What Blood Tests Matter Before Trying To Conceive?
If you’re thinking about trying to conceive, you’ve probably already started thinking about prenatal supplements, healthy eating and lifestyle changes.
Before you go making significant changes to your diet or supplement routine, one of the most valuable steps you can take is to understand what’s happening inside your body.
Blood tests can help identify nutrient deficiencies, hormone imbalances and underlying health conditions that may impact fertility, pregnancy outcomes and your future baby’s health. They can also help guide more personalised nutrition and supplement recommendations before pregnancy.
Not sure where to start with preconception health? Download our free Ultimate Preconception Lifestyle Checklist for a practical guide to the supplements, nutrition and lifestyle factors worth considering before trying to conceive.
While not every blood test is necessary for every person, there are several key markers worth discussing with your GP or healthcare team as part of your preconception planning.
Why Blood Tests Matter Before Pregnancy
Many of the nutritional and physiological changes that support a healthy pregnancy begin long before a positive pregnancy test.
In fact, important developmental processes occur very early in pregnancy, often before you even know you’re pregnant. Identifying nutrient deficiencies or health concerns beforehand allows time to address them before conception occurs.
Blood tests can help:
- Identify nutrient deficiencies
- Assess metabolic health
- Identify early fertility barriers and plan around them where possible
- Screen for underlying medical conditions
- Inform personalised supplement recommendations
- Support fertility and pregnancy planning
- Provide reassurance so that you can head into pregnancy with confidence
Importantly, blood tests don’t just tell us whether something is deficient. They can also provide insight into whether your nutrient stores are likely to support the increased demands of pregnancy.
While some blood tests are particularly relevant for pregnancy preparation, others can provide important insights into sperm health and male fertility. In this guide, we’ll cover the most common investigations discussed during preconception care and explain why they matter.
Blood Glucose Response & Metabolic Health
Metabolic health plays an important role in both fertility and pregnancy outcomes.
As part of a preconception assessment, your healthcare team may recommend:
- Fasting Blood Glucose
- Fasting Insulin
- HbA1c (where appropriate)
These markers provide information about how your body regulates blood sugar and insulin.
This can be particularly important for people with:
- PMOS (previously known as PCOS)
- Insulin resistance
- Prediabetes
- Type 2 diabetes
- A family history of diabetes
- Previous gestational diabetes
Impaired glucose regulation can impact ovulation, hormone balance and overall reproductive health. Identifying concerns before pregnancy provides an opportunity to implement nutrition and lifestyle strategies that support both fertility and long-term health.
Iron Status & Anaemia Screening
Iron deficiency is the most common nutrient deficiency in the world, and pregnancy is the time of the highest demands in your life, being prepared with good stores beforehand can help support you during pregnancy and help you feel more energetic too!
Your healthcare provider may recommend:
Full Blood Count (FBC)
A Full Blood Count assesses your red blood cells and can help identify anaemia.
Iron Studies
Iron studies typically include markers such as ferritin, transferrin, saturation and serum iron, providing a more complete picture of your iron status.
Iron plays an important role in oxygen transport, energy production and healthy foetal development. Because iron requirements increase significantly during pregnancy, identifying and addressing low iron stores before conception can help support both maternal and fetal health while reducing the risk of iron deficiency during pregnancy.
Folate, Vitamin B12 & Homocysteine
Folate and vitamin B12 are two of the most important nutrients to consider before pregnancy.
Blood tests may include:
- Serum Folate
- Vitamin B12
- Active B12
- Homocysteine
Folate is critical for healthy neural tube formation and rapid cell division in early pregnancy and is important around the time of implantation, often before you even know you’re pregnant.
Vitamin B12 is a water-soluble vitamin plays a role in brain and nervous system function. If deficient in Vitamin B12, you may have difficulty falling pregnant, as inadequate levels can cause changes in the blood that affect egg development and ovulatory function.
Homocysteine is an amino acid that can provide additional insight into folate and vitamin B12 metabolism.
When preparing for pregnancy, the goal isn’t simply to avoid deficiency. It’s to ensure nutrient stores are well-positioned to support conception and a healthy pregnancy.
Wondering if you’re focusing on the right nutrition changes? Our free masterclass, The 4 Surprising Mistakes You’re Making With Your Fertility Diet, breaks down the common nutrition mistakes we see when trying to conceive.
Vitamin D & Fertility
Vitamin D deficiency is surprisingly common, even in Australia, and it’s one of the blood tests we frequently review during preconception consultations.
It is widely recognised that having sufficient vitamin D levels is important not only during pregnancy but also while trying to conceive. Emerging research continues to highlight the role vitamin D may play in reproductive health, fertility outcomes and pregnancy success. As well as programming for immune-related concerns in pregnancy such as allergies and eczema.
A simple blood test can determine your vitamin D status and whether supplementation may be appropriate.
Thyroid Function & Fertility
The thyroid gland produces hormones that influence metabolism, energy production and reproductive function including how regularly you ovulate.
Preconception thyroid testing may include:
- Thyroid Stimulating Hormone (TSH)
- Free T3
- Free T4
In some circumstances, your healthcare provider may also recommend thyroid antibody testing, particularly if there are symptoms or a history suggestive of autoimmune thyroid disease such as a family history of Hashimoto’s or Graves’ disease.
Even mild thyroid dysfunction may have implications for fertility and pregnancy, making this an important area to investigate before trying to conceive.
Explore More: Why You Need to Be Thinking About Pre-Conception Nutrition Now!
Hormone Testing (When Appropriate)
Not everyone requires reproductive hormone testing before pregnancy.
However, if you’re experiencing irregular menstrual cycles, have a diagnosis such as PMOS (previously known as PCOS)… or are experiencing difficulty conceiving, your healthcare provider may recommend additional investigations.
These may include:
- Anti-Müllerian Hormone (AMH)
- Free Androgen Index (FAI)
- Sex Hormone Binding Globulin (SHBG)
- Free Testosterone
- Luteinizing Hormone (LH)
- Follicle Stimulating Hormone (FSH)
- Oestradiol (E2)
- Progesterone
These tests can provide insight into what hormones are doing at the right point in the cycle and can highlight whether interventions may be needed to help support this at various points in the cycle with your fertility speicalist.
Inflammation & Digestive Health
Digestive health and nutrient absorption are often overlooked aspects of fertility care, but can be part of the picture for some people.
Read More: Gut Symptoms – Can They Impact Fertility?
Additional investigations may include:
Coeliac Disease Screening
Undiagnosed coeliac disease may affect nutrient absorption and reproductive health.
Testing may involve:
- Coeliac serology
- Coeliac genetic testing (where appropriate)
C-Reactive Protein (CRP)
CRP is a marker of inflammation that may be used alongside other investigations to provide additional insight into overall health.
While these tests don’t directly measure fertility, they can help identify underlying factors that may influence nutritional status and wellbeing.
Cholesterol & Liver Health
Many people are surprised to learn that cholesterol and liver function are often included in preconception assessments. They are important to paint a picture of overall metabolic health and also thinking about future health risk factors for pregnancy and beyond.
These tests may include:
Lipid Profile
- Total Cholesterol
- LDL Cholesterol
- HDL Cholesterol
- Non-HDL Cholesterol
- Triglycerides
Liver Function Tests
These markers provide information about overall metabolic health. These can include:
- AST
- ALT
- GGT
- Bilirubin
Infection & Immunity Screening
While not nutrition-related tests, infection and immunity screening are commonly discussed during preconception care. These are important screenings that are standard, even if you’ve been in a committed long-term relationship.
Depending on your circumstances, your healthcare provider may recommend screening for:
- HIV
- Syphilis
- Chlamydia
- Gonorrhoea
- Rubella
- Measles
- Mumps
- Varicella
- Cytomegalovirus (CMV)
- Hepatitis B
- Hepatitis C
These investigations can help identify infections, previous exposures, assess immunity and guide appropriate management before pregnancy such as boosters.
Genetic Carrier Screening
Thanks to recent advocacy, Preconception Genetic Carrier Screening is now covered by Medicare in Australia for 3 of the most common heritable genetic conditions. Even without a family history of these concerns, you can be a silent carrier, and your partner may be too, which combined may result in a 1 in 4 risk of your child being affected by a serious genetic condition.
The three covered conditions include:
- Cystic Fibrosis
- Spinal Muscular Atrophy (SMA)
- Fragile X Syndrome
This information allows individuals and couples to make informed decisions and discuss options with their healthcare team.
Related reading: How to Choose a Prenatal Vitamin
Additional Testing For Some Individuals
If you have been restricting dairy long-term, have a history of low energy availability, amenorrhoea or nutritional deficiencies, your healthcare team may recommend additional investigations such as a bone mineral density (DEXA) scan.
Why “Normal” Blood Tests May Not Tell The Full Story
One of the most common things we hear from clients is:
“My doctor said everything was normal.”
While laboratory reference ranges are incredibly valuable for identifying disease and significant deficiencies, they don’t always tell us whether your nutritional status is optimised for conception and pregnancy.
For example, someone may fall within the laboratory reference range for iron, vitamin D or vitamin B12, yet still have room for improvement before pregnancy.
Blood tests should always be interpreted within the context of:
- Your fertility goals and timeline
- Medical history
- Dietary intake
- Symptoms
- Lifestyle factors
- Supplement use
This is where reviewing blood work through a fertility nutrition lens can be incredibly valuable.
How Can A Fertility Dietitian Help Interpret Blood Tests?
At The Dietologist, we regularly review blood work to identify opportunities to optimise nutritional status before conception.
As Australia’s trusted authority in fertility nutrition, our team of fertility dietitians provide personalised support through our virtual clinic, helping individuals and couples across Australia understand their blood test results and translate them into practical nutrition and supplement strategies.
A fertility dietitian can help:
Identify Nutrient Gaps
Blood tests can help uncover nutrient deficiencies or suboptimal levels that may benefit from targeted nutrition support.
Review Your Supplement Routine
Not all prenatal supplements are created equal.
We can assess whether your current supplements are appropriate for your individual needs and whether any adjustments may be beneficial.
Translate Results Into Practical Nutrition Strategies
Knowing your ferritin or B12 level is one thing.
Understanding what foods, dietary patterns and supplementation strategies may help improve those levels is another.
We help bridge the gap between pathology results and practical, evidence-based action.
Support Complex Fertility Cases
Blood test interpretation can be particularly valuable if you’re navigating:
- PMOS (previously known as PCOS)
- Endometriosis
- IVF
- Recurrent pregnancy loss
- Thyroid conditions
- Vegetarian or vegan diets
- Gastrointestinal conditions affecting nutrient absorption
Collaborate With Your Healthcare Team
We work alongside GPs, fertility specialists and other healthcare providers to ensure your nutrition plan supports your broader fertility care.
What About Male Fertility Blood Tests?
When trying to conceive, it’s important to remember that fertility isn’t solely influenced by female health factors alone. Sperm contributes half of the genetic material required to create an embryo, which means a partner’s health matters too.
While semen analysis remains the primary test used to assess sperm health, blood tests can provide valuable insight into nutritional status, hormone balance and overall reproductive health.
Depending on your health history and fertility goals, your healthcare provider may recommend assessing:
Explore More: How Bad Is Alcohol for Sperm, REALLY?
Nutritional Status
- Full Blood Count
- Iron Studies
- Vitamin D
- Folate
- Vitamin B12 (particularly if following a vegetarian or vegan diet)
- Zinc
- Selenium
Reproductive Hormones
- Follicle Stimulating Hormone (FSH)
- Luteinising Hormone (LH)
- Total Testosterone
- Free Testosterone
- Sex Hormone Binding Globulin (SHBG)
- Prolactin
Metabolic Health
- Fasting Blood Glucose
- Fasting Insulin
- HbA1c
- Cholesterol or Lipid Profile
- Liver Function Tests
- Thyroid Function Tests
Other Important Preconception Screening
- STI Screening
- Infectious Disease Screening
- Genetic Carrier Screening (where appropriate)
Not every test will be relevant for every individual. The most appropriate investigations will depend on your medical history, fertility goals and any existing health conditions.
Frequently Asked Questions
What blood tests should I ask my doctor for before trying to conceive?
The most appropriate tests will depend on your individual circumstances, medical history and fertility goals. Common preconception investigations discussed by fertility healthcare professionals may include a Full Blood Count, Iron Studies, Vitamin B12, Active B12, Folate, Homocysteine, Vitamin D, Thyroid Function Tests (TSH, T3 and T4), Blood Glucose and Insulin testing, a Lipid Profile, Liver Function Tests and Coeliac Screening.
Depending on your symptoms and health history, additional investigations such as reproductive hormone testing (including AMH, FAI, SHBG and Free Testosterone, FSH, LH, E2, Progesterone), thyroid antibodies, inflammatory markers (CRP), STI and infectious disease screening, and genetic carrier screening may also be recommended.
The most appropriate investigations will vary between individuals, which is why it’s important to discuss testing with your healthcare team.
How long before trying to conceive should I get blood tests done?
Ideally, at least three months before trying to conceive. This provides enough time to address nutrient deficiencies, review supplements and make meaningful nutrition and lifestyle changes before pregnancy occurs.
Can a fertility dietitian order blood tests?
In Australia, fertility dietitians cannot directly order pathology testing. However, we can recommend investigations to discuss with your GP or fertility specialist and help interpret the results from a fertility nutrition perspective.
Should my partner have blood tests too?
Absolutely.
Fertility is not solely a female health issue. Sperm contributes half of the genetic material required to create an embryo, and factors such as nutrient deficiencies, thyroid dysfunction, metabolic health and hormone imbalances may influence male reproductive health.
Can blood tests tell me if I’m fertile?
Not exactly.
Some blood tests can provide information about factors that may influence fertility, but no single blood test can determine whether you can or cannot conceive.
Fertility is influenced by many factors including age, egg quality, sperm quality, reproductive health, medical conditions and lifestyle factors.
Ready To Understand What Your Blood Test Results Actually Mean?
Our Fertility Nutrition Intensive is designed to help you cut through the noise and gain clarity on what matters most for your fertility journey.
During this comprehensive 2-hour consultation, we’ll review your health history, dietary intake, supplements, pathology results and fertility goals to create a personalised nutrition and supplement plan tailored to your needs.
Whether you’re preparing to conceive naturally, planning IVF, managing PMOS or endometriosis, or simply wanting to optimise your reproductive health before pregnancy, our fertility dietitians are here to support you.
Book a Fertility Nutrition Intensive today and take the first step towards getting pregnant, staying pregnant and having a healthy baby, on your terms.
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