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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">akusherstvo</journal-id><journal-title-group><journal-title xml:lang="en">Obstetrics, Gynecology and Reproduction</journal-title><trans-title-group xml:lang="ru"><trans-title>Акушерство, Гинекология и Репродукция</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2313-7347</issn><issn pub-type="epub">2500-3194</issn><publisher><publisher-name>IRBIS LLC</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.17749/2313-7347.2020.14.1.34-43</article-id><article-id custom-type="elpub" pub-id-type="custom">akusherstvo-623</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>ОRIGINAL ARTICLES</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>ОРИГИНАЛЬНЫЕ СТАТЬИ</subject></subj-group></article-categories><title-group><article-title>First trimester prenatal screening in multiple pregnancies. Part II: serum proteins PAPP-A and β-hCG as markers of adverse pregnancy outcomes</article-title><trans-title-group xml:lang="ru"><trans-title>Пренатальный скрининг первого триместра при многоплодной беременности. Часть II: сывороточные белки PAPP-A и β-ХГЧ как маркеры неблагоприятных исходов беременности</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-5888-0774</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Цибизова</surname><given-names>В. И.</given-names></name><name name-style="western" xml:lang="en"><surname>Tsibizova</surname><given-names>V. I.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Цибизова Валентина Ивановна - врач отделения функциональной и ультразвуковой диагностики.</p><p>197341 Санкт-Петербург, ул. Аккуратова, д. 2</p></bio><bio xml:lang="en"><p>Valentina I. Tsibizova - MD, Departments of Functional and Ultrasound Diagnostics.</p><p>2 Akkuratova St., Saint Petersburg 197341</p></bio><email xlink:type="simple">tsibizova.v@gmail.com</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-1809-0270</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Говоров</surname><given-names>И. Е.</given-names></name><name name-style="western" xml:lang="en"><surname>Govorov</surname><given-names>I. E.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Говоров Игорь Евгеньевич - кандидат медицинских наук, акушер-гинеколог, доктор философии по медицине, НИЛ оперативной гинекологии Института перинатологии и педиатрии, Scopus Author ID: 57188586021. Researcher ID: P-1257-2015.</p><p>197341 Санкт-Петербург, ул. Аккуратова, д. 2</p></bio><bio xml:lang="en"><p>Igor E. Govorov - MD, PhD, Obstetrician-Gynecologist, Research Laboratory of Operative Gynecology, Institute of Perinatology and Pediatrics, Scopus Author ID: 57188586021, Researcher ID: P-1257-2015.</p><p>2 Akkuratova St., Saint Petersburg 197341</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Первунина</surname><given-names>Т. М.</given-names></name><name name-style="western" xml:lang="en"><surname>Pervunina</surname><given-names>T. M.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Первунина Татьяна Михайловна - кандидат медицинских наук, директор Института перинатологии и педиатрии.</p><p>197341 Санкт-Петербург, ул. Аккуратова, д. 2</p></bio><bio xml:lang="en"><p>Tatiana М. Pervunina - MD, PhD, Director of the Institute of Perinatology and Pediatrics.</p><p>2 Akkuratova St., Saint Petersburg 197341</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-2943-0883</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Комличенко</surname><given-names>Э. В.</given-names></name><name name-style="western" xml:lang="en"><surname>Komlichenko</surname><given-names>E. V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Комличенко Эдуард Владимирович - доктор медицинских наук, зам. директора Института перинатологии и педиатрии, Researcher ID: N-5315-2015.</p><p>197341 Санкт-Петербург, ул. Аккуратова, д. 2</p></bio><bio xml:lang="en"><p>Eduard V. Komlichenko - MD, Dr Sci Med, Deputy Director of the Institute of Perinatology and Pediatrics, Researcher ID: N-5315-2015.</p><p>2 Akkuratova St., Saint Petersburg 197341</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кудряшова</surname><given-names>Е. К.</given-names></name><name name-style="western" xml:lang="en"><surname>Kudryashova</surname><given-names>E. K.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Кудряшова Елена Константиновна - заведующий отделением медико-генетической консультации.</p><p>194291 Санкт-Петербург, пр. Луначарского, д. 45-49</p></bio><bio xml:lang="en"><p>Elena K. Kudryashova - Head of the Department of Medical Genetic Counseling, Leningrad Regional CH.</p><p>45-49 Lunacharsky Ave., Saint Petersburg 194291</p></bio><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-3367-9844</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Блинов</surname><given-names>Д. В.</given-names></name><name name-style="western" xml:lang="en"><surname>Blinov</surname><given-names>D. V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Блинов Дмитрий Владиславович - кандидат медицинских наук, руководитель по медицинским и научным вопросам, ИПиСМ; врач-невролог, Клинический Госпиталь Лапино, ГК Мать и Дитя, Researcher ID: E-8906-2017, RSCI: 9779-8290.</p><p>127006 Москва, ул. Садовая-Триумфальная, д. 4-10; 143081 Московская область, Лапино, 1-ое Успенское шоссе, д. 111</p></bio><bio xml:lang="en"><p>Dmitry V. Blinov - MD, PhD, MBA, Head of Medical and Scientific Affairs, IPand SM; Neurologist, Lapino Clinic Hospital, GC Mother and Child, Researcher ID: E-8906-2017. RSCI: 9779-8290.</p><p>45-49 Lunacharsky Ave., Saint Petersburg 194291</p></bio><xref ref-type="aff" rid="aff-3"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7415-4633</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Макацария</surname><given-names>А. Д.</given-names></name><name name-style="western" xml:lang="en"><surname>Makatsariya</surname><given-names>A. D.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Макацария Александр Давидович - доктор медицинских наук, академик РАН, профессор, заведующий кафедрой акушерства и гинекологии Клинического института детского здоровья имени Н.Ф. Филатова Первый МГМУ им. И.М. Сеченова, Scopus Author ID: 6602363216, Researcher ID: M-5660-2016.</p><p>109004 Москва, ул. Земляной Вал, д. 62</p></bio><bio xml:lang="en"><p>Alexander D. Makatsariya - MD, Dr Sci Med, Academician of RAS, Professor, Head of the Department of Obstetrics and Gynecology, Scopus Author ID: 6602363216, Researcher ID: M-5660-2016.</p><p>62 St. Zemlyanoi Val, Moscow 109004</p></bio><xref ref-type="aff" rid="aff-4"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-4467-240X</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Ди Ренцо</surname><given-names>Д. К.</given-names></name><name name-style="western" xml:lang="en"><surname>Di Renzo</surname><given-names>G. C.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Ди Ренцо Джан Карло - профессор кафедры акушерства и гинекологии Первый МГМУ им. И.М. Сеченова; директор Центра пренатальной и репродуктивной медицины Университета Перуджи; почетный генеральный секретарь Международной федерации акушеров-гинекологов (FIGO), Scopus Author ID: 7103191096. Researcher ID: P-3819-2017.</p><p>109004 Москва, ул. Земляной Вал, д. 62; Умбрия, Перуджа, Piazza Italia</p></bio><bio xml:lang="en"><p>Gian Carlo Di Renzo - MD, Professor, Department of Obstetrics and Gynecology, SU; Director of the Center for Prenatal and Reproductive Medicine, University of Perugia,; Honorary Secretary General of the International Federation of Gynecology and Obstetrics (FIGO), Scopus Author ID: 7103191096, Researcher ID: P-3819-2017.</p><p>62 St. Zemlyanoi Val, Moscow 109004; Umbria, Perugia, Piazza Italia</p></bio><xref ref-type="aff" rid="aff-5"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>ФГБУ «Национальный медицинский исследовательский центр имени В.А. Алмазова» Министерства здравоохранения Российской Федерации</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Almazov National Medical Research Centre, Health Ministry of Russian Federation</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>ГБУЗ Ленинградская областная клиническая больница</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Leningrad Regional Clinical Hospital</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-3"><aff xml:lang="ru"><institution>Институт Превентивной и Социальной Медицины; Клинический госпиталь Лапино, ГК «Мать и Дитя»</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Institute for Preventive and Social Medicine; Lapino Clinical Hospital, GC «Mother and Child»</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-4"><aff xml:lang="ru"><institution>ФГАОУ ВО Первый Московский государственный медицинский университет имени И.М. Сеченова Министерства здравоохранения Российской Федерации (Сеченовский университет)</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Sechenov University</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-5"><aff xml:lang="ru"><institution>ФГАОУ ВО Первый Московский государственный медицинский университет имени И.М. Сеченова Министерства здравоохранения Российской Федерации (Сеченовский университет); Центр пренатальной и репродуктивной медицины Университета Перуджи</institution><country>Италия</country></aff><aff xml:lang="en"><institution>Sechenov University; Center for Prenatal and Reproductive Medicine, University of Perugia</institution><country>Italy</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2020</year></pub-date><pub-date pub-type="epub"><day>02</day><month>04</month><year>2020</year></pub-date><volume>14</volume><issue>1</issue><fpage>34</fpage><lpage>43</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Tsibizova V.I., Govorov I.E., Pervunina T.M., Komlichenko E.V., Kudryashova E.K., Blinov D.V., Makatsariya A.D., Di Renzo G.C., 2020</copyright-statement><copyright-year>2020</copyright-year><copyright-holder xml:lang="ru">Цибизова В.И., Говоров И.Е., Первунина Т.М., Комличенко Э.В., Кудряшова Е.К., Блинов Д.В., Макацария А.Д., Ди Ренцо Д.К.</copyright-holder><copyright-holder xml:lang="en">Tsibizova V.I., Govorov I.E., Pervunina T.M., Komlichenko E.V., Kudryashova E.K., Blinov D.V., Makatsariya A.D., Di Renzo G.C.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.gynecology.su/jour/article/view/623">https://www.gynecology.su/jour/article/view/623</self-uri><abstract><sec><title>Aim</title><p>Aim: to evaluate the ability of serum biochemical markers in pregnant woman - PAPP-A (pregnancy-associated plasma protein-A) and β-hCG (the в-subunit of human chorionic gonadotropin) studied in the first trimester (11+0-13+6) during combined prenatal screening to predict adverse perinatal outcomes of multiple pregnancy that occurred spontaneously and as a result of in vitro fertilization (IVF).</p></sec><sec><title>Materials and methods</title><p>Materials and methods. The main group consisted from 65 women with pregnancy occurred as a result of IVF; comparison group included 56 women with spontaneous pregnancy. All pregnancies were multiple and their outcomes were known. Serum PAPP-A and β-hCG levels were measured in the first trimester. The results were expressed in absolute values and in MoM (multiples of median). Subgroups were compared with mono- and dichorionic pregnancies, complicated and uncomplicated pregnancies, distributed according to MoM index: within the reference values (0.5-2.0), below or above the reference values.</p></sec><sec><title>Results</title><p>Results. PAPP-A MoM values in the spontaneous pregnancy group were 1.12 [0.8; 1.57], in the IVF group - 1.35 [1.11; 1.72] (p = 0.01). In subgroup of low PAPP-A MoM antenatal fetal death occurred in 50 %, in subgroup of normal PAPP-A MoM - in 14.58 %, in subgroup of high PAPP-A MoM - in 5.88 % (p = 0.011). In addition, a positive correlation was found between serum PAPP-A level and time of fetal death (rs = 0.564; p = 0.036). Low PAPP-A MoM values were associated with 50 % fetal mortality, 75 % of them were attributable to pregnancy as a result of IVF.</p></sec><sec><title>Conclusion</title><p>Conclusion. Identification of adverse outcomes in multiple pregnancies is still a difficult task, but evaluation of serum biochemical markers during the first trimester screening can help in early diagnosis of necessity and extent of timely prophylaxis.</p></sec></abstract><trans-abstract xml:lang="ru"><sec><title>Цель исследования</title><p>Цель исследования: оценить способность биохимических маркеров сыворотки крови беременной - PAPP-A (англ. pregnancy-associatedplasmaprotein-A, ассоциированный с беременностью протеин-А плазмы) и β-ХГЧ (свободная бета-субъединица хорионического гонадотропина человека), исследованных в I триместре (11+0-13+6) во время комбинированного пренатального скрининга, прогнозировать неблагоприятные перинатальные исходы многоплодной беременности, наступившей спонтанно и в результате экстракорпорального оплодотворения (ЭКО).</p></sec><sec><title>Материалы и методы</title><p>Материалы и методы. В основную группу вошли 65 женщин, беременность у которых наступила в результате ЭКО; 56 женщин со спонтанно наступившей беременностью составили группу сравнения. Во всех случаях беременности были многоплодными и были известны их исходы. ВI триместре измеряли уровни PAPP-A и β-ХГЧ в сыворотке крови. Результаты выражали в абсолютных значениях и в МоМ (англ. multiplesofmedian - значение, кратное медиане). Сравнивали подгруппы с моно- и дихориальными беременностями, осложненными и неосложненными беременностями, распределенные по показателю МоМ: в пределах референтных значений (0,5-2,0), ниже или выше границ референтных значений.</p></sec><sec><title>Результаты</title><p>Результаты. Значения PAPP-AMoM в группе спонтанных беременностей составили 1,12 [0,8; 1,57], в группе ЭКО - 1,35 [1,11; 1,72] (р = 0,01). В подгруппе PAPP-AMoM ниже референтных значений антенатальная гибель плода встречалась с частотой 50 %, в подгруппе нормального PAPP-AMoM - 14,58 %, в подгруппе PAPP-AMoM выше референтных значений - 5,88 % (р = 0,011). Кроме того, положительная корреляционная связь выявлена между уровнем PAPP-A в сыворотке и сроком антенатальной гибели плода (rs = 0,564; р = 0,036). Низкие показатели РАРР-А МоМ были связаны с 50 % летальностью плода, 75 % из которой приходились на беременности в результате ЭКО.</p></sec><sec><title>Заключение</title><p>Заключение. На сегодняшний день выявление неблагоприятных исходов в многоплодной беременности все еще является сложной задачей, но оценка биохимических маркеров сыворотки крови в течение скрининга I триместра может помочь в ранней диагностике с целью определения необходимости и объема мер своевременной профилактики.</p></sec></trans-abstract><kwd-group xml:lang="ru"><kwd>многоплодная беременность</kwd><kwd>скрининг I триместра</kwd><kwd>ассоциированный с беременностью протеин-А плазмы</kwd><kwd>РАРР-А</kwd><kwd>свободная бета-субъединица хорионического гонадотропина человека</kwd><kwd>β-ХГЧ</kwd><kwd>биохимический скрининг</kwd><kwd>двойня</kwd><kwd>экстракорпоральное оплодотворение</kwd><kwd>ЭКО</kwd></kwd-group><kwd-group xml:lang="en"><kwd>multiple pregnancy</kwd><kwd>first trimester screening</kwd><kwd>pregnancy-associated plasma protein-A</kwd><kwd>PAPP-A</kwd><kwd>human chorionic gonadotropin</kwd><kwd>free β-hCG</kwd><kwd>biochemical screening</kwd><kwd>twins</kwd><kwd>in vitro fertilization</kwd><kwd>IVF</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Alhamdan D., Bora S., Condous G. Diagnosing twins in early pregnancy. Best Pract Res Clin Obstet Gynecol. 2009;23(4):453—6. DOI: 10.1016/j.bpobgyn.2009.02.003.</mixed-citation><mixed-citation xml:lang="en">Alhamdan D., Bora S., Condous G. Diagnosing twins in early pregnancy. Best Pract Res Clin Obstet Gynecol. 2009;23(4):453—6. DOI: 10.1016/j.bpobgyn.2009.02.003.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Santolaya J., Faro R. Twins-twice more trouble? Clin Obstet Gynecol. 2012;55(1):296—306. DOI: 10.1097/GRF.0b013e3182446f51.</mixed-citation><mixed-citation xml:lang="en">Santolaya J., Faro R. Twins-twice more trouble? Clin Obstet Gynecol. 2012;55(1):296—306. DOI: 10.1097/GRF.0b013e3182446f51.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Chauhan S.P., Scardo J.A., Hayes E. et al. Twins: prevalence, problems, and preterm births. Am J Obstet Gynecol. 2010;203(4):305—15. DOI: 10.1016/j.ajog.2010.04.031.</mixed-citation><mixed-citation xml:lang="en">Chauhan S.P., Scardo J.A., Hayes E. et al. Twins: prevalence, problems, and preterm births. Am J Obstet Gynecol. 2010;203(4):305—15. DOI: 10.1016/j.ajog.2010.04.031.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Qin J.B., Wang H., Sheng X. et al. Assisted reproductive technology and risk of adverse obstetric outcomes in dichorionic twin pregnancies: a systematic review and meta-analysis. Fertil Steril. 2016;105(5):1180-92. DOI: 10.1016/j.fertnstert.2015.12.131.</mixed-citation><mixed-citation xml:lang="en">Qin J.B., Wang H., Sheng X. et al. Assisted reproductive technology and risk of adverse obstetric outcomes in dichorionic twin pregnancies: a systematic review and meta-analysis. Fertil Steril. 2016;105(5):1180-92. DOI: 10.1016/j.fertnstert.2015.12.131.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Spencer K. Screening for trisomy 21 in twin pregnancies in the first trimester using free p-hCG and PAPP-A, combined with fetal nuchal translucency thickness. Prenat Diagn. 2000;20(2):91-5. DOI: 10.1002/(sici)1097-0223(200002)20:2&lt;91::aid-pd759&gt;3.0.co;2-x.</mixed-citation><mixed-citation xml:lang="en">Spencer K. Screening for trisomy 21 in twin pregnancies in the first trimester using free p-hCG and PAPP-A, combined with fetal nuchal translucency thickness. Prenat Diagn. 2000;20(2):91-5. DOI: 10.1002/(sici)1097-0223(200002)20:2&lt;91::aid-pd759&gt;3.0.co;2-x.</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Gjerris A.C., Tabor A., Loft A. et al. First trimester prenatal screening among women pregnant after IVF/ICSI. Hum Reprod Update. 2012;18(4):350-9. DOI: 10.1093/humupd/dms010.</mixed-citation><mixed-citation xml:lang="en">Gjerris A.C., Tabor A., Loft A. et al. First trimester prenatal screening among women pregnant after IVF/ICSI. Hum Reprod Update. 2012;18(4):350-9. DOI: 10.1093/humupd/dms010.</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Linskens I.H., Spreeuwenberg M.D., Blankenstein M.A., van Vugt J.M. Early first-trimester free beta-hCG and PAPP-A serum distributions in monochorionic and dichorionic twins. Prenat Diagn. 2009;29(1):74-8. DOI: 10.1002/pd.2184.</mixed-citation><mixed-citation xml:lang="en">Linskens I.H., Spreeuwenberg M.D., Blankenstein M.A., van Vugt J.M. Early first-trimester free beta-hCG and PAPP-A serum distributions in monochorionic and dichorionic twins. Prenat Diagn. 2009;29(1):74-8. DOI: 10.1002/pd.2184.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Khalil A., Rodgers M., Baschat A. et al. ISUOG Practice Guidelines: role of ultrasound in twin pregnancy. Ultrasound Obstet Gynecol. 2016;47(2):247-63. 10.1002/uog.15821.</mixed-citation><mixed-citation xml:lang="en">Khalil A., Rodgers M., Baschat A. et al. ISUOG Practice Guidelines: role of ultrasound in twin pregnancy. Ultrasound Obstet Gynecol. 2016;47(2):247-63. 10.1002/uog.15821.</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Gjerris A., Loft A., Pinborg A. et al. The effect of a ‘vanishing twin’on biochemical and ultrasound first trimester screening markers for Down’s syndrome in pregnancies conceived by assisted reproductive technology. Hum Reprod. 2008;24(1):55-62. DOI: 10.1093/humrep/den362.</mixed-citation><mixed-citation xml:lang="en">Gjerris A., Loft A., Pinborg A. et al. The effect of a ‘vanishing twin’on biochemical and ultrasound first trimester screening markers for Down’s syndrome in pregnancies conceived by assisted reproductive technology. Hum Reprod. 2008;24(1):55-62. DOI: 10.1093/humrep/den362.</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Chasen S.T., Martinucci S., Perni S.C., Kalish R.B. First-trimester biochemistry and outcomes in twin pregnancy. J Reprod Med. 2009;54(5):312-4.</mixed-citation><mixed-citation xml:lang="en">Chasen S.T., Martinucci S., Perni S.C., Kalish R.B. First-trimester biochemistry and outcomes in twin pregnancy. J Reprod Med. 2009;54(5):312-4.</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Amor D.J., Xu J., Halliday J.L. et al. Pregnancies conceived using assisted reproductive technologies (ART) have low levels of pregnancy-associated plasma protein-A (PAPP-A) leading to a high rate of false-positive results in first trimester screening for Down syndrome. Hum Reprod. 2009;24(6):1330-8. DOI: 10.1093/humrep/dep046.</mixed-citation><mixed-citation xml:lang="en">Amor D.J., Xu J., Halliday J.L. et al. Pregnancies conceived using assisted reproductive technologies (ART) have low levels of pregnancy-associated plasma protein-A (PAPP-A) leading to a high rate of false-positive results in first trimester screening for Down syndrome. Hum Reprod. 2009;24(6):1330-8. DOI: 10.1093/humrep/dep046.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Giorgetti C., Vanden Meerschaut F., De Roo C. et al. Multivariate analysis identifies the estradiol level at ovulation triggering as an independent predictor of the first trimester pregnancy-associated plasma protein-A level in IVF/ICSI pregnancies. Hum Reprod. 2013;28(10):2636—42. DOI: 10.1093/humrep/det295.</mixed-citation><mixed-citation xml:lang="en">Giorgetti C., Vanden Meerschaut F., De Roo C. et al. Multivariate analysis identifies the estradiol level at ovulation triggering as an independent predictor of the first trimester pregnancy-associated plasma protein-A level in IVF/ICSI pregnancies. Hum Reprod. 2013;28(10):2636—42. DOI: 10.1093/humrep/det295.</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Tul N., Novak-Antolic Ż. Serum PAPP-A levels at 10-14 weeks of gestation are altered in women after assisted conception. Prenat Diagn. 2006;26(13):1206-11. DOI: 10.1002/pd.1589.</mixed-citation><mixed-citation xml:lang="en">Tul N., Novak-Antolic Ż. Serum PAPP-A levels at 10-14 weeks of gestation are altered in women after assisted conception. Prenat Diagn. 2006;26(13):1206-11. DOI: 10.1002/pd.1589.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Dunne C., Cho K., Shan A. et al. Peak serum estradiol level during controlled ovarian stimulation is not associated with lower levels of pregnancy-associated plasma protein-A or small for gestational age infants: a cohort study. J Obstet Gynaecol Can. 2017;39(10):870-9. DOI: 10.1016/j.jogc.2017.01.031.</mixed-citation><mixed-citation xml:lang="en">Dunne C., Cho K., Shan A. et al. Peak serum estradiol level during controlled ovarian stimulation is not associated with lower levels of pregnancy-associated plasma protein-A or small for gestational age infants: a cohort study. J Obstet Gynaecol Can. 2017;39(10):870-9. DOI: 10.1016/j.jogc.2017.01.031.</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Chasen S.T., Perni S.C., Predanic M. et al. Does a “vanishing twin” affect first-trimester biochemistry in Down syndrome risk assessment? Am J Obstet Gynecol. 2006;195(1):236-9. DOI: 10.1016/j.ajog.2006.01.044.</mixed-citation><mixed-citation xml:lang="en">Chasen S.T., Perni S.C., Predanic M. et al. Does a “vanishing twin” affect first-trimester biochemistry in Down syndrome risk assessment? Am J Obstet Gynecol. 2006;195(1):236-9. DOI: 10.1016/j.ajog.2006.01.044.</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Saygan-Karamursel B., Tekęam O., Aksu T. et al. Perinatal outcomes of spontaneous twins compared with twins conceived through intracytoplasmic sperm injection. JPerinat Med. 2006;34(2):132-8. DOI: 10.1515/JPM.2006.024.</mixed-citation><mixed-citation xml:lang="en">Saygan-Karamursel B., Tekęam O., Aksu T. et al. Perinatal outcomes of spontaneous twins compared with twins conceived through intracytoplasmic sperm injection. JPerinat Med. 2006;34(2):132-8. DOI: 10.1515/JPM.2006.024.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Asztalos E.V., Hannah M.E., Hutton E.K. et al. Twin Birth Study: 2-year neurodevelopmental follow-up of the randomized trial of planned cesarean or planned vaginal delivery for twin pregnancy. Am J Obstet Gynecol. 2016;214(3):371.e1-371.e19. DOI: 10.1016/j.ajog.2015.12.051.</mixed-citation><mixed-citation xml:lang="en">Asztalos E.V., Hannah M.E., Hutton E.K. et al. Twin Birth Study: 2-year neurodevelopmental follow-up of the randomized trial of planned cesarean or planned vaginal delivery for twin pregnancy. Am J Obstet Gynecol. 2016;214(3):371.e1-371.e19. DOI: 10.1016/j.ajog.2015.12.051.</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Corsello G., Piro E. The world of twins: an update. J Matern Fetal Neonatal Med. 2010;23(Suppl 3):59-62. DOI: 10.3109/14767058.2010.508218.</mixed-citation><mixed-citation xml:lang="en">Corsello G., Piro E. The world of twins: an update. J Matern Fetal Neonatal Med. 2010;23(Suppl 3):59-62. DOI: 10.3109/14767058.2010.508218.</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Suhag A., Berghella V. Intrauterine growth restriction (IUGR): etiology and diagnosis. Curr Obstet Gynecol Rep. 2013;2(2):102-11. DOI: 10.1007/s13669-013-0041-z.</mixed-citation><mixed-citation xml:lang="en">Suhag A., Berghella V. Intrauterine growth restriction (IUGR): etiology and diagnosis. Curr Obstet Gynecol Rep. 2013;2(2):102-11. DOI: 10.1007/s13669-013-0041-z.</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Bebbington M., Tiblad E., Huesler-Charles M. et al. Outcomes in a cohort of patients with Stage 1 twin-to-twin transfusion syndrome. Ultrasound Obstet Gynecol. 2010;36(1):48-51. DOI: 10.1002/uog.7612.</mixed-citation><mixed-citation xml:lang="en">Bebbington M., Tiblad E., Huesler-Charles M. et al. Outcomes in a cohort of patients with Stage 1 twin-to-twin transfusion syndrome. Ultrasound Obstet Gynecol. 2010;36(1):48-51. DOI: 10.1002/uog.7612.</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
