Saturday, 19th May 2018
19 May 2018
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Common test during pregnancy

Common test during pregnancy

Pregnancy in human beings has a duration of 40 weeks in total. This 40 week is divided into three trimesters

  • the first trimester is from the date of conception till 12 weeks
  • the second trimester is from 12 weeks to 28 weeks
  • the third trimester if from 28 weeks to 40 weeks

Many changes take place in the woman’s body during each trimester so she has to undergo many tests to find out if there are any abnormal changes in her body. Each trimester has many specific investigations which are a must for a woman to have a healthy baby and to safeguard her health as well. Now we will see what all test has to be done during each trimester and the significance of doing each test

In the first trimester

A) Urine gravindex or urine pregnancy test(UPT)

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This is the first test that is done in pregnancy. This test is done to confirm that the woman is pregnant. The pregnancy test is a test that measures human chorionic gonadotropin (HCG), which is a hormone produced during pregnancy. Chorionic gonadotropin appears in the blood and urine of pregnant women from 10 days after conception.


The woman is asked to give her first early morning sample of urine. But it is not a must that the early morning sample has to be given it can be done any time of the day provided she has not passed urine for at least 3 hours. But if the pregnancy is past 45 days anytime and any number of urine test will show a positive result if she is surely pregnant. The test usually becomes positive if the blood HCG level is 25-50 mIU/ml.

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There is a kit available for doing this test. A drop of the lady’s urine is put in the specified region in the kit plate or in some kit the strip is inserted into the bottle containing the patient’s urine. In about a minute lines appear in the test area.


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If there is one line then it is indicative of a negative result that means the lady is not pregnant but if there are two lines it is a positive result and it means the patient is pregnant

Difficulties in this test


Sometimes this test can give a false positive or false negative result. False positive means the patient is not pregnant but the result shows a positive result and in false negative, the patient is actually pregnant but this result shows a negative result
False positive may be due to

  • tumours such as  ovarian germ cell tumours and gestational trophoblastic disease which produce HCG
  • if the patient has taken HCG for infertility treatment
  • in most cases, the patient is actually pregnant but must have undergone a miscarriage
  • drugs such as anticonvulsants, antiparkinson drugs, hypnotics, and tranquillizers may cause false-positive results.
  • The presence of protein in the urine (proteinuria), blood in the urine (hematuria), or excess pituitary gonadotropin may also cause a false positive.

The false negative test is mostly due to late conception and the HCG level has not reached the desired level. Certain drugs such as diuretics and promethazine (an antihistamine) may cause false-negative urine results

Accuracy of the test
  • 97%
Weakly positive gravindex

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In this, the second line is very faint and people are confused if they are pregnant or not. This usually happens when the HCG level is low but in most cases the patient is pregnant so treat her as pregnant but confirm her pregnancy by a USG may be after 10 days or go ahead with a serum B-HCG which is by far more accurate and give drugs which are most needed and not all for such patients. In most cases of weakly positive urine gravindex, the patient is actually pregnant and but has undergone a miscarriage.

B) Serum B-HCG

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Some doctors prefer to do this test directly. But this is a more invasive test so it would be better if we can reserve it for the very much needy patients. In this test also the HCG level in the patient’s blood is measured and accordingly, results are given.

Conditions where this test is done
  • to confirm pregnancy
  • when to some reason a person wants to confirm her pregnancy early because this is the first test to become positive
  • for gestational trophoblastic tumour this test is done in serial intervals and only if the level returns to normal a person has to become pregnant
  • in patients with weakly positive urine gravindex
  • in patients in whom the scan findings do not correspond to her date, this is a confirmation as to how old her baby is
  • to rule out ectopic pregnancy and to find out if her baby is really intrauterine

This is also done in the early morning hours.

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is first cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

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Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed. The puncture site is covered with an adhesive bandage to stop any bleeding.


The blood level of hCG in a woman with an ectopic pregnancy usually rises at a slower rate than normal. Typically, HCG levels double about every two days for the first four weeks of a normal pregnancy, then slow to every 31/2 days by six weeks. Those with failing pregnancies will also frequently have a longer doubling time early on or may even show falling hCG concentrations during the doubling period. HCG concentrations will drop rapidly following a miscarriage. If HCG does not fall to undetectable levels, it may indicate remaining hCG-producing tissue that will need to be removed

Concise HCG level chart by weeks number post LMP Vs BHCG concentrations in unit mIU/L:

Normal level of b-HCG subunit in men is <5 mIU/mL (<5 IU/L)
Normal beta subunit HCG in non-pregnant women is <5 mIU/mL (<5 IU/L)
Postmenopausal females have hCG beta subunit of <9.5 mIU/ml
3 weeks LMP: 5 – 50 mIU/ml
4 weeks LMP: 5 – 426 mIU/ml
5 weeks LMP: 18 – 7,340 mIU/ml
6 weeks LMP: 1,080 – 56,500 mIU/ml
7 – 8 weeks LMP: 7, 650 – 229,000 mIU/ml
9 – 12 weeks LMP: 25,700 – 288,000 mIU/ml
13 – 16 weeks LMP: 13,300 – 254,000 mIU/ml
17 – 24 weeks LMP: 4,060 – 165,400 mIU/ml
25 – 40 weeks LMP: 3,640 – 117,000 mIU/ml

{But each lab have their own normal value which they give in brackets so it is better to go with that}

A low hCG level can indicate:
  • Miscalculation of pregnancy dating
  • Possible miscarriage or blighted ovum
  • Ectopic pregnancy

A high hCG level can indicate:

In both the above cases, it’s better to repeat the test after a gap of 48-72 hours


There is very little risk in having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks of having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Blood accumulating under the skin (hematoma)
  • Infection (a slight risk any time the skin is broken)

Know about HCG

The above two test is done based on a hormone called Human Chorionic Gonadotrophin so it would be better to know about this hormone

During pregnancy, cells in the developing placenta make human chorionic gonadotropin or hCG. The placenta is the sac that nourishes the egg after it’s fertilised and attaches to the uterine wall.


HCG can first be detected in a blood sample about 11 days after conception. Levels of hCG continue to double every 48 to 72 hours. They reach their peak around eight to 11 weeks after conception. HCG levels then decline and level off, remaining steady for the rest of your pregnancy.

The HCG test is done for the following reasons

  • confirm pregnancy
  • determine the approximate age of the fetus
  • diagnose an abnormal pregnancy, such as an ectopic pregnancy
  • diagnose a potential miscarriage
  • screen for Down’s syndrome

C) Dating ultrasound

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This is a scan done during the 6 weeks of pregnancy. It is done not only for confirmation but also to confirm whether the date told by the patient corresponds to the size of the foetus so that her date of delivery can be accurately predicted.

Ultrasound can be done in two ways

  • transabdominal ultrasound
  • transvaginal ultrasound

For many women, especially after 8 weeks gestation, sufficient information about the baby may be obtained with transabdominal ultrasound only. However, in the early pregnancy, the developing embryo is very small (at 6 weeks gestation, the baby is only 5-9mm long) and a transvaginal ultrasound may be required to get a better image of the baby.

Transabdominal ultrasound 

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It is non-invasive and is done in about 20 minutes. For early pregnancy, a patient has to be in full bladder for her uterus to be visible with the baby. The gel is applied onto the patient’s abdomen and the transducer of the USG machine in placed on her abdomen and the baby is visualised. Visualising the baby is a definitive sign of pregnancy.

Transvaginal ultrasound

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This is also noninvasive but may be more uncomfortable for some apprehensive patients. A full bladder is not needed for this procedure. It gives more accurate images and the baby can be seen earlier in a transvaginal USG than abdominal USG. For this USG there is a special transducer which is only about 2 cm in diameter. It is cleaned and sterilised as per protocol and before inserting the probe is covered with a very thin sheath mostly a condom and then gel is applied over the sheath and the probe is inserted into the vagina

Baby’s appearance in dating USG

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Before 5 weeks gestation, the developing pregnancy is too small to detect on ultrasound. The endometrium (the lining of the uterus where the pregnancy will grow) should appear thick and secretory. One of the ovaries will have an ovulation cyst called a haemorrhagic corpus luteum. This ovarian cyst is a normal part of getting pregnant, as the egg forming your baby was released from this cyst. The corpus luteum will gradually resolve (get smaller) as the pregnancy continues.

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At 5-6 weeks gestation, a small gestation (pregnancy) sac is seen within the uterus. A transvaginal ultrasound is usually required to see the baby at this stage of the pregnancy. Your baby is just a tiny embryo. Although the ultrasound may see your baby, it measures only a few millimetres long, and it is too early to always detect the baby’s heartbeat. You should not be concerned if we cannot see the baby’s heartbeat at this early stage, as this can be normal. The yolk sac is the another structure that is usually identified at this early stage. The yolk sac lies within the gestation sac and looks like a little round circle inside the pregnancy sac. Seeing a yolk sac helps the doctor confirm the presence of a developing pregnancy within the uterus, even before the embryo is seen. This is useful if there are concerns that your pregnancy may not be correctly located in the uterus (an ectopic pregnancy).

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At 6-7 weeks gestation, your baby is growing bigger and now measures 5-9mm long. From now until the end of the first trimester, the embryo will be measured from one end to the other, called the crown-rump-length or CRL.  The baby’s heartbeat will be detected at this stage.

Use of dating scan
  • Confirming the correct dates of your pregnancy
  • Confirming the presence of your baby’s heartbeat
  • Confirming the location of your pregnancy
  • Determining the number of babies present
  • Identifying pregnancies at increased risk of miscarriage or pregnancy loss
  • Checking other pelvic organs to rule out fibroids in your uterus or ovarian cyst
  • It may also detect a serious problem with either you or your pregnancy, some of which require further investigations or treatment.
What they see in this scan
  • Assess the size of your baby
  • Assess the location of the pregnancy
  • Assess the gestation sac
  • Assess the number of babies
  • Assess the baby’s heartbeat
  • Assess the uterus and ovaries

D) Blood glucose test

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Many doctors prefer to do all blood investigations once the dating scan is over but I don’t prefer that because in a country like India we have to be cost effective as well. I prefer to do the tests once the women reach her 12th week of pregnancy because the chance of miscarriage is greatly reduced by this time. But it would be good to do a blood glucose level once the baby has been seen in the dating scan



This test can be done using a glucometer.This process involves washing your hands before the procedure, wearing gloves during the procedure and while handling any devices contaminated with the person’s blood, including the test strip and needle. Dispose of the lancet and test strip in appropriate containers and wash your hands after the procedure. If the blood glucose meter will be used for multiple people, it should be thoroughly cleaned and disinfected between A prick is made at the tip of the index finger with the lancet after cleaning the site with spirit and a drop of blood is applied to the glucostrip inserted into the machine. Within one minute the machine would give you the result. The pricked placed is pressed with a cotton to stop any more bleeding for just about 5 minutes.

  • A normal fasting (no food for eight hours) blood sugar level is between 70 and 99 mg/dL
  • A normal blood sugar level two hours after eating is less than 140 mg/dL
Diabetes is diagnosed by any one of the following:
  1. Two consecutive fasting blood glucose tests that are equal to or greater than 126 mg/dL
  2. Any random blood glucose that is greater than 200 mg/dL
  3. An A1c test that is equal to or greater than 6.5 percent. A1c is an easy blood test that gives a three-month average of blood sugars
  4. A two-hour oral glucose tolerance test with any value over 200 mg/dL

Sometimes you may have symptoms of fatigue, excessive urination or thirst, or unplanned weight loss. However, often people have no symptoms of high blood glucose and find a diabetes diagnosis surprising.

Effects on the mother and baby by diabetes in the first trimester

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  • excessive urination – polyurea
  • excessive thirst – polydipsia
  • excessive hunger – polyphagia
  • tiredness and fatigue due to swinging in the glucose values
  • more chance of infection with special mentioning to candidiasis which may lead to abortion and sepsis
  • more chances of abortion
  • abnormal babies

E) Triple screening test

Read our post to know about this investigation

F) Blood investigations

Various blood investigations have to be done in the first trimester to detect diseases which can cause complication in pregnancy and delivery. For doing these investigations blood has to be taken from the woman who is pregnant


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A health professional usually draws the blood from a vein.

If the blood is being drawn from a vein, the skin is cleaned with antiseptic and an elastic band (tourniquet) is placed around the upper arm to apply pressure and cause the veins to swell with blood. A needle is inserted into a vein (usually in the arm inside of the elbow or on the back of the hand) and blood is withdrawn and collected in a vial or syringe.

After the procedure, the elastic band is removed, then the needle is removed and the area is covered with cotton or a bandage to stop the bleeding. Collecting the blood for the test will only take a few minutes.

Test performed on this blood

i) Haemoglobin

A drop of blood contains millions of red blood cells or erythrocytes.   These specialised cells are like flattened discs, which gives them a much greater surface area with which to exchange oxygen and carbon dioxide in the lungs and with body cells.  Red blood cells are able to carry oxygen so efficiently because of a special protein inside them: haemoglobin.  In fact, it is the haemoglobin that is responsible for the colour of the red blood cell.  Haemoglobin contains a haem prosthetic group that has an iron atom at its centre.  When the iron is bound to oxygen, the haem group is red in colour (oxyhaemoglobin), and when it lacks oxygen (deoxygenated form) it is blue-red.  As blood passes through the lungs, the haemoglobin picks up oxygen because of the increased oxygen pressure in the capillaries of the lungs, and can then release this oxygen to body cells where the oxygen pressure in the tissues is lower.  In addition, the red blood cells can pick up the waste product, carbon dioxide, some of which is carried by the haemoglobin (at a different site from where it carries the oxygen), while the rest is dissolved in the plasma.  The high carbon dioxide levels in the tissues lower the pH, and the binding of haemoglobin to carbon dioxide causes a conformational change that facilitates the release of oxygen.  The carbon dioxide is then released once the red blood cells reach the lungs.

So it is important that this Haemoglobin is kept in normal level throughout pregnancy. If the level reduces it can lead to a condition called anaemia which can have adverse effects both on the mother and on the foetus

So the level of haemoglobin is routinely tested to see if it is within normal levels and to detect any early symptoms of anaemia and to correct it as soon as possible

Usually haemoglobin levels are tested every month

Normal values
  • Pregnant woman : 12.1 to 15.1 g/dL

But this value keeps changing throughout pregnancy and so has to be tested regularly. If the value is less than this then the condition is called anaemia and of the values are more than this value it is called polycythemia

Risk factors for anaemia

All pregnant women are at risk for becoming anaemic. That’s because they need more iron and folic acid than usual. But the risk is higher if you:

  • Are pregnant with multiples (more than one child)
  • Have had two pregnancies close together
  • Vomit a lot because of morning sickness
  • Are a pregnant teenager
  • Don’t eat enough foods that are rich in iron
  • Had anaemia before you became pregnant
Effects of anaemia in pregnancy

Severe or untreated iron-deficiency anaemia during pregnancy can increase your risk of having:

  • A preterm or low-birth-weight baby
  • A blood transfusion (if you lose a significant amount of blood during delivery)
  • Postpartum depression
  • postpartum haemorrhage
  • A baby with anaemia
  • A child with developmental delays
ii) Spot glucose test

This is done to rule out diabetes during pregnancy. No diet restriction is needed before the test. Go after a normal meal to your lab. In the lab, they will give you 50g of glucose which you have to take mixed in water. After 30 minutes blood is drawn from your vein and tested

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A normal value is up to 140mg/dl. Values above this is considered to be high risk for diabetes and the person will have to undergo GTT or glucose tolerance test

This test is only a screening test and is not diagnostic of diabetes. Only after doing a GTT can we confirm the presence of diabetes.

iii) Blood group and type

This is another important test that is done during pregnancy. Your blood group and that of your partner can have adverse effects on your baby. More than the blood type it is the negative and positive blood combination that plays havoc with the baby.

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If a woman is positive there stops the testing because whether the baby is going to be positive or negative it won’t have any effect on the baby. But if the woman is Rh negative then it can cause problems. But not all babies land in problem it is only under certain conditions that the baby can go for problem

If a woman is Rh negative then her husband has to get his blood group checked. If he is also negative then no problem because you’re going to definitely have a Rh negative baby. But if your partner is Rh positive then it can cause problems to the baby if the baby also happens to be Rh positive

Chances for the baby to be Rh positive depends on whether the partner is homozygous positive or heterozygous positive. If he is homozygous positive then the baby will be 100% positive but if the partner is heterozygous positive then the baby has chance of being positive only 50%

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People who are RhD-positive have a protein on their red blood cells called D antigen. If you’re RhD-negative, you don’t have this.

Most of us are RhD-positive because we each inherit two copies of the rhesus gene, one from each parent. These genes are either positive or negative. The positive gene is dominant and always wins out.

    • If you inherit one positive and one negative gene, you will be RhD-positive.
    • If you inherit two positive genes you will also be positive.
    • If both parents are RhD-negative, there’s no chance that any of their babies could be RhD-positive. This is because neither parent has a positive gene to pass on.
  • If both parents are RhD-positive but both carry one positive and one negative gene, the odds are that their baby will be rhesus-positive, too.
  • However, it’s also possible for those same parents to have a RhD-negative child if they both pass on their negative gene to their baby.
  • If one parent is RhD-negative and one parent is RhD-positive, their baby could be RhD-positive or negative.

Usually, the antibodies against the baby develop only when mothers and babies blood mixes and this happens at the time of delivery so the first child escapes it is only the subsequent children who are affected.

Effects of Rh factor on baby

Rh antibodies are harmless until the mother’s second or later pregnancies. If she is ever carrying another Rh-positive child, her Rh antibodies will recognise the Rh proteins on the surface of the baby’s blood cells as foreign, and pass into the baby’s bloodstream and attack those cells. This can lead to swelling and rupture of the baby’s RBCs. A baby’s blood count can get dangerously low when this condition, known as the hemolytic or Rh disease of the newborn, happens.

iv) VDRL

The VDRL test is a screening test for syphilis which is a sexually transmitted disease. It measures substances, called antibodies, that your body may produce if you have come in contact with the bacteria that causes syphilis. This bacteria is called Treponema pallidum. Syphilis screening is a routine part of prenatal care during pregnancy.

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The basis of the VDRL test is that body produces antibody when infected, and in this test the antibody is detected by subjecting the serum to an antigen, which is composed of a colorless alcoholic solution of beef cardiolipin, cholesterol, and lecithin.


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In this test, heated serum or unheated cerebrospinal fluid is mixed with reagin (a purified mixture of lipids such as cardiolipin, lecithin, and cholesterol) on a glass slide, and flocculation, or clumping, of the mixture is read microscopically as “reactive” (if clumping occurs) or “nonreactive” (if there is no clumping). VDRL test is positive in most cases of primary syphilis and is almost always positive in secondary syphilis.

Effect of syphilis on the foetus

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Congenital syphilis is still a cause of perinatal morbidity and mortality. Untreated maternal infection leads to adverse pregnancy outcomes, including early fetal loss, stillbirth, prematurity, low birth weight, neonatal and infant death, and congenital disease among newborns. Clinical manifestations of congenital syphilis are influenced by gestational age, stage of maternal syphilis, maternal treatment, and immunological response of the fetus. Adequate treatment of maternal infection is effective for preventing maternal transmission to the fetus and for treating a fetal infection. Hence this is a must test during pregnancy.

v) HIV

These are tests that check if you’ve been infected with HIV. The most common tests are described below.

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An antibody test (also called immunoassay) checks for antibodies to the HIV virus. Your health care provider may order the test for you to have done at a lab. Or, you may have it done at a testing centre or use a home kit. These tests can detect antibodies starting a few weeks after you’re infected with the virus. The antibody test is usually done on the blood — This test is done by drawing blood from a vein, or by a finger prick. A blood test is the most accurate because blood has a higher level of antibodies than other body fluids.


Depending on the laboratory’s practice, negative results may be retested with one other assay, or the initial negative result may be considered reliable enough. (Repeat testing after a time interval may, however, be suggested if there is good reason to think there has been a recent exposure to HIV, or there are possible symptoms of seroconversion.)

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All laboratories will also retest positive samples using one or two different types of assay to the one first used. The new test kits should work on different principles to the first one so that they are unlikely to give false positive results to the same samples. Moreover, they should have a higher specificity than the first test. In other words, they should accurately identify the largest number of HIV-negative samples. For example, a test with a specificity of 99.9% will correctly identify 999 of 1000 HIV-negative people.

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Only after this sequence of tests has been completed will the doctor who arranged the tests be informed of the results, which remain preliminary. If tests on the first sample were consistent with HIV infection, it is still essential to test a second, follow-up blood sample. This will check against possible clerical errors such as the original sample having been mislabelled.

Effect of AIDS in pregnancy

AIDS depletes the body’s immune system, making it tougher to fight off disease and infection.

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In most cases, HIV isn’t passed to the baby in utero (though it can happen). That’s because the  placenta provides a barrier between the mum’s blood and the baby’s blood. There’s a chance that your baby could become infected at birth, but doctors have gotten really good at decreasing that possibility. With treatment, doctors can decrease the chance of your baby getting HIV/AIDS to about 1 percent.

Self protection


HIV testing is also done to safeguard health personnel from contracting the disease from the patient. The health personnel take extra precaution while treating and AIDS infected patients such as wearing double glove,  goggles and other precautions to prevent contracting the disease

vi) HbsAg

Hepatitis B is liver inflammation caused by the hepatitis B virus (HBV). HBV is one of five types of hepatitis virus. The others are hepatitis A, C, D, and E.

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Hepatitis B is highly contagious. It spreads through contact with infected blood, saliva, and other bodily fluids. Symptoms may not occur for a few days or longer after contracting the virus. However, you are still contagious, even without symptoms.

Possible methods of transmission include:

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  • transfer from mother to baby during birth
  • being pricked with a contaminated needle
  • close contact with a person with HBV
  • oral, vaginal, and anal sex
  • using an infected toothbrush or razor

The presence of hepatitis B surface antigen (HBsAg) in the blood indicates that the patient is currently infected with the virus. HBsAg appears an average of four weeks after initial exposure to the virus. Individuals who recover from acute hepatitis B infections clear the blood of HBsAg within approximately four months after the onset of symptoms. These individuals develop antibodies to HBsAg (anti-HBs). Anti-HBs provides complete immunity to subsequent hepatitis B viral infection. Similarly, individuals who are successfully vaccinated against hepatitis B produce anti-HBs in the blood.

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Patients who fail to clear the virus during an acute episode develop chronic hepatitis B. The diagnosis of chronic hepatitis B is made when the HBsAg is present in the blood for at least six months. In chronic hepatitis B, HBsAg can be detected for many years, and anti-HBs does not appear.

Effect of hepatitis

HBV does not cross the placenta because of its size, and it cannot infect the fetus unless there have been breaks in the maternal-fetal barrier, such as those that occur during amniocentesis. Women who are infected can transmit HBV to the infant during delivery. Consequently, unless adequate prophylaxis is provided, the newborn is at high risk to develop a chronic HBV infection, with its known long-term complications. 

 Perinatal transmission from the mother to her newborn baby is the most important mode of infection. If a pregnant woman is an HBV carrier and is also positive for hepatitis B “e” antigen (HBeAg), her newborn baby has a 90% likelihood of becoming infected. Approximately 25% of infected infants will become chronic carriers. Most HBsAg carriers are asymptomatic, potentially infectious, and a constant source of new infections. 
Self protection
Hepatitis B is a life threatening disease so the medical professional has to safeguard themselves against the disease so it’s a must that the patient be screened for the disease and in case the patient is found positive adequate precaution has to be taken both for the medical professional and the newborn

vii) BT CT

This is bleeding time and clotting time. This is done to rule out any bleeding diathesis in the pregnant woman. In case of any such condition has been found the doctor can be well prepared at the time of delivery to encounter any bleeding episodes with adequate blood and other prerequisites.
Clotting time (CT)
In order for blood to clot, the enzyme thrombin must be generated from the plasma precursor prothrombin. Thrombin then converts soluble fibrinogen into insoluble fibrin. Generation of thrombin involves the sequential activation of a number of other plasma clotting factor, this process is also being assisted by Ca++ and by factors released by platelets and damaged tissues . The time taken for blood to clot mainly reflects the time required for the generation of thrombin in this manner. If the plasma concentration of prothrombin or of some of the other factors is low (or if the factor is absent, or functionally inactive), clotting time will be prolonged. The expected range for clotting time is 4-10 mins.
Method of doing the test

Bleeding time (BT)
This test measures the time taken for blood vessel constriction and platelet plug formation to occur. No clot is allowed to form so that the arrest of bleeding depends exclusively on blood vessel constriction and platelet action.
Method of doing the test
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Finger of a subject is sterilised with spirit and pricked with sterilised needle. Time of pricking is noted. Take the stain of the punctured point on a filter paper in 30 seconds and keep taking stain of blood in 20-second intervals until the bleeding stops. The time of no stain has come is noted properly; it is the bleeding time of the subject
Hereditary causes of abnormal bleeding time are as follows:
  •  von Willebrand disease
  • Glanzmann thrombasthenia (GP IIb/IIIa deficiency)
  • Bernard-Soulier syndrome (deficient GP1bIX-X)
  • Connective-tissue diseases ( Ehlers-Danlos syndrome, Wiskott-Aldrich syndrome, Chédiak-Higashi syndrome, hereditary hemorrhagic telangiectasia [HHT])
Acquired causes of abnormal bleeding time are as follows:
 Medications (aspirin, nonsteroidal anti-inflammatory drugs [NSAIDs], antibiotics [penicillin, cephalosporins], anticoagulants [eg, heparin, streptokinase], tricyclic antidepressants, antipsychotics, theophylline)
  •  Vitamin C deficiency
  • Alcohol intoxication
  • Uremia
  • Liver failure
  • Leukemias
  • Myelodysplastic syndrome
  • Amyloidosis

viii) FT3 FT4 TSH

The thyroid gland is normally regulated by thyroid-stimulating hormone (TSH), also called thyrotropin, which is secreted by the pituitary. TSH stimulates the thyroid gland to produce and release the thyroid hormones thyroxine (T4) and triiodothyronine (T3) . T4 and T3 are released from the thyroid into the bloodstream, where they are bound to the serum proteins thyroxine-binding prealbumin, (also called transthyretin), albumin, and thyroxine-binding globulin (TBG). TBG normally accounts for about 75% of the bound hormones. About 0.03% of the total serum T4 and 0.3% of the total serum T3 are free. Only free T4 and T3 are metabolically active.

By a negative feedback mechanism increased levels of free thyroid hormones (T4 and T3) inhibit TSH secretion from the pituitary, whereas decreased levels of T4 and T3 cause an increase in TSH release from the pituitary. TSH secretion is also influenced by thyrotropin-releasing hormone (TRH) synthesised in the hypothalamus. TRH causes release of TSH

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Suppression of TSH with an elevation of free T4 is a common finding during the first trimester of pregnancy [1,11,12]. These findings are believed to be caused by stimulation of the TSH receptor by hCG which results in an increase in FT4 and subsequently suppresses TSH levels [11]. These changes are  particularly pronounced in patients with hyperemesis gravidarum where FT4 levels may reach 37.6 and TSH may be suppressed to undetectable levels [13]

A suppressed TSH with normal FT4 and FT3 can usually be observed with repeat laboratories q 4 weeks until it normalises

Normal values
Serum Units first trimester second trimester third trimester Reference
Free T3 pmol/L 3 – 5.7 2.8 – 4.2 2.4 –  4.1 15
Free T4 ng/dL 0.86  – 1.87 0.64  – 1.92 0.64  – 1.92 16
pmol/L 11.1  – 24.1 8.2 – 24.7 8.2 – 24.7 15
ng/dL 0.86 – 1.77 0.63 – 1.29 0.66 – 1.12 15
pmol/L 11.1 – 22.9 8.1 – 16.7 8.5 – 14.4 15
Thyroid stimulating hormone (TSH) µU/mL OR
0.2 – 3.5 0.2 – 3.5 0.2 – 3.5 16
µU/mL OR
0.03 – 2.3 0.03 – 3.7 0.13 – 3.4 15


G) Urine analysis

two of pregnancy’s trickier problems are gestational diabetes(high blood sugar during pregnancy) and preeclampsia(pregnancy-induced high blood pressure), both of which have markers that show up in your urine. That’s why at each and every prenatal visit, your doctor will want to test your urine
The presence of glucose (or sugar) may indicate the beginning of gestational diabetes, while the protein in your urine during pregnancy can be a sign of preeclampsia. In order for your practitioner to confirm either condition, more tests need to be done.
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You provide the sample (so strategically time your drinking and tinkling before each visit), and then a nurse or technician either uses a dipstick or puts a few drops of urine onto testing strips (one for protein in the urine during pregnancy, another for glucose). A quick colour change indicates a positive test.

ix) ECG – Electrocardiogram

This electrocardiographic study, employing unipolar leads, is concerned particularly with late pregnancy and the early puerperium, for a change occurring in either period would be more apparent in relation to values obtained in the other. Its purposes are: first, to define the positional changes in terms of the mean electrical axis of QRS and the electrocardiographic position, and, second, to determine whether there is any evidence of ventricular hypertrophy.

These two conditions have to be diagnosed early since the cardiac load after delivery will be high and any abnormality in the heart can lead to serious consequence so it’s mandatory to take adequate precautions before delivery.

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Also, the anaesthetist would ask for an ECG in case the patient has to undergo a cesarean section.

An ECG in advance will give us time to correct any faults and get a cardiologist opinion and if needed an Echocardiogram in needed cases

Take ECG twice once in the first trimester and the second in the third trimester of pregnancy

In the second trimester

Anomaly 4D USG

3D scans show still pictures of your baby in three dimensions. 4D scans show moving 3D images of your baby, with time being the fourth dimension.  With 3D and 4D scans, you see your baby’s skin rather than her insides. You may see the shape of your baby’s mouth and nose, or be able to spot her yawning or sticking her tongue out.

3D and 4D scans are considered as safe as 2D scans because the images are made up of sections of two-dimensional images converted into a picture.

3D and 4D scans may nonetheless provide more information about a known abnormality. Because these scans can show more detail from different angles, they can help in the diagnosis of cleft lip. This can help doctors to plan the repair after birth.

Also, any limb abnormalities like absence of a finger or portion of hand or leg can be made out in 4D scan so the patient has the option to decide the outcome of the pregnancy and be prepared

Usually, this scanning is combined with the 2D scan so the internal organs also have done in detail to rule out any anomaly of the internal organs

Ideal time for doing this USG is 22 weeks but not late than 26 weeks since the baby becomes big and viewing the baby as a whole is not possible

In anomaly USG all fetal parameters are measured, i.e. head, abdomen, spine, Doppler’s blood flow and baby’s kidneys. The fetal heart will be examined for any congenital heart abnormalities. The fetal anomaly scan also looks for any fetal or placental abnormalities. The baby’s full anatomy may include an examination of the face for cleft palate and hare lip, limbs, bladder and brain in this detailed scan. Low lying placenta may be also diagnosed at this anomaly or detailed fetal ultrasound scan. If the placenta was found to be low lying or covering the internal cervical os which may or may not if persist, become placenta praevia in future.

Here we show you a you tube video showing the difference between 2D 3D and 4D USG

In the third trimester

A) Interval USG

This is done around the 32 weeks of pregnancy to if the baby’s growth is as per her dates and previous scans. It is done to detect early IUGR and oligohydramnios so that further test and medications can be given to prevent advanced problems. Because in many cases they are correctable problem and the baby can be saved and also morbidity can be reduced to a great extent

B) Term USG

The term in a pregnant patient means the part of pregnancy which falls between 37 – 40 weeks. A patient can deliver her baby anytime in this time although she has been given a due date. Babies born in this period are healthy and fully developed. So it’s mandatory to do a scan at 37 weeks before the patient gets her labour pains. Because in this final scan we look for the following and based on that the course of delivery can be decided


  • the position of the head – whether the head is in the lower or upper pole is noted
  • the weight of the baby
  • whether the baby is fully grown based on parameters like femur length and abdominal circumference
  • the position of the placenta
  • the liquor around the baby and an AFI(amniotic fluid index) is determined
  • the baby’s heart rate
  • if needed it is combined with a doppler study to see the blood flow to the placenta and the baby
  • also, cord around the neck is ruled out

C) Non-stress test

A nonstress test (NST) measures fetal heart rate, fetal movement and uterine activity in the third trimester to make sure there’s no fetal distress.

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This is done once at 37 weeks as a routine to assess the well-being of the baby so that we can give time for the patient to get into spontaneous labour without any interference from the medical professional

How a non-stress test is done during pregnancy

You’ll sit in a chair or lean back on a gurney or exam table, and a stretchy belt monitor will be placed around your belly. Fastened onto it are two monitors, which are then strategically positioned: one to pick up the baby’s heart rate, the other to sense uterine contractions. And no mindless magazine-flipping for you, Mom — you’ve got a job to do: You’ll hold a clicker contraption (like a buzzer on a game show), and each time you feel the baby move, you’ll click it. The monitoring goes on for 20 to 40 minutes. A baby who moves a lot and has a normal heart rate is classified as “reactive.” He is considered healthy and likely to remain so for the next three to seven days. A “nonreactive” baby is not necessarily in danger, but more tests are likely to be required to detect fetal distress, and in that case, early delivery might be considered.

Normal NST

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  • the fetal heart rate is between 120-160beats/min
  • variability of 10 beats
  • at least three accelerations that are the fetal heart rate should increase from the baseline by 20 beats for at least three times in 10 mins
  • no deceleration that is the fetal heart rate should not fall below 110bpm

Any NST other than this is abnormal and such patients need close monitoring with other test and investigations

Monthly investigations

  • hemoglobin
  • blood glucose level
  • urine analysis

Investigations which may be needed

A) Glucose tolerance test

This is done for patients who have a spot glucose level above 140 and anytime during pregnancy when the routine blood investigation for sugar shows a value higher than 160. In healthy people, glucose levels in the blood always rise after a meal but they soon return to normal as the glucose is used up or stored. A glucose tolerance test helps to distinguish between this normal pattern and the patterns seen in diabetes and pre-diabetes.

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How the test is done

For the days leading up to the test, you should eat a normal diet without restricting what you eat. The night before the test your doctor may ask you to stop eating 8-12 hours before you are due to have the test. You will usually be allowed to drink water but may be asked to avoid sugary drinks.

On the morning of the test, your doctor or nurse will take a sample of blood before the test begins. This is known as the fasting sample; it provides a comparison of the other test results. To do this you may have a small needle placed into a vein in the back of your hand.

You will then be given a drink which contains a particular amount of sugar (in the form of 100g of glucose) and water.

Then blood is drawn at an interval of one hour three times. At the same time patient has to give her urine sample also.

Normal values
Glucose tolerance test in pregnancy
Normal values with 100g of glucose
Time period Values
Fasting 92mg/dl
1 hour 180 mg/dl
2 hour 153 mg/dl
3 hour 120mg/dl

Any value higher than this should be considered abnormal and the patient will have to take an opinion from a diabetologist and follow his advice

B) Indirect Coomb’s test(ICT)

A Coombs’ test is a type of blood test. It is named after the person who invented it, Dr Robin Coombs. There are two types of Coombs’ test. The direct Coombs’ test involves looking directly at red blood cells found in a sample of blood. The indirect Coombs’ test looks at the liquid part of the blood (the plasma).

The direct Coombs’ test is sometimes called the direct antiglobulin test (DAT). The indirect Coombs’ test is sometimes called the indirect antiglobulin test (IAT).

Both types of Coombs’ test are looking for antibodies which may attack red blood cells and lead to them being destroyed.


ICT is  used to check that a pregnant mother’s blood does not contain antibodies that might cause her baby harm.

It is done on mothers who are Rh negative with a Rh positive partner

The test is first done in the 12th week of pregnancy then again repeated at 24-28 weeks and then at 37 weeks of preganancy

If the test is negative then the mother is not sensitised and does not have antibodies aginst the baby and her baby is fine but if the test turns to be positive then the baby has to be closely monitored and pregnancy should be terminated once the baby is mature and the mother should be given antiD immunoglobulin.

C) Doppler study


Doctors often use Doppler Ultrasound during pregnancy to check fetal umbilical blood flow, placental blood flow and blood flow in the heart and brain. Using the Doppler Ultrasound results, doctors can determine if restricted blood flow due to sickle cell anemia, RH sensitization or restricted blood vessels is to blame for fetal abnormalities. Restricted blood flow to the fetus could cause:

  • Lower birth weight
  • Reduced size
  • Impaired development

If sickle cell anemia is diagnosed, children may undergo a special form of Doppler Ultrasound known as the Transcranial Doppler to evaluate risk of stroke.



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