In short
- Check three months ahead. That is the time needed to raise ferritin and to adjust a thyroid dose.
- Folic acid 400 µg daily starts before conception, not once pregnancy is confirmed. This is not a blood test, but it is the most important step.
- Key tests: rubella immunity, TSH with anti-TPO, ferritin with a complete blood count, blood group with RhD and infections that can be treated.
- Rubella vaccination is not allowed during pregnancy, so the only time to check is before it.
- AMH is not a fertility test for every woman, and do not do thrombophilia tests without a history.
Most tests before pregnancy are not meant to predict whether you will conceive. They are meant to sort out what can be sorted out while there is still time. Some of these steps will no longer be available during pregnancy.
Why exactly three months ahead
Three months is not a random number. That is how long three processes take:
- Iron stores. After you start replacing iron, ferritin moves within two to three months. Pregnancy greatly increases iron use, so the starting point matters.
- Thyroid. After a dose change, the value is only meaningful after six to eight weeks. In pregnancy the need for the hormone rises as early as the first trimester.
- Vaccination. The rubella vaccine is a live vaccine and is not allowed during pregnancy. After vaccination, a waiting period before conception is recommended.
What makes sense to check
| Test | Why | What follows if abnormal |
|---|---|---|
| Rubella IgG antibodies | Infection in pregnancy can seriously harm the foetus. Vaccination during pregnancy is not possible. | If you are not protected, vaccination before conception. |
| TSH, and if abnormal fT4 and anti-TPO | An untreated underactive thyroid affects fertility and the course of pregnancy. | Talk to your doctor; in pregnancy lower cut-offs apply. |
| Ferritin with CRP and a complete blood count | Pregnancy uses a lot of iron. Empty stores before pregnancy mean tiredness and risk later on. | Replacement as directed by your doctor, follow-up after 3 months. |
| Blood group and RhD | Information you will certainly need in pregnancy; better to have it earlier. | For an RhD-negative woman, care follows a protocol. |
| HBsAg, HCV antibodies, HIV, syphilis | All four infections can be managed, and transmission to the child prevented or greatly reduced. | If positive, care with a specialist. |
| Glucose, HbA1c if needed | Uncontrolled sugar before conception matters more than during pregnancy. | Get it under control before conception. |
| Vitamin D | Deficiency is common in winter and simple to correct. | Supplement at the dose set by your doctor. |
| Chickenpox (varicella), if you have not had it | The same reason as for rubella. | Vaccination before conception. |
What makes sense for your partner
If pregnancy does not happen after a year of regular trying, the work-up always starts with both partners. If the woman is over 35, the limit is six months. For the man the first test is a semen analysis, not hormones. Blood comes into play only if the semen analysis is abnormal. Then morning testosterone, LH, FSH and prolactin are considered.
Before a planned pregnancy it also makes sense for the partner to be checked for sexually transmitted infections, if that is not already known.
What you do not need to do before pregnancy
- AMH in every woman. AMH estimates ovarian reserve. It does not predict whether you will conceive this cycle, and it does not predict the timing of menopause. It makes sense in an infertility work-up and before fertility procedures. It is not a routine test when planning.
- Thrombophilia tests without a history. Without recurrent pregnancy loss or thrombosis in the family, these tests do not change what is done. They do cause worry.
- Food intolerance tests. They have no diagnostic value. They lead to needless dietary restriction at exactly the time when variety matters most.
- A full hormone panel in a woman with regular cycles. A regular cycle is in itself a good sign that the axis is working.
Folic acid: the one step you should not delay
Taking 400 µg of folic acid daily before conception and in the first weeks of pregnancy reduces the risk of neural tube defects. The key is to start before conception. The neural tube closes in the first weeks, often before a woman knows she is pregnant.
For some women the doctor prescribes a higher dose. Examples: after a previous pregnancy with a neural tube defect, with diabetes, or with certain medicines. The dose is set by the doctor, not by the report.
Important: your gynaecologist takes over the care of your pregnancy. Self-paid tests before conception are preparation, not a replacement for care. Always bring the report to your first visit.
Frequently asked questions
When should I have the tests before pregnancy?
About three months before you plan to conceive. That is how long it takes to raise ferritin and adjust a thyroid dose. Rubella vaccination is also not possible during pregnancy.
Do I need AMH?
Not routinely. AMH estimates ovarian reserve and makes sense in an infertility work-up or before fertility treatment. It does not predict conception in a given cycle and does not predict menopause.
Why does rubella immunity matter?
Because infection in pregnancy can seriously harm the foetus, and the vaccine is live and not allowed during pregnancy. Before pregnancy is therefore the only time you can do something about it.
When should I start folic acid?
Before conception, not once pregnancy is confirmed. The neural tube closes in the first weeks, often before a woman knows she is pregnant. The usual dose is 400 µg daily.
What should my partner check?
Before a planned pregnancy, sexually transmitted infections. If pregnancy does not happen after a year, the first test is a semen analysis. Hormones follow only if that is abnormal.
Sources: WHO — folic acid 400 µg before conception and in early pregnancy · ATA — thyroid management before and during pregnancy · NIJZ (Slovenian National Institute of Public Health) — rubella and varicella vaccination, contraindicated in pregnancy · WHO/ECDC — screening for HIV, syphilis, HBV and HCV when planning pregnancy · ESHRE — infertility work-up and the role of AMH · BSG 2021 — iron deficiency.
