{"id":274787,"date":"2026-04-09T13:06:34","date_gmt":"2026-04-09T13:06:34","guid":{"rendered":"https:\/\/pharmeasy.in\/blog\/?p=274787"},"modified":"2026-04-09T13:06:34","modified_gmt":"2026-04-09T13:06:34","slug":"diagnostic-nt-scan-vs-double-marker-test-timing-differences-results-how-they-work-together","status":"publish","type":"post","link":"https:\/\/pharmeasy.in\/blog\/diagnostic-nt-scan-vs-double-marker-test-timing-differences-results-how-they-work-together\/","title":{"rendered":"NT Scan vs Double Marker Test: Timing, Differences, Results & How They Work Together"},"content":{"rendered":"\n\n<\/head>

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<\/span>Introduction<\/strong><\/span><\/h2>\n\n\n\nDuring early pregnancy, women undergo several screening tests to\u00a0monitor\u00a0the baby\u2019s growth and\u00a0development\u00a0and\u00a0detect\u00a0potential abnormalities,\u00a0making it an important stage of care 1<\/a><\/sup>.\u00a0Among these, the\u00a0most commonly advised\u00a0tests include\u00a0the\u00a0nuchal translucency (NT) scan and the double marker test. Both play\u00a0an important role\u00a0in the early weeks of pregnancy (first trimester)2<\/a>,3<\/a><\/sup>.<\/p>\n\n\n\n
These tests help evaluate the risks of genetic disorders like Down syndrome\u00a0in babies\u00a0by combining the scanning reports with certain biochemical markers\u00a0(measurable biological molecules)\u00a0in the mother\u2019s body 2<\/a>,3<\/a><\/sup>.\u00a0<\/p>\n\n\n\n
This article might help you better understand\u00a0what the NT scan and the double marker test\u00a0are,\u00a0their differences,\u00a0and how they are helpful together\u00a0to provide a more comprehensive risk assessment during early pregnancy.\u00a0<\/p>\n\n\n\n
<\/span>What Is an NT Scan?<\/strong><\/span><\/h2>\n\n\n\nAn NT scan is a specialised ultrasound performed during the first trimester of pregnancy, usually between\u00a011\u00a0to\u00a013weeks\u00a0+ 6days 3<\/a><\/sup>.\u00a0It is done to measure the\u00a0thickness of the nuchal fold (fluid-filled space)\u00a0on the back of the baby\u2019s neck.\u00a0This measurement is\u00a0known as nuchal translucency 2<\/a><\/sup>.<\/p>\n\n\n\n
This test helps\u00a0assess the risk of several genetic abnormalities, growth or developmental problems, and\u00a0structural\u00a0heart disease in babies.\u00a0In these conditions, greater fluid tends to accumulate in the nuchal space. Thus,\u00a0an increase in fluid,\u00a0shown as increased thickness of the nuchal space,\u00a0might\u00a0indicate\u00a0a\u00a0higher\u00a0risk\u00a0of these conditions.\u00a0However,\u00a0it\u00a0does\u00a0not confirm a problem\u00a0as\u00a0it\u00a0is just a\u00a0screening (not diagnostic)\u00a0test. Also,\u00a0there might be differences\u00a0in the values based on laboratories,\u00a0and the result is usually combined with other tests to estimate the risk 2<\/a><\/sup>.<\/p>\n\n\n\n
<\/span>What Is a Double Marker Test?<\/strong><\/span><\/h2>\n\n\n\nThe double marker test<\/a><\/strong> is\u00a0a\u00a0screening blood test done during the first trimester, normally between 10 to\u202f13 weeks\u00a0+ 6 days\u202fof\u202fpregnancy 4<\/a><\/sup>,\u00a0ideally along with the NT scan.\u00a0It measures the levels of two components in the mother\u2019s\u00a0blood,\u00a0free beta-human chorionic gonadotropin (\u03b2-hCG)\u00a0and\u00a0pregnancy-associated plasma protein-A\u00a0(PAPP-A), a hormone and\u00a0a\u00a0protein secreted by the placenta\u00a0(the tissue that connects the mother to the baby)\u00a0that helps in the proper functioning of the placenta and normal development of the baby 5<\/a>,6<\/a><\/sup>.<\/p>
<\/div>

Feature<\/strong>\u00a0<\/strong>\u00a0<\/td>	NT Scan<\/strong>\u00a0<\/td>	Double Marker Test<\/strong>\u00a0<\/td><\/tr>
Type of test\u00a0<\/td>	Ultrasound (Imaging)^{2<\/a><\/sup>\u00a0<\/td>}	Blood test (Laboratory)^{3<\/a><\/sup>\u00a0<\/td><\/tr>}
Procedure\u00a0\u00a0<\/td>	Non-invasive\u00a0(surface test without inserting any instruments into the body)^{2<\/a><\/sup>\u00a0<\/td>}	Simple blood collection^{3<\/a><\/sup>\u00a0<\/td><\/tr>}
What it measures\u00a0<\/td>	Thickness of the\u00a0skin fold\u00a0behind the baby\u2019s neck^{2<\/a><\/sup>\u00a0<\/td>}	Levels of PAPP-A and free-hCG^{3<\/a><\/sup>\u00a0<\/td><\/tr>}
Interpretation\u00a0<\/td>	Based on gestational age\u00a0using percentiles^{7<\/a><\/sup>\u00a0<\/td>}	MoM (Multiple of Median- compares your values to the average for your pregnancy stage)^{3<\/a><\/sup>\u00a0<\/td><\/tr>}
Purpose\u00a0<\/td>	Assess structural\u00a0(congenital\u00a0heart\u00a0disease)\u00a0and genetic abnormalities (e.g. Down syndrome)^{2<\/a><\/sup>\u00a0<\/td>}	Assess the risk of genetic disorders such as Down syndrome, Edward syndrome, etc^{3<\/a><\/sup>.\u00a0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<\/span>How Do These Tests Work Together?<\/strong><\/span><\/h2>\n\n\n\nYou might have understood\u00a0what NT scan and double marker test\u00a0are. But do you know that they might give more\u00a0accurate\u00a0results when combined rather than performed individually?\u00a0<\/p>\n\n\n\nYes, the\u00a0NT scan and\u00a0the double\u00a0marker test are used together in early pregnancy to check the baby\u2019s health more accurately8<\/a><\/sup>.\u00a0While\u00a0the\u00a0NT scan\u00a0assesses physical changes by\u00a0measuring\u00a0the skin fold or fluid-filled space behind baby\u2019s neck,\u00a0the\u00a0double marker test\u00a0evaluates wo biochemical components in the mother\u2019s blood\u00a0to estimate\u00a0the\u00a0risk of genetic conditions\u00a0and structural issues.\u00a0The results from both tests are combined\u00a0using a\u00a0reliable\u00a0risk algorithm\u00a0that include mother\u2019s\u00a0age, NT\u00a0report, and serum markers\u00a0to give one overall risk score2<\/a>,3<\/a><\/sup>.\u00a0<\/p>\n\n\n\n As the combined\u00a0results of these tests may give\u00a0a more\u00a0accurate\u00a0picture than alone, it might\u00a0help\u00a0your\u00a0doctor\u00a0estimate the chances of certain chromosome-related conditions like Down syndrome.\u00a0If the risks look too high, the doctor may suggest further testing for confirmation3<\/a>,8<\/a><\/sup>.\u00a0<\/p>\n\n\n\n <\/span>When Are These Tests Done?<\/strong><\/span><\/h2>\n\n\n\nBoth the\u00a0NT scan and the double marker test\u00a0are done during the first trimester, usually between 10\u00a0and\u00a014 weeks.\u00a0<\/p>\n\n\n\n\nNT\u00a0Scan:<\/strong>\u00a0Typically done between 10\u00a0weeks and 13 weeks + 6 days, when the baby\u2019s\u00a0neck\u00a0is clearly visible\u00a0and measured under the ultrasound3<\/a><\/sup>.<\/li>\n\n\n\n Double Marker Test:<\/strong>\u00a0Usually\u00a0performed between 10 to 14 weeks\u00a0(10\u00a0weeks and 13 weeks + 6 days),\u00a0using a blood sample from the mother3<\/a><\/sup>.<\/li>\n<\/ul>\n\n\n\n<\/span>Conclusion<\/strong><\/span><\/h2>\n\n\n\nThe\u00a0NT scan and double marker test\u00a0are two\u00a0of\u00a0the most important tests performed during the pregnancy period\u00a0to detect\u00a0chromosomal conditions, such as Down syndrome and other genetic\u00a0and structural\u00a0abnormalities.\u00a0These tests, when used together, might increase the accuracy\u00a0of assessment rather than\u00a0when\u00a0tested alone. Doctors can evaluate single and combined risk scores by\u00a0combining\u00a0ultrasound outcomes from\u00a0the\u00a0NT scan and biochemical results from\u00a0the\u00a0double marker test.\u00a0Based on these\u00a0results, they can assess whether further tests are\u00a0required, which\u00a0might\u00a0help\u00a0ensure\u00a0timely\u00a0and proper care during early pregnancy.\u00a0<\/p>\n\n\n\n<\/span>Frequently Asked Questions (FAQs)<\/strong><\/span><\/h2>\n\n\n\nShould an NT scan and double marker test be done on the same day?<\/strong>\u00a0<\/strong> The NT scan and double marker test are performed\u00a0between 11\u00a0and\u00a014 weeks, as\u00a0testing combining them might give more\u00a0accurate\u00a0results rather than being done alone3<\/a>,8<\/a><\/sup>.\u00a0Therefore,\u00a0it might be good enough to perform these tests on the same day, which might make the procedure less hectic for the mother and might\u00a0make it\u00a0easy to correlate\u00a0the results.\u00a0<\/p> <\/div> In which month is the double marker test done?<\/strong>\u00a0<\/strong> The double marker test is usually performed between 10\u00a0and 13\u00a0weeks+ 6 days\u00a0of pregnancy4<\/a><\/sup>,\u00a0which means between\u00a0the\u00a03^{rd<\/sup>\u00a0and 4^{th<\/sup>\u00a0months.\u00a0\u00a0<\/p> <\/div>}} Can the NT scan or\u00a0double\u00a0marker test confirm if my\u00a0baby\u00a0has a genetic condition?<\/strong><\/strong> NT scan and\u00a0double\u00a0marker tests\u00a0may not confirm\u00a0a baby\u2019s genetic conditions,\u00a0as they are only screening tests. They only\u00a0evaluate\u00a0the risk\u00a0of a baby having a genetic disorder. To confirm the genetic condition, the doctors perform\u00a0prenatal diagnostic testing, such as\u00a0chorionic villus sampling or amniocentesis4<\/a><\/sup>.<\/p> <\/div> What happens if one test is normal and the other shows\u00a0high risk?<\/strong><\/strong> If both the results show different\u00a0risk values, then they may not be interpreted by the doctor separately.\u00a0Instead,\u00a0both results\u00a0may be\u00a0combined to calculate a single overall risk score for conditions.\u00a0If the\u00a0combined result is\u00a0low risk, the pregnancy is usually considered normal,\u00a0and if it is high,\u00a0further tests may be recommended.\u00a0However, these\u00a0aren\u2019t\u00a0diagnostic\u00a0tests but\u00a0just screening tests. Further diagnostic tests\u00a0such as amniocentesis\u00a0may be performed to confirm the abnormalities\u00a0if risk is high in these4<\/a>,8<\/a><\/sup>.<\/p> <\/div> Do these tests pose any risk to the mother or baby?<\/strong>\u00a0<\/strong> These tests\u00a0are\u00a0usually\u00a0considered safe for both mother and\u00a0the\u00a0baby,\u00a0as they include\u00a0non-radiation\u00a0imaging and\u00a0a simple blood collection procedure.\u00a0However, sometimes\u00a0the double marker test can cause\u00a0small,\u00a0possibly rare\u00a0side effects like bruising,\u00a0bleeding, or localised\u00a0pain that\u00a0may occur in\u00a0the\u00a0mother\u00a0after blood collection4<\/a><\/sup>.<\/p> <\/div> <\/div>\n\n\n\n <\/span>References<\/strong><\/span><\/h2>\n\n\n\n1. Healthdirect Australia. Routine antenatal tests [Internet]. Canberra: Healthdirect Australia; [cited 2026 Apr 9]. Available from: https:\/\/www.healthdirect.gov.au\/routine-antenatal-tests\u00a0<\/a><\/p>\n\n\n\n 2. MedlinePlus. Nuchal translucency test [Internet]. Bethesda (MD): U.S. National Library of Medicine; [cited 2026 Apr 9]. Available from: https:\/\/medlineplus.gov\/ency\/article\/007561.htm\u00a0<\/a><\/p>\n\n\n\n 3. Shiefa S,\u00a0Amargandhi\u00a0M, Bhupendra J,\u00a0Moulali\u00a0S, Kristine T. First Trimester Maternal Serum Screening Using Biochemical Markers PAPP-A and Free \u03b2-hCG\u00a0for Down Syndrome, Patau Syndrome and Edward Syndrome.\u00a0Ind J Clin\u00a0Biochem<\/em>. 2013;28(1):3-12. doi:10.1007\/s12291-012-0269-9. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/24381414\/<\/a><\/p>\n\n\n\n 4. Maines J, Langaker MD. Prenatal genetic screening [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan\u2013 [updated 2025 Apr 18; cited 2026 Apr 9]. Available from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK557702\/<\/a>\u00a0<\/p>\n\n\n\n 5. Ogino MH, Tadi P. Physiology, Chorionic Gonadotropin. In:\u00a0StatPearls<\/em>.\u00a0StatPearls\u00a0Publishing; 2026. Accessed March 31, 2026. Available from: http:\/\/www.ncbi.nlm.nih.gov\/books\/NBK556118\/\u00a0<\/a><\/p>\n\n\n\n 6.\u00a0Papamichail M,\u00a0Fasoulakis\u00a0Z, Daskalakis G, Theodora M,\u00a0Rodolakis\u00a0A,\u00a0Antsaklis\u00a0P. Importance of Low Pregnancy Associated Plasma Protein-A (PAPP-A) Levels During the First Trimester as a Predicting Factor for Adverse Pregnancy Outcomes: A Prospective Cohort Study of 2636 Pregnant Women.\u00a0Cureus<\/em>. 14(11):e31256. doi:10.7759\/cureus. 31256. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/36505175\/<\/a><\/p>\n\n\n\n 7. Kaul A, Radhakrishnan P. Performance of Common Down Syndrome Screening Methods Used in India with Construction of an Indian\u00a0Normogram\u00a0for Nuchal Translucency\/Crown\u2013Rump Length Measurements in 14,337 Subjects.\u00a0J Obstet\u00a0Gynecol\u00a0India<\/em>. 2019;69(S2):142-146. doi:10.1007\/s13224-018-1196-3. Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/31686747\/<\/a><\/p>\n\n\n\n 8. Heidari R,\u00a0Akbariqomi\u00a0M,\u00a0Motevaseli\u00a0E, et al. Performance and Predictive Value of First Trimester Screening Markers for Down Syndrome in Iranian Pregnancies.\u00a0J Family\u00a0Reprod\u00a0Health<\/em>. 2018;12(3):121-128.\u00a0Available from: https:\/\/pubmed.ncbi.nlm.nih.gov\/31223317\/<\/a><\/p>\n\n\n\n Disclaimer<\/em><\/strong>: The information provided here is for educational\/awareness purposes only and is not intended to be a substitute for medical treatment by a healthcare professional and should not be relied upon to diagnose or treat any medical condition. The reader should consult a registered medical practitioner to determine the appropriateness of the information and before consuming any medication. PharmEasy does not provide any guarantee or warranty (express or\u00a0implied) regarding the accuracy, adequacy, completeness, legality, reliability or usefulness of the information; and disclaims any liability arising thereof.<\/em>\u00a0<\/p>\n\n\n\n Links and product recommendations in the information<\/em>\u00a0provided here are advertisements of third-party products available on the website. PharmEasy does not make any representation on the accuracy or suitability of such products\/services. Advertisements do not influence the editorial decisions or content. The information in this blog is subject to change without notice. The authors and administrators reserve the right to modify, add, or remove content without notification. It is your responsibility to review this disclaimer regularly for any changes.<\/em><\/p>\n<\/body><\/html>\n \r\n \r\n \r\n \r\n <\/a>\r\n <\/span>\r\n<\/div>\r\n \r\n \r\n <\/a>\r\n <\/span>\r\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"Introduction During early pregnancy, women undergo several screening tests to\u00a0monitor\u00a0the baby\u2019s growth and\u00a0development\u00a0and\u00a0detect\u00a0potential abnormalities,\u00a0making it an important stage of care1.\u00a0Among these, the\u00a0most commonly advised\u00a0tests include\u00a0the\u00a0nuchal translucency (NT) scan and the double marker test. Both play\u00a0an important role\u00a0in the early weeks of pregnancy (first trimester)2,3. These tests help evaluate the risks of genetic disorders like Down [\u2026]","protected":false},"author":164,"featured_media":274817,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_wp_rev_ctl_limit":""},"categories":[10435],"tags":[14167,14169],"acf":[],"_embedded":{"wp:featuredmedia":[{"source_url":"https:\/\/pharmeasy.in\/blog\/wp-content\/uploads\/2026\/04\/nt-scan-vs-double-marker-test.webp"}]},"_links":{"self":[{"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/posts\/274787"}],"collection":[{"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/users\/164"}],"replies":[{"embeddable":true,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/comments?post=274787"}],"version-history":[{"count":7,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/posts\/274787\/revisions"}],"predecessor-version":[{"id":274840,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/posts\/274787\/revisions\/274840"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/media\/274817"}],"wp:attachment":[{"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/media?parent=274787"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/categories?post=274787"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pharmeasy.in\/blog\/wp-json\/wp\/v2\/tags?post=274787"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}}