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Dive into the research topics where Jan B. Derks is active.

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Featured researches published by Jan B. Derks.


The Lancet | 2015

2 year neurodevelopmental and intermediate perinatal outcomes in infants with very preterm fetal growth restriction (TRUFFLE): A randomised trial

C. Lees; Neil Marlow; Aleid G. van Wassenaer-Leemhuis; Birgit Arabin; C. M. Bilardo; Christoph Brezinka; Sandra Calvert; Jan B. Derks; Anke Diemert; Johannes J. Duvekot; E. Ferrazzi; T. Frusca; Wessel Ganzevoort; Kurt Hecher; Pasquale Martinelli; E. Ostermayer; A. T. Papageorghiou; Dietmar Schlembach; K. T. M. Schneider; B. Thilaganathan; Tullia Todros; A. Valcamonico; Gerard H.A. Visser; Hans Wolf

BACKGROUND No consensus exists for the best way to monitor and when to trigger delivery in mothers of babies with fetal growth restriction. We aimed to assess whether changes in the fetal ductus venosus Doppler waveform (DV) could be used as indications for delivery instead of cardiotocography short-term variation (STV). METHODS In this prospective, European multicentre, unblinded, randomised study, we included women with singleton fetuses at 26-32 weeks of gestation who had very preterm fetal growth restriction (ie, low abdominal circumference [<10th percentile] and a high umbilical artery Doppler pulsatility index [>95th percentile]). We randomly allocated women 1:1:1, with randomly sized blocks and stratified by participating centre and gestational age (<29 weeks vs ≥29 weeks), to three timing of delivery plans, which differed according to antenatal monitoring strategies: reduced cardiotocograph fetal heart rate STV (CTG STV), early DV changes (pulsatility index >95th percentile; DV p95), or late DV changes (A wave [the deflection within the venous waveform signifying atrial contraction] at or below baseline; DV no A). The primary outcome was survival without cerebral palsy or neurosensory impairment, or a Bayley III developmental score of less than 85, at 2 years of age. We assessed outcomes in surviving infants with known outcomes at 2 years. We did an intention to treat study for all participants for whom we had data. Safety outcomes were deaths in utero and neonatal deaths and were assessed in all randomly allocated women. This study is registered with ISRCTN, number 56204499. FINDINGS Between Jan 1, 2005 and Oct 1, 2010, 503 of 542 eligible women were randomly allocated to monitoring groups (166 to CTG STV, 167 to DV p95, and 170 to DV no A). The median gestational age at delivery was 30·7 weeks (IQR 29·1-32·1) and mean birthweight was 1019 g (SD 322). The proportion of infants surviving without neuroimpairment did not differ between the CTG STV (111 [77%] of 144 infants with known outcome), DV p95 (119 [84%] of 142), and DV no A (133 [85%] of 157) groups (ptrend=0·09). 12 fetuses (2%) died in utero and 27 (6%) neonatal deaths occurred. Of survivors, more infants where women were randomly assigned to delivery according to late ductus changes (133 [95%] of 140, 95%, 95% CI 90-98) were free of neuroimpairment when compared with those randomly assigned to CTG (111 [85%] of 131, 95% CI 78-90; p=0.005), but this was accompanied by a non-significant increase in perinatal and infant mortality. INTERPRETATION Although the difference in the proportion of infants surviving without neuroimpairment was non-significant at the primary endpoint, timing of delivery based on the study protocol using late changes in the DV waveform might produce an improvement in developmental outcomes at 2 years of age. FUNDING ZonMw, The Netherlands and Dr Hans Ludwig Geisenhofer Foundation, Germany.


British Journal of Obstetrics and Gynaecology | 1997

Antenatal corticosteroid therapy and fetal behaviour: a randomised study of the effects of betamethasone and dexamethasone

Eduard J. H. Mulder; Jan B. Derks; Gerard H. A. Visser

Objectives To compare the effects of maternal betamethasone and dexamethasone administration on fetal behaviour and fetal heart rate variation.


British Journal of Obstetrics and Gynaecology | 1995

The effects of maternal betamethasone administration on the fetus

Jan B. Derks; Eduard J. H. Mulder; Gerard H. A. Visser

Objective To examine prospectively the effects of maternal betamethasone administration on fetal heart rate variation, body, breathing and eye movements and the rest‐activity cycle.


Pediatrics | 2009

Maternal Allopurinol During Fetal Hypoxia Lowers Cord Blood Levels of the Brain Injury Marker S-100B

Helen L. Torrance; Manon J. Benders; Jan B. Derks; Carin M. A. Rademaker; Arie Bos; Paul P. van den Berg; Mariangela Longini; Giuseppe Buonocore; MariaElena Venegas; Hernando Baquero; Gerard H. A. Visser; Frank van Bel

BACKGROUND: Fetal hypoxia is an important determinant of neonatal encephalopathy caused by birth asphyxia, in which hypoxia-induced free radical formation plays an important role. HYPOTHESIS: Maternal treatment with allopurinol, will cross the placenta during fetal hypoxia (primary outcome) and reduce S-100B and free radical formation (secondary outcome). METHODS: In a randomized, double-blind feasibility study, 53 pregnant women in labor (54 fetuses) with a gestational age of >36 weeks and fetal hypoxia, as indicated by abnormal/nonreassuring fetal heart rate tracing or fetal scalp pH of <7.20, received 500 mg of allopurinol or placebo intravenously. Severity of fetal hypoxia, brain damage and free radical formation were assessed by arterial cord blood lactate, S-100B and non-protein-bound-iron concentrations, respectively. At birth, maternal and cord blood concentrations of allopurinol and its active metabolite oxypurinol were determined. RESULTS: Allopurinol and oxypurinol concentrations were within the therapeutic range in the mother (allopurinol > 2 mg/L and/or oxypurinol > 4 mg/L) but not always in arterial cord blood. We therefore created 3 groups: a placebo (n = 27), therapeutic allopurinol (n = 15), and subtherapeutic allopurinol group (n = 12). Cord lactate concentration did not differ, but S-100B was significantly lower in the therapeutic allopurinol group compared with the placebo and subtherapeutic allopurinol groups (P < .01). Fewer therapeutic allopurinol cord samples had measurable non–protein-bound iron concentrations compared with placebo (P < .01). CONCLUSIONS: Maternal allopurinol/oxypurinol crosses the placenta during fetal hypoxia. In fetuses/newborns with therapeutic allopurinol/oxypurinol concentrations in cord blood, lower plasma levels of the brain injury marker protein S-100B were detected. A larger allopurinol trial in compromised fetuses at term seems warranted. The allopurinol dosage must be adjusted to achieve therapeutic fetal allopurinol/oxypurinol concentrations.


PLOS ONE | 2010

Antioxidant treatment alters peripheral vascular dysfunction induced by postnatal glucocorticoid therapy in rats.

Emilio A. Herrera; Misha M. Verkerk; Jan B. Derks; Dino A. Giussani

Background Postnatal glucocorticoid therapy in premature infants diminishes chronic lung disease, but it also increases the risk of hypertension in adulthood. Since glucocorticoid excess leads to overproduction of free radicals and endothelial dysfunction, this study tested the hypothesis that adverse effects on cardiovascular function of postnatal glucocorticoids are secondary to oxidative stress. Therefore, combined postnatal treatment of glucocorticoids with antioxidants may diminish unwanted effects. Methodology/Principal Findings Male rat pups received a course of dexamethasone (Dex), or Dex with vitamins C and E (DexCE), on postnatal days 1–6 (P1–6). Controls received vehicle (Ctrl) or vehicle with vitamins (CtrlCE). At P21, femoral vascular reactivity was determined via wire myography. Dex, but not DexCE or CtrlCE, increased mortality relative to Ctrl (81.3 versus 96.9 versus 90.6 versus 100% survival, respectively; P<0.05). Constrictor responses to phenylephrine (PE) and thromboxane were enhanced in Dex relative to Ctrl (84.7±4.8 versus 67.5±5.7 and 132.7±4.9 versus 107.0±4.9% Kmax, respectively; P<0.05); effects that were diminished in DexCE (58.3±7.5 and 121.1±4.3% Kmax, respectively; P<0.05). Endothelium-dependent dilatation was depressed in Dex relative to Ctrl (115.3±11.9 versus 216.9±18.9, AUC; P<0.05); however, this effect was not restored in DexCE (68.3±8.3, AUC). Relative to Ctrl, CtrlCE alone diminished PE-induced constriction (43.4±3.7% Kmax) and the endothelium-dependent dilatation (74.7±8.7 AUC; P<0.05). Conclusions/Significance Treatment of newborn rats with dexamethasone has detrimental effects on survival and peripheral vasoconstrictor function. Coadministration of dexamethasone with antioxidant vitamins improves survival and partially restores vascular dysfunction. Antioxidant vitamins alone affect peripheral vascular function.


Archives of Disease in Childhood | 2012

Long-term neuroprotective effects of allopurinol after moderate perinatal asphyxia: follow-up of two randomised controlled trials

Joepe J. Kaandorp; Frank van Bel; Sylvia Veen; Jan B. Derks; Floris Groenendaal; Monique Rijken; Elise Roze; Monica Uniken Venema; Carin M. A. Rademaker; Arend F. Bos; Manon J.N.L. Benders

Objective Free-radical-induced reperfusion injury has been recognised as an important cause of brain tissue damage after birth asphyxia. Allopurinol reduces the formation of free radicals, thereby potentially limiting the amount of hypoxia–reperfusion damage. In this study the long-term outcome of neonatal allopurinol treatment after birth asphyxia was examined. Design Follow-up of 4 to 8 years of two earlier performed randomised controlled trials. Setting Leiden University Medical Center, University Medical Center Groningen and University Medical Center Utrecht, The Netherlands. Patients Fifty-four term infants were included when suffering from moderate-to-severe birth asphyxia in two previously performed trials. Intervention Infants either received 40 mg/kg allopurinol (with an interval of 12 h) starting within 4 h after birth or served as controls. Main outcome measures Children, who survived, were assessed with the Wechsler Preschool and Primary Scales of Intelligence test or Wechsler Intelligence Scale for Children and underwent a neurological examination. The effect of allopurinol on severe adverse outcome (defined as mortality or severe disability at the age of 4–8 years) was examined in the total group of asphyxiated infants and in a predefined subgroup of moderately asphyxiated infants (based on the amplitude integrated electroencephalogram). Results The mean age during follow-up (n=23) was 5 years and 5 months (SD 1 year and 2 months). There were no differences in long-term outcome between the allopurinol-treated infants and controls. However, subgroup analysis of the moderately asphyxiated group showed significantly less severe adverse outcome in the allopurinol-treated infants compared with controls (25% vs 65%; RR 0.40, 95%CI 0.17 to 0.94). Conclusions The reported data may suggest a (neuro)protective effect of neonatal allopurinol treatment in moderately asphyxiated infants.


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


American Journal of Physiology-heart and Circulatory Physiology | 1997

Dynamics of cardiovascular responses to repeated partial umbilical cord compression in late-gestation sheep fetus

Dino A. Giussani; Nobuya Unno; Susan L. Jenkins; Richard A. Wentworth; Jan B. Derks; Jason H. Collins; Peter W. Nathanielsz

We characterized the detailed hemodynamics of fetal blood pressure, heart rate, common umbilical blood flow, and femoral blood flow responses to partial compression of the umbilical cord and tested the hypothesis that repeated cord compression modulates fetal cardiovascular responses in 10 chronically instrumented fetal sheep at approximately 130 days of gestation. In five fetuses (group I), partial compression of the umbilical cord was induced 12 times, each for 5 min at 15-min intervals. Each cord compression reduced common umbilical blood flow by 50% and produced modest falls in fetal pH (7.33 +/- 0 to 7.29 +/- 0) and arterial PO2 (21.1 +/- 0.2 to 16.8 +/- 0.2 mmHg) and a mild increase in arterial PCO2 (49.9 +/- 0.5 to 54.9 +/- 0.4 mmHg). Sham experiments were performed in five other fetuses (group II). Second-by-second analysis of group I fetal cardiovascular data revealed a clear biphasic response to partial cord compression. Phase I (1st min of cord compression) was characterized by a rapid bradycardia and a rapid femoral vasoconstriction (primary response); phase II (minutes 2-5 of cord compression) was characterized by a delayed bradycardia and a return of femoral vascular resistance toward baseline (secondary response). Repeated cord compression abolished the primary, but not the secondary, cardiovascular responses. These results demonstrate that fetal cardiovascular responses to stress may be modified by preexposure to repeated intrauterine challenges.We characterized the detailed hemodynamics of fetal blood pressure, heart rate, common umbilical blood flow, and femoral blood flow responses to partial compression of the umbilical cord and tested the hypothesis that repeated cord compression modulates fetal cardiovascular responses in 10 chronically instrumented fetal sheep at ∼130 days of gestation. In five fetuses ( group I), partial compression of the umbilical cord was induced 12 times, each for 5 min at 15-min intervals. Each cord compression reduced common umbilical blood flow by 50% and produced modest falls in fetal pH (7.33 ± 0 to 7.29 ± 0) and arterial [Formula: see text] (21.1 ± 0.2 to 16.8 ± 0.2 mmHg) and a mild increase in arterial[Formula: see text] (49.9 ± 0.5 to 54.9 ± 0.4 mmHg). Sham experiments were performed in five other fetuses ( group II). Second-by-second analysis of group I fetal cardiovascular data revealed a clear biphasic response to partial cord compression. Phase I (1st min of cord compression) was characterized by a rapid bradycardia and a rapid femoral vasoconstriction (primary response); phase II ( minutes 2-5of cord compression) was characterized by a delayed bradycardia and a return of femoral vascular resistance toward baseline (secondary response). Repeated cord compression abolished the primary, but not the secondary, cardiovascular responses. These results demonstrate that fetal cardiovascular responses to stress may be modified by preexposure to repeated intrauterine challenges.


Acta Paediatrica | 2007

Life before birth: effects of cortisol on future cardiovascular and metabolic function.

Peter W. Nathanielsz; Kathie A. Berghorn; Jan B. Derks; Dino A. Giussani; C. Docherty; Nobuya Unno; Anthony P. Davenport; Michelle A. Kutzler; S. Koenen; G. H A Visser; Mark J. Nijland

The concept of fetal programming is an area that is now under rigorous investigation in many laboratories throughout the world. We need to engender a fascination in all segments of society, not just pregnant women, about life in the womb.


Obstetrical & Gynecological Survey | 2008

Acute tocolysis for uterine activity reduction in term labor: a review.

Roel de Heus; Eduard J. H. Mulder; Jan B. Derks; Gerard H. A. Visser

This review critically evaluates the efficacy of different tocolytics in reducing uterine pressure and contractions in term labor. The available evidence supports the use of beta-adrenergic-receptor agonists such as terbutaline or ritodrine; they appear to have an immediate and comparable profound effect on uterine activity in term labor. However, the preferred type of beta-adrenergic receptor agonist and dosage are unclear. The oxytocin receptor antagonist atosiban has a high specificity for the uterus with limited or no systemic effects and could therefore be an attractive alternative for use in term labor. The evidence on the tocolytic potency of a single bolus of atosiban for tocolysis in term labor is encouraging but limited and needs further research. Moreover, atosiban lacks United States Food and Drug Administration approval. Literature documenting efficacy and safety of nitroglycerin or magnesium sulfate in term labor is far from convincing. The theoretical basis for the use of tocolytics for nonreassuring intrapartum fetal heart rate patterns is to reduce the aggravating influence of uterine contractions. However, the clinical evidence that tocolytics in term active labor are actually beneficial in improving neonatal outcome is very limited. Target Audience: Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader should be able to outline the available literature pertaining to tocolysis for term labor and appraise the effectiveness of various tocolytics in term labor.

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Johannes J. Duvekot

Erasmus University Rotterdam

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E. Ferrazzi

Boston Children's Hospital

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