# What do abnormal alpha-fetoprotein (AFP) test results mean during pregnancy? Canonical page: https://clinicsjo.com/en/faq/what-do-abnormal-alpha-fetoprotein-afp-test-results-mean-during-pregnancy Language: en Category: pregnancy Publisher: ClinicsJo Published: 2026-09-13T17:52:52.878Z Content updated: 2026-09-13T17:52:52.878Z Translation (ar): https://clinicsjo.com/ar/faq/what-do-abnormal-alpha-fetoprotein-afp-test-results-mean-during-pregnancy Receiving abnormal results on an alpha-fetoprotein (AFP) test during pregnancy does not mean a confirmed diagnosis of a problem; rather, it indicates an increased risk of a potential birth defect or genetic disorder in the fetus [\[2\]](). This screening, typically performed between weeks 15 and 20 of pregnancy, measures the level of the AFP protein in the mother's blood, which is primarily produced by the fetal liver [\[2\]](). Abnormal results always require further testing to accurately determine the cause. ## Implications of Abnormal AFP Levels Abnormal AFP levels can indicate several possibilities, with implications varying based on whether levels are high or low: - **High AFP levels:** Higher-than-normal levels may increase the risk of the fetus having neural tube defects (NTDs), such as spina bifida or anencephaly [\[2\]](). Neural tube defects occur when the fetal neural tube does not close completely during the first month of pregnancy, leading to abnormalities in the brain, spinal cord, or spine [\[1\]](). Elevated levels may also be associated with abdominal wall or esophageal defects in the fetus [\[2\]](). - **Low AFP levels:** Lower-than-normal levels may indicate an increased risk of the fetus having genetic disorders such as Down syndrome or Edwards syndrome (trisomy 18) [\[2\]](). ## Common Causes of Abnormal AFP Results It is important to know that abnormal results do not necessarily mean there is a serious health problem. Several common reasons can lead to abnormal AFP levels: - **Incorrect pregnancy dating:** This is considered one of the most common causes. AFP levels change naturally as pregnancy progresses; if the estimated due date is inaccurate, AFP levels may appear abnormal when they are actually normal for the true gestational age [\[2\]](). - **Multiple pregnancies:** In cases of twins or higher-order multiples, the fetuses produce larger amounts of AFP, leading to higher levels in the mother's blood [\[2\]](). - **False-positive results:** Sometimes, screening results may appear abnormal without any actual health problem existing in the fetus [\[2\]](). ## Next Steps Following Abnormal AFP Results If your AFP test results are abnormal, your healthcare provider will recommend additional tests to evaluate the situation accurately. The goal is to confirm or rule out a health problem: 1. **Re-evaluating gestational age:** The first step is often an ultrasound scan to accurately determine the gestational age [\[2\]](). 2. **Detailed ultrasound:** A high-resolution ultrasound can be performed to evaluate the fetal structure in detail and look for any anatomical signs of neural tube defects or other abnormalities [\[2\]](). 3. **Confirmatory tests:** If concerns persist after initial tests, amniocentesis may be suggested. This procedure involves withdrawing a small sample of the amniotic fluid surrounding the fetus to directly analyze AFP levels or to perform additional genetic testing [\[2\]](). It is essential to discuss all available options with your healthcare provider to understand the significance of the results based on your individual case. These tests can provide crucial information to help you and your doctor make informed decisions regarding pregnancy care. For more information on neural tube defects, you can visit [Neural Tube Defects: Preconception Screening, Prevention, and Management (Arabic)](). ## Medical references - [About Neural Tube Defects (NTDs)]() - [Alpha-Fetoprotein (AFP) Test]() General health education; not a substitute for individualized clinical assessment. Citation URL: https://clinicsjo.com/en/faq/what-do-abnormal-alpha-fetoprotein-afp-test-results-mean-during-pregnancy#answer