Test Catalog

Test Id : FMSS2

Maternal Serum Screening, Integrated, Specimen #2, Alpha Fetoprotein, Hcg, Estriol, and Inhibin A

Useful For
Suggests clinical disorders or settings where the test may be helpful

Helpful to identify pregnancies at increased risk of having a child with Down syndrome (trisomy 21), Open Neural Tube Defect (ONTD, spina bifida) and trisomy 18 (T18). This test is not diagnostic.

The patient information provided with the Integrated, Specm1 will be used to calculate the risks for this report.

Method Name
A short description of the method used to perform the test

Quantitative Chemiluminescent Immunoassay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Maternal Serum Screen INT, Sp-2

Lists additional common names for a test, as an aid in searching


Sequential Maternal Screening

Specimen Type
Describes the specimen type validated for testing


Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Specimen must be drawn between 14 weeks, 0 days and 24 weeks, 6 days gestation (based on the CRL). Recommended time for maternal serum screening is 16 to 18 weeks gestation. Acceptable date ranges to draw the second samples will be provided in the Integrated-1 report.


Draw blood in a plain red-top tube(s), serum gel tube is acceptable. Spin down and send 3 mL of serum refrigerated in a plastic vial.


Separate from cells ASAP or within 2 hours of collection.


This test requires that a previous first trimester specimen, Maternal Serum Screening, Integrated, Specimen #1, PAPP-A, NT (ARUP test ID: 3000147), has been performed.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis Mild reject; Gross reject
Lipemia NA
Icterus NA
Other Plasma

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
Frozen 365 days
Ambient 72 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Helpful to identify pregnancies at increased risk of having a child with Down syndrome (trisomy 21), Open Neural Tube Defect (ONTD, spina bifida) and trisomy 18 (T18). This test is not diagnostic.

The patient information provided with the Integrated, Specm1 will be used to calculate the risks for this report.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

This test combines a first-and second-trimester specimen to screen low-risk pregnancies for Down syndrome (DS), open neural tube defects (ONTD) and trisomy 18 (T18).

Collection of two blood samples is required for this test. A first trimester ultrasound to measure the fetal nuchal translucency (NT) is optional (see special instructions).

Patient demographics and analyte/ultrasound measurements are used to calculate multiple of the median (MoM) values for each of the laboratory analytes and the NT. The pattern of the MoM values is used to calculate post-test risks for ONTD, DS and T18.

Markers used for assessment of risk include first-trimester PAPP-A with or without NT and second-trimester AFP, hCG, unconjugated estriol (uE3), and dimeric Inhibin A.

A DS risk of 1 in 110 or worse is reported as abnormal. This risk cutoff predicts a detection rate of 87 percent at a screen positive rate of 1.0%.

A T18 risk of 1 in 100 or worse is reported as abnormal. This risk cutoff predicts a detection rate of 90 percent at a screen positive rate of <0.5%.

ARUP uses a singleton AFP MoM cutoff of >or=2.5. If the interpretation is "high AFP," there is an increased risk of an ONTD in the pregnancy. This cutoff value predicts a detection rate of 80% at a screen positive rate of 1.5%. High AFP also occurs in unrecognized twin pregnancies and with underestimated gestational age.

Pregnancies at an increased risk for ONTD with an AFP MoM <2.5, but a risk of 1 in 250 or worse, are also reported as abnormal. This is usually due to a family history of ONTD, the use of certain seizure medications by the patient during pregnancy, or the presence of maternal insulin-dependent diabetes, any of which increases a patient's priori risk for ONTD.

An increased risk of congenital steroid sulfatase deficiency or Smith-Lemli-Opitz syndrome (uE3 <or=0.14 MoM) and poor fetal outcome (hCG >or=3.5 MoM) is reported as "see note."

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Provides information to assist in interpretation of the test results

An interpretive report will be provided.  See clinical information sections. Part 2 must be completed in order to receive an interpretable result. If the second specimen is not received for sequential screening, the results are uninterpretable and no maternal risk will be provided.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A screen interpreted as "normal" misses approximately 15% of Down syndrome, 20% of open neural tube defects and 10% of trisomy 18 cases.

Abnormal results require follow-up with targeted ultrasound, genetic counseling and consideration of fetal diagnostic testing.

Method Description
Describes how the test is performed and provides a method-specific reference

PAPP-A is pregnancy-associated plasma protein A and is a sequential immunoenzymatic assay that uses two monoclonal antibodies and external calibrators.


AFP and hCG are both measured using a non-competitive immunoassay that uses one antibody to capture the protein to a solid phase, another antibody to detect the protein, and external calibrators.


The estriol assay is a solid phase competitive immunoassay that uses an anti-estriol polyclonal antibody, labeled estriol, a solid phase antibody directed against the estriol antibody, and external calibrators.


Inhibin-A is measured using a non-competitive microtiter immunoassay that uses a detection antibody to subunit a, a capture antibody to inhibin subunit BA, and external calibrators.


Calculation of post-test risks uses a multivariate log Gaussian model. Risk estimates for DS and T18 are influenced strongly by maternal age.

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Sunday - Saturday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 8 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

ARUP Laboratories

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  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
FMSS2 Maternal Serum Screen INT, Sp-2 Not Provided
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
Z5170 Patient's AFP 1834-1
Z5171 MoM for AFP 20450-3
Z5172 Patient's uE3 2250-9
Z5173 MoM for uE3 20466-9
Z5174 Patient's hCG, 2nd Trimester 19080-1
Z5175 hCG MoM, 2nd Trimester 20465-1
Z5176 Patient's DIA 23883-2
Z5177 MoM for DIA 35738-4
Z5178 PAPP-A Maternal 32046-5
Z5179 MoM for PAPP-A 32123-2
Z5180 Nuchal Translucency (NT) 12146-7
Z5181 MoM for NT 49035-9
Z5182 Nuchal Translucency (NT), Twin B 12146-7
Z5183 MoM for NT, Twin B 49035-9
Z5184 Maternal Screen Interpretation 49586-1
Z5185 Maternal Age At Delivery 21612-7
Z5186 Maternal Weight 29463-7
Z5187 Estimated Due Date 11778-8
Z5188 Gestational Age for Second Specimen 18185-9
Z5189 Dating 21299-3
Z5190 Number of Fetuses 11878-6
Z5191 Maternal Race 21484-1
Z5192 Insulin Req Maternal Diabetes 44877-9
Z5193 Smoking 64234-8
Z5194 Family Hx Neural Tube Defect 8670-2
Z5195 Family History of Aneuploidy 32435-0
Z5196 Specimen 19151-0
Z5197 Crown Rump Length 11957-8
Z5198 Crown Rump Length, Twin B 11957-8
Z5199 Sonographer Certification Number 49089-6
Z5200 Sonographer Name 49088-8
Z5201 Ultrasound Date 34970-4
Z5202 EER Maternal Serum, Integrated, Sp2 11526-1

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports