A impossibilidade de engravidar pode desencadear consequências psíquicas importantes, visto que barra a mulher no momento em que ela sente-se pronta para vivenciar a experiência da maternidade. Nesse sentido, a reprodução assistida vem possibilitando a maternidade para aquelas que não conseguiam conceber uma criança naturalmente. Contudo, percebe-se que os impactos emocionais não estão restritos à descoberta da infertilidade, estando presentes durante o processo do tratamento. Assim, para aquelas que obtiverem sucesso no tratamento, questiona-se a configuração da experiência de maternidade em meio a este contexto, que muitas vezes está atravessado por outro aspecto: a gravidez múltipla. Para abordar este fenômeno de forma ampla, foram realizados dois estudos. O Estudo 1 tinha como objetivo investigar a experiência da implantação de múltiplos embriões em mulheres que se submeteram à técnica FIV. Para tanto, foram analisadas entrevistas de mulheres que se submeteram à FIV e que mencionaram esta questão de implantação de múltiplos embriões espontaneamente. As entrevistas ocorreram no 3º trimestre gestacional destas participantes, contando inicialmente com 21 mulheres, restando após a seleção que discriminou as que não haviam trazido este tema 14 participantes. Percebeu-se que o tema da experiência da implantação em si foi comum estando presente nos relatos das 14 mulheres. Contudo, a gravidez múltipla despertara vivências distintas em relação à gravidez singular, pois na gravidez singular fantasias quanto à implantação de múltiplos embriões foram vivenciadas, mas nas mulheres que conceberam uma gravidez múltipla estas tinham se tornado concretas, de forma que estas mulheres pareciam estar se preparando para maternidade com mais de um bebê. O Estudo 2 tinha como objetivo investigar a experiência da maternidade de uma gravidez múltipla nesse contexto. Para tanto, contou com três mulheres que estavam no seu 3º trimestre gestacional. Neste estudo, ficou evidenciado o sofrimento destas mulheres ao se defrontarem com a infertilidade conjugal e ao se submeterem a tratamentos invasivos. Contudo, verificou-se que a experiência da gravidez pode reprimir este sofrimento para que estas mulheres vivenciem integralmente a experiência da maternidade. Neste sentido, este estudo levantou a discussão de que as TRA se configuram como uma forma distinta de concepção, entretanto, não levam a uma forma distinta de maternidade. / The impossibility of getting pregnant can lead to significant psychological effects, because it represents an obstacle for a woman at a time when she feels ready to go through the experience of motherhood. In this sense, assisted reproduction has enabled the experience of motherhood for those who could not conceive a child naturally. However, the emotional impact is not restricted to the discovery of infertility, being present, often, during the treatment process. Besides, for those who are successful in treatment, it is wondered how is the experience of motherhood in this context, that can still be influenced by another aspect: multiple pregnancy. Two studies were carried out. The first study was aimed to investigate the experience of implantation of multiple embryos into women who underwent IVF technique. To this end, interviews of women who underwent IVF and who mentioned the issue of implantation of multiple embryos spontaneously were analyzed. The interviews took place in the third trimester of pregnancy, with 14 women. It was noticed that the theme of the experience of implantation itself was common to all these women. However, multiple pregnancy revealed different experiences in singular as compared to singular pregnancy. Whereas in singular pregnancy the implantation of multiple embryos was only a ´possibility which was not later confirmed, in women who conceived a multiple pregnancy the fantasy became reality, so these woman seemed to be preparing for motherhood with more than one baby. The second study was designed to investigate the experience of motherhood in the context of multiple pregnancy. This involved three women who were in their third trimester of pregnancy. In this study, it became evident the suffering of these women when they were confronted with the couple’s infertility and had to undergo invasive treatments. However, it was found that the experience of pregnancy can suppress this suffering so that these women can experience the full experience of motherhood. Thus, this study raised the discussion that although TRA involves a distinct form of conception, it does not imply a distinct form of maternity.

A impossibilidade de engravidar pode desencadear consequências psíquicas importantes, visto que barra a mulher no momento em que ela sente-se pronta para vivenciar a experiência da maternidade. Nesse sentido, a reprodução assistida vem possibilitando a maternidade para aquelas que não conseguiam conceber uma criança naturalmente. Contudo, percebe-se que os impactos emocionais não estão restritos à descoberta da infertilidade, estando presentes durante o processo do tratamento. Assim, para aquelas que obtiverem sucesso no tratamento, questiona-se a configuração da experiência de maternidade em meio a este contexto, que muitas vezes está atravessado por outro aspecto: a gravidez múltipla. Para abordar este fenômeno de forma ampla, foram realizados dois estudos. O Estudo 1 tinha como objetivo investigar a experiência da implantação de múltiplos embriões em mulheres que se submeteram à técnica FIV. Para tanto, foram analisadas entrevistas de mulheres que se submeteram à FIV e que mencionaram esta questão de implantação de múltiplos embriões espontaneamente. As entrevistas ocorreram no 3º trimestre gestacional destas participantes, contando inicialmente com 21 mulheres, restando após a seleção que discriminou as que não haviam trazido este tema 14 participantes. Percebeu-se que o tema da experiência da implantação em si foi comum estando presente nos relatos das 14 mulheres. Contudo, a gravidez múltipla despertara vivências distintas em relação à gravidez singular, pois na gravidez singular fantasias quanto à implantação de múltiplos embriões foram vivenciadas, mas nas mulheres que conceberam uma gravidez múltipla estas tinham se tornado concretas, de forma que estas mulheres pareciam estar se preparando para maternidade com mais de um bebê. O Estudo 2 tinha como objetivo investigar a experiência da maternidade de uma gravidez múltipla nesse contexto. Para tanto, contou com três mulheres que estavam no seu 3º trimestre gestacional. Neste estudo, ficou evidenciado o sofrimento destas mulheres ao se defrontarem com a infertilidade conjugal e ao se submeterem a tratamentos invasivos. Contudo, verificou-se que a experiência da gravidez pode reprimir este sofrimento para que estas mulheres vivenciem integralmente a experiência da maternidade. Neste sentido, este estudo levantou a discussão de que as TRA se configuram como uma forma distinta de concepção, entretanto, não levam a uma forma distinta de maternidade. / The impossibility of getting pregnant can lead to significant psychological effects, because it represents an obstacle for a woman at a time when she feels ready to go through the experience of motherhood. In this sense, assisted reproduction has enabled the experience of motherhood for those who could not conceive a child naturally. However, the emotional impact is not restricted to the discovery of infertility, being present, often, during the treatment process. Besides, for those who are successful in treatment, it is wondered how is the experience of motherhood in this context, that can still be influenced by another aspect: multiple pregnancy. Two studies were carried out. The first study was aimed to investigate the experience of implantation of multiple embryos into women who underwent IVF technique. To this end, interviews of women who underwent IVF and who mentioned the issue of implantation of multiple embryos spontaneously were analyzed. The interviews took place in the third trimester of pregnancy, with 14 women. It was noticed that the theme of the experience of implantation itself was common to all these women. However, multiple pregnancy revealed different experiences in singular as compared to singular pregnancy. Whereas in singular pregnancy the implantation of multiple embryos was only a ´possibility which was not later confirmed, in women who conceived a multiple pregnancy the fantasy became reality, so these woman seemed to be preparing for motherhood with more than one baby. The second study was designed to investigate the experience of motherhood in the context of multiple pregnancy. This involved three women who were in their third trimester of pregnancy. In this study, it became evident the suffering of these women when they were confronted with the couple’s infertility and had to undergo invasive treatments. However, it was found that the experience of pregnancy can suppress this suffering so that these women can experience the full experience of motherhood. Thus, this study raised the discussion that although TRA involves a distinct form of conception, it does not imply a distinct form of maternity.

A impossibilidade de engravidar pode desencadear consequências psíquicas importantes, visto que barra a mulher no momento em que ela sente-se pronta para vivenciar a experiência da maternidade. Nesse sentido, a reprodução assistida vem possibilitando a maternidade para aquelas que não conseguiam conceber uma criança naturalmente. Contudo, percebe-se que os impactos emocionais não estão restritos à descoberta da infertilidade, estando presentes durante o processo do tratamento. Assim, para aquelas que obtiverem sucesso no tratamento, questiona-se a configuração da experiência de maternidade em meio a este contexto, que muitas vezes está atravessado por outro aspecto: a gravidez múltipla. Para abordar este fenômeno de forma ampla, foram realizados dois estudos. O Estudo 1 tinha como objetivo investigar a experiência da implantação de múltiplos embriões em mulheres que se submeteram à técnica FIV. Para tanto, foram analisadas entrevistas de mulheres que se submeteram à FIV e que mencionaram esta questão de implantação de múltiplos embriões espontaneamente. As entrevistas ocorreram no 3º trimestre gestacional destas participantes, contando inicialmente com 21 mulheres, restando após a seleção que discriminou as que não haviam trazido este tema 14 participantes. Percebeu-se que o tema da experiência da implantação em si foi comum estando presente nos relatos das 14 mulheres. Contudo, a gravidez múltipla despertara vivências distintas em relação à gravidez singular, pois na gravidez singular fantasias quanto à implantação de múltiplos embriões foram vivenciadas, mas nas mulheres que conceberam uma gravidez múltipla estas tinham se tornado concretas, de forma que estas mulheres pareciam estar se preparando para maternidade com mais de um bebê. O Estudo 2 tinha como objetivo investigar a experiência da maternidade de uma gravidez múltipla nesse contexto. Para tanto, contou com três mulheres que estavam no seu 3º trimestre gestacional. Neste estudo, ficou evidenciado o sofrimento destas mulheres ao se defrontarem com a infertilidade conjugal e ao se submeterem a tratamentos invasivos. Contudo, verificou-se que a experiência da gravidez pode reprimir este sofrimento para que estas mulheres vivenciem integralmente a experiência da maternidade. Neste sentido, este estudo levantou a discussão de que as TRA se configuram como uma forma distinta de concepção, entretanto, não levam a uma forma distinta de maternidade. / The impossibility of getting pregnant can lead to significant psychological effects, because it represents an obstacle for a woman at a time when she feels ready to go through the experience of motherhood. In this sense, assisted reproduction has enabled the experience of motherhood for those who could not conceive a child naturally. However, the emotional impact is not restricted to the discovery of infertility, being present, often, during the treatment process. Besides, for those who are successful in treatment, it is wondered how is the experience of motherhood in this context, that can still be influenced by another aspect: multiple pregnancy. Two studies were carried out. The first study was aimed to investigate the experience of implantation of multiple embryos into women who underwent IVF technique. To this end, interviews of women who underwent IVF and who mentioned the issue of implantation of multiple embryos spontaneously were analyzed. The interviews took place in the third trimester of pregnancy, with 14 women. It was noticed that the theme of the experience of implantation itself was common to all these women. However, multiple pregnancy revealed different experiences in singular as compared to singular pregnancy. Whereas in singular pregnancy the implantation of multiple embryos was only a ´possibility which was not later confirmed, in women who conceived a multiple pregnancy the fantasy became reality, so these woman seemed to be preparing for motherhood with more than one baby. The second study was designed to investigate the experience of motherhood in the context of multiple pregnancy. This involved three women who were in their third trimester of pregnancy. In this study, it became evident the suffering of these women when they were confronted with the couple’s infertility and had to undergo invasive treatments. However, it was found that the experience of pregnancy can suppress this suffering so that these women can experience the full experience of motherhood. Thus, this study raised the discussion that although TRA involves a distinct form of conception, it does not imply a distinct form of maternity.

Thesis (M.D.)-University of Natal, Durban, 1979.

The main goal of this thesis is the analysis of multiple-births in Czech Republic between the years of 1950 and 2005 including the international comparison and assess of the influence of assisted reproduction on occurrence of multiple-births. The thesis is divided into five different parts. The first part is dedicated to the analysis of fertility according to a succession of births in Czech Republic while using the indicators of total fertility, the average age of mothers in the time of childbirth and the total number of new-born babies. The second part focuses on multiple-births considering both historical and contemporary point of view and on possible risks for both the mother and the foetus. Next part describes the assisted reproduction, its history, present and commonly used methods. The fourth part is dedicated to the influence of assisted reproduction on the occurrence of multiple-births and to the analysis of multiple-births with the use of absolute and relative number of mono-births and multiple-births indicators, indicators of total fertility, masculinity index, the rate of stillborn babies and the proportion of children born outside of marriage. The last part compares the development of multiple-births within the European countries according to NIDI 1999 classification.

Made available in DSpace on 2014-07-22T13:14:48Z (GMT). No. of bitstreams: 2 Paula Coelho.pdf: 741288 bytes, checksum: e8d1b8f480ab01982538dd474c9291b4 (MD5) license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Departamento de Ensino. Programa de Pós-Graduação em Saúde da Criança e da Mulher. Rio de Janeiro, RJ, Brasil. / Objetivos: O presente estudo teve como objetivo analisar aspectos maternos, obstétricos e perinatais da gestação gemelar em população assistida em unidade terciária do Rio de Janeiro, estabelecendo o perfil da gestação gemelar, identificando os eventuais danos relacionados à morbimortalidade perinatal do segundo gemelar, tendo como referencia o que nasceu primeiro e as principais morbidades determinantes da morbimortalidade neonatal dos gêmeos, independentemente da localização na cavidade uterina. Metodologia: Através de estudo de coorte, de caráter retrospectivo, foram analisados prontuários de 613 gestações gemelares do Instituto Fernandes Figueira/ Fundação Oswaldo Cruz no período de janeiro de 1993 a dezembro de 2007. Participaram do estudo gestações exclusivamente duplas, cujas pré-natais e partos foram integralizados na instituição. Resultados: A prevalência da gemelidade no período estudado foi de 4,0%. Dentre as principais intercorrências maternas destacaram-se a anemia (47,8%), trabalho de parto prematuro (39,1%), síndromes hipertensivas (25,5%) e rotura prematura das membranas (18,2%). Na população estudada a operação cesariana foi quase sempre eleita como via de parto preferencial (74,4%). A principal morbidade neonatal foi a prematuridade, que atingiu 66,1% dos conceptos. Um significativo contingente de recém-nascidos apresentou intercorrências no período neonatal (65,3%), sendo as condições mais prevalentes: alterações respiratórias (29,2%), metabólicas (27,7%), infecciosas (27,3%) e hematológicas (19,3%). Quanto aos danos relacionados ao segundo gemelar, não se observou, no geral, diferença estatisticamente significativa quando comparado com o primeiro na maioria dos desfechos elegíveis, exceto o baixo peso ao nascer, índices de Apgar inferior a sete no quinto minuto de vida, além de intercorrências hematológicas e nutricionais. No que tange ao determinismo da mortalidade neonatal na gestação gemelar, chama atenção que a condução do parto por via vaginal nos recém-nascidos com peso abaixo de 2500g, as apresentações não cefálicas, o baixo peso ao nascer, os baixos índices de Apagar e as morbidades neonatais se mostraram como fatores determinantes da mortalidade neonatal em qualquer um dos produtos da concepção, independentemente da localização intra-uterina. Conclusões: Dada a alta prevalência de resultados ominosos para o binômio, especialmente a prematuridade e complicações obstétricas, ressalta-se a importância de referenciar casos de gestação gemelar para unidade terciária. Os resultados neonatais indicam tendência dos gemelares em apresentarem complicações, não sendo demonstrado pelo presente estudo o pior prognóstico do segundo gemelar. / Objectives: This study aimed to examine aspects of maternal, obstetric and perinatal outcomes of twin pregnancy in a population assisted at a tertiary center in Rio de Janeiro, establishing the profile of the twin pregnancy, identifying the damage related to perinatal morbidity and mortality of the second twin, with the references the first born and the main determinants of morbidity and neonatal mortality and morbidity of twins, regardless of location in the uterine cavity. Methodology: Through a retrospective, cohort study, 613 twin pregnancies from Instituto Fernandes Figueira were analyzed from january 1993 to december 2007. The study included only twin pregnancies, whose prenatal care and delivery were conducted into the institution. Results: The prevalence of twin pregnancy during the study period was 4.0%. The major contributors to maternal problems were anemia (47.8%), preterm labor (39.1%), hypertensive disorders (25.5%) and premature rupture of membranes (18.2%). In these situations the caesarean section was almost always chosen as the preferred mode of delivery (74.4%). The major neonatal morbidity was prematurity, which reached 66.1% of fetuses. A significant number of newborns had complications in the neonatal period (65.3%), being the most prevalent conditions: respiratory disorders (29.2%), metabolic (27.7%), infection (27.3%) and hematologic (19.3%). Concerning the demages related to the second twin, it wasn’t found in general, statistically significant difference compared to its co-twin in most outcomes, except for low birth weight, Apgar score below seven, hematological and nutritional complications. Regarding the determinism of neonatal mortality in twin pregnancy what draws attention is the fact that: vaginal delivery, non-cephalic presentations, low birth weight, low Apgar scores and neonatal morbidities were shown as determinants of neonatal mortality in any of the products of conception, regardless of the location in the uterus Conclusion: Given the high prevalence of ominous results for the pair, especially prematurity and obstetric complications, the study highlights the importance of referring cases of twin pregnancy to tertiary hospitals. Neonatal results indicate the tendency in twins to undergo complications, the worse.

The presented thesis deals with the topic of development of communication abilities in preterm infants from the perspective of special education. The thesis is for clarity divided into several parts. In the first part of the text the issue of incidence of premature births in the Czech Republic is discussed, following subsections are devoted to the definition and distribution of characteristics bonding with immaturity of child and approach selected health problems associated with postpartum adaptation and subsequent psychomotor development of child. The following chapter which analyzes the system of care for premature newborns in the Czech Republic focuses on two forms of care, acute care and followed-up. Next part has been devoted to issue of premature infants from logopedical perspective and describes the physiological process of development of communication abilities of child and based on current knowledge, especially foreign research, analyzes the peculiarities of speech development of preterm infants. The last and key part of the work, based on case studies, analyzes the specifics of development of communication abilities of four originally extremely and very preterm children of multiple pregnancies in the background of the their overall psychomotor development. KEYWORDS premature infant,...

[pt] Atualmente, milhares de crianças são concebidas ao redor do mundo através de tratamentos de reprodução assistida (TRA). Estes trouxeram como grande consequência o aumento considerável de gestações múltiplas. Considerando a relevância atribuída pela psicanálise à experiência da maternidade e à relação mãe-bebê devido às suas implicações sobre o psiquismo materno e sobre o desenvolvimento psíquico do bebê, a gravidez múltipla concebida através de TRA revela-se uma experiência distinta da experiência da maternidade classicamente estudada pelos psicanalistas. Por esta razão, esta tese busca analisar, através de um estudo de caso de uma mãe que concebeu uma gravidez trigemelar através de TRA, a experiência da maternidade atravessada por estas peculiaridades, assim como o desenvolvimento psíquico e emocional de cada um dos trigêmeos nos dois primeiros anos de vida. Para tanto, foi realizada uma observação de bebês através do Método Esther Bick, conciliada com uma entrevista realizada quando os bebês estavam com um ano de idade. Nas análises apresentadas, questões peculiares ao caso foram exploradas, como a terceirização de cuidados constatada, tornando o entendimento do vínculo estabelecido da mãe com os seus bebês um desafio para a autora. Consequentemente, a pesquisadora buscou compreender como os bebês lidaram com a ausência materna. Elementos relacionados ao fenômeno de transmissão geracional foram identificados de forma distintas com cada um dos bebês. Foi observado como o vínculo materno e a constituição inata de cada um dos bebês perpassou o processo de constituição subjetiva de cada um dos bebês, sendo este discutido individualmente. Buscou-se propor uma reflexão que pode ser estendida para outros casos de maternidade gemelar, acerca de como esta vivência é experienciada pelas mãe de gêmeos e de como os irmãos gêmeos podem vir a construir sua vida psíquica. / [en] Currently, thousands of children are conceived around the world through assisted reproductive treatments (ART). These have brought about as a consequence the considerable increase of multiple pregnancies. Considering the relevance attributed by psychoanalysis to the experience of motherhood and the mother-baby relationship due to its implications on the maternal psyche and on the psychic development of the baby, multiple pregnancy conceived through ART reveals a distinct experience of the experience of motherhood classically Studied by psychoanalysts. For this reason, the author of this thesis sought to analyze, through a case study of a mother who conceived a pregnancy triplets through ART, the experience of motherhood crossed by these peculiarities, as well as the psychic and emotional development of each of the triplets, in the first two years of their lives. Therefore, an observation of infants was performed by Esther Bick method, conciled with an interview conducted when the babies were one year old. In the analysis presented, issues peculiar to the case were explored, such as the outsourcing of care found, making the understanding of the bond established between the mother and her babies a challenge for the author. Consequently, the researcher sought to understand how the babies dealt with maternal absence. Elements related to the phenomenon of generational transmission were identified differently with each of the babies. It was observed how the maternal bond and the innate constitution of each of the babies crossed the process of subjective constitution of each one of the babies, being discussed individually. It was sought to propose a reflection that could be extended to other cases of twin motherhood, about how this experience is experienced by the mother of twins and how the twin brothers can build their psychic life.

Abstract Respiratory distress syndrome, RDS, is a multifactorial lung disease of premature infants. The main cause of RDS is a deficiency of pulmonary surfactant, a lipoprotein mixture required to reduce surface tension at the air-liquid interface and to prevent generalized atelectasis of the alveolar ducts and alveoli. Prematurity is the most important factor predisposing to RDS. During the past decade the number of multiple pregnancies has increased significantly as a result of diversified infertility treatments and advanced maternal age. Due to the considerably higher rate of preterm births of multiples compared to singletons, RDS is one of the major causes of morbidity among them. The objectives of the present research were to evaluate the incidence and risk factors of RDS in twins compared to singletons, and to assess the role of SP-A and SP-B gene variations and gene-environment interactions in the susceptibility to the disease in a population of preterm twins and higher order multiples. This research showed that during the past fifteen years the gestational age-specific incidence of RDS has declined. Twin infants do not have increased risk of RDS except when born very immaturely at a very early gestational age. The presenting twin is less susceptible to RDS than the non-presenting twin or singleton infant after 28 weeks of gestation until term. Additionally the SP-B Ile131Thr polymorphism was shown to affect the susceptibility specifically in the presenting twin. The role of SP-A polymorphisms in the risk of RDS in twins turned out to be different from that in singletons. The major allele and genotype of SP-A1 were associated with a decreased risk of RDS in near-term twin infants. The threonine allele in SP-B Ile131Thr appeared interactively with SP-A1 to associate with the risk of RDS both in twins and in singletons: associating with a lower risk of RDS in singletons at very early gestation, but surprisingly associating with a protection in twins and multiples from RDS near term. The risk of RDS, defined by the interaction of SP-A and SP-B alleles, was additionally associated with the fetal mass. Thus, the difference in the susceptibility to RDS in premature singletons and multiples may depend on the size of the conceptus. In an evaluation of the genetic risk factors for RDS, the classical twin study method comparing the concordance of a disease between MZ and DZ twins underestimates the extent of heredity. Several predominant intrauterine and perinatal environmental factors contribute to disease susceptibility regardless of zygosity and are suspected to override the hereditary components of RDS. Twin gestation was shown to be an effect modifier in the genetic susceptibility to RDS. / Tiivistelmä Vastasyntyneen hengitysvaikeusoireyhtymä, RDS-tauti, on hyvin monitekijäinen ennenaikaisena syntyneiden lasten sairaus. Taudin tärkein syy on keuhkojen pintajännitystä alentavan aineen, surfaktantin, puute ennenaikaisessa synnytyksessä. Surfaktantti on rasva-proteiiniseos, joka alentaa keuhkorakkuloiden pintajännitystä ja estää rakkuloiden kasaan painumisen hengityksen aikana. Epäkypsyys on tärkein RDS-taudin kehittymiselle altistava tekijä. Viimeisen vuosikymmenen aikana monisikiöiset raskaudet ovat lisääntyneet merkittävästi keinohedelmöitysten ja synnyttäjien kohonneen iän seurauksena. RDS-tauti on monisikiösynnytyksissä tärkeä sairastavuutta aiheuttava tekijä, koska monisikiöraskaudet päättyvät huomattavasti useammin ennenaikaisesti kuin yksösraskaudet. Tämän tutkimuksen tarkoituksena oli selvittää RDS-taudin ilmaantuvuutta ja riskitekijöitä kaksosilla verrattuna yksösiin, tutkia surfaktanttiproteiinien A ja B geenivaihtelua sekä geenien ja ympäristötekijöiden vuorovaikutusta kaksosten ja monisikiöisistä raskauksista syntyneiden lasten RDS-taudissa. Tutkimus osoitti, että viimeisten viidentoista vuoden aikana RDS-taudin raskausikäkohtainen ilmaantuvuus on vähentynyt. Vain hyvin epäkypsillä, ennenaikaisilla kaksosilla on lisääntynyt riski sairastua RDS-tautiin verrattuna yksösiin. 28 raskausviikon jälkeen ensimmäisenä syntyvällä kaksosella on pienempi riski saada RDS-tauti kuin toisena syntyvällä tai yksösellä. Lisäksi surfaktanttiproteiini B:n (SP-B) geenin eksonin 4 monimuotoisuus osoittautui vaikuttavan RDS-taudin alttiuteen erityisesti ensin syntyvällä kaksosella. Surfaktanttiproteiini A:n (SP-A) geenin yhteys RDS-taudin riskiin osoittautui olevan erilainen kaksosilla verrattuna yksösiin. Lähes täysiaikaisilla kaksosilla SP-A1 geenin valta-alleeli ja genotyyppi liittyivät RDS-taudin vähentyneeseen riskiin. SP-B geenin eksonin 4 treoniini alleeli osoittautui liittyvän yhdessä SP-A1 valtagenotyypin kanssa RDS-taudin riskiin sekä yksösillä että kaksosilla: hyvin ennenaikaisilla yksösillä geenien yhteisvaikutus lisäsi riskiä, kun taas lähes täysiaikaisilla kaksosilla sama geenien yhteisvaikutus yllättäen suojeli RDS-taudilta. SP-A ja SP-B geenien vuorovaikutuksen kautta välittyvä RDS-taudin riski oli lisäksi yhteydessä sikiön kokoon. Siten ennenaikaisena syntyneiden yksösten ja monisikiöisten RDS-taudin alttiuden ero voi olla riippuvainen sikiön koosta. Klassinen kaksostutkimusmenetelmä, jossa verrataan identtisten ja ei-identtisten kaksosten sairastuvuutta, aliarvioi perimän määräämien tekijöiden osuutta RDS-taudin synnyssä. Useat hallitsevat kohdunsisäiset ja synnytykseen liittyvät ympäristötekijät vaikuttavat RDS-taudin syntyyn ja kumoavat perimän osuutta. Kaksosuus osoittautui olevan periytymisen vaikutusta muokkaava tekijä RDS-taudissa.

L’infertilité touche environ 11 à 15 % des couples au Canada. Les modalités de la procréation médicalement assistée (PMA) incluent la stimulation ovarienne (SO), l’insémination intra-utérine (IIU) et les techniques de la reproduction assistée (TRA). Les grossesses multiples sont parmi les effets indésirables les plus communs de l’utilisation des TRA. Toutefois, il n’y a pas de consensus sur l’ampleur du risque de grossesses multiples associé à l’utilisation des modalités de la PMA. De plus, il n’est pas clair si les modalités de la PMA sont associées à un risque élevé de malformations congénitales majeures (MCM) d’un ou plusieurs systèmes et organes du corps humain. Un projet de recherche en trois volets a été développé afin de répondre à ces questions. Dans un premier volet, une étude cas-témoin a été conduite afin de quantifier le risque de naissances multiples associé à l’utilisation des modalités de la PMA. Comparativement à une conception spontanée (CS), le recours à la SO seule, l’IIU, et les TRA étaient associés à une augmentation significative de plus de quatre, neuf et 31 fois du risque de naissances multiples, respectivement. Les femmes ayant fait appel à une IIU+SO ou aux TRA avaient un risque accru de naissances multiples (odds ratio (OR)ajusté, 1,98; IC95%, 1,12-3,49; ORajusté, 6,81; IC95%, 3,72-12,49, respectivement) comparativement à l’utilisation de la SO seule. Dans un deuxième volet, une analyse cas-témoin a été conduite afin de quantifier le risque de MCM associés à l’utilisation des modalités de la PMA. Comparée à une CS, l'utilisation des TRA était associée à une augmentation du risque des malformations du système urogénitale (ORajusté, 3,11; IC95%, 1,33–7,27) et l'utilisation de l'IIU était associée à un risque accru des malformations du système musculosquelettique (ORajusté, 2,02; IC95%, 1,10–3,71). L'utilisation des TRA était associée à une augmentation du risque des malformations du système urogénitale (ORajusté, 7,18; IC95%, 1,59-32,53) par rapport à l’utilisation de la SO seule. Dans un troisième volet, les résultats de la revue systématique et méta-analyse ont démontré que l'utilisation de la SO seule et l’IIU±SO étaient associée à une augmentation significative de presque 9 fois du risque de grossesses multiples par rapport à une CS. Des augmentations similaires ont été observées suite à l’utilisation du citrate de clomifène seul. Par rapport à une CS, l'utilisation de la SO seule était associée à une augmentation significative de 48% du risque des malformations du système musculosquelettique, de 73% le risque des malformations du système nerveux, de 76% le risque de malformations congénitales du système digestif, de 68% le risque de malformations des yeux, des oreilles, du visage et du cou, et plus de deux fois le risque de malformations congénitales du système respiratoire. L'utilisation de l'IIU était associée à une augmentation significative de 52% du risque de malformations du système urogénitales et de 54% du risque de malformations musculosquelettiques par rapport à une CS. Bien que le risque de grossesses multiples associées aux TRA puisse être contrôlé par le transfert d'un embryon unique, un suivi particulier devrait être accordée au risque de grossesses multiples associé à l’utilisation des traitements n’impliquant pas un transfert d’embryons. L’effet tératogène potentiel associé à l’utilisation des modalités de la PMA doit être considéré dans la prise des décisions thérapeutiques. La mise en place d’un registre de la PMA pour la surveillance des effets périnataux indésirables devient nécessaire / Infertility affects 11 to 15% of couples in Canada. The modalities of medically assisted reproduction (MAR) include ovarian stimulation (OS), intrauterine insemination (IUI) and assisted reproduction techniques (ART). Multiple pregnancies are among the most common side effects of using ART. However, there is no consensus on the magnitude of the risk of multiple pregnancies associated with the use of MAR modalities. In addition, it is unclear whether the modalities of MAR are associated with a high risk of major congenital malformations (MCM) affecting one or more specific organ system. A three-part research project was developed to answer these questions. In the first part, a case-control study was conducted to quantify the risk of multiple births associated with the use of the three MAR modalities. Compared to spontaneous conception (SC), the use of OS alone, IUI, and ART was associated with a significant increase of more than four, nine, and 31 times the risk of multiple births, respectively. Women who used IUI with OS or ART had an increased risk of multiple births (adjusted odds ratio (OR), 1.98; 95%CI, 1.12-3.49; adjusted OR, 6.81; 95%CI, 3.72-12.49, respectively) compared to the use of OS alone. In a second part, a case-control analysis was conducted in order to quantify the risk of MCM associated with the use of MAR modalities. Compared to SC, the use of ART was associated with an increased risk of urogenital malformations (adjusted OR, 3.11; 95%CI, 1.33–7.27) and the use of IUI was associated with increased risk of musculoskeletal malformations (adjusted OR, 2.02; 95% CI, 1.10–3.71). The use of ART was associated with an increased risk of urogenital malformations (adjusted OR, 7.18; 95% CI 1.59-32.53) compared to the use of OS alone. In a third part, results of the systematic review and meta-analysis demonstrated that the use of OS alone and IUI ± OS were associated with a significant increase of nine times the risk of multiple pregnancies compared to a SC. Similar increases have been found following the use of clomiphene citrate alone. Compared to SC, the use of OS alone was associated with a significant 48% increased risk of musculoskeletal malformations, 73% increased risk of malformations of the nervous system, 76% increased risk of digestive system malformations, 68% increased risk of malformations of the eye, ear, face and neck, and more than twice the risk of congenital respiratory system malformations. The use of IUI was associated with a significant 52% increased risk of urogenital malformations and 54% increased risk of musculoskeletal malformations compared to SC. Although the risk of multiple pregnancies associated with ART can be controlled using a single embryo transfer in IVF cycles, monitoring the risk of multiple pregnancies associated with the use of treatments that do not involve embryo transfer is essential. The potential teratogenic effect associated with the use of MAR modalities should be considered when making therapeutic decisions. The establishment of a registry for the surveillance of MAR adverse perinatal outcomes becomes necessary.