Prenatal Examination Schedule and Items

Prenatal examinations refer to specialized medical assessments conducted during pregnancy. These examinations typically include measurements of height and weight, blood pressure, abdominal circumference, gynecological internal examination, breast examination, external pelvic measurement, blood typing, anemia screening, electrocardiogram (ECG), and serological testing for syphilis, among others—providing valuable insights into fetal health.

Timing and Components of Prenatal Examinations

1. First Trimester

First prenatal visit: Conducted by week 12 of gestation. This initial visit establishes the maternal health record, confirms gestational age, estimates the due date, and assesses high-risk factors for pregnancy. Routine tests include blood pressure, body mass index (BMI), fetal heart rate, complete blood count (CBC), urinalysis, blood type, fasting blood glucose, liver and renal function tests, hepatitis B surface antigen (HBsAg), Treponema pallidum (syphilis) serology, HIV screening, and ECG. For women who have not undergone premarital or preconception health checks, additional screening for thalassemia is recommended. Those with pet exposure should also undergo parasitic infection screening.

2. Second Trimester: Routine visits every four weeks

Week 16: Second prenatal visit. Results from the initial prenatal assessment are reviewed. The most critical test at this stage is the Down syndrome screening (triple or quadruple screen). Patients must fast after midnight the night before the test and arrive at the hospital the following morning on an empty stomach. Accuracy of this screening depends on menstrual cycle history, maternal weight and height, precise gestational age, and estimated fetal size.

Week 20: Third prenatal visit. The most important component is a detailed anomaly scan (fetal ultrasound) to detect structural abnormalities. Performed around week 20, this ultrasound evaluates fetal anatomy—including head circumference, abdominal circumference, femur length, and spinal integrity—to identify major congenital anomalies.

Week 24: Fourth routine prenatal visit. The key test is the oral glucose tolerance test (OGTT) for gestational diabetes mellitus (GDM), typically performed between weeks 24–28. Patients should avoid food after 8 p.m. the night before and limit fluid intake. During the OGTT, the glucose solution should be consumed slowly over 3–5 minutes—not all at once. Light physical activity after ingestion helps lower postprandial blood glucose levels.

3. Third Trimester: Routine visits every two weeks

Week 28: Anemia prevalence increases significantly during this period; therefore, iron-deficiency anemia screening is essential—and any detected anemia should be treated prior to delivery. Starting at week 28, prenatal visits occur every two weeks. The fifth and sixth visits include standard assessments: blood pressure, weight, fundal height, abdominal circumference, fetal heart rate, obstetric ultrasound, CBC, and urinalysis.

Week 32: From weeks 32–34, fetal heart rate monitoring (non-stress test or NST) is added to routine assessments. Patients may assume a comfortable position—avoiding supine positioning—for optimal monitoring. If fetal movement is minimal during monitoring, the fetus may simply be asleep; gentle abdominal stimulation can often awaken the baby.

Week 36: Ninth prenatal visit. A comprehensive ultrasound is performed to evaluate biparietal diameter (BPD), placental maturity grade, amniotic fluid volume, and estimated fetal weight (EFW). Based on these parameters, clinicians assess current fetal growth and project birth weight at term. If fetal growth restriction is suspected, nutritional supplementation is advised.

4. Near Term (from estimated due date): Weekly visits

Weeks 37–40: Assessments include blood pressure, weight, fundal height, abdominal circumference, fetal heart rate, fetal presentation, cervical examination, CBC, urinalysis, fetal heart rate monitoring, and fetal position evaluation. In addition to monitoring fetal heart rate, providers perform a thorough fetal position assessment to determine eligibility for vaginal delivery versus assisted delivery (e.g., cesarean section or instrumental vaginal delivery).

The above outlines the full schedule and components of prenatal examinations. We hope this information proves helpful.