Maternal Serum Screening
Down Syndrome, Trisomy 18 and Neural Tube Defects
First Trimester Screening
March 2011
All the screening approaches have benefits and limitations that need to be taken into consideration. In first trimester screening, the woman learns early in the pregnancy if they are at high risk, and earlier genetic counseling and diagnostic procedures such as CVS could be offered. In addition if the woman decides to terminate the pregnancy the risk of complications is less during early pregnancy compared to the second trimester.
The limitations of first trimester screening include the fact the NT measurements need to be performed by trained and certified sonographers, which might not be available in all areas or hospitals. In addition, in the first trimester, a risk for neural tube defect could not be provided. Therefore, another sample needs to be sent during the second trimester for measuring maternal alpha-fetoprotein and determine the risk for neural tube defect.
First Trimester Screening |
Jump to section:
- Introduction
- What is Maternal Serum Screening?
- Who Should Be Offered Maternal Serum Screening?
- Maternal Serum Screening: Options
- Maternal Serum Screening: Risk Calculation
- First Trimester Serum Screening
- Nuchal Translucency (NT)
- Nuchal Translucency (NT)
- Nuchal Translucency (NT)
- First Trimester Serum Screening
- First Trimester Screening
- Second Trimester Screening
- Second Trimester Screening
- Second Trimester Screening
- Sequential Screening
- Sequential Screening
- Sequential Screening
- Sequential Screening
- Mayo Medical Laboratories Maternal Serum Screening Options
- References
- Questions?


