Despite a shift in clinical practice favouring cesarean section for breech presentation, adequate... more Despite a shift in clinical practice favouring cesarean section for breech presentation, adequate skills are still needed for a safe vaginal breech birth. This case report illustrates the physiological mechanism of vaginal breech birth. The accompanying pictures are a testimony to the "hands-off" approach and could be used for educational purposes.
Surprisingly, the genetics of preterm delivery have received very little attention in the literat... more Surprisingly, the genetics of preterm delivery have received very little attention in the literature. Possible explanations are the inability to obtain accurate information on the length of gestation in family studies and the heterogeneous nature of this disorder. In contrast to the many studies which consider the relative contribution of both genetic and environmental variance to the total variance of birthweight, few studies have examined the genetic basis of the duration of gestation in man. It is argued that both genetic and epidemiological approaches are needed to separate the effects of heredity and the environment on the duration of gestation.
Objectives The objectives of this study are to analyse the perinatal management decisions made in... more Objectives The objectives of this study are to analyse the perinatal management decisions made in a multidisciplinary setting following the prenatal diagnosis of fetal anomalies and to evaluate to what extent, in clinical practice, decisions about obstetric management are attuned to those about neonatal management. Methods Data on perinatal management of 318 consecutive singleton pregnancies presented to a multidisciplinary perinatal team in a tertiary centre were collected retrospectively. Results The multidisciplinary perinatal team decided upon non-aggressive obstetric management in 20% of the cases and consented to termination of pregnancy in 10% of the cases. The multidisciplinary perinatal team decided upon neonatal management in 112(36%) of all fetuses. In 100(89%) of these fetuses, standard neonatal management, and in 12(11%), no neonatal life-sustaining treatment was decided upon. Implementation of the decisions of the multidisciplinary perinatal team on the various management modalities ranged from 88 to 100%. Conclusion The multidisciplinary perinatal team worked well in making decisions about obstetric management. In 30% of the cases, this concerned end-of-life decisions. However, for the majority of cases, the perinatal team did not plan neonatal management before birth and thereby did not attune obstetric and neonatal management to each other. This probably reflects the different attitudes towards end-of-life decisions between obstetricians and neonatologists. However, to ensure a consistent perinatal management, a multidisciplinary perinatal team has to make prenatal decisions about both obstetric and neonatal management. Copyright 2004 John Wiley & Sons, Ltd.
Objective To assess ethnic differences in participation in prenatal screening for Down syndrome i... more Objective To assess ethnic differences in participation in prenatal screening for Down syndrome in the Netherlands. Methods Participation in prenatal screening was assessed for the period 1 January 2009 to 1 July 2009 in a defined postal code area in the southwest of the Netherlands. Data on ethnic origin, socio-economic background and age of participants in prenatal screening were obtained from the Medical Diagnostic Centre and the Department of Clinical Genetics. Population data were obtained from Statistics Netherlands. Logistic regression models were used to assess ethnic differences in participation, adjusted for socio-economic and age differences. The overall participation in prenatal screening was 3865 out of 15 093 (26%). Participation was 28% among Dutch women, 15% among those from Turkish ethnic origin, 8% among those from North-African origin, 15% among those from Aruban/Antillean origin and 26% among women from Surinamese origin. Conclusions Compared to Dutch women, those from Turkish, North-African, Aruban/Antillean and other non-Western ethnic origin were less likely to participate in screening. It was unexpected that women from Surinamese origin equally participated. It should be further investigated to what extent participation and nonparticipation in these various ethnic groups was based on informed decision-making.
The development of a non-invasive prenatal diagnostic test using fetal nucleated red blood cells ... more The development of a non-invasive prenatal diagnostic test using fetal nucleated red blood cells (NRBCs) isolated from the maternal circulation is hampered by the low frequency of these cells in maternal blood, requiring extensive enrichment procedures before any analytical procedure can be performed. In order to improve and simplify these procedures, we have used in vitro expanded erythroid cells derived from male umbilical cord blood in a model system for the isolation of fetal NRBCs from maternal blood. Erythroblast cells were expanded in vitro to high cell numbers and were immunophenotypically identical to fetal NRBCs isolated from maternal blood. Magnetic activated cell sorting (MACS) isolation procedures were optimized using in vitro expanded male NRBCs diluted up to 1 in 400,000 with female peripheral blood mononucleated cells. The number of recovered male cells was determined using two-colour fluorescence in situ hybridization with X and Y chromosomal probes. Using this model system, an NRBC isolation technique is described. It is based on a one-step MACS enrichment protocol for CD71 positive cells, which showed a significant (Wilcoxon signed ranks test, p<0.05) two-fold higher yield of male NRBCs than previously described MACS methodologies, in which CD71 positive cells were enriched after depletion of other cell types. Application of these isolation strategies to maternal blood samples resulted in a similar improved enrichment of male fetal cells after the direct enrichment of CD71 positive cells.
The potential relationship between daily physical activity and pregnancy outcome remains unclear ... more The potential relationship between daily physical activity and pregnancy outcome remains unclear because of the wide variation in study designs and physical activity assessment measures. We sought to prospectively quantify the potential effects of the various domains of physical activity on selected birth outcomes in a large unselected population. The sample consisted of 11,759 singleton pregnancies from the Avon longitudinal study of parents and children, United Kingdom. Information on daily physical activity was collected by postal questionnaire for self-report measures. Main outcome measures were birth weight, gestational age at delivery, preterm birth and survival. After controlling for confounders, a sedentary lifestyle and paid work during the second trimester of pregnancy were found to be associated with a lower birth weight, while 'bending and stooping' and 'working night shifts' were associated with a higher birth weight. There was no association between physical exertion and duration of gestation or survival. Repetitive boring tasks during the first trimester was weakly associated with an increased risk of preterm birth (\37 weeks) (adjusted odds ratio [OR] = 1.25, 95% CI 1.04-1.50). 'Bending and stooping' during the third trimester was associated with a reduced risk of preterm birth (adjusted OR = 0.73, 95% CI 0.63-0.84). Demanding physical activities do not have a harmful effect on the selected birth outcomes while a sedentary lifestyle is associated with a lower birth weight. In the absence of either medical or obstetric complications, pregnant women may safely continue their normal daily physical activities should they wish to do so.
Background: In The Netherlands the incidence of neonatal herpes was 2.0-2.9 per 100,000 live birt... more Background: In The Netherlands the incidence of neonatal herpes was 2.0-2.9 per 100,000 live births during the period 1981-1998. The low incidence warranted a rather conservative prevention policy. Objectives: To monitor for potential changes in the incidence of neonatal herpes in The Netherlands between 1999 and 2005, which may affect the prevention policy. Study design: Questionnaires were sent to all virological laboratories, the gynaecological and paediatric departments of every university hospital and half the number of the general hospitals in The Netherlands. The questionnaires pertained to the incidence of proven cases of neonatal herpes, the numbers of caesarean sections performed for the prevention of neonatal herpes and the numbers of pregnant women with genital herpes. Results: In the period 1999-2005 33 cases of neonatal herpes were reported, yielding an incidence of 3.2 cases per 100,000 live births per year. The estimated annual numbers of pregnant women with genital herpes ranged from 200 to 240. Approximately 9 caesarean sections were performed annually to prevent neonatal herpes. Conclusions: In The Netherlands neonatal herpes is still a rare condition. From the findings of this study it is concluded that it is not necessary to revise the Dutch guidelines for the prevention of neonatal herpes simplex infection.
(1) To describe the characteristics of decision-making about management of unborn infants with se... more (1) To describe the characteristics of decision-making about management of unborn infants with serious anomalies by a multidisciplinary perinatal team. (2) To evaluate the impact of multidisciplinary team discussions on the degree to which decisions about the management of unborn infants with serious anomalies are supported. (3) To evaluate the impact of the team discussions on the arguments used by physicians for their preferences concerning management. Prospective analysis of 78 cases discussed within the multidisciplinary perinatal team of a tertiary centre by means of an anonymous one-page questionnaire with structured questions pertaining to the opinion of the responder on medical management of each case. We did not find systematic differences between specialties prior to the discussion of cases. However, discussion with the multidisciplinary perinatal team improved decision-making about management of unborn infants with serious anomalies by enhancing the degree of support for the decisions taken. The discussions of the team did not change the physicians' arguments mentioned for their preferences. Multidisciplinary team discussions improve decision-making about management of unborn infants with serious congenital anomalies.
Despite a shift in clinical practice favouring cesarean section for breech presentation, adequate... more Despite a shift in clinical practice favouring cesarean section for breech presentation, adequate skills are still needed for a safe vaginal breech birth. This case report illustrates the physiological mechanism of vaginal breech birth. The accompanying pictures are a testimony to the "hands-off" approach and could be used for educational purposes.
Surprisingly, the genetics of preterm delivery have received very little attention in the literat... more Surprisingly, the genetics of preterm delivery have received very little attention in the literature. Possible explanations are the inability to obtain accurate information on the length of gestation in family studies and the heterogeneous nature of this disorder. In contrast to the many studies which consider the relative contribution of both genetic and environmental variance to the total variance of birthweight, few studies have examined the genetic basis of the duration of gestation in man. It is argued that both genetic and epidemiological approaches are needed to separate the effects of heredity and the environment on the duration of gestation.
Objectives The objectives of this study are to analyse the perinatal management decisions made in... more Objectives The objectives of this study are to analyse the perinatal management decisions made in a multidisciplinary setting following the prenatal diagnosis of fetal anomalies and to evaluate to what extent, in clinical practice, decisions about obstetric management are attuned to those about neonatal management. Methods Data on perinatal management of 318 consecutive singleton pregnancies presented to a multidisciplinary perinatal team in a tertiary centre were collected retrospectively. Results The multidisciplinary perinatal team decided upon non-aggressive obstetric management in 20% of the cases and consented to termination of pregnancy in 10% of the cases. The multidisciplinary perinatal team decided upon neonatal management in 112(36%) of all fetuses. In 100(89%) of these fetuses, standard neonatal management, and in 12(11%), no neonatal life-sustaining treatment was decided upon. Implementation of the decisions of the multidisciplinary perinatal team on the various management modalities ranged from 88 to 100%. Conclusion The multidisciplinary perinatal team worked well in making decisions about obstetric management. In 30% of the cases, this concerned end-of-life decisions. However, for the majority of cases, the perinatal team did not plan neonatal management before birth and thereby did not attune obstetric and neonatal management to each other. This probably reflects the different attitudes towards end-of-life decisions between obstetricians and neonatologists. However, to ensure a consistent perinatal management, a multidisciplinary perinatal team has to make prenatal decisions about both obstetric and neonatal management. Copyright 2004 John Wiley & Sons, Ltd.
Objective To assess ethnic differences in participation in prenatal screening for Down syndrome i... more Objective To assess ethnic differences in participation in prenatal screening for Down syndrome in the Netherlands. Methods Participation in prenatal screening was assessed for the period 1 January 2009 to 1 July 2009 in a defined postal code area in the southwest of the Netherlands. Data on ethnic origin, socio-economic background and age of participants in prenatal screening were obtained from the Medical Diagnostic Centre and the Department of Clinical Genetics. Population data were obtained from Statistics Netherlands. Logistic regression models were used to assess ethnic differences in participation, adjusted for socio-economic and age differences. The overall participation in prenatal screening was 3865 out of 15 093 (26%). Participation was 28% among Dutch women, 15% among those from Turkish ethnic origin, 8% among those from North-African origin, 15% among those from Aruban/Antillean origin and 26% among women from Surinamese origin. Conclusions Compared to Dutch women, those from Turkish, North-African, Aruban/Antillean and other non-Western ethnic origin were less likely to participate in screening. It was unexpected that women from Surinamese origin equally participated. It should be further investigated to what extent participation and nonparticipation in these various ethnic groups was based on informed decision-making.
The development of a non-invasive prenatal diagnostic test using fetal nucleated red blood cells ... more The development of a non-invasive prenatal diagnostic test using fetal nucleated red blood cells (NRBCs) isolated from the maternal circulation is hampered by the low frequency of these cells in maternal blood, requiring extensive enrichment procedures before any analytical procedure can be performed. In order to improve and simplify these procedures, we have used in vitro expanded erythroid cells derived from male umbilical cord blood in a model system for the isolation of fetal NRBCs from maternal blood. Erythroblast cells were expanded in vitro to high cell numbers and were immunophenotypically identical to fetal NRBCs isolated from maternal blood. Magnetic activated cell sorting (MACS) isolation procedures were optimized using in vitro expanded male NRBCs diluted up to 1 in 400,000 with female peripheral blood mononucleated cells. The number of recovered male cells was determined using two-colour fluorescence in situ hybridization with X and Y chromosomal probes. Using this model system, an NRBC isolation technique is described. It is based on a one-step MACS enrichment protocol for CD71 positive cells, which showed a significant (Wilcoxon signed ranks test, p<0.05) two-fold higher yield of male NRBCs than previously described MACS methodologies, in which CD71 positive cells were enriched after depletion of other cell types. Application of these isolation strategies to maternal blood samples resulted in a similar improved enrichment of male fetal cells after the direct enrichment of CD71 positive cells.
The potential relationship between daily physical activity and pregnancy outcome remains unclear ... more The potential relationship between daily physical activity and pregnancy outcome remains unclear because of the wide variation in study designs and physical activity assessment measures. We sought to prospectively quantify the potential effects of the various domains of physical activity on selected birth outcomes in a large unselected population. The sample consisted of 11,759 singleton pregnancies from the Avon longitudinal study of parents and children, United Kingdom. Information on daily physical activity was collected by postal questionnaire for self-report measures. Main outcome measures were birth weight, gestational age at delivery, preterm birth and survival. After controlling for confounders, a sedentary lifestyle and paid work during the second trimester of pregnancy were found to be associated with a lower birth weight, while 'bending and stooping' and 'working night shifts' were associated with a higher birth weight. There was no association between physical exertion and duration of gestation or survival. Repetitive boring tasks during the first trimester was weakly associated with an increased risk of preterm birth (\37 weeks) (adjusted odds ratio [OR] = 1.25, 95% CI 1.04-1.50). 'Bending and stooping' during the third trimester was associated with a reduced risk of preterm birth (adjusted OR = 0.73, 95% CI 0.63-0.84). Demanding physical activities do not have a harmful effect on the selected birth outcomes while a sedentary lifestyle is associated with a lower birth weight. In the absence of either medical or obstetric complications, pregnant women may safely continue their normal daily physical activities should they wish to do so.
Background: In The Netherlands the incidence of neonatal herpes was 2.0-2.9 per 100,000 live birt... more Background: In The Netherlands the incidence of neonatal herpes was 2.0-2.9 per 100,000 live births during the period 1981-1998. The low incidence warranted a rather conservative prevention policy. Objectives: To monitor for potential changes in the incidence of neonatal herpes in The Netherlands between 1999 and 2005, which may affect the prevention policy. Study design: Questionnaires were sent to all virological laboratories, the gynaecological and paediatric departments of every university hospital and half the number of the general hospitals in The Netherlands. The questionnaires pertained to the incidence of proven cases of neonatal herpes, the numbers of caesarean sections performed for the prevention of neonatal herpes and the numbers of pregnant women with genital herpes. Results: In the period 1999-2005 33 cases of neonatal herpes were reported, yielding an incidence of 3.2 cases per 100,000 live births per year. The estimated annual numbers of pregnant women with genital herpes ranged from 200 to 240. Approximately 9 caesarean sections were performed annually to prevent neonatal herpes. Conclusions: In The Netherlands neonatal herpes is still a rare condition. From the findings of this study it is concluded that it is not necessary to revise the Dutch guidelines for the prevention of neonatal herpes simplex infection.
(1) To describe the characteristics of decision-making about management of unborn infants with se... more (1) To describe the characteristics of decision-making about management of unborn infants with serious anomalies by a multidisciplinary perinatal team. (2) To evaluate the impact of multidisciplinary team discussions on the degree to which decisions about the management of unborn infants with serious anomalies are supported. (3) To evaluate the impact of the team discussions on the arguments used by physicians for their preferences concerning management. Prospective analysis of 78 cases discussed within the multidisciplinary perinatal team of a tertiary centre by means of an anonymous one-page questionnaire with structured questions pertaining to the opinion of the responder on medical management of each case. We did not find systematic differences between specialties prior to the discussion of cases. However, discussion with the multidisciplinary perinatal team improved decision-making about management of unborn infants with serious anomalies by enhancing the degree of support for the decisions taken. The discussions of the team did not change the physicians' arguments mentioned for their preferences. Multidisciplinary team discussions improve decision-making about management of unborn infants with serious congenital anomalies.
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Papers by Hajo wildschut