For Clinicians

Preconception care.

What to screen for and treat before conception, and what the professional societies currently recommend. Sources are linked throughout.

Preventative Preconception Care: Recommended Workup

These three conditions are common among women of reproductive age, inexpensive to test for, and treatable before conception. Preconception diagnostic workup and treatment is often covered by insurance as preventative care and may reduce risks of pregnancy loss and other complications, even without a history of recurrent loss.

See Contributing Factors for what the trial evidence does and does not support for each.

Anemia
CBC + ferritin
  • Iron deficiency ~38.6% of US females 12–21; anemia 6.3%
  • Ferritin is not routinely screened, so deficiency without anemia is missed
  • Finnish cohort: miscarriage 28% → 13% after IV iron (observational, no control)
Diabetes
HbA1c
  • ~30% of reproductive-age women with diabetes are undiagnosed
  • More than half of those diagnosed are not at target
  • ADA preconception target: below 6.5% where safely achievable
Thyroid
TSH
  • ATA 2026: test TSH in all women with infertility or recurrent miscarriage
  • Overt hypothyroidism ~0.2% of women of childbearing age
  • Subclinical 2.4–6.0%, depending where the cut-off is set
Key stats

“Thyroid abnormalities were identified in 10% (4/40) of women … Of the 40 women who had bloods taken after 2 miscarriages, 4 (10%) were found to have anaemia.”

Tommy’s Graded Model of Miscarriage Care, April 2026, pilot at Birmingham Women’s Hospital, 40 women tested after two losses
No woman had both conditions, so 8 of the 40 tested, one in five, were found to have a treatable condition. Under usual UK care these blood tests would not be offered until a third loss.

“Approximately 30% of women with diabetes had undiagnosed diabetes.”

Azeez et al., Preventing Chronic Disease, 2019, NHANES 2011–2016, women aged 20–44
References
Tommy’s National Centre for Miscarriage Research. The Tommy’s Graded Model of Miscarriage Care: a framework for consistent care, 2026↗Weyand et al. Prevalence of iron deficiency and iron-deficiency anemia in US females aged 12–21. JAMA, 2023↗Tulenheimo-Silfvast et al. Association between iron deficiency and fertility. Acta Obstet Gynecol Scand, 2025↗Azeez et al. Hypertension and diabetes in non-pregnant women of reproductive age. Prev Chronic Dis, 2019↗ADA. Management of diabetes in pregnancy: Standards of Care in Diabetes—2026↗Korevaar et al. ATA 2026 guidelines for thyroid disease in preconception, pregnancy, and postpartum. Thyroid, 2026↗