What Tests Should Be Performed During Pregnancy?

Every pregnancy is unique in a woman’s life, regardless of how many times she has had the experience. However, one factor should be the same for all mothers-to-be: a well-done prenatal care, aimed at monitoring the pregnancy and trying to avoid complications that could harm both the pregnant woman and the fetus, is successful.

“The purpose of prenatal exams is to understand the health of this woman, assess laboratory parameters and understand how the pregnancy is going”, summarizes Rodrigo Buzzini, gynecologist, obstetrician and medical director of the Hospital and Maternity Pro Matre (SP).

Ideally, during pregnancy, the patient has eight to 12 appointments, in which the health of the mother and the fetus will be monitored.

If the mother is not up to date with the Pap smear, it is possible to perform it during pregnancy. The test is important to detect diseases in the cervix, such as inflammation, HPV and cancer.

Understand below what are the essential tests that every woman must undergo during prenatal care. It is important to note that pregnancies are evaluated on a case-by-case basis and the first consultations will indicate whether the woman should be accompanied by a reference service because there is a risk for her or the fetus or if she will be conducted during pregnancy in a prenatal period indicated for pregnancy low risk.

first trimester

The first three months will be the period in which the woman will have the greatest number of exams. At the initial consultation, as soon as the pregnancy is confirmed or if the woman has menstrual delay, you will be asked:

  • blood typing;
  • indirect coombs;
  • fasting blood glucose;
  • complete blood count;
  • urine summary and culture; feces;
  • thyroid (TSH);
  • serologies, which include HIV, toxoplasmosis, rubella, cytomegalovirus, hepatitis B and C;
  • quantitative of beta HCG.

During this first contact with the patient, in addition to asking if the woman knows the date of her last period, the doctor should ask if she has her vaccination book up to date.

It is essential that pregnant women receive immunizations for: flu (single dose); hepatitis B (three doses); dT, against diphtheria and tetanus (two doses); dTpa against diphtheria, tetanus and pertussis (single dose); and covid-19 (number of doses varies by manufacturer). In addition, an ultrasound will be requested.

“If we believe it is a very early pregnancy, until the eighth or tenth week, we will do the first transvaginal ultrasound to assess the pregnancy. The main objective here is to analyze whether it is a single or multiple pregnancy, whether it is inside the uterus, as well as the signs of fetal evolution and dating the pregnancy correctly”, explains Juliano Naliato, gynecologist and obstetrician DaVita Medical services.

In the second month, in addition to checking whether the blood tests previously done are good, the doctor schedules the morphological ultrasound of the first trimester. It is carried out between the 11th and 14th week of pregnancy and will identify the entire formation of the central nervous system and closure of the fetal neural tube, which includes pointing out changes such as anencephaly, for example.

It is also on this ultrasound that estimates of the risk of genetic malformations, such as Down syndrome, Edwards syndrome and Patau syndrome, are calculated. Buzzini emphasizes that the purpose of the test is to assess whether there is a risk of the fetus being born with any of these alterations and not to nail the result.

“There is a program within fetal medicine that estimates the risk of these malformations and helps a lot in conducting and specifying such conditions. If the exam indicates that the possibility of any of these alterations is high, it is necessary to refer the patient to specific exams that can give a accurate diagnosis,” explains Naliato.

second trimester

The second trimester is usually calmer for most women who have low-risk pregnancies, as nausea, vomiting, drowsiness and other discomforts considered normal during the first three months of pregnancy are significantly reduced at this stage. In addition, the risk of miscarriage, which often makes mothers apprehensive, is much lower in this new phase.

Between the 18th and 24th week of gestation, a second trimester morphological ultrasound is requested, which will show details of the fetus, such as the shape; the growth of important structures such as the central nervous system, heart and kidneys; and the internal anatomy, which includes the transmission of blood in the placenta and the amount of amniotic fluid. Furthermore, in this exam it is possible to find out the baby’s gender.

It is at this time of pregnancy that the pregnant woman’s blood pressure will be periodically controlled by the obstetrician. This care is important because hypertensive women are at risk of developing pre-eclampsia or eclampsia, complications that, if not treated correctly, can lead to premature birth and, in severe cases, maternal death.

Around the 24th week of pregnancy, the mother must undergo an exam called glycemic curve for the diagnosis of gestational diabetes and the other to verify if she has syphilis. In the final stretch of the second trimester, a fetal echocardiogram is performed through the mother’s womb, which exclusively assesses the baby’s cardiac structure in detail.

Third quarter

At 32 weeks of pregnancy, some tests done in the first trimester should be repeated, such as HIV, complete blood count and urine. If in early pregnancy there was a positive result for toxoplasmosis, the test should be done again.

In addition, a new ultrasound is performed to assess the growth of the fetus, the conditions of the amniotic fluid and the placenta and also to plan the delivery, which should take place from the 37th week of gestation onwards.

Thinking about the preparation for the day of the baby’s birth, when the pregnant woman is between 35 and 37 weeks of pregnancy, research is carried out for group B streptococcus. This bacterium is quite common in the reproductive tract and does not usually cause problems for women. However, if it comes into contact with the baby at the time of delivery, it can cause serious infections to the fetus, such as pneumonia or meningitis.

Using a cotton swab, material is collected from the mother’s vagina and anus to assess whether this type of bacteria exists there. “If it is positive or if at the time of giving birth the mother has not undergone this test, antibiotic prophylaxis will be given to the pregnant woman to avoid the risk of fetal contamination”, says Naliato.

Buzzini ends by emphasizing the importance not only of prenatal care, but also of the woman’s relationship with the doctor who accompanies her during pregnancy. “Although we have enormous advances in diagnostic tests and incredible ultrasounds, the obstetrician’s contact with the pregnant women during the consultation, the trusting relationship established there makes all the difference”, he concludes.