Research interests

My research is based around the use of prenatal and obstetric ultrasound in the prevention of fetal and obstetric complications and improving neonatale outcome. Ultrasound is one of the most frequently used diagnostic tools in pregnancy. It is used in all trimesters of pregnancy and for a large number of different indications. The research line is focus around three major topics:


- Fetal and chromosomal anomalies


Since 1994 we have been studying the value of first trimester ultrasound in the AMC, including the value of nuchal translucency measurement in the detection of fetal chromosomal anomalies and structural anomalies, especially cardiac anomalies. Our fetal medicine unit was the first to implement nuchal translucency measurement in screening for Down syndrome and has made a major contribution to the introduction of  the first trimester combined test for all pregnant women in the Netherlands. In 2014 we were part of the implementation study (TRIDENT 1) of the Non-Invasive Prenatal Test in screening for trisomy 21/18/13 which had been designed and was being carried out by the Dutch National NIPT consortium ( according to the rules of the Population Screening Act, and after positive advice had been given by the Health Council of the Netherlands. We are on the brink of starting the TRIDENT 2 an  implementation study, funded by the Ministry of Health, of NIPT as a first trier test. A license has been granted for three years (starting April 1, 2017) by the Ministry of Health. 

Moreover, we have been big advocates for the introduction of the 20 week anomaly scan to all pregnant women and have been offering this scan to our pregnant population since 2000. Once both the combined test and the second trimester anomaly scan were introduced in the Netherlands in 2007 the focus of research in the AMC has expanded to the evaluation of both first and second trimester ultrasound screening, including the validation of nationally used biometry and growth charts. In 2011 a grant was received to evaluate the effectiveness of the 20 week anomaly scan. Furthermore, the CAHAL collaboration (LUMC, VuMC and AMC) is conducting a large project to evaluate the effect of the introduction of prenatal screening on the detection of cardiac anomalies. In 2011 a National dating protocol was introduced in our country and our institute was granted money for the implementation. Another special interest has been the prenatal dysmorfology or the identification of genetic syndromes in utero.  


- Prevention of preterm birth

Since 2009, the focus of my research has widened to include the evaluation of ultrasound intervention in the prediction and prevention of obstetric complications such as preterm birth, pre-eclampsia, fetal growth restriction, uterine rupture, placental abruption, rupture of vasa previa and placenta accreta. Cervical length (CL) measured in the second trimester by transvaginal ultrasound, is inversely related to the risk of preterm birth and is currently one of the most accurate predictors. Measurement of the cervical length can be used to evaluate  strategies in order to prevent or treat threatening preterm birth. This research line started in 2009 with the TRIPLE P study evaluating the effectiveness of vaginal progesteron in the prevention of preterm birth in women with an asymptomatic short cervix during the 20 week scan. Recently we have finished two RCT's. The data of those trials are currently being analysed. The APOSTEL VI evaluated the effectiveness of a cervical pessary in the prevention of preterm birth in pregnant women after an episode of threatened preterm birth (i.e. contractions).  The PROMEXIL III trial evaluated if (repeated) abdominal amnioinfusion after very early PPROM (< 24 weeks' gestation) with associated oligohydramnios improves perinatal survival and prevents pylmonary hypoplasia an other neonatal morbidities. Currently our research group is conduction two RCT's to evaluate the best treatment strategy in the prevention of preterm birth. The QUADRUPLE P study aims to compare the effectiveness of vaginal progesteron and cervical pessary in women with singleton and multiple pregnancies and a short cervix. The PC study evaluates whether a cervical pessary can replace a cervical cerclage in women with at least one previous preterm birth and an indication for a primary or secondary cerclage in terms of effectiveness and costs. All above mentioned studies can be found at:

- Prevention of obstetrical complications

We are conduction a large prospective cohort study, the LUS trial which aims to evaluate the accuracy of antenatal sonographical measurement of the lower uterine segment thickness in the prediction of the risk of uterine rupture during a trial of labour in women with a previous Caesarean section. Other prospective cohort studies are deeply inbedded in clinical care and evaluate the incidence of placental pathology and abnormal placentation.






Fetal and Maternal Medicine

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