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Which Health Conditions Should Be Controlled Before Pregnancy?

Conditions such as diabetes, high blood pressure, epilepsy, thyroid disease and sickle cell disease may affect pregnancy. Good control before conception can reduce risks for both mother and baby.

7 min readBy Jeni Team9/2/2026

Educational only — not medical advice. If you have urgent symptoms, seek medical care.

If you live with a long-term health condition, preparing for pregnancy may require more than simply stopping contraception.

Pregnancy changes the body.

It can change:

  • blood pressure

  • blood sugar

  • blood volume

  • kidney function

  • how medicines behave

  • the demands placed on the heart and other organs

Some health conditions can also affect the developing baby.

That is why the best time to review many conditions is before pregnancy begins.

Quick Answer

Conditions that deserve particular attention before pregnancy include:

  • diabetes

  • high blood pressure

  • epilepsy

  • thyroid disease

  • sickle cell disease

  • heart disease

  • kidney disease

  • asthma

  • autoimmune diseases

  • significant mental health conditions

  • HIV and other chronic infections

Having one of these conditions does not automatically mean you cannot have a healthy pregnancy.

It means pregnancy should be planned carefully.

Why Does Control Before Pregnancy Matter?

Some of the baby's earliest development occurs before you may know you are pregnant.

If a medical condition is poorly controlled during this period, risks may already be increased.

Planning gives you time to:

control the condition → review medicines → reduce avoidable risks → then conceive.

Diabetes

If you have diabetes, good blood glucose control before pregnancy is particularly important.

Poorly controlled diabetes around conception and early pregnancy can increase the risk of:

  • miscarriage

  • congenital abnormalities

  • pregnancy complications

  • excessive fetal growth

  • stillbirth

  • complications during delivery

The exact risks depend on many factors, including how well the diabetes is controlled.

What Should I Do If I Have Diabetes?

Before trying to conceive:

  • speak with your diabetes or healthcare team

  • review your glucose control

  • review your medicines

  • discuss an appropriate blood glucose target

  • discuss folic acid requirements

  • assess for diabetes-related complications where appropriate

Some diabetes medicines may need to be changed before or during pregnancy.

Do not change them yourself.

What About Gestational Diabetes From a Previous Pregnancy?

Tell your healthcare professional.

A previous history of gestational diabetes increases your risk of developing it again and is also associated with a higher future risk of type 2 diabetes.

Preconception assessment may include checking your current blood glucose status.

High Blood Pressure

Chronic hypertension can increase pregnancy risks.

These can include:

  • pre-eclampsia

  • problems with fetal growth

  • placental complications

  • premature birth

Good blood pressure management before pregnancy can help reduce risk.

My Blood Pressure Medicine Works. Can I Just Continue It?

Maybe—but it needs review.

Some blood pressure medicines are not recommended during pregnancy.

Others are commonly used.

Do not simply stop your medicine.

Stopping treatment could cause dangerously high blood pressure.

Instead, tell your healthcare professional:

“I am planning a pregnancy.”

This allows them to choose an appropriate treatment plan.

Epilepsy

Most women with epilepsy can have successful pregnancies.

But pregnancy planning is particularly important because:

  • seizure control matters

  • some anti-seizure medicines carry greater fetal risks than others

  • medicine doses may need adjustment

  • folic acid requirements may differ

Should I Stop My Epilepsy Medicine Before Trying?

No.

Stopping anti-seizure medicine suddenly can cause seizures and may be dangerous for both you and a future pregnancy.

The goal is to find the safest effective treatment before conception, not to remove treatment without supervision.

Thyroid Disease

Both an underactive and overactive thyroid can affect reproductive and pregnancy health.

Poorly controlled thyroid disease can be associated with complications.

If you take thyroid medication, your thyroid function should be reviewed when planning pregnancy.

Treatment requirements may change once pregnancy occurs.

Sickle Cell Disease

Sickle cell disease requires careful pregnancy planning.

Pregnancy can increase the risk of complications such as:

  • painful crises

  • anaemia

  • infections

  • blood clots

  • pre-eclampsia

  • fetal growth problems

  • premature birth

Preconception review with clinicians familiar with sickle cell disease and pregnancy is valuable.

What If I Have Sickle Cell Trait?

Sickle cell trait is different from sickle cell disease.

If you have trait—for example, AS—your partner's genotype becomes important when planning children.

If both partners carry relevant haemoglobin variants, there may be a chance of having a child with sickle cell disease.

Genetic counselling can help you understand the possible combinations.

Asthma

Well-controlled asthma is important during pregnancy.

Do not stop your inhalers simply because you want to become pregnant.

Poorly controlled asthma and low oxygen levels can be harmful.

Most people should continue appropriate asthma treatment, with medicines reviewed by their healthcare professional.

Heart Disease

Pregnancy places additional demands on the cardiovascular system.

Some heart conditions tolerate pregnancy well.

Others can carry significant risk.

If you have known:

  • congenital heart disease

  • cardiomyopathy

  • valve disease

  • pulmonary hypertension

  • significant rhythm problems

  • previous heart surgery

seek specialist advice before conception.

For some severe heart conditions, pregnancy may carry substantial or even life-threatening risk.

Individual assessment is essential.

Kidney Disease

Pregnancy can place additional demands on the kidneys.

Chronic kidney disease can increase risks such as:

  • hypertension

  • pre-eclampsia

  • premature birth

  • fetal growth problems

  • worsening kidney function in some situations

Risk varies greatly depending on the severity of kidney disease.

Preconception review can help assess this.

Autoimmune Conditions

Conditions such as:

  • systemic lupus erythematosus

  • rheumatoid arthritis

  • antiphospholipid syndrome

may require pregnancy planning.

Why?

Because disease activity matters, and some medicines used to control autoimmune disease may not be appropriate in pregnancy.

For some conditions, pregnancy outcomes are better when the disease has been stable before conception.

HIV

People living with HIV can have healthy pregnancies and HIV-negative babies.

Effective antiretroviral treatment is extremely important.

If you have HIV and are planning pregnancy:

  • remain in care

  • continue treatment as prescribed

  • discuss your pregnancy plans

  • review your viral load and treatment

Do not stop antiretroviral therapy because you want to conceive.

Effective treatment greatly reduces the risk of transmission to the baby.

Hepatitis B or C

If you know you have chronic hepatitis B or C, discuss pregnancy planning with your healthcare professional.

Management may depend on:

  • the infection

  • liver health

  • viral levels

  • medicines being used

For hepatitis B, appropriate maternal and newborn care can greatly reduce transmission to the baby.

Mental Health Conditions

Mental health is part of preconception health.

Conditions such as:

  • depression

  • anxiety disorders

  • bipolar disorder

  • schizophrenia

may require careful planning.

This is particularly important if you take regular medication.

Should I Stop Psychiatric Medicines?

Not on your own.

Suddenly stopping some psychiatric medicines can lead to:

  • relapse

  • withdrawal symptoms

  • serious deterioration in mental health

The risks of medication must be weighed against the risks of untreated illness.

This should be done with the clinician managing your care.

PCOS

Polycystic ovary syndrome can affect:

  • ovulation

  • fertility

  • metabolic health

Some people with PCOS also have:

  • insulin resistance

  • higher body weight

  • increased diabetes risk

If you are planning pregnancy, assessment may help address both fertility and metabolic health.

Fibroids

Many women with fibroids become pregnant without difficulty.

Whether fibroids affect pregnancy or fertility depends partly on:

  • size

  • number

  • location

You do not automatically need treatment simply because an ultrasound shows a fibroid.

If you have significant symptoms or fertility problems, individual assessment is useful.

Endometriosis

Endometriosis can be associated with difficulty conceiving in some people.

If you have known endometriosis and want pregnancy, discuss whether you should:

  • start trying naturally

  • seek fertility assessment earlier

  • adjust current treatment

Some medicines used to manage endometriosis symptoms prevent ovulation and therefore are not used while actively trying to conceive.

Severe Anaemia

Anaemia is common in many populations, including among women of reproductive age.

Entering pregnancy with significant anaemia can make pregnancy more difficult for your body and increase health risks.

If you have symptoms such as:

  • persistent tiredness

  • weakness

  • shortness of breath

  • dizziness

  • palpitations

or a known history of anaemia, assessment before pregnancy may be helpful.

The cause should be identified rather than automatically taking iron indefinitely.

What About Obesity?

Higher body weight can be associated with:

  • irregular ovulation

  • reduced fertility

  • diabetes

  • hypertension

  • pregnancy complications

If weight reduction is recommended, even modest sustainable changes may improve health.

But pregnancy planning should be individualized.

Avoid extreme diets or unregulated weight-loss products.

What About Being Underweight?

Very low body weight can also affect:

  • hormones

  • ovulation

  • menstrual cycles

  • nutritional status

If periods have stopped or become very irregular because of low weight or restrictive eating, addressing this before pregnancy is important.

Do I Need to Be Completely “Cured” Before Trying?

Not necessarily.

Many chronic conditions cannot be cured.

The goal is usually:

stable + well controlled + appropriately treated.

For example, someone with hypertension may still need medication.

Someone with epilepsy may still need anti-seizure medicine.

Someone with HIV will continue antiretroviral treatment.

Successful preparation does not mean having no medical conditions.

It means entering pregnancy with the best possible management plan.

What Should I Ask My Healthcare Professional?

If you have a medical condition, ask:

Is my condition well controlled enough for pregnancy?

Are my medicines appropriate?

Do I need different folic acid supplementation?

Do I need any tests before trying?

Should I see a specialist?

Could pregnancy make my condition worse?

Could my condition affect the baby?

Should I seek antenatal care earlier once pregnant?

When Should I Delay Trying Temporarily?

Sometimes a healthcare professional may recommend delaying conception while:

  • blood sugar is brought under better control

  • blood pressure treatment is changed

  • a potentially harmful medicine is replaced

  • a disease flare settles

  • a vaccine is completed

  • severe anaemia is treated

  • an important investigation is completed

This is not necessarily telling you:

“You cannot have a baby.”

It may mean:

“Let's make pregnancy safer first.”

What If I Become Pregnant Before My Condition Is Controlled?

Do not panic and do not stop medicines automatically.

Contact your healthcare professional promptly.

Tell them:

  • when your last period occurred

  • which medicines you take

  • your medical condition

  • any recent test results

Early review allows the treatment plan to be adjusted.

Your Partner's Health Matters Too

Some health conditions and medicines can affect male fertility.

Your partner should mention pregnancy plans to a healthcare professional if he has:

  • chronic illness

  • previous cancer treatment

  • testicular disease or surgery

  • sexual or ejaculation problems

  • medicines known to affect sperm production

Preparing for pregnancy is a shared process.

Remember This

Having a chronic medical condition does not automatically prevent you from having a healthy pregnancy.

But planning matters.

If you have:

diabetes

high blood pressure

epilepsy

thyroid disease

sickle cell disease

heart or kidney disease

HIV

an autoimmune condition

or another significant long-term illness:

review it before conception.

Do not stop important medicines yourself.

The goal is simple:

Get the condition as stable as possible, use the safest appropriate treatment, and enter pregnancy with a plan.