFTs (weekly to monthly).
  • Itch relief — emollients with menthol, antihistamines (chlorphenamine for sleep). Ursodeoxycholic acid may help itch but doesn't reduce stillbirth.
  • Timing of birth (RCOG) — based on peak bile acids:
    • 100 or more — offer birth at 35–36 weeks.
    • 40–99 — offer birth at 38–39 weeks.
    • 19–39 (with no other risk factors) — consider birth from 40 weeks.
• After birth — itching settles within days; check LFTs at least 4 weeks after birth. High recurrence (up to 90%) in future pregnancies; may recur with combined pill.

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Acute Fatty Liver of Pregnancy

• What it is: A rare, life-threatening liver failure in the third trimester (or just after birth). Linked to a fetal fatty acid oxidation defect (LCHAD deficiency).
• Features:
  • Nausea, vomiting, abdominal pain, malaise, headache.
  • Jaundice; polydipsia (diabetes insipidus).
  • Confusion (encephalopathy).
• Tests:
  • Raised bilirubin and transaminases.
  • Hypoglycaemia (a key clue).
  • Coagulopathy (raised INR, low fibrinogen).
  • AKI; raised urate, ammonia, white cell count.
  • Swansea criteria help diagnosis.
• Management: Immediate delivery after stabilisation; correct glucose and clotting; HDU/ICU; liver unit involvement. Test the baby for LCHAD deficiency.

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Thyroid Disease in Pregnancy

• Normal changes — hCG lowers TSH in the first trimester; use trimester-specific ranges and free T4.
• Hypothyroidism:
  • Poorly treated hypothyroidism is linked to miscarriage, pre-eclampsia, and lower IQ in the child.
  • Increase levothyroxine by 25–50% (or take two extra doses a week) as soon as pregnancy is confirmed.
  • Aim for TSH in the trimester range (e.g. under 2.5 mU/L in the first trimester); check TFTs every 4–6 weeks.
  • Return to the pre-pregnancy dose after birth.
• Hyperthyroidism:
  • Gestational thyrotoxicosis — from high hCG (with hyperemesis, twins, molar pregnancy); mild, settles by 16–20 weeks; usually no antithyroid drugs.
  • Graves' disease — propylthiouracil in the first trimester, then switch to carbimazole (PTU can cause liver toxicity); lowest dose to keep free T4 at the upper end of normal. Radioiodine is contraindicated.
  • TSH receptor antibodies cross the placenta — fetal and neonatal thyrotoxicosis; monitor fetal heart rate and growth; check the baby.
• Postpartum thyroiditis — 3–6 months after birth: a hyperthyroid phase (beta-blocker only) then a hypothyroid phase (levothyroxine if symptomatic); often anti-TPO positive; recurs.

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Anaemia in Pregnancy

• Definition (UK) — Hb under 110 g/L in the first trimester, under 105 in the second and third, and under 100 after birth.
• Iron deficiency — the commonest cause (increased demand, poor stores, short pregnancy intervals, heavy periods before pregnancy).
• Management:
  • Check ferritin if needed (ferritin under 30 µg/L means iron deficiency).
  • Oral iron (e.g. ferrous sulfate 200 mg once daily, or on alternate days to improve absorption); recheck Hb in 2–4 weeks (should rise).
  • IV iron — if oral iron isn't tolerated or doesn't work, or late in pregnancy (after the first trimester).
  • Treat before birth — it reduces the need for transfusion after PPH.
• Other causes — folate deficiency (twins, poor diet, antiepileptics), B12 deficiency, haemoglobinopathies (sickle cell, thalassaemia — specialist joint care).
• Sickle cell disease — high risk of crises, VTE, pre-eclampsia, growth restriction: folic acid 5 mg, aspirin, LMWH, penicillin prophylaxis, hydroxycarbamide stopped before conception.

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VTE in Pregnancy

• Why it matters: Thrombosis and thromboembolism are among the leading direct causes of maternal death in the UK (MBRRACE-UK). Pregnancy raises VTE risk about 4–6 times, and it's highest after birth (especially after caesarean).
• Risk assessment (RCOG) — at booking, on any admission, and after birth:
  • Previous VTE (highest risk); thrombophilia.
  • Age over 35; BMI 30 or more; smoking; parity 3 or more.
  • Medical conditions (cancer, heart failure, SLE, IBD, sickle cell, nephrotic syndrome).
  • Pre-eclampsia; IVF; multiple pregnancy.
  • Caesarean (especially in labour), prolonged labour, PPH over 1 litre, preterm birth, stillbirth.
  • Immobility, dehydration, hyperemesis, long-haul travel, infection.
• Prophylaxis — LMWH (dosed by booking weight):
  • Previous VTE (not provoked by major surgery) — throughout pregnancy and 6 weeks after.
  • 4 or more risk factors — from the first trimester; 3 — from 28 weeks.
  • After birth — 10 days if 2 or more risk factors (or after any caesarean in labour); 6 weeks if high risk.
  • Stop LMWH when labour starts or 12–24 hours before planned birth (epidural timing).
• Diagnosis:
  • D-dimer is not useful (raised in normal pregnancy).
  • DVT — compression duplex ultrasound (left leg more common; consider iliac vein thrombosis if back or buttock pain).
  • PE — ECG and chest X-ray first; if leg symptoms, do a Doppler first (a DVT avoids chest imaging). Then CTPA or V/Q scan — both have very low radiation doses for the baby; V/Q gives less radiation to the mother's breasts, CTPA slightly less to the fetus.
  • Start LMWH while waiting for tests unless contraindicated.
• Treatment:
  • Treatment-dose LMWH (by weight) for the rest of the pregnancy and at least 6 weeks after birth (at least 3 months in total).
  • Warfarin is fine after birth (and with breastfeeding) — not in pregnancy. Avoid DOACs in pregnancy and breastfeeding.
  • Massive PE with shock — thrombolysis can be given.
  • Anti-Xa monitoring only in extremes of weight or kidney impairment.

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Rhesus Disease and Red Cell Antibodies

• What it is: An RhD-negative mother exposed to RhD-positive fetal blood makes anti-D antibodies. In a later pregnancy, these cross the placenta and destroy fetal red cells — haemolytic disease of the fetus and newborn (anaemia, hydrops, jaundice, kernicterus, stillbirth).
• Prevention — anti-D immunoglobulin for RhD-negative women without existing anti-D antibodies:
  • Routine antenatal prophylaxis (RAADP) — at 28 weeks (single 1,500 IU dose) or at 28 and 34 weeks (two doses).
  • After birth — if the baby is RhD-positive (cord blood test), within 72 hours, with a Kleihauer test to measure how much fetal blood entered the mother (more anti-D if a large bleed).
  • Sensitising events, within 72 hours:
    • Under 12 weeks — ectopic (surgical), surgical miscarriage, abortion from 10 weeks, molar pregnancy.
    • From 12 weeks — miscarriage, bleeding, abdominal trauma, CVS or amniocentesis, ECV, intrauterine death.
    • Under 20 weeks — 250 IU; 20 weeks or more — 500 IU plus a Kleihauer test.
  • Cell-free fetal DNA testing (from the mother's blood) can show whether the baby is RhD-negative, so anti-D can be avoided (NICE DG25).
• Other antibodies — anti-c and anti-Kell (Kell also suppresses fetal red cell production) can cause severe disease.
• If antibodies are present — regular titres; fetal medicine referral; middle cerebral artery Doppler (high peak velocity = fetal anaemia); intrauterine transfusion; planned delivery; neonatal care (phototherapy, exchange transfusion).

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Epilepsy in Pregnancy

• Epilepsy (including SUDEP) is a major cause of indirect maternal death in the UK — often linked to stopping medication.
• Before pregnancy:
  • Valproate — must not be used in women who could become pregnant unless a pregnancy prevention programme is in place (MHRA). Switch with specialist support before conception.
  • Topiramate — also has a pregnancy prevention programme.
  • Lamotrigine and levetiracetam have the lowest risks.
  • Folic acid 5 mg.
• In pregnancy:
  • Don't stop drugs — seizures are risky for mother and baby.
  • Lamotrigine levels fall (doses often need increasing); review levels or symptoms.
  • Anomaly scan; growth scans in some.
  • Seizures in labour — treat with benzodiazepines; a first seizure after 20 weeks is eclampsia until proven otherwise.
• After birth:
  • Vitamin K for the baby (as for all babies).
  • Breastfeeding is encouraged with most antiepileptics.
  • Safety — change nappies on the floor, don't bathe the baby alone, sleep deprivation triggers seizures (share night feeds).
  • Reduce lamotrigine to pre-pregnancy dose over days–weeks.

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Other Medical Conditions

• Heart disease — the leading overall cause of maternal death in the UK (cardiomyopathy, MI, aortic dissection):
  • Take chest pain, breathlessness lying flat, palpitations and collapse seriously — ECG, troponin, imaging.
  • Peripartum cardiomyopathy — heart failure in the last month of pregnancy or months after birth.
  • Pulmonary hypertension, severe mitral stenosis and Marfan syndrome with aortic dilatation are very high risk.
• Asthma — continue all inhalers; oral steroids if needed; poorly controlled asthma is the bigger risk.
• SLE and antiphospholipid syndrome — aspirin (and LMWH in APS); continue hydroxychloroquine; anti-Ro antibodies cause congenital heart block (fetal echo monitoring).
• CKD — see the CKD chapter (pre-eclampsia risk; aspirin).
• Migraine — often improves; paracetamol, metoclopramide; sumatriptan acceptable; low-dose aspirin or propranolol for prevention.
• Inflammatory bowel disease — keep in remission; most drugs safe except methotrexate.
• Mental health — continue antidepressants if needed; perinatal mental health team for serious illness (see the Labour, Birth and Postnatal Care chapter).
• Substance misuse — opioid substitution (methadone, buprenorphine) safer than withdrawal; neonatal abstinence syndrome; safeguarding.
• Cancer in pregnancy — breast cancer most often; surgery and chemotherapy (after the first trimester) can be given.

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Obesity in Pregnancy

• BMI 30 or more — raised risk of miscarriage, congenital anomalies, gestational diabetes, pre-eclampsia, VTE, stillbirth, macrosomia, shoulder dystocia, caesarean, wound infection and PPH.
• Care:
  • Folic acid 5 mg and vitamin D.
  • OGTT at 24–28 weeks.
  • Aspirin if BMI 35 or more plus another moderate risk factor.
  • VTE risk assessment (LMWH if needed — dose by weight).
  • BMI 40 or more — antenatal anaesthetic review; serial growth scans (fundal height is unreliable); birth in an obstetric unit.
  • Don't try to lose weight in pregnancy, but avoid excess weight gain; healthy diet and activity.
• After bariatric surgery — wait 12–18 months before pregnancy; nutritional deficiencies (iron, B12, folate, vitamin D); avoid OGTT after gastric bypass (dumping) — use glucose monitoring instead.

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Group B Streptococcus

• What it is: Group B streptococcus (GBS) lives harmlessly in the gut and vagina of about 1 in 4 women, but can cause serious early-onset infection in newborns (sepsis, pneumonia, meningitis).
• Screening: Not routinely offered in the UK (risk-based approach); found incidentally on swabs or urine.
• Intrapartum antibiotic prophylaxis (RCOG) — IV benzylpenicillin as soon as possible in labour (3 g, then 1.8 g every 4 hours; clindamycin if allergic) for:
  • GBS found in this pregnancy (swab or urine).
  • Previous baby with GBS disease.
  • Preterm labour (before 37 weeks).
  • Fever in labour (38 °C or more) — broad-spectrum antibiotics covering GBS.
  • GBS in a previous pregnancy — offer prophylaxis or testing at 35–37 weeks.
• GBS bacteriuria — treat at diagnosis and in labour.
• Not needed for planned caesarean before labour with intact membranes.
• Baby — observe at-risk babies (NICE NG195 neonatal infection); low threshold for antibiotics.

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Chickenpox in Pregnancy

• Risks:
  • Mother — varicella pneumonia, hepatitis, encephalitis (more severe in pregnancy, especially smokers).
  • Fetus — fetal varicella syndrome (skin scarring, limb defects, eye and brain problems) if infected before 20 weeks (about 1–2%).
  • Newborn — severe neonatal varicella if the mother develops the rash from 5 days before to 2 days after birth.
• Exposure in a pregnant woman:
  • Ask about past chickenpox; if unsure, check VZV IgG urgently.
  • Not immune — oral antiviral prophylaxis (aciclovir or valaciclovir) from day 7 to day 14 after exposure (UKHSA); VZIG is reserved for some cases.
  • Avoid contact with other pregnant women and newborns until 21 days after exposure (28 if VZIG given).
• Chickenpox in pregnancy:
  • Oral aciclovir if she presents within 24 hours of the rash and is 20 weeks or more (consider before 20 weeks).
  • Admit if chest symptoms, neurological symptoms, haemorrhagic rash, severe illness or immunosuppression — IV aciclovir.
  • Fetal medicine referral for scans (fetal varicella syndrome).
  • Neonatal team if near term.
• Shingles in pregnancy — low risk to the baby (antibodies already present).

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Rubella, CMV, Toxoplasma, Parvovirus and Listeria

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HIV, Hepatitis B, Syphilis and Herpes

• HIV:
  • Antiretroviral therapy for all; continue or start as early as possible.
  • Viral load under 50 copies/mL at 36 weeks — vaginal birth can be planned.
  • Higher viral load — planned caesarean; IV zidovudine during labour or caesarean if viral load over 1,000 or unknown.
  • Baby — antiretroviral PEP (2–4 weeks); HIV PCR tests.
  • Feeding — formula is safest; women with an undetectable viral load who choose to breastfeed can be supported with close monitoring (BHIVA).
  • With good care, transmission is under 0.5%.
• Hepatitis B:
  • Baby gets hepatitis B vaccine within 24 hours of birth (then at 4, 8, 12 and 16 weeks and 1 year, with a blood test at 1 year).
  • Hepatitis B immunoglobulin as well for high-risk babies (mother e-antigen positive, high viral load, or acute infection).
  • Tenofovir in the third trimester for mothers with a high viral load.
  • Breastfeeding is fine.
• Syphilis — rising in the UK; benzathine penicillin; untreated causes miscarriage, stillbirth and congenital syphilis (rash, snuffles, hepatosplenomegaly, later bone and teeth problems). Partner treatment; neonatal assessment.
• Genital herpes:
  • Primary infection in the third trimester (within 6 weeks of birth) — high risk of neonatal herpes: planned caesarean recommended; aciclovir.
  • Primary infection earlier — aciclovir, then daily suppressive aciclovir from 36 weeks; vaginal birth.
  • Recurrent herpes — low risk; suppressive aciclovir from 36 weeks; vaginal birth.
  • Neonatal herpes — skin, eye and mouth, CNS (encephalitis), or disseminated infection; high mortality; IV aciclovir.
• Hepatitis C — vertical transmission about 5%; no intervention reduces it; test the baby at 18 months (antibody) or earlier by PCR; treat the mother after birth.

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Drug Reference Table