Red Flags
- Active teratogenic medication (isotretinoin, methotrexate, mycophenolate, valproate, warfarin) — switch to safer alternative ≥1–3 months before conception per drug; counsel about contraception until switch confirmed[1]
- Uncontrolled diabetes (HbA1c ≥8%) at preconception — major fetal anomaly and miscarriage risk; defer pregnancy until HbA1c <6.5% with stable insulin/oral therapy[1]
- Active or recent rubella, varicella, or measles — vaccinate ≥1 month before conception; live vaccines contraindicated in pregnancy[1]
- Active substance use (alcohol, smoking, illicit drugs) — counselling, cessation support, and screening before conception; impacts fetal development from earliest weeks[1]
First-line treatment
Interventions
- Reproductive life plan and contraception until ready[1]Clarify timing, family-building goals, contraception choice; intervals ≥18 months between pregnancies reduce adverse outcomes; effective contraception during high-risk medication switching
- Lifestyle optimisation — weight, exercise, smoking, alcohol, illicit drugs[1]Target BMI 18.5–24.9; smoking and alcohol cessation; aerobic exercise; balanced diet; reduce caffeine to <200 mg/day; sleep hygiene
- Vaccination update (≥4 weeks before conception for live vaccines)[1]MMR, varicella, hepatitis B, HPV; influenza and Tdap during pregnancy; COVID-19 per local schedule; rabies and travel vaccines as needed
- Chronic disease optimisation[1]Diabetes (HbA1c <6.5%), hypertension (target <140/90 with safe agents), epilepsy (single ASM at lowest effective dose, switch valproate), thyroid disease, autoimmune (SLE quiescent ≥6 months), mental health (medication review with psychiatrist)
First-line drug therapy
| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Folic acid[1] | B-vitamin (water-soluble) | 400 µg PO daily for ≥1 month before conception through first 12 weeks pregnancy. High-dose 5 mg/day if previous NTD-affected pregnancy, diabetes, antiepileptic drugs, BMI ≥30, sickle cell, thalassaemia | — | Reduces neural tube defect risk; high-dose for high-risk groups; combined supplements include vitamin B12 — check B12 if vegan |
| Iodine[1] | Trace element supplement | 150 µg PO daily (often as part of pregnancy multivitamin) preconception and through pregnancy and lactation | — | Critical in iodine-deficient regions; ensure use of iodised salt; do not over-supplement (>500 µg) — thyroid suppression |
| Vitamin D supplementation[1] | Fat-soluble vitamin | 400–1000 IU PO daily; higher doses for documented deficiency (treat to 25-OH vit D ≥50 nmol/L) | — | Common deficiency in many populations; check baseline if risk factors (limited sun exposure, malabsorption, dark skin) |
| Iron supplementation if anaemic or at risk[1] | Iron salt or iron-folate combination | Elemental iron 30–60 mg PO daily for prevention; 100–200 mg/day for treatment of iron deficiency anaemia | — | Preconception correction reduces gestational anaemia risk; iron-folate combination preparations widely available |
Folic acid[1]
B-vitamin (water-soluble)
- Adult
- 400 µg PO daily for ≥1 month before conception through first 12 weeks pregnancy. High-dose 5 mg/day if previous NTD-affected pregnancy, diabetes, antiepileptic drugs, BMI ≥30, sickle cell, thalassaemia
- Paediatric
- —
Reduces neural tube defect risk; high-dose for high-risk groups; combined supplements include vitamin B12 — check B12 if vegan
Iodine[1]
Trace element supplement
- Adult
- 150 µg PO daily (often as part of pregnancy multivitamin) preconception and through pregnancy and lactation
- Paediatric
- —
Critical in iodine-deficient regions; ensure use of iodised salt; do not over-supplement (>500 µg) — thyroid suppression
Vitamin D supplementation[1]
Fat-soluble vitamin
- Adult
- 400–1000 IU PO daily; higher doses for documented deficiency (treat to 25-OH vit D ≥50 nmol/L)
- Paediatric
- —
Common deficiency in many populations; check baseline if risk factors (limited sun exposure, malabsorption, dark skin)
Iron supplementation if anaemic or at risk[1]
Iron salt or iron-folate combination
- Adult
- Elemental iron 30–60 mg PO daily for prevention; 100–200 mg/day for treatment of iron deficiency anaemia
- Paediatric
- —
Preconception correction reduces gestational anaemia risk; iron-folate combination preparations widely available
Safety-net
- Take folic acid every day from at least one month before stopping contraception — most neural tube defects happen before pregnancy is known[1]
- Tell your prescriber and dentist about pregnancy plans before any new medication, X-ray, or vaccination[1]
- If you have diabetes, epilepsy, hypertension, autoimmune disease, or take long-term medication, see your specialist before conceiving — many drugs need switching[1]
Referral criteria
- Pre-existing diabetes, hypertension, cardiac disease, epilepsy, autoimmune disease, or thrombophiliaJoint preconception clinic with relevant specialist[1]
- Family history or personal carrier status for genetic disease (thalassaemia, sickle cell, CF, fragile X, BRCA, SMA)Clinical genetics[1]
- Recurrent miscarriage, prior stillbirth, or prior pregnancy with congenital anomalyMaternal-fetal medicine and obstetrician with subspecialty interest[1]
- Substance use disorder, mental health condition requiring teratogen-risk medication, intimate partner violenceMultidisciplinary team — addiction, psychiatry, social work[1]
Clinical summary
Risk assessment, vaccination, supplementation, and chronic disease optimisation for women and couples planning pregnancy.