Third trimester blood tests

Prenatal Tests: Third Trimester (for Parents)

Reviewed by: Thinh Phu Nguyen, MD

Fetal Medicine at Nemours Children's Health

en español Exámenes prenatales: Tercer trimestre

Throughout your pregnancy, you'll want to know how your baby is growing. Prenatal tests can offer valuable information about your health and the health of your growing child.

If your doctor recommends a screening or test, be sure to learn about the risks and benefits. Most parents find that prenatal tests offer them peace of mind while helping to prepare them for their baby's arrival. But it's your choice to accept or decline a test.

Routine Screenings & Other Tests

Your first visit to the obstetrician should have included a full physical, urine (pee) test, and blood test to check for things like:

• your blood type and Rh factor. If your blood is Rh negative and your partner's is Rh positive, you may develop antibodies that prove dangerous to your fetus. This can be prevented through an injection given around the 28th week of pregnancy.
• anemia, a low red blood cell count
• hepatitis B, syphilis, and HIV
• immunity to German measles (rubella) and chickenpox (varicella)
• cystic fibrosis and spinal muscular atrophy. Health care providers now routinely offer to screen for these disorders even when there's no family history.

You can expect to get your urine tested and your weight and blood pressure checked at every (or almost every) visit until you deliver. These tests can identify conditions such as gestational diabetes and preeclampsia (dangerously high blood pressure).

Throughout your third trimester, you'll be offered more tests depending on your age, health, family medical history, and other things. These can include:

• Ultrasound: An ultrasound is a safe and painless test that uses sound waves to make images that show the baby's shape and position in the uterus. Third-trimester ultrasounds can examine the placenta, and sometimes are part of a test called a biophysical profile (BPP) to see whether the baby is getting enough oxygen. Women with high-risk pregnancies may have multiple ultrasounds in their third trimester.
• Glucose screening: This test checks for gestational diabetes, a short-term form of diabetes that develops in some women during pregnancy and can cause health problems for the baby, especially if it is not diagnosed or treated. You'll drink a sugary liquid, then have a blood test an hour later to check glucose levels.
• Group B strep test: Between your 35th and 37th weeks of pregnancy, the doctor will check you for group B streptococcus (GBS) infection. GBS bacteria are found naturally in the vaginas of many women but can cause serious infections in newborns. This test involves swabbing the vagina and rectum. A woman whose test comes back positive must go to the hospital as soon as labor begins so that intravenous (IV) antibiotics can be started to help protect the baby from becoming infected.
• Nonstress test: A nonstress test (NST) is usually done when a health care provider wants to check on the health of the fetus, such as in a high-risk pregnancy or when the due date has passed. The test checks to see if the baby responds normally to stimulation and is getting enough oxygen. A baby that doesn't respond isn't necessarily in danger, but more testing might be needed.
• Contraction stress test: This test stimulates the uterus with pitocin, a synthetic form of oxytocin (a hormone secreted during childbirth), to determine the effect of contractions on fetal heart rate. It may be recommended when an earlier test indicated a problem and can see whether the baby's heart rate is stable during contractions.

Remember that tests are offered to you — it's your choice whether to have them.

To decide which tests are right for you, talk with your health care provider about why a test is recommended, its risks and benefits, and what the results can — and can't — tell you.

Reviewed by: Thinh Phu Nguyen, MD

Date reviewed: July 2022

Tests You Might Receive in 3rd Trimester of Pregnancy

Written by WebMD Editorial Contributors

These tests are common in the third trimester of pregnancy:

Blood and urine tests: Your doctor will continue to check your urine for protein and sugar and any signs of infection, keeping a close eye for signs of preeclampsia, a complication that is most common in the last weeks of pregnancy. You may have blood tests again for anemia.

Other measurements: Weight, blood pressure, and fundal height measurements also continue. Your baby's heartbeats are loud and clear!

Pelvic exams: In the last few weeks of pregnancy, your doctor will start doing pelvic exams again. This is to see if the cervix has started the ripening process for birth. Ripening is the softening, thinning, and opening (dilating) of the cervix.

These changes can happen slowly or quickly during the weeks, days, or hours before birth. So it's not uncommon to dilate a few centimeters a few weeks before your due date and then to stop dilating. This process is somewhat unpredictable.

Group B streptococcus screening: Vaginal and rectal swabs are taken at 35 to 37 weeks of pregnancy to detect group B strep bacteria. Although group B strep can be present in up to 30% of all healthy women, it's the leading cause of life-threatening infections in newborns and can also cause intellectual disability, impaired vision, and hearing loss. Women who test positive are treated with antibiotics during delivery to protect the baby from contracting the infection at birth. As an alternative, your physician or midwife may choose not to test for strep but to treat you in labor if certain risk factors develop.

Electronic fetal heart monitoring: Electronic fetal heart monitoring is done during pregnancy, labor, and delivery to monitor the heart rate of the fetus. The fetal heart rate can indicate whether the fetus is doing well or is in trouble and can be done any time after 20 weeks.

Nonstress test: Done weekly in many high-risk pregnancies, such as in cases where a women is carrying more than one fetus, or has diabetes or high blood pressure, this test involves using a fetal monitor strapped across the mother's abdomen to measure the baby's heart rate as it moves. It's also used for monitoring overdue babies.

Contraction stress test: Also done in high-risk pregnancies, a fetal monitor measures the baby's heart rate in response to contractions stimulated either by oxytocin (Pitocin) or nipple stimulation. Doctors use the measurements to predict how well the baby will cope with the stress of labor.

Ultrasound: Most pregnant women have just one or perhaps two ultrasounds. If you're having twins, you'll have this test more often, perhaps right up until birth, to check the position and growth of your babies. When needed, doctors can combine non-stress tests with ultrasound. This allows your doctor to check the babies' breathing motions, body movements, and muscle tone as well as the amount of amniotic fluid.

Biophysical profile: Can be done with just an ultrasound or with a combination of a nonstress test and an ultrasound.

Health & Pregnancy Guide

1. Getting Pregnant
2. First Trimester
3. Second Trimester
4. Third Trimester
5. Labor and Delivery
6. Pregnancy Complications
7. All Guide Topics

3rd trimester (from 29 - 40 weeks), find out the prices for a set of tests and take them in Moscow

Synonyms: Tests for pregnant women in the third trimester. Pregnancy: 3rd trimester (29-40 weeks).

Profile composition:

No. 5 Blood test. Complete blood count (without leukocyte formula and ESR) (Complete Blood Count, CBC)

No. 11

No. 139 ESR (Erythrocyte Sedimentation Rate, ESR)

No. 1 APTT (APTT, activated partial (partial) thromboplastin time, cephalin-kaolin time, Activated Partial Thromboplastin Time, APTT) , Prothrombin, INR)

No. 3 Fibrinogen (Fibrinogen)

No. 16 Glucose (in the blood) (Glucose)

No. 28 Total protein (in the blood) (Protein total)

No. 13 Bilirubin total (Bilirubin total)

No. 26 Urea (blood) (Urea)

No. 68 Antibodies to HIV 1 and 2 and HIV antigen 1 and 2 (HIV Ag/Ab Combo)

No. 73 HBsAg , qualitative test (HBs antigen, hepatitis B surface antigen, Australian antigen)

No. 79 Anti-HCV-total (antibodies to hepatitis C virus antigens)

No. 70 IgM and IgG antibodies to treponema pallidum antigens, total (IgG, IgM antibodies to Treponema pallidum antigens) (AntiTreponema pallidum IgG, IgM, Syphilis TP EIA, Total)

General information about the comprehensive study "Pregnancy: 3rd trimester"

During pregnancy, a woman's body undergoes major physiological changes. First of all, they are aimed at creating optimal conditions for the growth and development of the fetus. During this period, it is important to regularly undergo scheduled examinations that allow you to control the course of pregnancy, monitor the health of the woman and the fetus, and determine possible complications and risks. nine0005

From the 27th week, the third trimester of pregnancy begins. Laboratory studies recommended during this period include a complete blood count, basic biochemical parameters, tests to assess the state of the blood coagulation system, a blood test for the presence of antibodies to infections that are potentially dangerous to the fetus.

A comprehensive examination of pregnant women in the third trimester allows assessing the state of carbohydrate and protein metabolism, liver and kidney function, parameters of the blood coagulation system

, identifying anemia, inflammation, suggesting the presence of allergies, identifying pathogens of a number of infections dangerous to the fetus. nine0005

Specifics of application of tests of profile “Pregnancy: 3rd trimester”

Clinical blood test is one of the main laboratory tests in health assessment. Deviations of indicators from the norm allow to reveal anemia, inflammation, make an assumption about the presence of allergies, etc.

Determination of APTT (activated partial thromboplastin time), prothrombin, INR (international normalized ratio), fibrinogen characterizes the state of the blood coagulation system. Studies are used to assess the process of thrombosis and identify pathologies associated with it. nine0005

Blood glucose testing is aimed at identifying or assessing the risk of developing diabetes and other diseases associated with impaired carbohydrate metabolism.

Serum total protein is measured to assess protein metabolism. During pregnancy, the level of total protein begins to decrease at the end of the first trimester, reaches a minimum by the end of pregnancy, and after childbirth quickly returns to normal. The change in its concentration also serves as an important diagnostic parameter in a number of pathologies associated with severe metabolic disorders. nine0005

Determination of the activity of aminotransferases (ALT, AST), bilirubin and its fractions in the blood is mainly used in the diagnosis and control of the course of diseases of the liver and biliary tract: hepatitis, liver failure, cholecystitis, cholelithiasis, etc. Some pathological conditions associated with pregnancy, may be accompanied by an increase in the level of transaminases (acute fatty liver during pregnancy, cholestasis of pregnancy, preeclampsia, HELLP syndrome, etc.) and bilirubin (severe preeclampsia, intrahepatic cholestasis of pregnancy). nine0005

Serum creatinine is measured to assess kidney function. An increase in the level indicates a decrease in the glomerular filtration rate in renal dysfunction of any origin.

Urea is the main nitrogen-containing breakdown product of proteins, reflecting the total level of residual (non-protein) nitrogen in the blood. Determination of the level of urea in the blood is used to assess kidney function.

During pregnancy, the rate of excretion of urea and creatinine increases, so the level of these metabolites in the blood serum decreases. nine0005

Testing for HIV-1 and 2 antibodies and HIV-1 and 2 antigen is used to detect HIV infection, including at an early stage.

The hepatitis B surface antigen is the earliest marker of infection detected during the incubation period (from the moment of infection to the onset of the first symptoms) of the disease and used to diagnose hepatitis B.

Determination of total antibodies to hepatitis C virus antigens is used for primary screening for this a disease that is often asymptomatic. nine0005

Treponemal pallidum antigen class M and G total antibody test is a specific treponemal test used for screening and comprehensive diagnosis of syphilis. The result allows you to confirm the diagnosis already at the first clinical manifestations.

What can affect the result of the study “Pregnancy: 3rd trimester

Violation of the rules for preparing for the study may affect the results of the tests.

Test material

See related tests.

Method of determination

See relevant tests.

Deadlines

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Units

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Reference values ​​

See relevant tests.

Interpretation of results

Interpretation of test results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.

Pregnancy 3rd Trimester Interpretation

See related tests.

Main literature:

1. Obstetrics: national guide / ed. G. M. Savelyeva, G. T. Sukhikh, V. N. Serov, V. E. Radzinsky. - 2nd ed., revised. and additional - M. : GEOTAR-Media. - 2018. - 1088 p.
2. Alyaev Yu. G., Glybochko P. V., Pushkar D. Yu. Urology. Russian clinical guidelines //M.: GEOTAR-Media. – 2017.
3. WHO. Newsletters. HIV AIDS. – 2021.
4. WHO. Newsletters. Hepatitis C. - 2021.
5. WHO. Newsletters. Rubella. – 2019.
6. Wu A. G. B. Tietz Clinical Manual of Laboratory Testing. 4th ed. per. from English / V.V. Menshikov // M.: Labora. - 2013. - 1280 p.
7. Dedov I. I. et al. Algorithms for Specialized Medical Care for Patients with Diabetes Mellitus Edited by I. Dedov, M. V. Shestakova, A. Yu. Mayorova 9th issue // Diabetes mellitus. - 2019. - T. 22. - No. 1S1. - S. 1-144.
8. Dedov I. I. Endocrinology: a national guide / ed. I. I. Dedova, G. A. Melnichenko. - 2nd ed., revised. and additional – M. : GEOTAR-Media. - 2021. - 1112 p.
9. Dolgov VV, Menshikov VV Clinical laboratory diagnostics. National leadership //M.: GEOTAR-Media. - 2016. - 688 p.
10. Clinical guidelines. HIV infection in adults. – 2020.
11. Clinical guidelines. Normal pregnancy. – 2020.
12. Clinical guidelines. Acute hepatitis B (HB) in adults.
13. Clinical guidelines. Syphilis. – 2020.
14. Clinical guidelines. Chronic viral hepatitis B (CHBV) in adults. – 2019.
15. Clinical guidelines. Chronic viral hepatitis C (CHC) in adults. – 2019.
nine0133 Order of the Ministry of Health of the Russian Federation dated October 20, 2020 No. 1130n "On approval of the Procedure for the provision of medical care in the field of obstetrics and gynecology".
16. Yushchuk ND, Vengerov Yu. Ya. Infectious diseases: national guidelines. 3rd edition. – 2021.

Citizens | Ministry of Health of the Kaliningrad Region

1. General (clinical) blood test.

2. Biochemical blood test (total protein, urea, creatinine, total bilirubin, direct bilirubin, alanine transaminase (hereinafter - ALT), aspartate transaminase (hereinafter - AST), glucose, total cholesterol.

3. Coagulogram - platelet count, clotting time, bleeding time, platelet aggregation, activated partial thromboplastin time (hereinafter referred to as APTT), fibrinogen, determination of prothrombin (thromboplastin) time. nine0005

4. Determination of antibodies of classes M, G (IgM, IgG) to the rubella virus in the blood, to the herpes simplex virus (HSV), to cytomegalovirus (CMV), determination of antibodies to toxoplasma in the blood.

5. General analysis of urine.

6. Determination of the main blood groups (A, B, 0) and Rh-affiliation. In Rh-negative women:

a) examination of the father of the child for group and Rh-affiliation.

7. Determination of antibodies to pale treponema (Treponema pallidum) in the blood, determination of antibodies of classes M, G to the human immunodeficiency virus HIV-1 and HIV-2 in the blood, determination of antibodies of classes M, G to the antigen of viral hepatitis B and viral hepatitis C in blood. nine0005

8. Microscopic examination of the discharge of female genital organs for gonococcus, microscopic examination of the vaginal discharge for fungi of the genus Candida.

9. PCR chlamydial infection,

PCR gonococcal infection,

PCR mycoplasma infection,

PCR trichomoniasis.