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Featured researches published by A.J. Bensdorp.


BMJ | 2015

Prevention of multiple pregnancies in couples with unexplained or mild male subfertility: randomised controlled trial of in vitro fertilisation with single embryo transfer or in vitro fertilisation in modified natural cycle compared with intrauterine insemination with controlled ovarian hyperstimulation

A.J. Bensdorp; R. I. Tjon-Kon-Fat; P. M. M. Bossuyt; C.A.M. Koks; G.J.E. Oosterhuis; Annemieke Hoek; Peter G.A. Hompes; F. J. Broekmans; Harold R. Verhoeve; J.P. de Bruin; R. van Golde; Sjoerd Repping; B.J. Cohlen; M. D. A. Lambers; van Peter Bommel; Denise A. M. Perquin; J.M.J. Smeenk; M. J. Pelinck; Judith Gianotten; Diederik A. Hoozemans; J. W. M. Maas; M.J. Eijkemans; F. van der Veen; B.W. Mol; M. van Wely

Objectives To compare the effectiveness of in vitro fertilisation with single embryo transfer or in vitro fertilisation in a modified natural cycle with that of intrauterine insemination with controlled ovarian hyperstimulation in terms of a healthy child. Design Multicentre, open label, three arm, parallel group, randomised controlled non-inferiority trial. Setting 17 centres in the Netherlands. Participants Couples seeking fertility treatment after at least 12 months of unprotected intercourse, with the female partner aged between 18 and 38 years, an unfavourable prognosis for natural conception, and a diagnosis of unexplained or mild male subfertility. Interventions Three cycles of in vitro fertilisation with single embryo transfer (plus subsequent cryocycles), six cycles of in vitro fertilisation in a modified natural cycle, or six cycles of intrauterine insemination with ovarian hyperstimulation within 12 months after randomisation. Main outcome measures The primary outcome was birth of a healthy child resulting from a singleton pregnancy conceived within 12 months after randomisation. Secondary outcomes were live birth, clinical pregnancy, ongoing pregnancy, multiple pregnancy, time to pregnancy, complications of pregnancy, and neonatal morbidity and mortality Results 602 couples were randomly assigned between January 2009 and February 2012; 201 were allocated to in vitro fertilisation with single embryo transfer, 194 to in vitro fertilisation in a modified natural cycle, and 207 to intrauterine insemination with controlled ovarian hyperstimulation. Birth of a healthy child occurred in 104 (52%) couples in the in vitro fertilisation with single embryo transfer group, 83 (43%) in the in vitro fertilisation in a modified natural cycle group, and 97 (47%) in the intrauterine insemination with controlled ovarian hyperstimulation group. This corresponds to a risk, relative to intrauterine insemination with ovarian hyperstimulation, of 1.10 (95% confidence interval 0.91 to 1.34) for in vitro fertilisation with single embryo transfer and 0.91 (0.73 to 1.14) for in vitro fertilisation in a modified natural cycle. These 95% confidence intervals do not extend below the predefined threshold of 0.69 for inferiority. Multiple pregnancy rates per ongoing pregnancy were 6% (7/121) after in vitro fertilisation with single embryo transfer, 5% (5/102) after in vitro fertilisation in a modified natural cycle, and 7% (8/119) after intrauterine insemination with ovarian hyperstimulation (one sided P=0.52 for in vitro fertilisation with single embryo transfer compared with intrauterine insemination with ovarian hyperstimulation; one sided P=0.33 for in vitro fertilisation in a modified natural cycle compared with intrauterine insemination with controlled ovarian hyperstimulation). Conclusions In vitro fertilisation with single embryo transfer and in vitro fertilisation in a modified natural cycle were non-inferior to intrauterine insemination with controlled ovarian hyperstimulation in terms of the birth of a healthy child and showed comparable, low multiple pregnancy rates. Trial registration Current Controlled Trials ISRCTN52843371; Nederlands Trial Register NTR939.


BMC Women's Health | 2009

The INeS study: prevention of multiple pregnancies: a randomised controlled trial comparing IUI COH versus IVF e SET versus MNC IVF in couples with unexplained or mild male subfertility

A.J. Bensdorp; Carolien A. M. Koks; Jur Oosterhuis; Annemieke Hoek; Peter G.A. Hompes; F. J. Broekmans; Harold R. Verhoeve; Jan Bruin; Janne Meije van Weert; Maaike Traas; J. W. M. Maas; Nicole Beckers; Sjoerd Repping; Ben W. J. Mol; Fulco van der Veen; Madelon van Wely

BackgroundMultiple pregnancies are high risk pregnancies with higher chances of maternal and neonatal mortality and morbidity. In the past decades the number of multiple pregnancies has increased. This trend is partly due to the fact that women start family planning at an increased age, but also due to the increased use of ART.Couples with unexplained or mild male subfertility generally receive intrauterine insemination IUI with controlled hormonal stimulation (IUI COH). The cumulative pregnancy rate is 40%, with a 10% multiple pregnancy rate.This study aims to reveal whether alternative treatments such as IVF elective Single Embryo Transfer (IVF e SET) or Modified Natural Cycle IVF (MNC IVF) can reduce the number of multiple pregnancy rates, but uphold similar pregnancy rates as IUI COH in couples with mild male or unexplained subfertility. Secondly, the aim is to perform a cost effective analyses and assess treatment preference of these couples.Methods/DesignWe plan a multicentre randomised controlled clinical trial in the Netherlands comparing six cycles of intra-uterine insemination with controlled ovarian hyperstimulation or six cycles of Modified Natural Cycle (MNC) IVF or three cycles with IVF-elective Single Embryo Transfer (eSET) plus cryo-cycles within a time frame of 12 months.Couples with unexplained subfertility or mild male subfertility and a poor prognosis for treatment independent pregnancy will be included. Women with anovulatory cycles, severe endometriosis, double sided tubal pathology or serious endocrine illness will be excluded.Our primary outcome is the birth of a healthy singleton. Secondary outcomes are multiple pregnancy, treatment costs, and patient experiences in each treatment arm. The analysis will be performed according tot the intention to treat principle. We will test for non-inferiority of the three arms with respect to live birth. As we accept a 12.5% loss in pregnancy rate in one of the two IVF arms to prevent multiple pregnancies, we need 200 couples per arm (600 couples in total).DiscussionDetermining the safest and most cost-effective treatment will ensure optimal chances of pregnancy for subfertile couples with substantially diminished perinatal and maternal complications. Should patients find the most cost-effective treatment acceptable or even preferable, this could imply the need for a world wide shift in the primary treatment.Trial registrationCurrent Controlled Trials ISRCTN 52843371


Human Reproduction Update | 2014

Prognostic profiles and the effectiveness of assisted conception: secondary analyses of individual patient data

N.M. van den Boogaard; A.J. Bensdorp; K. Oude Rengerink; K. Barnhart; Sohinee Bhattacharya; Inge M. Custers; Christos Coutifaris; A. J. Goverde; David S. Guzick; E.C. Hughes; Pam Factor-Litvak; P. Steures; Peter G.A. Hompes; F. van der Veen; B.W. Mol; P. M. M. Bossuyt

BACKGROUND At present, it is unclear which treatment strategy is best for couples with unexplained or mild male subfertility. We hypothesized that the prognostic profile influences the effectiveness of assisted conception. We addressed this issue by analysing individual patient data (IPD) from randomized controlled trials (RCTs). METHODS We performed an IPD analysis of published RCTs on treatment strategies for subfertile couples. Eligible studies were identified from Cochrane systematic reviews and we also searched Medline and EMBASE. The authors of RCTs that compared expectant management (EM), intracervical insemination (ICI), intrauterine insemination (IUI), all three with or without controlled ovarian stimulation (COS) and IVF in couples with unexplained or male subfertility, and had reported live birth or ongoing pregnancy as an outcome measure, were invited to share their data. For each individual patient the chance of natural conception was calculated with a validated prognostic model. We constructed prognosis-by-treatment curves and tested whether there was a significant interaction between treatment and prognosis. RESULTS We acquired data from 8 RCTs, including 2550 couples. In three studies (n = 954) the more invasive treatment strategies tended to be less effective in couples with a high chance of natural conception but this difference did not reach statistical significance (P-value for interaction between prognosis and treatment outcome were 0.71, 0.31 and 0.19). In one study (n = 932 couples) the strategies with COS (ICI and IUI) led to higher pregnancy rates than unstimulated strategies (ICI 8% versus 15%, IUI 13% versus 22%), regardless of prognosis (P-value for interaction in all comparisons >0.5), but at the expense of a high twin rate in the COS strategies (ICI 6% versus 23% and IUI 3% versus 30%, respectively). In two studies (n = 373 couples), the more invasive treatment strategies tended to be more effective in couples with a good prognosis but this difference did not reach statistical significance (P-value for interaction: 0.38 and 0.68). In one study (n = 253 couples) the differential effect of prognosis on treatment effect was limited (P-value for interaction 0.52), perhaps because prognosis was incorporated in the inclusion criteria. The only study that compared EM with IVF included 38 couples, too small for a precise estimate. CONCLUSIONS In this IPD analysis of couples with unexplained or male subfertility, we did not find a large differential effect of prognosis on the effectiveness of fertility treatment with IUI, COS or IVF.


Reproductive Biomedicine Online | 2017

A revised prediction model for natural conception

A.J. Bensdorp; Jan Willem van der Steeg; Pieternel Steures; J. Dik F. Habbema; Peter G.A. Hompes; Patrick M. Bossuyt; Fulco van der Veen; Ben Willem J. Mol; Marinus J.C. Eijkemans; Y.M. van Kasteren; P.F.M. van der Heijden; Willem Schöls; M.H. Mochtar; G.L.M. Lips; J. Dawson; Harold R. Verhoeve; S. Milosavljevic; P.G.A. Hompes; L.J. van Dam; Alexander Sluijmer; H.E. Bobeck; Rob E. Bernardus; M.C.S. Vermeer; J.P. Dörr; P.J.Q. van der Linden; H.J.M. Roelofs; Jan M. Burggraaff; G.J.E. Oosterhuis; M.H. Schouwink; Peter X. J. M. Bouckaert

One of the aims in reproductive medicine is to differentiate between couples that have favourable chances of conceiving naturally and those that do not. Since the development of the prediction model of Hunault, characteristics of the subfertile population have changed. The objective of this analysis was to assess whether additional predictors can refine the Hunault model and extend its applicability. Consecutive subfertile couples with unexplained and mild male subfertility presenting in fertility clinics were asked to participate in a prospective cohort study. We constructed a multivariable prediction model with the predictors from the Hunault model and new potential predictors. The primary outcome, natural conception leading to an ongoing pregnancy, was observed in 1053 women of the 5184 included couples (20%). All predictors of the Hunault model were selected into the revised model plus an additional seven (womans body mass index, cycle length, basal FSH levels, tubal status,history of previous pregnancies in the current relationship (ongoing pregnancies after natural conception, fertility treatment or miscarriages), semen volume, and semen morphology. Predictions from the revised model seem to concur better with observed pregnancy rates compared with the Hunault model; c-statistic of 0.71 (95% CI 0.69 to 0.73) compared with 0.59 (95% CI 0.57 to 0.61).


Human Reproduction | 2018

Natural conception rates in couples with unexplained or mild male subfertility scheduled for fertility treatment: a secondary analysis of a randomized controlled trial

R van Eekelen; R. I. Tjon-Kon-Fat; P. M. M. Bossuyt; N van Geloven; M.J. Eijkemans; A.J. Bensdorp; F. van der Veen; Ben W. Mol; M. van Wely

STUDY QUESTION What is the natural conception rate over the course of 12 months in couples with unexplained or mild male subfertility who are scheduled for fertility treatment and have a predicted unfavourable prognosis for natural conception? SUMMARY ANSWER The natural conception rate over the course of 12 months in couples who were allocated to treatment was estimated to be 24.5% (95% CI: 20-29%). WHAT IS KNOWN ALREADY After starting treatment, couples often perceive unsuccessful cycles as evidence of definitive failure even though they are still able to conceive naturally in between and after treatment. The magnitude of the natural conception rate for couples who chose to commence treatment is unknown, as is whether the calculated prognosis before commencing treatment is still applicable. STUDY DESIGN, SIZE, DURATION We performed a secondary analysis of a randomized controlled trial including couples with unexplained or mild male subfertility and an unfavourable prognosis for natural conception. Couples were allocated to either three cycles IVF with single embryo transfer (SET), six cycles of IVF in a modified natural cycle (MNC) or six cycles of IUI with controlled ovarian hyperstimulation (IUI-COH). The detailed data collection in this trial allowed us to study the conception rates in periods that couples were not receiving treatment. PARTICIPANTS/MATERIALS, SETTINGS, METHODS We split the dataset into periods during which couples were treated and periods during which they were not treated. Couples could conceive naturally in the periods before, in between and after treatment cycles. The outcome was ongoing pregnancy, thus natural conception rate refers to natural conception leading to ongoing pregnancy. We performed a Cox proportional hazards analysis with female age, duration of subfertility and a time-varying covariate with four categories: IVF-SET, IVF-MNC, IUI-COH and no treatment. We used this Cox model to estimate the natural conception rate over 12 months of no treatment. MAIN RESULTS AND THE ROLE OF CHANCE Out of 602 included couples, there were 342 ongoing pregnancies, of which 77 (23%) resulted from natural conception. The estimated natural conception rate over 12 months was 24.5% (95% CI: 20-29%) on cohort level. Estimated rates for female age varying between 18 and 38 years and duration of subfertility between 1 and 3 years ranged from 22 to 35%. LIMITATIONS, REASONS FOR CAUTION We considered couples at risk for natural conception when not receiving treatment, whereas they might not have had periovulatory sexual intercourse. As couples were scheduled for treatment, it is possible that these couples were less inclined to try to conceive naturally, potentially leading to an underestimation of their natural conception rate if they kept trying to conceive. WIDER IMPLICATIONS OF THE FINDINGS Couples with unexplained subfertility who are about to start fertility treatment, still have about a one in four chance of ongoing pregnancy due to natural conception over 12 months. This information can add to the counselling of couples who commenced fertility treatment after failed cycles and to emphasize not to cease their natural attempts. STUDY FUNDING/COMPETING INTEREST(S) The INeS trial was supported by a grant from ZonMW, the Dutch Organization for Health Research and Development (120620027), and a grant from Zorgverzekeraars Nederland, the Dutch association of health care insurers (09-003). The funders had no role in study design, collection, analysis and interpretation of the data. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck and Guerbet. No other potential conflicts of interest reported. TRIAL REGISTRATION NUMBER The INeS trial was registered at the Dutch trial registry (NTR 939).


Human Reproduction | 2015

Is IVF—served two different ways—more cost-effective than IUI with controlled ovarian hyperstimulation?

R.I. Tjon-Kon-Fat; A.J. Bensdorp; P.M.M. Bossuyt; C.A.M. Koks; G.J.E. Oosterhuis; Annemieke Hoek; Peter G.A. Hompes; F. J. Broekmans; Harold R. Verhoeve; J.P. de Bruin; R. van Golde; Sjoerd Repping; B.J. Cohlen; M. D. A. Lambers; P.F. van Bommel; Denise A. M. Perquin; J.M.J. Smeenk; M. J. Pelinck; Judith Gianotten; Diederik A. Hoozemans; J. W. M. Maas; Henk Groen; M.J. Eijkemans; F. van der Veen; B.W.J. Mol; M. van Wely


Cochrane Database of Systematic Reviews | 2016

Assisted reproductive technologies for male subfertility

Maartje Cissen; A.J. Bensdorp; Ben J. Cohlen; Sjoerd Repping; Jan Bruin; Madelon van Wely


Fertility and Sterility | 2016

Dizygotic twin pregnancies after medically assisted reproduction and after natural conception: maternal and perinatal outcomes.

A.J. Bensdorp; Chantal W.P.M. Hukkelhoven; Fulco van der Veen; Ben Willem J. Mol; Cornelis B. Lambalk; Madelon van Wely


Human Reproduction | 2016

IUI and IVF for unexplained subfertility: where did we go wrong?

R.I. Tjon-Kon-Fat; A.J. Bensdorp; I. Scholten; Sjoerd Repping; M. van Wely; B.W.J. Mol; F. van der Veen


European Journal of Obstetrics & Gynecology and Reproductive Biology | 2016

Dropout rates in couples undergoing in vitro fertilization and intrauterine insemination

A.J. Bensdorp; R. I. Tjon-Kon-Fat; Harold R. Verhoeve; Carolien A. M. Koks; Peter G.A. Hompes; Annemieke Hoek; Jan Bruin; Ben J. Cohlen; Diederik A. Hoozemans; Frank J. Broekmans; Peter van Bomme; J.M.J. Smeenk; Ben Willem J. Mol; Fulco van der Veen; Madelon van Wely

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Annemieke Hoek

University Medical Center Groningen

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M. van Wely

University of Amsterdam

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