Screening Tests During Pregnancy

Screening tests during pregnancy are examinations performed to assess the expectant mother’s health and the baby’s development and to determine the likelihood of certain chromosomal or structural differences. These tests do not provide a definitive diagnosis; instead, they help assess the risk of conditions that may require closer monitoring of the pregnancy.

Screening tests during pregnancy are performed through blood tests, ultrasound measurements, or a combined evaluation of these methods, depending on the expectant mother’s individual characteristics and the gestational week. The results are interpreted together with information such as age, medical history, and ultrasound findings. A high-risk result does not necessarily mean that the baby has the condition in question. Diagnostic examinations may be considered when deemed necessary.

Screening tests during pregnancy are planned to evaluate the likelihood of certain chromosomal differences and developmental problems in the baby. Blood samples obtained from the expectant mother, ultrasound measurements, and data such as gestational age are assessed together. These tests can be used to calculate the risk of Down syndrome, Edwards syndrome, and Patau syndrome.

Each screening test indicates whether the likelihood of a particular condition is low or high rather than providing a definitive diagnosis. A high-risk result does not necessarily mean that the baby has a chromosomal difference. In such cases, detailed ultrasound, genetic counseling, or diagnostic tests may be considered.

The weeks during which the tests are performed may vary depending on the method used, the laboratory protocol, and the characteristics of the pregnancy.

At What Week Are Screening Tests Performed During Pregnancy?

The period during which screening tests are performed in pregnancy is determined according to the type of test and the condition being assessed. Each test must be performed at the appropriate stage of pregnancy to obtain a meaningful result. Test timing is planned not only according to the date of the last menstrual period but also by considering ultrasound findings and previous assessments.

The main factors that may affect the period during which a screening test is performed include:

• Confirmation of gestational age through ultrasound measurements
• Presence of a singleton or multiple pregnancy
• Detection of risk in previous screening results
• The expectant mother’s age and medical history
• Having passed the appropriate time window for the test
• Whether the pregnancy occurred naturally or through assisted reproductive techniques

An incorrectly calculated gestational age may make it difficult to interpret some test results. If there is a discrepancy between the date of the last menstrual period and ultrasound measurements, the test date may be rescheduled. Ultrasound measurements are particularly important for determining gestational age in expectant mothers with irregular menstrual cycles.

If a screening test cannot be performed within the recommended period, another method appropriate for the gestational age may be considered. However, because the conditions assessed and the methods used to calculate risk differ, the tests may not be directly interchangeable. The appropriate examination should be selected based on personal health information and the course of the pregnancy.

Screening results do not provide a definitive diagnosis. If a high risk is identified, detailed ultrasound examination, genetic counseling, or diagnostic testing options are evaluated by the physician.

A low-risk screening result does not show with certainty that the condition assessed is absent. Similarly, a high-risk result does not mean that the baby definitely has the chromosomal or structural difference in question. For this reason, screening and diagnostic tests are considered separately. Results should not be interpreted in isolation but together with other examination findings and the overall course of the pregnancy.

If a high risk is identified, the results are considered together with the gestational week, ultrasound findings, and the expectant mother’s medical history. When deemed necessary, genetic counseling, detailed ultrasound, or diagnostic methods such as amniocentesis and chorionic villus sampling may be considered.

Frequently Asked Questions About Screening Tests During Pregnancy

For information about screening tests during pregnancy and an assessment process appropriate for your gestational week, you can contact Denge Tıp.