Assisted reproductive technologies have become a common method used to treat infertility. These techniques have advanced quickly since the first birth of an in vitro fertilization (IVF) baby in 1978, at the Royal Oldham Hospital in the United Kingdom. Currently, IVF with or without intracytoplasmic sperm injection, is used throughout the world to achieve oocyte retrieval, fertilization, implantation of an embryo, clinical pregnancy, ongoing clinical pregnancy, and a live-born infant. The rationale for selecting one type of fertility treatment over another is multifactorial: the confirmed or unconfirmed cause of infertility, the age of the gamete donor and the recipient, the availability of the type of treatment, and the cost associated with the treatment. The ultimate goal of any fertility treatment is to achieve a successful pregnancy that results in a healthy infant. However, the literature is equivocal on the effects of fertility treatment cycles on the health outcomes of infants and mothers. Presently, there are thirty-six fertility treatment centres across Canada, eighteen of which reside in Ontario. A national, comprehensive database of assisted reproductive technology treatment cycles (Canadian Assisted Reproductive Technologies Register (CARTR) Plus) began collecting data in 2013, and has made the research objectives of this doctoral thesis feasible. Before this data collection system, population-wide studies involving fertility treatments were not possible in Canada. Two understudied issues associated with IVF are the impact of fertility treatments on the maternal serum screening markers used in prenatal screening programs to identify fetal aneuploidies; and the association between fertility treatments and adverse perinatal outcomes, such as preeclampsia and stillbirth. Given the increasing number of women who are using fertility treatments to conceive, it is imperative that studies investigating the association with adverse outcomes are conducted. As the science supporting fertility treatment procedure has advanced, so has prenatal screening. One of the first screening tests that are performed for newly pregnant women, including women who conceived following IVF, is maternal serum screening. The first objective of this doctoral thesis was to systematically review the literature on the association between IVF treatment and maternal serum screening marker levels and nuchal translucency (NT) thickness. After the search and screening of the literature there were 40 studies that were included in this systematic review. A decrease in pregnancy-associated plasma protein A (PAPP-A) and an increase in total human chorionic gonadotropin (hCG) was consistently reported for IVF pregnancies. However, since the levels of the other maternal serum screening markers reported also varied we were unable to generalize about the differences between prenatal screening results in the IVF population. These results led to investigating maternal serum screening marker levels among IVF patients in Ontario, Canada. The second objective of this thesis was three-fold: 1) to investigate the accuracy of IVF identification on the Ontario prenatal screening record, relative to reference standard on the CARTR Plus database; 2) to compare the prenatal screening markers in IVF versus non-IVF pregnancies in the population of Ontario; and 3) to propose updated IVF adjustment factors for prenatal screening in the Ontario population, based on the more accurate coding for IVF status in the CARTR Plus database. Significant differences between IVF and non-IVF groups, based on both the prenatal screening requisition information and CARTR Plus information, were found among the ethnicity adjusted mean multiple of the median (MoM)s for several prenatal screening markers: alpha-fetoprotein (AFP), PAPP-A, unconjugated estriol (µE3), first trimester hCG, total hCG, and dimeric inhibin A (DIA). When we developed the proposed adjustment factors for all CARTR Plus identified pregnancies we found that for PAPP-A, total hCG, and µE3 the mean adjusted marker MoMs were significantly closer to 1.00, as compared to the prenatal screening adjusted or the unadjusted mean marker MoMs. Currently, there is no adjustment made to the other maternal serum screening markers and NT measurement. The third objective was to examine the effect of type of infertility on placental-mediated adverse outcomes (preeclampsia, intrauterine growth restriction, placental abruption, and stillbirth). Type of infertility was classified as male factor (sperm count, poor sperm motility, and abnormal sperm morphology), female factor (ovulation disorders, tubal infertility, and uterine or cervical causes), and unexplained infertility. No significant associations were found between type of conception and the composite outcome, as well as each individual primary outcome. Similarly, the type of infertility was not associated with the composite outcome or any of the individual primary outcomes, except for female factor infertility, which was associated with increased probability of placental abruption. Overall, the results from this doctoral thesis suggest that there are substantial differences seen in maternal serum screening marker MoMs among women who use IVF to conceive, suggesting that appropriate adjustment factors should be employed to ensure accurate results for determining the risk of Down syndrome and trisomy 18. Additionally, although the literature has shown an association between fertility treatment and placental-mediated adverse outcomes no significant associations were found in the population of Ontario. Further studies should be performed to confirm the results of these observational studies.

Statement of problem: We have shown that the C677T 5,10 methylenetetrahydrofolate reductase (MTHFR) variant is associated with elevated maternal serum α-fetoprotein (MSAFP), the most common screening test for neural tube defects (NTD). Therefore, past contradictory studies of NTDs and C677T MTHFR may have been biased because of changes in case populations after prenatal diagnosis and termination of pregnancy. Further, an unexplained elevation of MSAFP is known to increase the risk for later pregnancy complications. Is the C677T MTHFR variant a predisposing genetic variant for both NTDs and later complications of pregnancy? Methods: A retrospective study of women with pregnancies resulting in NTD outcome and women with unexplained elevations of MSAFP was undertaken. Women and their partners were genotyped for the C677T MTHFR allele. Couples with a pregnancy resulting in a NTD outcome were compared to couples whose pregnancy outcome did not involve. Couples with unexplained elevations of MSAFP who did and did not have later complications of pregnancy were also compared. Allele frequencies for all groups were then compared against the previously established Manitoba population allele frequency (based on 977 consecutive newborn metabolic screening bloodspots). A review of all studies of NTDs and association with the C677T MTHFR variant was undertaken to determine if the association between the variant and MSAFP is a source of bias. NTD incidence was examined before and after folic acid food fortification introduced in Canada in 1999. Results: There is an increase in the allele frequency of the C677T MTHFR variant in parents with an unexplained elevated MSAFP followed by later complications of pregnancy. The C677T MTHFR variant is also a contributing genetic factor to NTDs worldwide. The incidence of NTDs in Manitoba has decreased by 37% since food fortification with folic acid was introduced. Conclusions: The C677T MTHFR variant is a contributing genetic factor to both later complications of pregnancy after an unexplained elevation of MSAFP and to NTDs. This variant is folate sensitive and folic acid fortification has reduced the incidence of NTDs. / February 2005

Statement of problem: We have shown that the C677T 5,10 methylenetetrahydrofolate reductase (MTHFR) variant is associated with elevated maternal serum α-fetoprotein (MSAFP), the most common screening test for neural tube defects (NTD). Therefore, past contradictory studies of NTDs and C677T MTHFR may have been biased because of changes in case populations after prenatal diagnosis and termination of pregnancy. Further, an unexplained elevation of MSAFP is known to increase the risk for later pregnancy complications. Is the C677T MTHFR variant a predisposing genetic variant for both NTDs and later complications of pregnancy? Methods: A retrospective study of women with pregnancies resulting in NTD outcome and women with unexplained elevations of MSAFP was undertaken. Women and their partners were genotyped for the C677T MTHFR allele. Couples with a pregnancy resulting in a NTD outcome were compared to couples whose pregnancy outcome did not involve. Couples with unexplained elevations of MSAFP who did and did not have later complications of pregnancy were also compared. Allele frequencies for all groups were then compared against the previously established Manitoba population allele frequency (based on 977 consecutive newborn metabolic screening bloodspots). A review of all studies of NTDs and association with the C677T MTHFR variant was undertaken to determine if the association between the variant and MSAFP is a source of bias. NTD incidence was examined before and after folic acid food fortification introduced in Canada in 1999. Results: There is an increase in the allele frequency of the C677T MTHFR variant in parents with an unexplained elevated MSAFP followed by later complications of pregnancy. The C677T MTHFR variant is also a contributing genetic factor to NTDs worldwide. The incidence of NTDs in Manitoba has decreased by 37% since food fortification with folic acid was introduced. Conclusions: The C677T MTHFR variant is a contributing genetic factor to both later complications of pregnancy after an unexplained elevation of MSAFP and to NTDs. This variant is folate sensitive and folic acid fortification has reduced the incidence of NTDs.

Statement of problem: We have shown that the C677T 5,10 methylenetetrahydrofolate reductase (MTHFR) variant is associated with elevated maternal serum α-fetoprotein (MSAFP), the most common screening test for neural tube defects (NTD). Therefore, past contradictory studies of NTDs and C677T MTHFR may have been biased because of changes in case populations after prenatal diagnosis and termination of pregnancy. Further, an unexplained elevation of MSAFP is known to increase the risk for later pregnancy complications. Is the C677T MTHFR variant a predisposing genetic variant for both NTDs and later complications of pregnancy? Methods: A retrospective study of women with pregnancies resulting in NTD outcome and women with unexplained elevations of MSAFP was undertaken. Women and their partners were genotyped for the C677T MTHFR allele. Couples with a pregnancy resulting in a NTD outcome were compared to couples whose pregnancy outcome did not involve. Couples with unexplained elevations of MSAFP who did and did not have later complications of pregnancy were also compared. Allele frequencies for all groups were then compared against the previously established Manitoba population allele frequency (based on 977 consecutive newborn metabolic screening bloodspots). A review of all studies of NTDs and association with the C677T MTHFR variant was undertaken to determine if the association between the variant and MSAFP is a source of bias. NTD incidence was examined before and after folic acid food fortification introduced in Canada in 1999. Results: There is an increase in the allele frequency of the C677T MTHFR variant in parents with an unexplained elevated MSAFP followed by later complications of pregnancy. The C677T MTHFR variant is also a contributing genetic factor to NTDs worldwide. The incidence of NTDs in Manitoba has decreased by 37% since food fortification with folic acid was introduced. Conclusions: The C677T MTHFR variant is a contributing genetic factor to both later complications of pregnancy after an unexplained elevation of MSAFP and to NTDs. This variant is folate sensitive and folic acid fortification has reduced the incidence of NTDs.

Lipid soluble carotenoids are micronutrients present in human milk that serve as precursors of vitamin A and also play an important role protecting cells from damage arising from photooxidative processes and reactive oxygen species. Fatty acids comprise about 3-5% of human milk and are mainly present as triglycerides. They are a major energy source for the infant and are necessary to support cell growth required for normal development and maturation of critical organs. Transport of carotenoids into milk has been little studied and there has been no previous investigation of the relationship of carotenoid transport with that of individual fatty acid secretion into milk. In the present study, levels of the carotenoids, lutein, zeaxanthin, b-cryptoxanthin, and b-carotene, in maternal serum, infant cord blood, and milk obtained from 74 Peruvian mothers were measured by HPLC methods. The fat content and fatty acid profile of maternal milk were determined by GC-FID and confirmed by GC-MS. Twenty nine fatty acids were identified and quantified after conversion to methyl esters. Statistical analysis was employed to investigate potential trends and relationships among the carotenoids in all three fluids as well as between carotenoids and fatty acids present. Concentrations of lutein in maternal serum and milk as well as maternal serum and infant cord blood were highly correlated (r =0.43, p

The field of prenatal screening and diagnosis has developed rapidly over the past half-century, enabling possibilities for detecting anomalies in reproduction that were never before contemplated. A simple blood sample can aid in the identification of several conditions in the fetus early in the pregnancy. If a fetus is found to be affected by Down syndrome, anencephalus, spina bifida, or Edward's syndrome, a decision must then be made whether to continue or terminate the pregnancy. As prenatal screening becomes increasingly commonplace and part of routine maternal care, researchers are faced with the challenge of understanding its effects at the level of the population and monitoring trends over time. Greater uptake of prenatal screening, when followed by prenatal diagnosis and termination, has important implications for both congenital anomaly surveillance and infant and fetal mortality indicators. Research in Canada suggests that this practice has led to reductions in the congenital-anomaly specific infant mortality rate and increases in the stillbirth rate.(1, 2) The current study is a population-based, epidemiological exploration of demographic predictors of maternal serum screening (MSS) and amniocentesis uptake, with special attention to variations in birth outcomes resulting from different patterns of use. To accomplish our objectives, multiple data sources (vital statistics, hospital and physician services, cytogenetic and MSS laboratory information) were compiled to create a comprehensive maternal-fetal-infant dataset. Data spanned a six-year period (2000-2005) and involved 93,171 pregnancies. A binary logistic regression analysis found that First Nations status, rural-urban health region of residence, maternal age group, and year of test all significantly predicted MSS use. Uptake was lower in women living in a rural health region, First Nations women, and those under 30 years of age. The study dataset identified ninety-four terminations of pregnancy following detection of a fetal anomaly (TOPFA), which led to a lower live birth prevalence of infants with Down syndrome, Trisomy 18, and anencephalus. While a significant increasing trend was observed for the overall infant mortality rate in Saskatchewan between 2001-2005, a clear trend in one direction or the other could not be seen in regards to infant deaths due to congenital anomaly. First Nations status and maternal age were important predictors of both MSS and amniocentesis testing, and appeared to influence the decision to continue or terminate an affected pregnancy. The fact that First Nations women were less likely to screen (9.6% vs. 28.4%) and to have diagnostic follow-up testing (18.5% vs. 33.5%), meant that they were less likely to obtain a prenatal diagnosis when the fetus had a chromosomal anomaly compared to other women (8.3% vs. 27.0%). This resulted in a lower TOPFA rate compare to the rest of the population (0.64 vs. 1.34, per 1,000 pregnancies, respectively) and a smaller difference between the live birth prevalence and incidence of Down syndrome and Trisomy 18 for First Nations women. Women under 30 years of age were much less likely to receive a prenatal diagnosis when a chromosomal anomaly was present (18.4% vs. 31.8%). While risk for a chromosomal anomaly is considerably lower for younger mothers, 53.5% of all pregnancies with chromosomal anomalies and 40.7% of DS pregnancies belonged to this group. Consistent with other studies pregnancy termination rates following a prenatal congenital anomaly diagnosis are high (eg. 74.1% of prenatally diagnosed Down syndrome or Trisomy 18 cases), but these rates may be misleading in that they are based on women who chose to proceed to prenatal diagnosis. The fact that two-thirds (67.3%) of Saskatchewan women who received an increased-risk result declined amniocentesis, helps to put this finding into context. Strong surveillance systems and reasonable access to research datasets will be an on-going challenge for the province of Saskatchewan and should be viewed as a priority. Pregnancies and congenital anomalies are two particularly challenging outcomes to study in the absence of perinatal and congenital anomaly surveillance systems. Still pregnancies that never reach term must be accounted for, in order to describe the true state of maternal-fetal-infant health and to study its determinants. While our study was able to identify some interesting trends and patterns, it is only a snapshot in time. Key to the production of useful surveillance and evaluation is timely information. The current system is not timely, nor is it user-friendly for researchers, health regions or governments. Data compilation for the current study was a gruelling and cumbersome process taking more than five years to complete. A provincial overhaul is warranted in both the mechanism by which researchers access data and in the handling of data. The Better Outcomes Registry & Network (BORN) in Ontario is an innovative perinatal and congenital anomaly surveillance system worthy of modelling.(3) Academic papers in non-ethics' journals typically focus on the technical or programmatic aspects of screening and do not effectively alert the reader to the complex and profound moral dilemmas raised by the practice. A discussion of ethics was felt necessary to ensure a well-rounded portrayal of the issue, putting findings into context and helping to ensure their moral relevance did not remain hidden behind the scientific complexities. Here I lay out the themes of the major arguments in a descriptive manner, recognizing that volumes have been written on the ethics of both screening and abortion. A major ethical tension arising within the context of population based prenatal screening is the tension between community morality and the principle of respect for personal autonomy. Prenatal screening and selective termination have been framed as a purely private or medical matter, thereby deemphasizing the social context in which the practice has materialized and the importance of community values. I consider how a broader sociological perspective, one that takes into account the relevance of community values and limitations of the clinical encounter, could inform key practice and policy issues involving prenatal screening. It is my position that the community's voice must be invited to the conversation and public engagement processes should occur prior to any additional expansion in programming. I end with a look at how the community’s voice might be better heard on key issues, even those issues that at first glance seem to be the problems of individuals. As Rayna Rapp (2000) (4) poignantly observed, women today are 'moral pioneers' not by choice, but by necessity. By elucidating the effects of prenatal screening and the extent of the practice of selective termination in the province, the true occurrence of important categories of congenital anomalies in our province can be observed. Without this knowledge it is very difficult to identify real increases or decreases in fetal and infant mortality over time as the etiologies are complex. Evidence suggests a large and increasing impact of TOPFA on population-based birth and mortality statistics nationally, whereas in Saskatchewan the effect appears to be less pronounced. Appreciation of the intervening effect of new reproductive technologies will be increasingly important to accurate surveillance, research, and evaluation as this field continues to expand.

Σκοπός της παρούσας προοπτικής µελέτης είναι η διερεύνηση της σχέσης µεταξύ των επιπέδων της α-φετοπρωτείνης και της β-hCG στον ορό της µητέρας κατά το β' τρίµηνο της κύησης και της δυσµενούς έκβασης της κύησης σε τυχαίο δείγµα εγκύων γυναικών της Νοτιο-Δυτικής Ελλάδος. Υλικό - Μέθοδος: 130 υγιείς γυναίκες ελληνικής καταγωγής µε αυτόµατη έναρξη της εγκυµοσύνης µελετήθηκαν για τα επίπεδα της AFP και της β-hCG στον ορό τους µεταξύ της 13ης-24ης εβδοµάδας της κύησης και παρακολουθήθηκαν για δυσµενή έκβαση της εγκυµοσύνης. Επίπεδα AFP καθώς και επίπεδα β-hCG στον ορό της εγκύου 2 φορές µεγαλύτερα του µέσου όρου για την ηλικία της κύησης θεωρήθηκαν µη φυσιολογικά. Η στατιστική ανάλυση έγινε µε τη δοκιµασία Pearson's x2. Αποτέλεσµα: Αυξηµένα επίπεδα AFP στον ορό της µητέρας βρέθηκαν σε 27 από τις 130 γυναίκες που µελετήθηκαν (20,7%). Μεταξύ αυτών µόνο 4 γυναίκες (14,8%) ανέπτυξαν επιπλοκές της κύησης. Επίσης αυξηµένα επίπεδα β-hCG βρέθηκαν σε 14 από τις 130 γυναίκες που µελετήθηκαν (10,77%). Όµως µεταξύ αυτών καµία γυναίκα δεν ανέπτυξε επιπλοκές κατά τη διάρκεια της παρούσας κύησης. Συµπέρασµα: Ένας πολυπαραγοντικός έλεγχος της λειτουργίας του πλακούντα κατά το β' τρίµηνο της εγκυµοσύνης µε Doppler των µητριαίων αρτηριών, µε έλεγχο της µορφολογίας του πλακούντα, µε έλεγχο των επιπέδων της AFP και της β-hCG στον ορό της εγκύου δυνατό να µας επιτρέψει την αναγνώριση εκείνων των εγκύων µε αυξηµένο κίνδυνο να αναπτύξουν σοβαρή πλακουντιακή ανεπάρκεια και επιπλοκές της κύησης. / In our prospective study, we investigated the association between midtrimester maternal serum AFP (ms-AFP) and midtrimester maternal serum β-hCG (ms-β- hCG) levels and adverse pregnancy outcome, in the South-Western Greek population. Materials and Methods: 130 healthy Greek women with spontaneous pregnancies, investigated for ms-AFP levels between 13th-24th weeks of gestation and followed for adverse pregnancy outcome. AFP levels > 2,0 multiples αnd β-hCG levels>2,0 multiples of the median value for gestation, were considered abnormal. Statistical analysis was performed by Pearson's chi-square test. Results: Elevated ms-AFP levels were detected in a total of 27 from the 130 women studied (20,7%). Among them, only 4 women (14,8%) developed pregnancy complications. Elevated ms-b-hCG levels were detected in total of 14 from the 130 women studied (10,77%). Νοne of them developed pregnancy complications. Conclusion: Multiparameter testing of placental function in the mid-trimester uterine artery Doppler, placental morphology, ms-AFP and ms-hCG screening may allow us to identify women with increased risk to develop severe placental insufficiency and pregnancy complications.

Objectif: Évaluer l'efficacité du dépistage de l’hypertension gestationnelle par les caractéristiques démographiques maternelles, les biomarqueurs sériques et le Doppler de l'artère utérine au premier et au deuxième trimestre de grossesse. Élaborer des modèles prédictifs de l’hypertension gestationnelle fondées sur ces paramètres. Methods: Il s'agit d'une étude prospective de cohorte incluant 598 femmes nullipares. Le Doppler utérin a été étudié par échographie transabdominale entre 11 +0 à 13 +6 semaines (1er trimestre) et entre 17 +0 à 21 +6 semaines (2e trimestre). Tous les échantillons de sérum pour la mesure de plusieurs biomarqueurs placentaires ont été recueillis au 1er trimestre. Les caractéristiques démographiques maternelles ont été enregistrées en même temps. Des courbes ROC et les valeurs prédictives ont été utilisés pour analyser la puissance prédictive des paramètres ci-dessus. Différentes combinaisons et leurs modèles de régression logistique ont été également analysés. Résultats: Parmi 598 femmes, on a observé 20 pré-éclampsies (3,3%), 7 pré-éclampsies précoces (1,2%), 52 cas d’hypertension gestationnelle (8,7%) , 10 cas d’hypertension gestationnelle avant 37 semaines (1,7%). L’index de pulsatilité des artères utérines au 2e trimestre est le meilleur prédicteur. En analyse de régression logistique multivariée, la meilleure valeur prédictive au 1er et au 2e trimestre a été obtenue pour la prévision de la pré-éclampsie précoce. Le dépistage combiné a montré des résultats nettement meilleurs comparés avec les paramètres maternels ou Doppler seuls. Conclusion: Comme seul marqueur, le Doppler utérin du deuxième trimestre a la meilleure prédictive pour l'hypertension, la naissance prématurée et la restriction de croissance. La combinaison des caractéristiques démographiques maternelles, des biomarqueurs sériques maternels et du Doppler utérin améliore l'efficacité du dépistage, en particulier pour la pré-éclampsie nécessitant un accouchement prématuré. / Objective: To evaluate the screening efficacy of maternal demographic characteristics, serum biomarkers and uterine artery Doppler (uaD) during the first and the second trimester for the hypertensive disorders of pregnancy. To elaborate prediction models of these diseases based on the combination of selected maternal demographic characteristics, maternal serum biomarkers and uaD indexes. Methods: This is a prospective pregnant cohort study of 598 singleton nulliparous consecutive women. UaD investigation was performed by transabdominal sonography between 11+0 and 13+6 weeks, and between 17+0 and 21+6 weeks. All the serum samples for measurement of several placental biomarkers were collected at the first trimester. Maternal demographic characteristics were recorded at the same time. Receiver operating characteristic curves and predictive values were used to analyze the predictive powers of the above parameters. Different combinations and their logistic regression predictive models were analyzed. Results: Among 598 women, 20 developed preeclampsia (3.3%), 7 developed early-onset preeclampsia (1.2%), 52 developed gestational hypertension (8.7%), 10 developed gestational hypertension with delivery before 37 weeks (1.7%). Second trimester uterine artery pulsatility index was the best predictor with statistical significance for all the outcomes. In the multivariable logistic regression analysis, the best predictive value in the first and second trimester was obtained for the prediction of early onset preeclampsia. The combined screening showed significantly better results compared to either maternal parameters or Doppler alone. Conclusion: As a single marker, second trimester Doppler has the highest predictive value for hypertensive disorders, preterm birth and SGA. Combination of the maternal demographic characteristics, maternal serum biomarker and uaD improves the screening efficacy, especially when this necessitates early delivery.

RÉSUMÉ Objectif: Évaluer l'efficacité du dépistage de l’hypertension gestationnelle par les caractéristiques démographiques maternelles, les biomarqueurs sériques et le Doppler de l'artère utérine au premier et au deuxième trimestre de grossesse. Élaborer des modèles prédictifs de l’hypertension gestationnelle fondées sur ces paramètres. Methods: Il s'agit d'une étude prospective de cohorte incluant 598 femmes nullipares. Le Doppler utérin a été étudié par échographie transabdominale entre 11 +0 à 13 +6 semaines (1er trimestre) et entre 17 +0 à 21 +6 semaines (2e trimestre). Tous les échantillons de sérum pour la mesure de plusieurs biomarqueurs placentaires ont été recueillis au 1er trimestre. Les caractéristiques démographiques maternelles ont été enregistrées en même temps. Des courbes ROC et les valeurs prédictives ont été utilisés pour analyser la puissance prédictive des paramètres ci-dessus. Différentes combinaisons et leurs modèles de régression logistique ont été également analysés. Résultats: Parmi 598 femmes, on a observé 20 pré-éclampsies (3,3%), 7 pré-éclampsies précoces (1,2%), 52 cas d’hypertension gestationnelle (8,7%) , 10 cas d’hypertension gestationnelle avant 37 semaines (1,7%). L’index de pulsatilité des artères utérines au 2e trimestre est le meilleur prédicteur. En analyse de régression logistique multivariée, la meilleure valeur prédictive au 1er et au 2e trimestre a été obtenue pour la prévision de la pré-éclampsie précoce. Le dépistage combiné a montré des résultats nettement meilleurs comparés avec les paramètres maternels ou Doppler seuls. Conclusion: Comme seul marqueur, le Doppler utérin du deuxième trimestre a la meilleure prédictive pour l'hypertension, la naissance prématurée et la restriction de croissance. La combinaison des caractéristiques démographiques maternelles, des biomarqueurs sériques maternels et du Doppler utérin améliore l'efficacité du dépistage, en particulier pour la pré-éclampsie nécessitant un accouchement prématuré. Mot clés: Hypertension gestationnelle, Doppler utérins, Biomarqueurs sériques maternels, Caractéristiques démographiques maternelles, Dépistage, Modèle prédictif Multivarié. / ABSTRACT Objective: To evaluate the screening efficacy of maternal demographic characteristics, serum biomarkers and uterine artery Doppler (uaD) during the first and the second trimester for the hypertensive disorders of pregnancy. To elaborate prediction models of these diseases based on the combination of selected maternal demographic characteristics, maternal serum biomarkers and uaD indexes. Methods: This is a prospective pregnant cohort study of 598 singleton nulliparous consecutive women. UaD investigation was performed by transabdominal sonography between 11+0 and 13+6 weeks, and between 17+0 and 21+6 weeks. All the serum samples for measurement of several placental biomarkers were collected at the first trimester. Maternal demographic characteristics were recorded at the same time. Receiver operating characteristic curves and predictive values were used to analyze the predictive powers of the above parameters. Different combinations and their logistic regression predictive models were analyzed. Results: Among 598 women, 20 developed preeclampsia (3.3%), 7 developed early-onset preeclampsia (1.2%), 52 developed gestational hypertension (8.7%), 10 developed gestational hypertension with delivery before 37 weeks (1.7%). Second trimester uterine artery pulsatility index was the best predictor with statistical significance for all the outcomes. In the multivariable logistic regression analysis, the best predictive value in the first and second trimester was obtained for the prediction of early onset preeclampsia. The combined screening showed significantly better results compared to either maternal parameters or Doppler alone. Conclusion: As a single marker, second trimester Doppler has the highest predictive value for hypertensive disorders, preterm birth and SGA. Combination of the maternal demographic characteristics, maternal serum biomarker and uaD improves the screening efficacy, especially when this necessitates early delivery. Key words: Hypertensive disorders of pregnancy, Doppler, Maternal serum biomarkers, Maternal demographic characteristics, Screening, Multivariable predictive model.