Preconception care

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]

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)

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

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]

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]

Risk assessment, vaccination, supplementation, and chronic disease optimisation for women and couples planning pregnancy.

1.FOGSI Good Clinical Practice Recommendations on Preconception Care (2016, refreshed 2022); WHO Preconception Care; ACOG Committee Opinion 762 (2018, reaffirmed 2023) (2022)