Before trying, the minimum is 11 preconception tests: complete blood count, fasting glucose and HbA1c, TSH and free T4, vitamin D, ferritin and iron, B12 and folic acid, blood type and Rh, complete serologies, a Pap smear, a transvaginal ultrasound and a dental evaluation. Your doctor may order more depending on your history. Don't settle for fewer.
| Test | What it assesses | When to collect |
|---|---|---|
| 1. Complete blood count | Anemia, infections | Any day |
| 2. Fasting glucose + HbA1c | Diabetes or insulin resistance | 8h fasting |
| 3. TSH and free T4 | Thyroid function | Morning |
| 4. Vitamin D (25-OH) | Vitamin D reserve | Any day |
| 5. Ferritin + iron | Iron reserves | 8h fasting |
| 6. Vitamin B12 + folic acid | Vitamins essential to the fetus | Any day |
| 7. Blood typing + Rh | Rh incompatibility | Any day |
| 8. Complete serologies | Rubella, toxo, HIV, hepatitis | Any day |
| 9. Pap smear | Cervical health | Outside menstruation |
| 10. Transvaginal ultrasound | Uterus, ovaries, endometrium | Follicular phase |
| 11. Dental evaluation | Oral health | Any time |
Source: Map to the Positive, Chapter 07. These are the minimum tests recommended by the leading international medical societies.
For several of these tests, the book gives the value to aim for before getting pregnant. In some cases it is stricter than the general reference range on the lab report.
| Marker | Target before trying | Why it matters |
|---|---|---|
| Hemoglobin | 12 g/dL or more (below indicates anemia) | Anemia can hinder implantation and a healthy pregnancy |
| Fasting glucose | Below 99 mg/dL | Insulin resistance affects ovulation, egg quality and implantation |
| HbA1c | Below 5.7% | Uncontrolled diabetes can cause fetal malformations |
| TSH | 0.5 to 2.5 mUI/L | Subclinical hypothyroidism is one of the most underdiagnosed causes of infertility |
| Vitamin D (25-OH) | Above 30 ng/mL | Low levels are linked to miscarriage, preeclampsia and gestational diabetes |
| Ferritin | Above 30 ng/mL | Iron is needed to form the blood volume of pregnancy |
The TSH target follows ASRM; it is more restrictive than the general “normal” range.
Vitamin D supplementation is often needed, under medical guidance. B12 is essential for healthy cell division of the embryo, and folic acid prevents neural tube defects: it's the most important supplement of preconception.
Serologies check your immunity to rubella, toxoplasmosis and cytomegalovirus (infections dangerous to the fetus) and rule out syphilis, HIV and hepatitis B and C. If you're susceptible to rubella, you need to be vaccinated before pregnancy.
The transvaginal ultrasound shows the anatomy of the uterus and any fibroids, polyps or ovarian cysts, and gives a first measure of ovarian reserve through the antral follicle count. Done by an experienced radiologist, it's an extremely valuable exam.
The dental evaluation belongs on the list because periodontitis (gum disease) is associated with a higher risk of premature birth, and complex dental treatments are harder during pregnancy. Resolve it before trying.
Your partner needs tests too. The male factor alone accounts for up to 30% of cases of infertility, so ignoring it throws away 30% of the chances.
The 11 tests are Chapter 07 of Map to the Positive, in Station I, Foundation, which also details your partner's tests and how to request his semen analysis. Station I then shows you what to do with the results, from smart supplementation to a preconception visit where you arrive with the printed list and your questions ready.
Take 30 days. If it does not give you more clarity than everything you have read for free so far, ask for a refund and you get every cent back. We cannot promise you a pregnancy. We can promise you will not be guessing.