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Fulco van der Veen

Publications and source records attributed to Fulco van der Veen.

At least 19 recordsLinked to original sources
PubMed2007

Intrauterine insemination in The Netherlands.

The aim of this retrospective study was to assess the results of intrauterine insemination (IUI) in The Netherlands, using data from 2003 taken from hospital annual reports and reports from individual gynaecologists. By extrapolation, the total number of IUI cycles performed that year nationwide, and the related outcomes, was estimated. IUI was performed in 91 of the country's 101 hospitals. Of these, 58 (64%) registered their IUI results and performed 19,846 IUI cycles. The mean pregnancy rate per cycle was 9.0% and the ongoing pregnancy rate per cycle was 7.3%. Multiple pregnancies occurred in 9.5% of the ongoing pregnancies. Extrapolation of the data suggested that approximately 28,500 IUI cycles were performed, of which approximately 2000 resulted in an ongoing pregnancy. The number of multiple pregnancies following IUI was estimated to be 180 (9.0%). According to the national IVF registry, 9761 IVF cycles were started in 2003, resulting in 2,028 ongoing pregnancies (20.8% per cycle) and 439 twin pregnancies (21.6% per ongoing pregnancy). In conclusion, the pregnancy rate per IUI cycle in The Netherlands (9.0%) was comparable with that reported in the international literature (8.7%). The contribution made by IUI to the number of multiple pregnancies in The Netherlands was much smaller than the contribution made by IVF.

Female↗
PubMed2006

Validation of a prediction model for the follicle-stimulating hormone response dose in women with polycystic ovary syndrome.

OBJECTIVE: To validate a published model for the prediction of the individual FSH response dose for gonadotropin induction of ovulation in polycystic ovary syndrome (PCOS). DESIGN: Structured, complete, and carefully monitored patient-based data collection to test the external validity of the prediction model. SETTING: Twenty-nine hospitals in The Netherlands. PATIENT(S): Eighty-five clomiphene citrate (CC)-resistant women with PCOS. INTERVENTION(S): Ovulation induction in a chronic low-dose step-up FSH regimen. MAIN OUTCOME MEASURE(S): Predicted individual FSH response dose, defined as follicle growth >10 mm in diameter on ultrasound. RESULT(S): The model, using the women's body mass index, CC response, initial serum FSH level, and initial serum insulin-to-glucose ratio was studied in the validation sample. Overall, the FSH response dose predicted by the model was higher than the observed response dose. The predictive performance of the model was poor, with an R(2) of 0.11, and the average prediction error was 35 IU. CONCLUSION(S): The external validity of the model predicting the individual FSH response dose was inadequate in women with CC-resistant PCOS undergoing ovulation induction with recombinant FSH in a low-dose step-up regimen.

Adult↗
PubMed2006

Quality of reporting of test accuracy studies in reproductive medicine: impact of the Standards for Reporting of Diagnostic Accuracy (STARD) initiative.

OBJECTIVE: To evaluate the extent to which test accuracy studies published in two leading reproductive medicine journals in the years 1999 and 2004 adhered to the Standards for Reporting of Diagnostic Accuracy (STARD) initiative parameters, and to explore whether the introduction of the STARD statement has led to an improved quality of reporting. DESIGN: Structured literature search. Articles that reported on the diagnostic performance of a test in comparison with a reference standard were eligible for inclusion. For each article we scored how well the 25 items of the STARD checklist were reported. These items deal with the study question, study participants, study design, test methods, reference standard, statistical methods, reporting of results, and conclusions. We calculated the total number of reported STARD items per article, summary scores for each STARD item, and the average number of reported STARD items per publication year. SETTING: Not applicable. PATIENT(S): Not applicable. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Quality of reporting. RESULT(S): We found 24 studies reporting on test accuracy in reproductive medicine in 1999 and 27 studies in 2004. The mean number of reported STARD items for articles published in 1999 was 12.1 +/- 3.3 (range 6.5-20) and 12.4 +/- 3.2 (range 7-17.5) in 2004, after publication of the STARD statement. Overall, less than half of the studies reported adequately on 50% or more of the STARD items. The reporting of individual items showed a wide variation. There was no significant improvement in mean number of reported items for the articles published after the introduction of the STARD statement. CONCLUSION(S): Authors of test accuracy studies in the two leading fertility journals poorly report the design, conduct, methodology, and statistical analysis of their study. Strict adherence to the STARD guidelines should be encouraged.

Clinical Trials as Topic↗
PubMed2006

Intrauterine insemination with controlled ovarian hyperstimulation versus expectant management for couples with unexplained subfertility and an intermediate prognosis: a randomised clinical trial.

BACKGROUND: Intrauterine insemination with controlled ovarian hyperstimulation is commonly used as first-line treatment for couples with unexplained subfertility. Since such treatment increases the risk of multiple pregnancy, a couple's chances of achieving an ongoing pregnancy without it should be considered to identify those most likely to benefit from treatment. We aimed to assess the incremental effectiveness of intrauterine insemination with controlled ovarian hyperstimulation compared with expectant management in couples with unexplained subfertility and an intermediate prognosis of a spontaneous ongoing pregnancy. METHODS: 253 couples with unexplained subfertility and a 30-40% probability of a spontaneous ongoing pregnancy within 12 months were randomly assigned either intrauterine insemination with controlled ovarian hyperstimulation for 6 months or expectant management for 6 months. The primary endpoint of this hospital-based study was ongoing pregnancy within 6 months. Analysis was by intention to treat. This trial is registered with the Dutch Trial Register and as an International Standard Randomised Clinical Trial, number ISRCTN72675518. FINDINGS: Of the 253 couples enrolled, 127 were assigned intrauterine insemination with controlled ovarian hyperstimulation and 126 expectant management. In the intervention group, 42 (33%) women conceived and 29 (23%) pregnancies were ongoing. In the expectant management group, 40 (32%) women conceived and 34 (27%) pregnancies were ongoing (relative risk 0.85, 95% CI 0.63-1.1). There was one twin pregnancy in each study group, and one woman in the intervention group conceived triplets. INTERPRETATION: A large beneficial effect of intrauterine insemination with controlled ovarian hyperstimulation in couples with unexplained subfertility and an intermediate prognosis can be excluded. Expectant management for 6 months is therefore justified in these couples.

Adult↗
PubMed2006

Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial.

OBJECTIVE: To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. DESIGN: Randomised clinical trial. SETTING: Multicentre trial in 20 Dutch hospitals. PARTICIPANTS: 228 women with polycystic ovary syndrome. INTERVENTIONS: Clomifene citrate plus metformin or clomifene citrate plus placebo. MAIN OUTCOME MEASURE: The primary outcome measure was ovulation. Secondary outcome measures were ongoing pregnancy, spontaneous abortion, and clomifene resistance. RESULTS: 111 women were allocated to clomifene citrate plus metformin (metformin group) and 114 women were allocated to clomifene citrate plus placebo (placebo group). The ovulation rate in the metformin group was 64% compared with 72% in the placebo group, a non-significant difference (risk difference - 8%, 95% confidence interval - 20% to 4%). There were no significant differences in either rate of ongoing pregnancy (40% v 46%; - 6%, - 20% to 7%) or rate of spontaneous abortion (12% v 11%; 1%, - 7% to 10%). A significantly larger proportion of women in the metformin group discontinued treatment because of side effects (16% v 5%; 11%, 5% to 16%). CONCLUSION: Metformin is not an effective addition to clomifene citrate as the primary method of inducing ovulation in women with polycystic ovary syndrome. TRIAL REGISTRATION: Current Controlled Trials ISRCTN55906981 [controlled-trials.com].

Adult↗
PubMed2006

High mutation rates have driven extensive structural polymorphism among human Y chromosomes.

Although much structural polymorphism in the human genome has been catalogued, the kinetics of underlying change remain largely unexplored. Because human Y chromosomes are clonally inherited, it has been possible to capture their detailed relationships in a robust, worldwide genealogical tree. Examination of structural variation across this tree opens avenues for investigating rates of underlying mutations. We selected one Y chromosome from each of 47 branches of this tree and searched for large-scale variation. Four chromosomal regions showed extensive variation resulting from numerous large-scale mutations. Within the tree encompassed by the studied chromosomes, the distal-Yq heterochromatin changed length > or = 12 times, the TSPY gene array changed length > or = 23 times, the 3.6-Mb IR3/IR3 region changed orientation > or = 12 times and the AZFc region was rearranged > or = 20 times. After determining the total time spanned by all branches of this tree (approximately 1.3 million years or 52,000 generations), we converted these mutation counts to lower bounds on rates: > or = 2.3 x 10(-4), > or = 4.4 x 10(-4), > or = 2.3 x 10(-4) and > or = 3.8 x 10(-4) large-scale mutations per father-to-son Y transmission, respectively. Thus, high mutation rates have driven extensive structural polymorphism among human Y chromosomes. At the same time, we found limited variation in the copy number of Y-linked genes, which raises the possibility of selective constraints.

Chromosomes, Human, Y↗
PubMed2006

Reproductive outcome after chromosome analysis in couples with two or more miscarriages: index [corrected]-control study.

OBJECTIVE: To compare reproductive outcomes in couples carrying a structural chromosome abnormality and non-carrier couples referred for chromosome analysis after two or more miscarriages. DESIGN: Index [corrected]-control study. SETTING: Six centres for clinical genetics in the Netherlands. PARTICIPANTS: 278 carrier couples and 427 non-carrier couples referred for chromosome analysis between 1992 and 2000 after two or more miscarriages before 20 weeks of gestation. Couples were followed up for at least 24 months after chromosome analysis. MAIN OUTCOME MEASURES: The birth of at least one healthy child, at least one more miscarriage, and viable offspring with unbalanced chromosomal abnormalities after parental chromosome analysis. RESULTS: Mean follow-up after chromosome analysis was 5.8 years. 120 of 247 (49%) carrier couples had one or more miscarriage after chromosome analysis compared with 122 of 409 (30%) non-carrier couples (difference 19%, 95% confidence interval 11% to 26%; P < 0.01). The percentage of couples with at least one healthy child was not significantly different in carrier couples (83%) and non-carrier couples (84%) (difference -1%, - 7% to 5%). Among 550 pregnancies in carrier couples, two viable unbalanced chromosome abnormalities were detected at prenatal diagnosis (0.4%) and the fetuses aborted and two children with an unbalanced karyotype were born (0.4%). CONCLUSIONS: Couples whose carrier status was ascertained after two or more miscarriages have a low risk of viable offspring with unbalanced chromosomal abnormalities. Their chances of having a healthy child are as high as non-carrier couples, despite a higher risk of miscarriage.

Abortion, Habitual↗
PubMed2006

Which factors play a role in clinical decision-making in subfertility?

Sixteen vignettes of subfertile couples were constructed by varying fertility history, post-coital test, sperm motility, FSH concentration and Chlamydia antibody titre (CAT). Thirty-five gynaecologists estimated probabilities of treatment-independent pregnancy, intrauterine insemination (IUI) and IVF. Thereafter, they chose IUI, IVF or no treatment. The relative contribution of each factor to probability estimates and to subsequent treatment decisions was calculated. Duration of subfertility and maternal age were the most important contributors for gynaecologists' estimates of treatment-independent pregnancy [relative contribution (RC) 41, 26%]. Maternal age and FSH concentration were the most important contributors in the estimates for IUI (RC: 51, 25%) and for IVF (RC: 64, 31%). The decision to start IVF was mainly determined by maternal age, duration of subfertility, FSH concentration and CAT. The relative contribution of maternal age and duration of subfertility was in concordance with existing prediction models, whereas previous pregnancy and FSH concentration were under- and overestimated respectively. In conclusion, maternal age, duration of subfertility and FSH concentration are the main factors in clinical decision-making in subfertility. Gynaecologists overestimate the importance of FSH concentration, but underestimate that of a previous pregnancy, as compared with their importance reported in prediction models and guidelines.

Adult↗
PubMed2005

Selective chromosome analysis in couples with two or more miscarriages: case-control study.

OBJECTIVE: To identify additional factors, such as maternal age or factors related to previous reproductive outcome or family history, and the corresponding probability of carrying a chromosome abnormality in couples with two or more miscarriages. DESIGN: Nested case-control study. SETTING: Six centres for clinical genetics in the Netherlands. PARTICIPANTS: Couples referred for chromosome analysis after two or more miscarriages in 1992-2000; 279 carrier couples were marked as cases, and 428 non-carrier couples served as controls. MAIN OUTCOME MEASURES: Independent factors influencing the probability of carrier status and the corresponding probability of carrier status. RESULTS: Four factors influencing the probability of carrier status could be identified: maternal age at second miscarriage, a history of three or more miscarriages, a history of two or more miscarriages in a brother or sister of either partner, and a history of two or more miscarriages in the parents of either partner. The calculated probability of carrier status in couples referred for chromosome analysis after two or more miscarriages varied between 0.5% and 10.2%. CONCLUSIONS: The probability of carrier status in couples with two or more miscarriages is modified by additional factors. Selective chromosome analysis would result in a more appropriate referral policy, could decrease the annual number of chromosome analyses, and could therefore lower the costs.

Abortion, Spontaneous↗
PubMed2005

Investigation of the infertile couple: a basic fertility work-up performed within 12 months of trying to conceive generates costs and complications for no particular benefit.

The current approach of the basic fertility work-up has been questioned recently in this journal. Based on new data on human fecundity, the authors advocated starting the fertility work-up after just 6 months of trying to conceive instead of the usual 12 months. In women younger than 39 years and with a regular cycle, there are several arguments why the basic fertility work-up should not be done earlier than after 12 months of child wish. Firstly, 50% of couples who have tried to conceive for 6 months without success will conceive in the next 6 months without any treatment. Secondly, the prevalence of fertility diseases is lower in couples who have been trying to conceive for 6 months as compared with those who have been trying for 12 months. Performance of a fertility work-up at this stage will lead to an increase in false-positive diagnoses compared with performing them at 12 months of subfertility. Thirdly, fertility treatment will have fewer additional effects in couples with good spontaneous conception prospects (6-12 months child wish), compared with subfertile couples who have poor prospects. At present, none of the available fertility treatments have success rates comparable with no intervention in these women, and postponement of treatment in such couples will prevent complications such as ovarian hyperstimulation syndrome and multiple pregnancies. We argue that the fertility work-up should not be offered to couples with a duration of child wish of <12 months, except for women with ovulation disorders and women of 39 years and older.

Adult↗
PubMed2005

Detection of chromosome abnormalities by quantitative fluorescent PCR in ectopic pregnancies.

OBJECTIVE: To evaluate the potential value of quantitative fluorescent polymerase chain reaction (QF-PCR) in the detection of chromosome abnormalities in ectopic pregnancies. METHODS: Seventy chorionic villi samples of ectopic pregnancies were studied by QF-PCR. Primers for chromosomes 16, 21, X and Y in chorionic villi were evaluated. Fluorescence in situ hybridization (FISH) was performed when results of QF-PCR showed aneuploidy, in case of unexplicable QF-PCR peaks, and in 10 cases with normal QF-PCR results. RESULTS: QF-PCR produced a result for chromosomes X and Y in 66 cases (94%), for chromosome 16 in 62 cases (89%) and for chromosome 21 in 55 cases (79%). Overall, QF-PCR produced a result for the chromosomes tested in 54 ectopic pregnancy cases (77%). Fifty-two of these results were normal disomic (96%) and two were abnormal, one trisomy 16 (2%) and one triploidy (2%). In 16 cases (23%) no definite QF-PCR results could be obtained for all chromosomes, 11 due to amplification failure, and 5 due to unexplicable QF-PCR peaks. In 10 cases with normal QF-PCR results, disomy was confirmed by FISH. The trisomy 16 was also confirmed by FISH. Furthermore, a result was obtained with FISH in 5 of the cases without definite QF-PCR results. CONCLUSION: Although QF-PCR can establish the chromosomal status in ectopic pregnancies for chromosomes 16, 21, X and Y in the majority of cases, the technical failure rate is still considerable and does not improve results when compared to cytogenetic techniques.

Adult↗
PubMed2005

Predicting ongoing pregnancy following ovulation induction with recombinant FSH in women with polycystic ovary syndrome.

BACKGROUND: Ovulation induction with recombinant FSH (rFSH) is common in women with polycystic ovary syndrome (PCOS) not responding to clomiphene citrate treatment, despite the associated risk of multiple pregnancies. We analysed clinical, ultrasonographic and endocrine parameters during initial screening of women with clomiphene citrate-resistant PCOS as predictors of ongoing pregnancy within 12 months of treatment following ovulation induction with rFSH. METHODS: Eighty-five women were allocated to receive rFSH as part of a multicentre clinical trial. rFSH was administered in a chronic low-dose step-up protocol. The primary end-point was an ongoing pregnancy within 12 months. A logistic model was built using clinical, ultrasonographic and endocrine parameters to predict the response to rFSH treatment, adjusted for the number of cycles performed. RESULTS: In total, 85 women underwent 272 treatment cycles with rFSH, of which 57 women (67%) achieved an ongoing pregnancy. Oligomenorrhoea, shorter duration of infertility and a lower free androgen index (FAI) were associated with higher chances of an ongoing pregnancy, resulting in a predictive model with a modest discriminative power (area under the curve 0.72, 95% confidence interval 0.64-0.79) that allowed us to distinguish between women with a probability of <5% of attaining an ongoing pregnancy and women with a probability of >25% of doing so. CONCLUSION: A model consisting of oligo/amenorrhoea, duration of infertility and FAI level allowed a distinction to be made between women with a poor chance and women with a good chance of achieving an ongoing pregnancy.

Adult↗
PubMed2005

Patients' preferences in deciding between intrauterine insemination and expectant management.

BACKGROUND: Intrauterine insemination (IUI) is a commonly used treatment in subfertile couples. We assessed patients' preferences for IUI relative to expectant management. METHODS: Forty subfertile couples were offered scenarios in which the treatment-independent pregnancy chance was varied against a fixed pregnancy chance after IUI without or with controlled ovarian hyperstimulation (COH) of 8% and 12% per cycle, respectively. The treatment-independent pregnancy chance within 12 months was initially set at 100%, and subsequently reduced until couples switched preferences. We also investigated the impact of the risks of ovarian hyperstimulation syndrome (OHSS) and multiple pregnancy on couples' preferences. RESULTS: When pregnancy was guaranteed within a year, all couples would opt for expectant management. Most couples switched to IUI without COH at a 60% chance of a treatment-independent pregnancy and to IUI with COH between a 40% and 60% chance. Where the risk of OHSS was set at 10%, a large majority of the couples preferred expectant management to IUI. At a multiple pregnancy risk of 100%, 77% of the couples would still prefer IUI. CONCLUSIONS: The majority of couples prefer IUI with or without COH when the treatment-independent pregnancy chance in the next 12 months is <50% and <40%, respectively. The risk of a multiple pregnancy does not affect their preference for IUI, whereas IUI is rejected when the risk of OHSS exceeds 10%.

Adult↗
PubMed2005

Predictors for treatment failure after laparoscopic electrocautery of the ovaries in women with clomiphene citrate resistant polycystic ovary syndrome.

BACKGROUND: Laparoscopic electrocautery has been put forward as the treatment of choice in women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). In order to make an informed treatment decision it would be helpful if we could identify women with PCOS with a high probability of treatment failure following electrocautery of the ovaries. METHODS: Eighty-three women with CC-resistant PCOS were allocated to receive laparoscopic electrocautery followed by CC when anovulation persisted as part of a randomized controlled trial. Multivariable logistic regression analyses using clinical, ultrasonographic and endocrinological parameters were performed to predict (i) failure to ovulate within 8 weeks after electrocautery, and (ii) failure to reach an ongoing pregnancy after electrocautery with or without CC. RESULTS: Of the 83 women, 56 (67%) ovulated within 8 weeks after electrocautery. The model for predicting anovulation after electrocautery included LH/FSH rate, year of menarche and glucose level. Women who were younger at menarche, had a lower LH/FSH ratio and a lower glucose level were more likely to have persistent anovulation. The area under the curve was 0.74. After electrocautery and CC, 41 women reached an ongoing pregnancy. No prognostic parameters could be identified to predict failure to reach an ongoing pregnancy after electrocautery followed by CC. CONCLUSIONS: Persistence of anovulation after electrocautery could be predicted and women with a high risk of persisting anovulation could be distinguished. We were, however, not able to predict treatment failure after electrocautery followed by CC.

Adult↗
PubMed2005

Treatment preferences and trade-offs for ovulation induction in clomiphene citrate-resistant patients with polycystic ovary syndrome.

OBJECTIVE: To investigate patient preferences and trade-offs for laparoscopic electrocautery of the ovaries relative to ovulation induction with recombinant FSH (rFSH) in patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). DESIGN: Assessment of preferences and trade-offs in a randomized controlled trial. SETTING: Academic hospital. PATIENT(S): Thirty-two CC-resistant patients with PCOS who had been randomly assigned to either laparoscopic electrocautery of the ovaries or ovulation induction with rFSH and 32 control patients with PCOS under treatment with CC. INTERVENTION(S): Preference for laparoscopic electrocautery relative to rFSH was established during an interview. Trade-offs between treatment burden and effectiveness were evaluated by varying hypothetical pregnancy rates after laparoscopic electrocautery until patients switched in their initial preference. MAIN OUTCOME MEASURE(S): Preference for laparoscopic electrocautery of the ovaries; trade-off between burden and effectiveness of treatment. RESULT(S): The majority of the patients would prefer electrocautery of the ovaries over ovulation induction with rFSH if both treatment strategies resulted in similar pregnancy rates. However, most patients were willing to trade off their preference for increased effectiveness: the percentage of patients who preferred electrocautery over rFSH sharply declined when the difference in hypothetical pregnancy rates was more than 5% in favor of rFSH. CONCLUSION(S): Patients with polycystic ovary syndrome are well able to express an informed preference for laparoscopic electrocautery of the ovaries or ovulation induction with rFHS. Preferences are guided by features of the respective treatments but seem to be dominated by their effectiveness and safety.

Clomiphene↗