Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Hajo I. J. Wildschut is active.

Publication


Featured researches published by Hajo I. J. Wildschut.


PLOS Medicine | 2012

Induction of Labor versus Expectant Management in Women with Preterm Prelabor Rupture of Membranes between 34 and 37 Weeks: A Randomized Controlled Trial

David van der Ham; Sylvia M. C. Vijgen; Jan G. Nijhuis; Johannes J. van Beek; Brent C. Opmeer; Antonius L.M. Mulder; Rob Moonen; Mariet Groenewout; Marielle van Pampus; Gerald Mantel; Kitty W. M. Bloemenkamp; Wim van Wijngaarden; Marko Sikkema; Monique C. Haak; Paula Pernet; Martina Porath; Jan Molkenboer; Simone Kuppens; Anneke Kwee; Michael Kars; Mallory Woiski; Martin Weinans; Hajo I. J. Wildschut; Bettina M.C. Akerboom; Ben Willem J. Mol; Christine Willekes

In a randomized controlled trial David van der Ham and colleagues investigate induction of labor versus expectant management for women with preterm prelabor rupture of membranes.


European Journal of Human Genetics | 2009

Rapid aneuploidy detection with multiplex ligation-dependent probe amplification: A prospective study of 4000 amniotic fluid samples

Diane Van Opstal; Marjan Boter; Danielle de Jong; Cardi van den Berg; Hennie T. Brüggenwirth; Hajo I. J. Wildschut; Annelies de Klein; Robert-Jan H. Galjaard

The introduction of prenatal screening requires rapid high-throughput diagnosis of common aneuploidies. Multiplex ligation-dependent probe amplification (MLPA) allows for quick, easily automated multiplex testing of these aneuploidies in one polymerase chain reaction. We performed a large prospective study using MLPA on 4000 amniotic fluid (AF) samples including all indications and compared its value to karyotyping and fluorescence in situ hybridization (FISH). MLPA can reliably determine common aneuploidies with 100% sensitivity and 100% specificity. Moreover, some mosaic cases and structural chromosome aberrations were detected as well. In cases of a male fetus, triploidies can be detected by an aberrant pattern of probe signals, which mimics maternal cell contamination (MCC). Macroscopic blood contamination was encountered in 3.2% of the AF samples. In 20% of these samples, an MLPA pattern was found consistent with MCC, although there were no false negatives of the most common aneuploidies. As the vast majority of inconclusive results (1.7%) is due to potential MCC, we designed a protocol in which we determine whether MLPA can be performed on blood-contaminated AF samples by testing if blood is of fetal origin. Then, the number of inconclusive results could be theoretically reduced to 0.05%. We propose an alternative interpretation of relative probe signals for rapid aneuploidy diagnosis (RAD). We discuss the value of MLPA for the detection of (submicroscopic) structural chromosome anomalies. MLPA is a reliable method that can replace FISH and could be used as a stand-alone test for RAD instead of karyotyping.


Journal of Epidemiology and Community Health | 2010

Ethnic differences in informed decision-making about prenatal screening for Down's syndrome

Mirjam P. Fransen; Marie-Louise Essink-Bot; Ineke Vogel; Johan P. Mackenbach; Eric A.P. Steegers; Hajo I. J. Wildschut

Background The aim of this study was to assess ethnic variations in informed decision-making about prenatal screening for Downs syndrome and to examine the contribution of background and decision-making variables. Methods Pregnant women of Dutch, Turkish and Surinamese origin were recruited between 2006 and 2008 from community midwifery or obstetrical practices in The Netherlands. Each woman was personally interviewed 3 weeks (mean) after booking for prenatal care. Knowledge, attitude and participation in prenatal screening were assessed following the ‘Multidimensional Measure of Informed Choice’ that has been developed and applied in the UK. Results In total, 71% of the Dutch women were classified as informed decision-makers, compared with 5% of the Turkish and 26% of the Surinamese women. Differences between Surinamese and Dutch women could largely be attributed to differences in educational level and age. Differences between Dutch and Turkish women could mainly be attributed to differences in language skills and gender emancipation. Conclusion Women from ethnic minority groups less often made an informed decision whether or not to participate in prenatal screening. Interventions to decrease these ethnic differences should first of all be aimed at overcoming language barriers and increasing comprehension among women with a low education level. To further develop diversity-sensitive strategies for counselling, it should be investigated how women from different ethnic backgrounds value informed decision-making in prenatal screening, what decision-relevant knowledge they need and what they take into account when considering participation in prenatal screening.


BMC Pregnancy and Childbirth | 2007

Induction of labour versus expectant management in women with preterm prelabour rupture of membranes between 34 and 37 weeks (the PPROMEXIL-trial)

David van der Ham; Jan G. Nijhuis; Ben Willem J. Mol; Johannes J. van Beek; Brent C. Opmeer; Denise Bijlenga; Mariette Groenewout; Birgit Arabin; Kitty W. M. Bloemenkamp; Wim van Wijngaarden; M.G.A.J. Wouters; Paula Pernet; Martina Porath; Jan Molkenboer; Jan B. Derks; Michael M. Kars; Hubertina C. J. Scheepers; Martin Weinans; Mallory Woiski; Hajo I. J. Wildschut; Christine Willekes

BackgroundPreterm prelabour rupture of the membranes (PPROM) is an important clinical problem and a dilemma for the gynaecologist. On the one hand, awaiting spontaneous labour increases the probability of infectious disease for both mother and child, whereas on the other hand induction of labour leads to preterm birth with an increase in neonatal morbidity (e.g., respiratory distress syndrome (RDS)) and a possible rise in the number of instrumental deliveries.Methods/DesignWe aim to determine the effectiveness and cost-effectiveness of immediate delivery after PPROM in near term gestation compared to expectant management. Pregnant women with preterm prelabour rupture of the membranes at a gestational age from 34+0 weeks until 37+0 weeks will be included in a multicentre prospective randomised controlled trial. We will compare early delivery with expectant monitoring.The primary outcome of this study is neonatal sepsis. Secondary outcome measures are maternal morbidity (chorioamnionitis, puerperal sepsis) and neonatal disease, instrumental delivery rate, maternal quality of life, maternal preferences and costs. We anticipate that a reduction of neonatal infection from 7.5% to 2.5% after induction will outweigh an increase in RDS and additional costs due to admission of the child due to prematurity. Under these assumptions, we aim to randomly allocate 520 women to two groups of 260 women each. Analysis will be by intention to treat. Additionally a cost-effectiveness analysis will be performed to evaluate if the cost related to early delivery will outweigh those of expectant management. Long term outcomes will be evaluated using modelling.DiscussionThis trial will provide evidence as to whether induction of labour after preterm prelabour rupture of membranes is an effective and cost-effective strategy to reduce the risk of neonatal sepsis.Controlled clinical trial registerISRCTN29313500


European Journal of Human Genetics | 2011

Rapid testing versus karyotyping in Down's syndrome screening: cost-effectiveness and detection of clinically significant chromosome abnormalities

Jean Gekas; David-Gradus van den Berg; Audrey Durand; Maud Vallée; Hajo I. J. Wildschut; Emmanuel Bujold; Jean-Claude Forest; François Rousseau; Daniel Reinharz

In all, 80% of antenatal karyotypes are generated by Downs syndrome screening programmes (DSSP). After a positive screening, women are offered prenatal foetus karyotyping, the gold standard. Reliable molecular methods for rapid aneuploidy diagnosis (RAD: fluorescence in situ hybridization (FISH) and quantitative fluorescence PCR (QF-PCR)) can detect common aneuploidies, and are faster and less expensive than karyotyping.In the UK, RAD is recommended as a standalone approach in DSSP, whereas the US guidelines recommend that RAD be followed up by karyotyping. A cost-effectiveness (CE) analysis of RAD in various DSSP is lacking. There is a debate over the significance of chromosome abnormalities (CA) detected with karyotyping but not using RAD. Our objectives were to compare the CE of RAD versus karyotyping, to evaluate the clinically significant missed CA and to determine the impact of detecting the missed CA. We performed computer simulations to compare six screening options followed by FISH, PCR or karyotyping using a population of 110 948 pregnancies. Among the safer screening strategies, the most cost-effective strategy was contingent screening with QF-PCR (CE ratio of


Prenatal Diagnosis | 2000

Accuracy of abnormal karyotypes after the analysis of both short- and long-term culture of chorionic villi

Cardi van den Berg; Diane Van Opstal; Helen Brandenburg; Hajo I. J. Wildschut; Nicolette S. den Hollander; Leen Pijpers; Robert Jan H. Galjaard; Frans J. Los

24 084 per Downs syndrome (DS) detected). Using karyotyping, the CE ratio increased to


Maternal and Child Health Journal | 2012

An Urban Perinatal Health Programme of Strategies to Improve Perinatal Health

Semiha Denktaş; Gouke J. Bonsel; E. J. Van der Weg; A. J. J. Voorham; Hanneke W. Torij; J.P. de Graaf; Hajo I. J. Wildschut; Ingrid Peters; Erwin Birnie; E.A.P. Steegers

27 898. QF-PCR missed only six clinically significant CA of which only one was expected to confer a high risk of an abnormal outcome. The incremental CE ratio (ICER) to find the CA missed by RAD was


Prenatal Diagnosis | 2010

Ethnic differences in participation in prenatal screening for Down syndrome: a register-based study.

Mirjam P. Fransen; Marleen Schoonen; Johan P. Mackenbach; Eric A.P. Steegers; Harry J. de Koning; Jacqueline A. M. Laudy; Robert-Jan H. Galjaard; Caspar W. N. Looman; Marie-Louise Essink-Bot; Hajo I. J. Wildschut

66 608 per CA. These costs are much higher than those involved for detecting DS cases. As the DSSP are mainly designed for DS detection, it may be relevant to question the additional costs of karyotyping.


European Journal of Human Genetics | 2007

Undergoing prenatal screening for Down's syndrome: presentation of choice and information in Europe and Asia

Sue Hall; Lyn S. Chitty; Elizabeth Dormandy; Amelia Hollywood; Hajo I. J. Wildschut; Albert Fortuny; Bianca Masturzo; Jiøí Šantavý; Madhulika Kabra; Runmei Ma; Theresa M. Marteau

We report in detail the cytogenetic results of 1838 consecutive chorionic villus samples with the availability of both short‐term culture (STC‐villi) and long‐term culture (LTC‐villi) preparations in 1561 cases (84.9%). A high degree of laboratory success (99.5%) and diagnostic accuracy (99.8%) was observed; in four cases of low mosaicism, all four associated with the final birth of a normal child, a small risk of uncertainty was accepted. The combined analysis of STC‐ and LTC‐villi reduced follow‐up amniocenteses by one‐third in comparison with the analysis of STC‐villi alone. We believe that the desired level of quality and accuracy of prenatal cytogenetics in chorionic villi can only be achieved when both STC‐ and LTC‐villi are available. We conclude that CVS might then be the mode of prenatal diagnosis of first choice in pregnancies with a high (cytogenetic) risk. Copyright


Prenatal Diagnosis | 2000

How useful is the in vitro expansion of fetal CD34+ progenitor cells from maternal blood samples for diagnostic purposes?

Mieke W. J. C. Jansen; Dik van Leenen; Helen Brandenburg; Hajo I. J. Wildschut; Juriy W. Wladimiroff; Rob E. Ploemacher

Promotion of a healthy pregnancy is a top priority of the health care policy in many European countries. Perinatal mortality is an important indicator of the success of this policy. Recently, it was shown that the Netherlands has relatively high perinatal death rates when compared to other European countries. This is in particular true for large cities where perinatal mortality rates are 20–50% higher than elsewhere. Consequently in the Netherlands, there is heated debate on how to tackle these problems. Without the introduction of measures throughout the entire perinatal health care chain, pregnancy outcomes are difficult to improve. With the support of health care professionals, the City of Rotterdam and the Erasmus University Medical Centre have taken the initiative to develop an urban perinatal health programme called ‘Ready for a Baby’. The main objective of this municipal 10-year programme is to improve perinatal health and to reduce perinatal mortality in all districts to at least the current national average of l0 per 1000. Key elements are the understanding of the mechanisms of the large health differences between women living in deprived and non-deprived urban areas. Risk guided care, orientation towards shared-care and improvement of collaborations between health care professionals shapes the interventions that are being developed. Major attention is given to the development of methods to improve risk-selection before and during pregnancy and methods to reach low-educated and immigrant groups.

Collaboration


Dive into the Hajo I. J. Wildschut's collaboration.

Top Co-Authors

Avatar

Eric A.P. Steegers

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Johan P. Mackenbach

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar

Juriy W. Wladimiroff

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar

Mirjam P. Fransen

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge