What to Check Before Pregnancy: Immunity, Chronic Conditions and Carrier Screening

Q: Do I have to have all of these?

**A1**: No. The high-priority items are rubella antibody titre and, if you have a chronic condition, how well it is controlled. Genetic carrier screening is optional, and declining is reasonable.

Q: Where do I go for these?

**A2**: Start by asking at an obstetrics and gynaecology clinic. For tests with local authority subsidy (such as rubella antibody testing), designated facilities may apply.

Q: Should my partner be tested too?

**A3**: Genetic carrier screening only means anything when both partners are tested. Rubella antibodies are also worth checking in a partner, from the point of view of not becoming a source of infection.

Q: How much does it cost?

**A4**: It varies considerably by test and by facility, and much of it is self-pay. Some tests can be covered by local authority subsidy, so it is worth checking.

When you first start thinking about pregnancy, "what should I get checked?" is not an obvious question. This article is a practical list of tests. The thinking behind preconception care itself is covered in What preconception care actually is.

International guidance on prepregnancy counselling suggests starting from a single question: "Would you like to become pregnant in the next year?" (PMID: 30575679). It applies whether you are currently using contraception or actively planning. It is not a one-off during your reproductive years — it is something to revisit whenever your circumstances change.

1. Antibody titres for infections

For infections that can affect a baby if you catch them for the first time during pregnancy, the question is whether you are already immune. If you have no antibodies, you can decide to be vaccinated before pregnancy.

| What is checked | Why | |---|---| | Rubella | Infection in early pregnancy causes congenital rubella syndrome. This is the highest priority item | | Measles | Infection during pregnancy is associated with miscarriage and preterm birth | | Varicella (chickenpox) | If you have no antibodies, vaccination before pregnancy can be considered | | Mumps | As above | | Hepatitis B | Relevant to preventing mother-to-child transmission |

★The rubella, measles, varicella and mumps vaccines are live vaccines. You need to avoid pregnancy for a period after vaccination. Always discuss the timing with your doctor.

In Japan, some municipalities subsidise rubella antibody testing and vaccination. It is worth checking what your own local authority offers.

2. Screening for sexually transmitted infections

Guidance recommends assessing, at the point of prepregnancy counselling, whether STI screening is needed (PMID: 30575679). Chlamydia in particular often produces no symptoms, and left untreated it can affect the fallopian tubes.

3. How well an existing condition is controlled

If you have a chronic condition, getting it well controlled before pregnancy is strongly recommended. This is more reliable than dealing with it after you conceive.

The following conditions in particular can affect the course of a pregnancy, and optimisation beforehand is recommended (PMID: 30575679).

Diabetes — glycaemic control before pregnancy matters
Hypertension — some antihypertensives cannot be used in pregnancy, so medication may need review
Thyroid disease — thyroid hormone in early pregnancy affects fetal development
Psychiatric conditions — whether to continue or change medication is a decision to make with your treating doctor, never alone

This is covered in more detail in Managing chronic conditions before pregnancy.

4. Reviewing what you are taking

Write down everything — prescriptions, over-the-counter medicines and supplements — and bring the list. Some medicines are better avoided in pregnancy, and some take time to switch away from.

★Do not stop anything on your own judgement. Stopping medication for a chronic condition without advice can be the more dangerous course.

5. Genetic carrier screening

Some inherited conditions can be carried without any symptoms. If both partners are carriers, there is a possibility the condition appears in a child.

International guidance holds that people receiving prepregnancy counselling should be offered the same screening for genetic conditions that is recommended for pregnant women (PMID: 30575679).

Conditions sometimes included are cystic fibrosis (CF), spinal muscular atrophy (SMA) and fragile X syndrome. However, which conditions are worth screening for depends on ancestry and region. Practice in Japan differs from Europe and North America, so it is worth discussing — including whether to have it at all — at a centre that offers genetic counselling.

This is an optional test. Choosing not to have it is an equally reasonable decision.

6. Questions you will be asked about daily life

Guidance recommends asking routinely about alcohol, tobacco and nicotine products, and drug use including prescription opioids. It also holds that screening for intimate partner violence should be done at the point of prepregnancy counselling (PMID: 30575679).

These can feel like awkward questions. They are not asked in order to judge you.

7. Folic acid

To reduce the risk of neural tube defects, folic acid is recommended from before pregnancy (PMID: 30575679). The neural tube closes before most people know they are pregnant, which is why starting after a positive test is too late.

Amounts and upper limits are covered in Folic acid: why the timing matters.

8. Dental care

There are periods during pregnancy when dental treatment is harder to arrange. If you have cavities or gum disease that need treating, it is easier to get it done beforehand.

When to go

Whenever you start thinking about pregnancy. If you have no antibodies and need a vaccine, you will need to leave a gap afterwards, so allowing a few months is sensible.

Frequently Asked Questions (FAQ)

Q1: Do I have to have all of these?

A1: No. The high-priority items are rubella antibody titre and, if you have a chronic condition, how well it is controlled. Genetic carrier screening is optional, and declining is reasonable.

Q2: Where do I go for these?

A2: Start by asking at an obstetrics and gynaecology clinic. For tests with local authority subsidy (such as rubella antibody testing), designated facilities may apply.

Q3: Should my partner be tested too?

A3: Genetic carrier screening only means anything when both partners are tested. Rubella antibodies are also worth checking in a partner, from the point of view of not becoming a source of infection.

Q4: How much does it cost?

A4: It varies considerably by test and by facility, and much of it is self-pay. Some tests can be covered by local authority subsidy, so it is worth checking.

Summary

What is worth checking before pregnancy: antibody titres for infections, STI screening, how well any chronic condition is controlled, what medicines you are taking, and genetic carrier screening (optional).

You do not need to do all of it at once. The high-priority items are rubella antibody titre and control of any existing condition, and checking just those two is worthwhile on its own.

"What if they find something" is a natural worry. But almost everything found before pregnancy is something that can be acted on. After conception, the range of available options narrows.

References

ACOG Committee Opinion No. 762: Prepregnancy Counseling. Obstet Gynecol. 2019. PMID: 30575679 (a committee opinion covering prepregnancy counselling in general — guidance on what to ask and offer, not a trial, and it is limited to that scope)

Written by the same author — a general guide to preconception care and fertility planning: https://www.amazon.com/dp/B0F771VNV5?tag=ttcguide-enblog-22