Throughout your pregnancy, blood tests are necessary to ensure the well-being of both you and your baby by checking for various important conditions.
If you have any questions about these tests, feel free to consult your GP or midwife.
Having a blood test in pregnancy
A simple process involves taking a small blood sample with a single needle to test for viruses, which is usually straightforward and hassle-free for most individuals.
If you’re worried about needles
If you experience any nerves or dizziness during or after the blood test, inform the healthcare professional conducting the test so they can assist in making you feel more comfortable.
Types of blood tests in pregnancy
A blood test will be conducted to examine your full blood count, blood group, and rhesus status.
Full blood count test for anaemia
This particular test is designed to detect anemia resulting from low iron levels, which can lead to symptoms like fatigue and difficulty breathing. Iron supplements and iron-rich foods can be beneficial.
During pregnancy, the rhesus factor protein test plays a crucial role in preventing complications.
Rhesus (Rh) factor
For pregnant women with a negative rhesus factor, the rhesus factor protein test is essential. To prevent complications, Anti-D injections may be recommended.
Other blood tests offered during pregnancy
Additional blood tests may be required based on medical history, family background, cultural ethnicity, or profession.
Oral glucose tolerance test
An oral glucose tolerance test (OGTT) is conducted to check for gestational diabetes, typically between 24 and 28 weeks of pregnancy.
Tests for sickle cell disease and thalassemia may also be conducted as necessary.
Sickle cell disease and thalassaemia screening
Individuals from specific regions may undergo testing for sickle cell disease and thalassemia due to genetic factors that could impact the baby’s health.
Thyroid function test
Regular blood tests for thyroid gland issues may be necessary during pregnancy to ensure the well-being of the baby.
More in Blood tests during pregnancy
Page last reviewed: 22 December 2023
Next review due: 22 December 2026
Gestational diabetes can develop at any point but is more prevalent during the second or third trimester. Timely detection and appropriate management are crucial in reducing risks for both the mother and the baby.
Who’s at risk of gestational diabetes
Risk factors for gestational diabetes include age, BMI, family history, previous pregnancies, and ethnic background. Women over the age of 25, with a BMI over 30, a family history of diabetes, a history of gestational diabetes in previous pregnancies, or from certain ethnic backgrounds such as Hispanic, African American, Native American, South or East Asian, or Pacific Islander, are at an increased risk of developing gestational diabetes. It is important for pregnant women with these risk factors to be screened for gestational diabetes to ensure early detection and proper management.
Symptoms of gestational diabetes
Gestational diabetes typically does not exhibit symptoms and is identified through routine blood sugar tests. Elevated blood sugar levels can lead to increased thirst or fatigue.
How gestational diabetes can affect your pregnancy
Gestational diabetes poses risks such as delivery complications, low blood sugar in the baby, and heightened future diabetes risk for the mother.
Screening for gestational diabetes
Screening for gestational diabetes involves an oral glucose tolerance test (OGTT) around 24-28 weeks of pregnancy for those at risk. This screening test helps to identify women who may have high blood sugar levels during pregnancy, which can lead to complications for both the mother and baby. If gestational diabetes is detected early, it can be managed through diet, exercise, and possibly medication to ensure a healthy pregnancy and delivery.
Treatments for gestational diabetes
Managing blood sugar levels through treatment can mitigate risks linked with gestational diabetes. Regular monitoring with a blood sugar testing kit is essential.
Lowering blood sugar levels through dietary changes and physical activity, such as walking, swimming, and prenatal yoga, can be advantageous. If lifestyle modifications are insufficient, medication may be necessary. Consistent monitoring during pregnancy and childbirth is vital.
Babies born to mothers with gestational diabetes may face a heightened risk of developing diabetes or obesity in later life. It is recommended to deliver before 41 weeks. Women with gestational diabetes should undergo regular blood tests post-delivery and seek medical attention if experiencing symptoms of elevated blood sugar levels.
Women with a history of gestational diabetes should be screened for diabetes before conceiving again. Depending on the results, earlier screening may be recommended in subsequent pregnancies. Blood tests like the glucose challenge test or oral glucose tolerance test are employed to diagnose gestational diabetes.
Gestational diabetes is typically asymptomatic and identified through routine testing between 24 and 28 weeks of pregnancy. Testing may be conducted earlier for those at higher risk. Monitoring and maintaining blood sugar levels are crucial for managing gestational diabetes.
Factors such as age, weight, and previous gestational diabetes may heighten the risk of developing diabetes during pregnancy. Early testing is advisable to assess the risk and initiate appropriate management.
If the fasting blood glucose exceeds 92 mg/dl (5.1 mmol/l), a second measurement should be taken the following day for confirming gestational diabetes. Values between 92 and 125 mg/dl (5.1-6.9 mmol/l) confirm the diagnosis. Values below 92 mg/dl necessitate another glucose tolerance test between the 24th and 28th week of pregnancy.
Values of 126 mg/dl (7.0 mmol/l) or higher indicate preexisting diabetes in the woman.
Alternatively, the long-term glucose value (HbA1c value) can be measured to assess if blood glucose levels have been elevated in the past 6 to 8 weeks, known as long-term blood sugar memory. In healthy individuals, this value is around 5 percent (31 mmol/mol).
If the value reaches up to 5.8 percent (40 mmol/mol), another fasting blood glucose test should be conducted the following day to rule out gestational diabetes. Values between 92 and 125 mg/dl (5.1-6.9 mmol/l) confirm the diagnosis of gestational diabetes.
If the HbA1c values range between 5.9 and 6.4 percent (41-46.5 mmol/mol), a diagnostic test using 75 grams of glucose is performed to confirm or exclude suspected gestational diabetes.
If the HbA1c value surpasses 6.4 percent (46.5 mmol/mol), the woman had diabetes prior to becoming pregnant.
If your healthcare provider deems it necessary to screen you for gestational diabetes, the standard testing period is between 24 and 28 weeks of pregnancy, although earlier testing may be conducted if you have heightened risk factors or have experienced it previously. The glucose challenge test or oral glucose tolerance test are common tests used to diagnose gestational diabetes.
What tests determine gestational diabetes?
The primary test for diagnosing gestational diabetes is the oral glucose tolerance test (OGTT), which is safe and straightforward for both you and your baby.
Oral glucose tolerance test (OGTT)
The OGTT lasts slightly over two hours and is typically conducted at the antenatal care clinic or a diabetes clinic.
How does an oral glucose test work?
The test entails fasting for 8-10 hours, a blood test, consuming a glucose drink, and another blood test after two hours to evaluate glucose processing.
Remember not to eat prior to or during the gestational diabetes test, but bringing a snack for afterward is advisable. You can have sips of water before and during the test.
A personal account of being referred for an OGTT due to a gestational diabetes risk factor.
Explore a personal narrative concerning the experience of having gestational diabetes.
After the test
A diagnosis of gestational diabetes is confirmed if your fasting blood sugar level is 5.6 mmol/l or higher, or if your 2-hour post-glucose blood sugar level is 7.8 mmol/l or higher.
Upon diagnosis, you should be directed to a specialized diabetes and antenatal clinic for appropriate care.
Gestational diabetes can manifest at any stage of pregnancy, so it’s important to report any symptoms to your midwife, even if initial tests yield negative results.
Managing gestational diabetes may involve monitoring your blood sugar levels, making dietary changes, and possibly taking insulin. Regular check-ups with your healthcare provider are essential to ensure the health of both you and your baby.
It’s important to follow the treatment plan outlined by your healthcare team and attend all scheduled appointments to ensure the best possible outcomes for you and your baby. With proper management, gestational diabetes can be well-controlled, and you can have a healthy pregnancy and delivery.
How do I prepare for a gestational diabetes test?
Prepare for the gestational diabetes test by fasting, but refer to the clinic leaflet for specific instructions.
Is 30 weeks too late for a glucose test?
If you encounter symptoms or have concerns about diabetes during pregnancy, discuss with your healthcare team for a tailored care plan.
Timely diagnosis of gestational diabetes is crucial, even if it develops beyond the 28th week of pregnancy.
It is recommended to have a glucose test between 24-28 weeks of pregnancy to screen for gestational diabetes. However, if you have not had a test by 30 weeks, it is still important to speak to your healthcare provider about getting tested. Gestational diabetes can develop at any point during pregnancy, so it’s better to be safe and get tested even if it’s later than the recommended timeframe.
What happens if you are diagnosed with gestational diabetes?
Following diagnosis, your healthcare team will recommend treatment options, blood sugar monitoring, and a balanced diet.
While some may manage gestational diabetes through diet and exercise, others may necessitate medication. Delve deeper into the available care options for gestational diabetes.