Throughout a woman’s pregnancy, several tests and scans are done to ensure the health and well-being of both mother and baby. These tests identify any maternal diseases, fetal birth defects, or any other risk factors that can harm either of them.
Antenatal care in the First Trimester
Basic tests were done on the first visit
The weight and height are measured to calculate the BMI (Body Mass Index) of the mother.
Blood Group is determined as A, B, AB, or O. This might be useful at a time of blood transfusion.
The presence or absence of the Rhesus factor is determined.
Blood hemoglobin level is measured to identify the necessity for iron supplements.
Blood screening tests for various infectious diseases are performed. These diseases include Syphilis, Rubella, Hepatitis, and HIV Aids.
Gonorrhea and Chlamydia cultures are done.
Blood pressure is measured to identify pregnancy-induced hypertension.
Blood sugar level is measured using an Oral Glucose Tolerance Test. In this test, sugar levels are measured at several time intervals by letting you drink a glucose solution after 8-10 hours of fasting.
A Pap smear is done to identify any signs of cervical cancer.
A Urine Full Report is obtained and urine is sent for culture.
A breast examination is also done.
Ultrasound scans in the first trimester
In the first trimester normally two ultrasound scans are performed.
Dating/viability scan– Within 6-10 weeks. It determines your baby’s position (ectopic or not), the presence of a heartbeat, number of fetuses, and due date.
Fetal nuchal translucency scan (NT): Within 11-13 weeks. It detects congenital abnormalities by examining the back of the fetal neck for any fluid accumulation and thickening.
Normally, transvaginal scans (TVS) are performed before 10 weeks of pregnancy. You will have to empty your bladder prior to a TVS. Abdominal ultrasounds are performed after 10 weeks of pregnancy.
Other screening tests
b>Pregnancy-associated plasma protein screening (PAPP-A): Abnormal levels of this placental protein in the blood indicate high risks of chromosomal abnormalities.
a chorionic gonadotropin (hCG)increased levels of this placental hormone indicate high risks of chromosomal abnormalities.
These maternal screening tests along with ultrasound scans can be used to detect congenital defects like Down syndrome or Trisomy 18.
Antenatal care in the Second Trimester
General tests like measuring weight, blood pressure, and serum hemoglobin levels will be carried out without any change.
Urine will be screened for the presence of glucose, proteins, or infections.
An oral glucose challenge test will be performed at 24-28 weeks to detect gestational diabetes. This test is a simplified version of OGTT and it doesn’t involve fasting.
Ultrasound scans in the second trimester
It is usually done within 18-20 weeks of pregnancy.
It confirms the due date.
It can be used to determine the sex of the baby.
It examines fetal and placental structures.
It can be used to detect any congenital anomalies like cleft lip, cleft palate etc.
It can be used to examine fetal movements.
It can be used to monitor the growth of the fetus.
It provides guidance in doing amniocentesis like complex procedures.
Alpha-fetoprotein screening (AFP): High serum levels of AFP indicate neural tubal defects, Down syndrome, and other congenital abnormalities.
Screening placental hormones like hCG, Inhibin, and Estriol.
Amniocentesis: This is an ultrasound-guided procedure in which a sample of amniotic fluid is taken out using a needle. Using this procedure chromosomal abnormalities and neural tube defects can be detected.
Chorionic villus sampling (CVS): In this test, a placental tissue sample is obtained for examination. It can be used to detect chromosomal abnormalities.
Antenatal tests in the Third Trimester
Fetal monitoring: Fetal heart rate is monitored using a Fetoscope or a hand-held Doppler device. This is continued during labor.
Group B Strep culture: This is a test used to detect the presence of Group B Streptococcus bacteria in the lower genital tract of a pregnant mother. It is normally done around 35-37weeks. These nasty bacteria can result in pre-term labor, chorioamnionitis, pyelonephritis, and even sepsis. They are capable of causing meningitis and pneumonia in the newborn.
Ultrasound scans in the third trimester
The Growth scan
It is used to monitor fetal growth.
It identifies the position of the placenta and the umbilical cord.
It measures the amount of amniotic fluid.
It helps to determine the position of the baby.