1T Maternal Fetal Screen

Synonyms

  • 1T MATERNAL FETAL SCREEN
  • 1TMFS
  • LAB4214

Cerner Name

1T Maternal Fetal Screen

Clinical Info

1T Maternal Fetal Screen is a first trimester screening test that combines both 1T Aneuploidy Screen and 1T Pre-Term Preeclampsia Screen into a single test.  It is used to identify patients at risk for the three most common fetal aneuploidies, trisomies 21, 18 and 13 and of developing preeclampsia prior to 37 weeks gestation.  For aneuploidy assessment, The test incorporates the maternal serum markers AFP, free βhCG, Inhibin A, PAPP-A  and PlGF and the fetal ultrasound markers nuchal translucency (NT) and nasal bone (NB -optional) Index An increased risk result means that further screening (ultrasound, NIPT) and/or diagnostic testing (amniocentesis) may be offered. For preterm preeclampsia screening, the test incorporates the maternal serum markers PAPP-A and PlGF, ultrasound evaluation of uterine artery pulsatility index (UtAD-PI) and measurement of mean arterial pressure. An increased risk result means that close monitoring (blood pressure, proteinuria etc.) and low dose aspirin should be considered

Specimen Sources

Blood, Arterial Blood, Capillary Blood, Central Line Blood, Venous

Specimen Types

Blood

Specimen Volume

0

Container

Gold Top Serum Separator Tube

Collection Instructions

Collection Instructions Collect blood by venipuncture, allow it to clot and separate the serum by centrifugation. 
Specimen Rejection Criteria:  Incorrect tube type
                                                 Insufficient volume
                                                 Fetal/maternal blood contamination
                                                 Out of gestational age range
Specimen draw is from 10.0 to 13.6 weeks gestation and must be before CVS or amniocentesis. 
NT, NB and UtAD-PI must all be assessed when the CRL is 45-84mm.   The Sonographer must be credentialed by the Fetal Medicine Foundation and the certification number must be provided.
Special Instructions:
The following Ask on Order Entry (AOE) patient information must be provided:
AOE1: Maternal Weight
AOE2: Race/Ethnicity
AOE3: Estimated Date of Delivery (EDD)
AOE4: Current Smoker
AOE5: Multiple Pregnancy Status
AOE6: Age of Egg Donor at Retrieval
AOE7: Previous Pregnancy with Down Syndrome
AOE8: Diabetes Status
AOE9: Ultrasound Date
AOE10: Sonographer (ID)
AOE11: Sonographer Supervisor MD (ID)
AOE12: CRL
AOE13: NT
AOE14: Nasal Bone
AOE15: BP Date
AOE16: Systolic BP Left Arm 1
AOE17: Diastolic BP Left Arm 1
AOE18: Systolic BP Right Arm 1
AOE19: Diastolic BP Right Arm 1
AOE20: Systolic BP Left Arm 2
AOE21: Diastolic BP Left Arm 2
AOE22: Systolic BP Right Arm 2
AOE23: Systolic BP Right Arm 2
AOE24: UtAD-PI Left
AOE25: UtAD-PI Right
AOE26: Maternal Height
AOE27: Obstetric History
AOE28: Date of Delivery Last Pregnancy:
AOE29: Gestational Weeks at Delivery of Last Pregnancy
AOE30: Gestational Days (0-6) at Delivery of Last Pregnancy
AOE31: Patient’s Mother with History of Preeclampsia
AOE32: Chronic Hypertension
AOE33: Systemic Lupus erythematosus
AOE34: Anti-phospholipid Syndrome
Complete information is necessary to interpret the test. Patient information may be provided to the laboratory using the Maternal Prenatal Screening request form (2006260603).  

Transport Instructions

Refrigerate prior to shipping for overnight delivery.
Transport Temperature: Ambient

Specimen Stability

6 days from date of draw

Methodology

Time-Resolved Amplified Cryptate Emission (TRACE) 
This test was developed, and its performance characteristics determined by Northwell Health Laboratories. It has not been cleared or approved by the Food and Drug Administration. The methods and performance characteristics have been reviewed and approved by the New York State Department of Health.

Days Performed

Monday through Friday.   TAT 1-2 business days upon receipt

Performing Laboratories

Northwell Health Laboratories

CPT

AFP- 82105 
Free βhCG -84704 
Inhibin A – 86336 
PAPP-A – 84163 
PlGF - 83520

PDM

251466

Results
Component Name Base Name Common Name External Name
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
MATERNAL WEIGHT, 2ND TRIMESTER MTWT MS MATERNAL WEIGHT MS Maternal Weight
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
CURRENT SMOKER CURSMOKER CURRENT SMOKER Current Smoker
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
MS RACE/ETHNICITY ETHNICITY MS RACE ETHNICITY
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
MS ESTIMATED DUE DATE EDUEDT MS ESTIMATED DUE DATE
MULTIPLE PREGNANCY STATUS MULPREGSTAT MULTIPLE PREGNANCY STATUS Multiple Pregnancy Status
OVERALL SCREENING RESULT SCREENRSLT OVERALL SCREENING RESULT Overall Screening Result
PREECLAMPSIA PREECLAMPSIA PREECLAMPSIA Preeclampsia
PRETERM PREECLAMPSIA PREPREECLAMP PRETERM PREECLAMPSIA Preterm Preeclampsia
PREECLAMPSIA RISK CUTOFF PREECLAMPRC PREECLAMPSIA RISK CUTOFF Preeclampsia Risk Cutoff
PRETERM PREECLAMPSIA INTERPRETATION PREPREEINT PRETERM PREECLAMPSIA INTERPRETATION Preterm Preeclampsia Interpretation
BEFORE SCREEN RISK PRETERM PREECLAMPSIA BSRPREECLAMP BEFORE SCREEN RISK PRETERM PREECLAMPSIA Before Screen Risk Preterm Preeclampsia
AFTER SCREEN RISK PRETERM PREECLAMPSIA ASRPREECLAMP AFTER SCREEN RISK PRETERM PREECLAMPSIA After Screen Risk Preterm Preeclampsia
PREECLAMPSIA INTERPRETATION PREECLAMPINT PREECLAMPSIA INTERPRETATION Preeclampsia Interpretation
DOWN SYNDROME RISK CUTOFF DOWNRISKCUT DOWN SYNDROME RISK CUTOFF Down Syndrome Risk Cutoff
DOWN SYNDROME RESULT DOWNRESULT DOWN SYNDROME RESULT Down Syndrome Result
BEFORE SCREENING RISK DOWN SYNDROME DOWNBSR BEFORE SCREENING RISK DOWN SYNDROME Before Screening Risk Down Syndrome
AFTER SCREENING RISK DOWN SYNDROME DOWNASR AFTER SCREENING RISK DOWN SYNDROME After Screening Risk Down Syndrome
AFTER SCREENING RISK DOWN SYNDROME TWIN A DOWNASRA AFTER SCREENING RISK DOWN SYNDROME A After Screening Risk Down Syndrome Twin A
AFTER SCREENING RISK DOWN SYNDROME TWIN B DOWNASRB AFTER SCREENING RISK DOWN SYNDROME B After Screening Risk Down Syndrome Twin B
DOWN SYNDROME INTERPRETATION INTERPDOW DOWN SYNDROME INTERPRETATION Down Syndrome Interpretation
TRISOMY 18/13 TRISOMY1813 TRISOMY 18 13 Trisomy 18/13 Result
BEFORE SCREENING RISK TRISOMY 18/13 BSRTRI1813 BEFORE SCREENING RISK TRISOMY 18 13 Before Screening Risk Trisomy 18/13
AFTER SCREENING RISK TRISOMY 18/13 ASRTRI1813 AFTER SCREENING RISK TRISOMY 18 13 After Screening Risk Trisomy 18/13
AFTER SCREENING RISK TRISOMY 18/13 TWIN A ASRTRI1813 AFTER SCREENING RISK TRISOMY 18 13 TWIN A After Screening Risk Trisomy 18/13 Twin A
AFTER SCREENING RISK TRISOMY 18/13 TWIN B ASRTRI1813 AFTER SCREENING RISK TRISOMY 18 13 TWIN B After Screening Risk Trisomy 18/13 Twin B
TRISOMY 18/13 INTERPRETATION TRISOMY1813I TRISOMY1813INTERP Trisomy 18/13 Interpretation
EXTREME ANALYTE ALERT EXTANAALRT EXTREME ANALYTE ALERT Extreme Analyte Alert
MATERNAL AGE AT EDD MATERNALAGE MATERNALAGE, EDD Maternal Age at EDD
NT NT NT Nt
NUCHAL TRANSLUCENCY MOM NUCHTRANS NUCHAL TRANSLUCENCY MOM Nuchal Translucency MoM
NT TWIN B TWINB NT TWIN B
NUCHAL TRANSLUCENCY MOM TWIN B NUCHTRANMOMB NUCHAL TRANSLUCENCY MOM TWIN B Nuchal Translucency MoM Twin B
MS NASAL BONE NASALBONE MS NASAL BONE
MS NASAL BONE TWIN B NASALBONE MS NASAL BONE TWIN B
AFP CONCENTRATION, 1ST TRIMESTER AFPCONC AFP CONCENTRATION, 1ST TRIMESTER AFP Concentration, 1st Trimester
AFP MOM AFPMOM AFP MOM AFP MoM
AFP PERCENTILE AFPPCT AFP PERCENTILE AFP Percentile
FREE BETA HCG 1ST TRIMESTER FBHCG1STTRI FREE BETA HCG 1ST TRIMESTER Free Beta hCG Concentration, 1st Trimester
FREE BETA HCG MOM FREEBETA FREE BETA HCG MOM Free Beta hCG MoM
FREE BETA HCG PERCENTILE FREEBETA FREE BETA HCG PERCENTILE Free Beta hCG Percentile
INHIBIN CONCENTRATION, 1ST TRIMESTER INHIBINCONC INHIBIN CONCENTRATION, 1ST TRIMESTER Inhibin Concentration, 1st Trimester
INHIBIN MOM INHIBIN INHIBIN MOM Inhibin MoM
INHIBIN PERCENTILE INHIBIN INHIBIN PERCENTILE Inhibin Percentile
PAPP-A VALUE PAPPAVAL PAPP A VALUE PAPP-A Concentration
PAPP-A MOM PAPPAMOM PAPP A MOM PAPP-A MoM
PAPP A PERCENTILE PAPPAPCT PAPP A PERCENTILE PAPP-A Percentile
PLGF PLGF PLGF PlGF Concentration
PLGF MOM PLGFMOM PLGF MOM PlGF MoM
PLGF PERCENTILE PLGFPCT PLGF PERCENTILE PlGF Percentile
1T MAP 1TMAP 1T MAP 1T MAP
MAP MOM MAPMOM MAP MOM MAP MoM
UTAD-PI MEAN UTADPIMEAN UTAD PI MEAN UtAD-PI Mean
UTAD-PI MOM UTADPIMOM UTAD PI MOM UtAD-PI MoM
PREGNANCY INTERVAL PREGINT PREGNANCY INTERVAL Pregnancy Interval
GA AT MAP GAATMAP GA AT MAP GA at MAP
DATE OF MAP DATEOFMAP DATE OF MAP Date of MAP
GA AT U/A GESTAGE GA AT UA GA at U/A
GESTATIONAL AGE GESTAGE GESTATIONAL AGE Gestational Age
MS SONOGRAPHER SONOG MS SONOGRAPHER
SONOGRAPHER SUPERVISOR SONOG SONOGRAPHER SUPERVISOR Sonographer Supervisor
DATE COMPLETED DATECOMP DATE COMPLETED Ultrasound Date
MS CRL CRLSCAN MS CRL
MS CRL TWIN B CRLSCANTWINB MS CRL TWIN B
UTAD-PI LEFT UTAD UTAD-PI LEFT UtAD-PI Left
UTAD-PI RIGHT UTAD UTAD-PI RIGHT UtAD-PI Right
BP DATE BP BP DATE BP Date
SYSTOLIC BP LEFT ARM 1 SBP SYSTOLIC BP LEFT ARM 1 Systolic BP Left Arm 1
DIASTOLIC BP LEFT ARM 1 DBP DIASTOLIC BP LEFT ARM 1 Diastolic BP Left Arm 1
SYSTOLIC BP RIGHT ARM 1 SBP SYSTOLIC BP RIGHT ARM 1 Systolic BP Right Arm 1
DIASTOLIC BP RIGHT ARM 1 DBP DIASTOLIC BP RIGHT ARM 1 Diastolic BP Right Arm 1
SYSTOLIC BP LEFT ARM 2 SBP SYSTOLIC BP LEFT ARM 2 Systolic BP Left Arm 2
DIASTOLIC BP LEFT ARM 2 DBP DIASTOLIC BP LEFT ARM 2 Diastolic BP Left Arm 2
SYSTOLIC BP RIGHT ARM 2 SBP SYSTOLIC BP RIGHT ARM 2 Systolic BP Right Arm 2
DIASTOLIC BP RIGHT ARM 2 DBP DIASTOLIC BP RIGHT ARM 2 Diastolic BP Right Arm 2
MATERNAL HEIGHT (IN) HEIGHT MATERNAL HEIGHT (IN) Maternal Height (in)
DIABETES STATUS DM DIABETES STATUS Diabetes Status
CHRONIC HYPERTENSION HTN CHRONIC HYPERTENSION Chronic Hypertension
SYSTEMIC LUPUS ERYTHEMATOSUS SLE SYSTEMIC LUPUS ERYTHEMATOSUS Systemic Lupus erythematosus
ANTI-PHOSPHOLIPID SYNDROME APLS ANTI-PHOSPHOLIPID SYNDROME Anti-phospholipid Syndrome
MOTHER HIST OF PREECLAMPSIA PRECLMPHX MOTHER HIST OF PREECLAMPSIA Mother Hist of Preeclampsia
OBSTETRIC HISTORY OBHX OBSTETRIC HISTORY Obstetric History
EGG DONOR AGE AT RETRIEVAL EGGDONORAGE EGG DONOR AGE AT RETRIEVAL Egg Donor Age at Retrieval
MS CHORIONICITY CHORIONICITY MS CHORIONICITY
DATE OF DELIVERY LAST PREGNANCY DATEOFPREG DATE OF DELIVERY LAST PREGNANCY Date of Delivery Last Pregnancy
GEST WEEKS AT LAST PREG GESTWKS GEST WEEKS AT LAST PREG Gest Weeks At Last Preg
GEST DAYS AT DEL LAST PREG GESTDAYS GEST DAYS AT DEL LAST PREG Gest Days at Del Last Preg
PREV PREG WITH DOWN SYNDROME PREVPREGDOWN PREV PREG WITH DOWN SYNDROME Prev Preg with Down Syndrome
GEN TEST INFORMATION GENTEST GEN TEST INFORMATION Disclaimer

Result Interpretation

Result Interpretation    Risk Calculation: 
Each marker level is converted into a multiple of the GA specific median (MoM) and is then adjusted as applicable based on the patient's race, weight, diabetic status, multiple pregnancy status, egg donor status, and smoking status.  The likelihood ratio for each analyte is calculated as the ratio of the probability density function in affected pregnancies divided by the probability density function for unaffected pregnancies.  
Patient specific risks for Down syndrome and trisomy18/13 are calculated using Bayes’ rule. The prior risk, based on demographic factors, is multiplied by the likelihood ratios for each maker appropriate for the condition screened. 
Patient specific risks for pre-term preeclampsia are calculated following the competing risks approach developed by the Fetal Medicine Foundation (FMF) using Bayes theorem to combine the a priori risk from maternal characteristics and medical history with the results of the  biophysical and biochemical measurements.   This approach assumes that if the pregnancy was to continue indefinitely all women would eventually develop PE and whether they do so or not depends on competition between which comes first, delivery or the development of PE. This approach allows the estimation of the individual patient-specific risks of delivery with preeclampsia before 37 weeks gestational age. 

An interpretive risk report including the patient's marker levels, cut-off values and risks for trisomy 21, trisomies 18/13 and pre-term preeclampsia will be provided.

Down’s Syndrome (trisomy 21) Interpretation: 
The risk cut-off is set equal to the first-trimester risk of a 35 year old (1/250).  This test may detect 98% of cases with Down’s syndrome at an approximate 2% false positive rate. 

Edward Syndrome (trisomy 18)/Patau Syndrome (trisomy 13) Interpretation: 
The risk cut-off is set equal to 1/100. This cut-off is chosen to balance the detection and false positive rates.  This test may detect 95% of cases with T18/13 at an approximate 0.5% false positive rate.

Pre-Term Preeclampsia Interpretation:
The risk cut-off is set equal to 1/150.  This test may detect over 80% of cases destined to develop preeclampsia necessitating delivery prior to 37weeks gestational age including over 90% of cases <34 weeks at an approximate 15% false positive rate.

Since the prior risk of twins is high, most twins will screen positive. Comparison of the after screening risk to the before screening risk may be of assistance in evaluating the pregnancy.

Test Follow Up: 
If the patient's risk is less than the cut-off risk the test is considered "Within Normal Range" and no further action is required. If the patient’s risk is greater than or equal to the cut-off risk the test is considered "Increased Risk". 

Patients at increased risk of trisomy 21 or trisomies 18/13 are offered detailed ultrasound, NIPT and/or diagnostic amniocentesis.

Patients at increased risk for preterm preeclampsia may be offered: 
1.    Education regarding the signs and symptoms of preeclampsia
2.    Increased monitoring including the option of home blood pressure monitoring
3.    Prophylactic low-dose aspirin starting prior to 16 weeks to reduce the risk of preeclampsia, IUGR and Preterm Delivery.

Upon receiving screening results, all information used in the risk calculations should be reviewed for accuracy (i.e., weight, diabetic status, gestational dating). If any information is incorrect, the laboratory should be contacted for recalculation of the estimated risks. ‘Within Range’ risk results typically do not warrant further evaluation. The screen results are dependent on accurate demographic information.  Inaccurate information can lead to significant alterations in the estimated risk. In particular, erroneous assessment of gestational age can result in false-positive or false-negative screen results. 

Disclaimers
This is a screening test, not a diagnostic test. A ‘Within Range’ risk result indicates low risk for the conditions screened but does not guarantee the absence of those conditions or other abnormalities. An ‘Increased Risk’ result indicates an increased risk for the condition screened but does not infer a definitive diagnosis. 

Cautions
Valid measurements of maternal serum markers cannot be made after CVS or amniocentesis. Triplets and higher order multiple pregnancies cannot be interpreted. In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results and the laboratory should be alerted if the result does not correlate with the clinical presentation.

Each center offering 1T  Maternal Fetal Screening to patients should establish a standard screening protocol, which provides pre- and post-screening education and appropriate follow-up for ‘Increased Risk’ results.

Clinical References 
1.    ACOG Practice Bulletin 226 - Screening for Fetal Chromosomal Abnormalities.  Obstet Gynecol VOL. 136, NO. 4, OCTOBER 2020. 
2.    NJ Wald, C Rodeck, AK Hackshaw, J Walters, L Chitty, AM Mackinson.  First and second trimester antenatal screening for Down’s syndrome:  the results of the Serum, Urine and Ultrasound Screening Study (SURUSS). (2003) Health Technology Assessment Vol. 7: No. 11. 
3.    Fergal D. Malone, M.D., Jacob A. Canick, Ph.D., Robert H. Ball, M.D., David A. Nyberg, M.D., Christine H. Comstock, M.D., Radek Bukowski, M.D., Richard L. Berkowitz, M.D., Susan J. Gross, M.D., Lorraine Dugoff, M.D., Sabrina D. Craigo, M.D., Ilan E. Timor-Tritsch, M.D., Stephen R. Carr, M.D., Honor M. Wolfe, M.D., Kimberly Dukes, Ph.D., Diana W. Bianchi, M.D., Alicja R. Rudnicka, Ph.D., Allan K. Hackshaw, M.Sc., Geralyn Lambert-Messerlian, Ph.D., Nicholas J. Wald, F.R.C.P., and Mary E. D’Alton, M.D., for the First- and Second-Trimester Evaluation of Risk (FASTER) Research Consortium* (2005) First-Trimester or Second-Trimester Screening, or Both, for Down’s Syndrome.  N Engl J Med 353;19 2001-2011. 
4.    Carmichael JB, Liu HP, Janik D, Hallahan TW, Nicolaides KH and Krantz DA.  Expanded conventional first trimester screening.  Prenatal Diagnosis 2017, 37, 802–807. 
5.    Rolnik DL, Wright D, Poon LC, et al. Aspirin versus placebo in pregnancies at high risk for preterm preeclampsia. N Engl J Med 2017;377: 613–22.
6.    Akolekar R, Syngelaki A, Poon L, Wright D, Nicolaides KH. Competing risks model in early screening for preeclampsia by biophysical and biochemical markers. Fetal Diagn Ther 2013;33: 8–15.
7.    Rolnik DL, Wright D, Poon LCY, et al.  ASPRE trial: performance of screening for pre-term pre-eclampsia. Ultrasound Obstet Gynecol 2017;50:492–5.
8.     Chaemsaithong P, Sahota DS, Poon LC.  First trimester preeclampsia screening and prediction. Am J Obstet Gynecol. 2022 Feb;226(2S):S1071-S1097.e2.
9.    Foster AB, Park, F, Hyett J.  Do first‐trimester screening algorithms for preeclampsia aligned to use of preventative therapies reduce the prevalence of pre‐term preeclampsia: A systematic review and meta‐analysis.  Prenatal Diagnosis. 2023;43:950–958.

Forms
Prenatal LAB4214 build edit