Why do you need a blood test for pregnancy?

Why do we need to have a blood test during pregnancy? Many people may not have thought about this question carefully. This is a routine examination and is of great benefit to eugenics. Blood tests can help us understand many diseases, such as blood sugar levels, whether we have bacterial infections, hepatitis, syphilis and other diseases. Blood tests can also monitor the normal growth and development of the fetus. Let us now understand in detail why blood tests are needed for pregnancy.

Early pregnancy

Blood draw in early pregnancy is mainly because the embryo is too small to be seen by B-ultrasound. At this time, blood draw needs to test basic progesterone and HCG to confirm whether the pregnancy is present, and at the same time to determine whether it is ectopic pregnancy and hydatidiform mole. It is a routine examination.

It is mainly aimed at pregnant women with a history of habitual miscarriage, and is used to preserve the fetus in the early stage; for pregnant women with no history of miscarriage or no abnormalities during pregnancy, they can wait about 40 days after the last menstrual period to use an early pregnancy test strip or B-ultrasound to check.

First prenatal checkup before 12 weeks of pregnancy

Blood draws in early pregnancy are mainly used for hospital file building. When the pregnancy is 12-14 weeks, the hospital will draw blood for file building tests, mainly including five items of hepatitis B, hepatitis C, hepatitis A, liver and kidney function, AIDS, syphilis, to have a basic understanding of various indicators of pregnant women. About 10 tubes of blood need to be drawn.

Second prenatal checkup at 13-16 weeks

The main item of the second prenatal check-up is screening for Down syndrome, which requires blood drawing for testing, and also requires understanding the functions of the heart, liver and kidneys. Regarding blood tests, assuming that there are no problems with the indicators, a routine blood test will be required at least once every month thereafter to test the various indicators of the pregnant mother. If any indicators are abnormal, the doctor will need to recheck in 2 weeks.

17-20 weeks third prenatal check-up

Check the routine monthly blood test indicators.

Because anemia is more likely to occur after the middle stage, you should eat more iron-rich foods, such as liver, spinach, raisins, oysters, eggs, etc.

Fourth prenatal checkup between 21-24 weeks

It is mainly used for screening of gestational diabetes, which requires blood drawing within a specified time after taking glucose to measure the blood sugar concentration. Most gestational diabetes screenings are done during the 24th week of pregnancy.

01 At this time, the expectant mother needs to drink 50g of sugar water, wait for 1 hour, and then have blood drawn. The result below 140 is normal; 02 If this index is above 140, gestational diabetes is suspected and she needs to return to the hospital for a second blood draw. This time she needs to fast for 8 hours and then drink 100g of sugar water. Blood will be drawn once after 1 hour, once after 2 hours, and again after 3 hours. A total of 4 blood draws are required. 03 If the results of the sugar screening are abnormal, guide the patient to control the diet, and recheck the fasting blood sugar and one-hour postprandial blood sugar after two weeks. If one of them is abnormal, continue to control the diet for two weeks. If the index is higher than the standard value for more than 2 times, it means that the expectant mother has gestational diabetes.

In terms of treatment, diet and insulin injections should be used to control the condition. Oral hypoglycemic drugs should never be used to treat the condition, so as to avoid fetal malformations.

25-28 weeks fifth prenatal checkup

Hepatitis B antigen, syphilis serum test, blood test

1. Hepatitis B antigen:

The most important thing at this stage is to draw blood for the expectant mother to check for hepatitis B. The purpose is to check whether the expectant mother herself is a carrier or has been infected with hepatitis B. If both hepatitis B tests of the expectant mother are positive, she must let the pediatrician know so that the newborn can be vaccinated within 24 hours after the expectant mother gives birth to the fetus to prevent the newborn from being infected.

2. Syphilis serum test:

In addition, it is necessary to confirm again whether the expectant mother's previous syphilis reaction was positive or negative, so that the expectant mother can be completely cured of syphilis before the fetus is born.

28-36 weeks Sixth prenatal checkup

The main purpose is to review blood tests and do various basic examinations. After 28 weeks, it is recommended that the examination be done every 2 weeks instead of every 4 weeks.