# Preconception Checklist: What to Do Before You Start Trying

> A midwife-reviewed, ACOG-grounded guide to the health steps that give conception — and early fetal development — the best possible start.

*Published 2026-06-25 · By Maya Ellison, CNM*

The short answer
ACOG recommends starting preconception preparation at least three months — and up to a year — before you try. The core steps are: begin 400 mcg of folic acid daily now, complete your vaccination review, audit all medications with your doctor, optimise nutrition, and reduce toxin exposures during the 90-day window that shapes the egg you will conceive with.

Nearly half of all pregnancies in the United States are unplanned, yet the health decisions made in the weeks and months *before* conception shape outcomes that no prenatal vitamin started after a positive test can fully catch up on. The neural tube closes in the first 28 days after conception — before most women know they are pregnant. The egg that will become your baby is already maturing in your ovary right now, three months before ovulation. That is the quiet urgency behind the preconception checklist.

What follows is built on [ACOG Committee Opinion No. 762](https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2019/01/prepregnancy-counseling) — the formal preconception counseling framework that guides clinical practice — supplemented with the functional and integrative lens that asks not just "what is the minimum safe threshold" but "what conditions give this pregnancy the best possible start." This is general information, not a substitute for personalised medical advice; bring this checklist to your preconception appointment and work through it with your provider.

## What does folic acid timing actually matter — and which form should you take?

Folic acid is the non-negotiable first item on every preconception checklist, and the timing is specific. **ACOG recommends 400 mcg daily for women at average risk, starting at least one month before conception and continuing through the first trimester.** Randomised trials have demonstrated that adequate periconceptional folic acid supplementation reduces neural tube defects — spina bifida and anencephaly — by 75 to 80 percent.

The urgency is biological: the neural tube forms and closes between days 18 and 28 after conception. That window frequently predates a positive pregnancy test. A woman who waits until she sees two lines has almost certainly already passed the critical period for neural tube closure. Beginning supplementation before conception is not caution for its own sake — it is the only way to guarantee adequate folate is present at the moment it matters most.

Higher-risk women — those who have previously carried a fetus with a neural tube defect, those taking valproate or methotrexate, or those with insulin-dependent diabetes, epilepsy, or a BMI above 35 kg/m² — should take **4 milligrams (mg) daily, beginning three months before conception** and continuing through 12 weeks postconception.

On the question of *form*: standard folic acid is synthetic and requires enzymatic conversion to the active form (5-MTHF or methylfolate) via the MTHFR enzyme. Common MTHFR gene variants impair this conversion in a meaningful proportion of women. Functional and integrative practitioners frequently recommend methylfolate — already in its active, bioavailable form — particularly for women with a known or suspected MTHFR variant. Many high-quality prenatal vitamins now include 5-MTHF as standard. A preconception blood draw can confirm your folate status and your provider can order MTHFR genotyping if warranted. *Talk to your provider about which form and dose is appropriate for you before switching products.*

Dietary folate matters alongside supplementation: dark leafy greens (spinach, kale, romaine), legumes, and fortified cereals are the strongest food sources. Food alone, however, is insufficient to guarantee the periconceptional blood levels needed for neural tube protection — supplementation is not optional even for women who eat well.

Practical step
Start your prenatal vitamin or standalone folate supplement today — not when you start trying. Set a recurring calendar reminder so the habit is established before the month you plan to begin.

## Which vaccinations need to be completed before you try — and why can't you get them during pregnancy?

Your preconception appointment is the last opportunity to receive live vaccines. Two live attenuated vaccines are contraindicated during pregnancy because of theoretical fetal risk from the live virus — and both require a wait of at least four weeks after the final dose before attempting conception.

  - **MMR (measles, mumps, rubella):** Rubella infection in the first trimester causes congenital rubella syndrome — cataracts, deafness, cardiac defects. If you lack documented immunity (prior vaccination or a positive serologic titer), the MMR vaccine is urgent. Allow at least one month before trying.

  - **Varicella (chickenpox):** Varicella infection during pregnancy carries risk of congenital varicella syndrome and severe maternal pneumonia. The two-dose series requires the final dose at least one month before conception.

  - **Influenza:** The *inactivated* flu vaccine is safe at any trimester and is recommended for women who will be pregnant during flu season (October through mid-May). The ideal window is October–November. Getting vaccinated before pregnancy means protection is already established when the immune shifts of early pregnancy begin.

  - **COVID-19:** Updated CDC and ACOG guidance through 2024 continues to recommend COVID-19 vaccination and boosters for women who are pregnant, planning pregnancy, or recently postpartum. COVID-19 infection is associated with elevated preterm birth risk.

  - **HPV:** ACOG supports HPV vaccination for eligible women up to age 26, but it is not recommended during pregnancy. Complete any remaining doses before you start trying.

Your preconception visit should include a full immunisation record review. Bring any documentation you have — your provider can order titers if your vaccination history is incomplete.

## How do you audit your medications — including supplements — before conception?

ACOG Committee Opinion No. 762 explicitly calls for a thorough review of all prescription and nonprescription medications — including vitamins, supplements, and herbal products — before conception. The goal is not to eliminate every medication; it is to identify known teratogens, assess the risk–benefit balance for continuing essential treatments, and make any necessary adjustments before an embryo is present.

Categories requiring particular attention include:

  - **Known teratogens requiring managed discontinuation or transition:** isotretinoin (Accutane), valproate, lithium, certain ACE inhibitors, warfarin, and methotrexate. These require a conversation with your prescribing physician — *never stop abruptly without medical guidance*.

  - **Antiepileptic drugs:** Women with epilepsy face a particular challenge; many anticonvulsants carry teratogenic risk, yet uncontrolled seizures are also dangerous. Specialist co-management is essential well before conception.

  - **Psychiatric medications:** Abrupt discontinuation of antidepressants can cause significant maternal harm. ACOG advises individualised counselling weighing untreated illness against fetal exposure — this is not a decision to make alone or in a hurry.

  - **GLP-1 medications (Ozempic, Wegovy, semaglutide):** These are paused before conception; discuss washout timing with your prescribing physician.

  - **Herbal products and high-dose supplements:** Some herbal preparations have not been studied in pregnancy and carry unknown risk. Review everything with your provider — including items labelled "natural."

On the supplement side, a functional preconception protocol grounded in emerging evidence extends beyond folate alone. A 2025 comprehensive review in *Nursing Research and Practice* confirmed that micronutrients including vitamin D, iron, selenium, and omega-3 fatty acids significantly affect oocyte quality, hormonal balance, and implantation. A 2024 umbrella review in *Nutrients* found robust evidence for CoQ10 supplementation (200–600 mg daily for 60–90 days) improving clinical pregnancy rates in women with diminished ovarian reserve, and omega-3 fatty acids improving per-cycle conception probability. Vitamin D deficiency is common and has been linked to ovulatory dysfunction. These are additions to a preconception conversation with your provider, not self-prescribed protocols.

## What else belongs on the preconception checklist?

ACOG's framework covers considerably more than the three headline items. A complete preconception visit addresses:

  - **Chronic disease optimisation:** Diabetes, hypertension, thyroid disease, and autoimmune conditions should be well-controlled before conception. A haemoglobin A1c in range before pregnancy meaningfully reduces fetal anomaly risk for women with insulin-dependent diabetes.

  - **Genetic carrier screening:** Expanded carrier panels can screen for conditions including cystic fibrosis, sickle cell disease, spinal muscular atrophy, and fragile X. Carrier screening is most actionable before pregnancy, when both partners can be tested and results can inform decisions without time pressure.

  - **STI screening and treatment:** Untreated STIs can affect fertility and pregnancy outcomes. Routine screening is standard at a preconception or well-woman visit.

  - **BMI and nutrition counselling:** ASRM data indicate that approximately 12% of all infertility cases are attributable to a woman being significantly over- or underweight. Both extremes affect ovulation. A 2023 systematic scoping review in *Human Reproduction Update* found that the Mediterranean dietary pattern showed the strongest, most consistent association with improved clinical pregnancy rates — high intake of vegetables, legumes, olive oil, and fish; low intake of ultra-processed foods and refined carbohydrates.

  - **Environmental and occupational exposure review:** ACOG's screening for teratogenic exposures deserves a practical addition: everyday endocrine-disrupting chemicals (EDCs) including BPA, phthalates, and PFAS are present in measurable quantities in virtually every pregnant woman in the United States and cross the placental barrier. Practical preconception steps include replacing plastic food and water containers with glass or stainless steel, choosing fragrance-free personal care products, and airing out new foam furniture and items before use. None of these requires heroic effort; the aggregate effect over a 90-day preconception window can be meaningful.

  - **Intimate partner violence (IPV) screening:** ACOG recommends IPV screening at preconception visits, recognising that pregnancy can alter relationship dynamics.

For women coming off hormonal contraception, the preconception window also carries a specific nutritional task: combined oral contraceptives are documented to deplete folate, vitamins B2, B6, B12, C, and E, and the minerals magnesium, selenium, and zinc. A high-quality prenatal vitamin containing methylfolate, B6 as pyridoxal-5-phosphate, and chelated minerals — started at least three months before you plan to conceive — supports repletion of those stores in the same window that your next egg is maturing.

*This article is general health information for educational purposes, not medical advice. Preconception health is deeply individual — bring this checklist to your provider and work through it together before you start trying.*

## Sources

1. [Prepregnancy Counseling, Committee Opinion No. 762](https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2019/01/prepregnancy-counseling)
2. [Preconceptional and Periconceptional Folic Acid Supplementation for the Prevention of Neural Tube Defects](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11723246/)
3. [Current Guidelines for Folic Acid Supplementation](https://www.ncbi.nlm.nih.gov/books/NBK593620/table/appa.tab2/)
4. [Nutritional Interventions for Enhancing Female Fertility: A Comprehensive Review of Micronutrients and Their Impact](https://pmc.ncbi.nlm.nih.gov/articles/PMC12343174/)
5. [The Role of Nutrient Supplements in Female Infertility: An Umbrella Review and Hierarchical Evidence Synthesis](https://pmc.ncbi.nlm.nih.gov/articles/PMC11722770/)
6. [Endocrine-Disrupting Chemicals & Reproductive Health](https://pmc.ncbi.nlm.nih.gov/articles/PMC6701840/)
7. [Assessing the influence of preconception diet on female fertility: a systematic scoping review](https://pmc.ncbi.nlm.nih.gov/articles/PMC10663051/)
8. [Definition of Infertility: A Committee Opinion (2023)](https://www.asrm.org/practice-guidance/practice-committee-documents/definition-of-infertility/)

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