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Flora E van Leeuwen

Publications and source records attributed to Flora E van Leeuwen.

At least 19 recordsLinked to original sources
PubMed2007

Physical activity and breast cancer: a systematic review.

BACKGROUND: Many epidemiologic studies have found an association between physical activity and breast cancer risk, although this has not been a consistent finding. METHODS: Studies were identified through a systematic review of literature available on PubMed through February 2006. We included all cohort and case-control studies that assessed total or leisure time activities in relation to occurrence or mortality of breast cancer. The fully adjusted risk estimates and 95% confidence intervals for the highest versus lowest level of activity were documented for each study as well as evidence for a dose-response relationship. Methodologic quality was also assessed. Due to statistical and methodologic heterogeneity among studies, we did not carry out statistical pooling. To draw conclusions, we performed a best-evidence synthesis taking study quality into account. RESULTS: Nineteen cohort studies and 29 case-control studies were evaluated. There was strong evidence for an inverse association between physical activity and postmenopausal breast cancer with risk reductions ranging from 20% to 80%. For premenopausal breast cancer, however, the evidence was much weaker. For pre- and postmenopausal breast cancer combined, physical activity was associated with a modest (15-20%) decreased risk. Evidence for a dose-response relationship was observed in approximately half of the higher-quality studies that reported a decreased risk. A trend analysis indicated a 6% (95% confidence interval = 3% to 8%) decrease in breast cancer risk for each additional hour of physical activity per week assuming that the level of activity would be sustained. CONCLUSIONS: There is evidence for an inverse association between physical activity and breast cancer risk. The evidence is stronger for postmenopausal breast cancer than for premenopausal breast cancer.

Breast Neoplasms↗
PubMed2006

Breast cancer survival and tumor characteristics in premenopausal women carrying the CHEK2*1100delC germline mutation.

PURPOSE: Women carrying a CHEK2*1100delC germline mutation have an increased risk of developing breast cancer. This study aims to determine the proportion of CHEK2*1100delC carriers in a premenopausal breast cancer population, unselected for family history of breast cancer, and to investigate tumor characteristics and disease outcome with sufficient follow-up. PATIENTS AND METHODS: We identified a retrospective cohort of 1,479 patients, who received surgery for invasive breast cancer between 1970 and 1994. All patients were diagnosed before age 50. Paraffin-embedded tissue blocks were collected for DNA isolation (normal tissue), subsequent CHEK2*1100delC analysis, and tumor revision. Median follow-up was 10.1 years. RESULTS: We detected a CHEK2*1100delC germline mutation in 54 patients (3.7%). Tumor characteristics of CHEK2*1100delC carriers did not differ significantly from those of noncarriers. CHEK2*1100delC carriers had a two-fold increased risk (hazard ratio [HR], 2.1; 95% CI, 1.0 to 4.3; P = .049) of developing a second breast cancer and they had worse recurrence-free survival (HR, 1.7; 95% CI, 1.2 to 2.4; P = .006) and worse breast cancer-specific survival (HR, 1.4; 95% CI, 1.0 to 2.1; P = .072) compared with noncarriers. The poorer disease outcome of CHEK2*1100delC carriers could not be explained by the increased risk of second breast cancer. CONCLUSION: Our study, which is representative for the premenopausal breast cancer population, reveals approximately 4% CHEK2*1100delC carriers have an increased risk of second breast cancer and a worse long-term recurrence-free survival rate. Their identification at time of diagnosis and prolonged intensive follow-up should be considered to optimize clinical management.

Adult↗
PubMed2006

Late cardiotoxicity after treatment for Hodgkin lymphoma.

We assessed cardiovascular disease (CVD) incidence in 1474 survivors of Hodgkin lymphoma (HL) younger than 41 years at treatment (1965-1995). Multivariable Cox regression and competing risk analyses were used to quantify treatment effects on CVD risk. After a median follow-up of 18.7 years, risks of myocardial infarction (MI) and congestive heart failure (CHF) were strongly increased compared with the general population (standardized incidence ratios [SIRs] = 3.6 and 4.9, respectively), resulting in 35.7 excess cases of MI and 25.6 excess cases of CHF per 10 000 patients/year. SIRs of all CVDs combined remained increased for at least 25 years and were more strongly elevated in younger patients. Mediastinal radiotherapy significantly increased the risks of MI, angina pectoris, CHF, and valvular disorders (2- to 7-fold). Anthracyclines significantly added to the elevated risks of CHF and valvular disorders from mediastinal RT (hazard ratios [HRs] were 2.81 and 2.10, respectively). The 25-year cumulative incidence of CHF after mediastinal radiotherapy and anthracyclines in competing risk analyses was 7.9%. In conclusion, risks of several CVDs are 3- to 5-fold increased in survivors of HL compared with the general population, even after prolonged follow-up, leading to increasing absolute excess risks over time. Anthracyclines further increase the elevated risks of CHF and valvular disorders from mediastinal radiotherapy.

Adult↗
PubMed2006

Decreased risk of stroke among 10-year survivors of breast cancer.

PURPOSE: To assess treatment-specific risk of cerebrovascular events in early breast cancer (BC) patients, accounting for cerebrovascular risk factors. PATIENTS AND METHODS: We studied the incidence of cerebrovascular accidents (CVA; stroke and transient ischemic attack [TIA]) in 10-year survivors of early BC (n = 4,414) treated from 1970 to 1986. Follow-up was 96% complete until January 2000. Treatment-specific incidence of CVA was evaluated by standardized incidence ratios (SIRs) based on comparison with general population rates and by Cox proportional hazards regression. RESULTS: After a median follow-up of 18 years, 164 strokes and 109 TIAs were observed, resulting in decreased SIRs of 0.8 (95% CI, 0.6 to 0.9) for stroke and 0.8 (95% CI, 0.7 to 1.0) for TIA. Significantly increased risk of stroke was found in women who had received hormonal treatment (HT; tamoxifen) and in women who had hypertension or hypercholesterolemia, with hazard ratios (HRs) of 1.9, 2.1, and 1.6, respectively. Patients irradiated on the supraclavicular area and/or internal mammary chain (IMC) did not experience a higher risk of stroke (HR = 1.0; 95% CI, 0.7 to 1.6) or TIA (HR = 1.4; 95% CI, 0.9 to 2.5) compared with patients who did not receive radiotherapy or who were irradiated on fields other than the supraclavicular area or IMC. CONCLUSION: Long-term survivors of BC experience no increased risk of cerebrovascular events compared with the general population. HT is associated with an increased risk of stroke. Radiation fields including the carotid artery do not seem to increase the risk of stroke compared with other fields.

Adult↗
PubMed2006

Risk of second cancer after treatment of aggressive non-Hodgkin's lymphoma; an EORTC cohort study.

BACKGROUND AND OBJECTIVES: Second cancer has been associated with non-Hodgkin's Lymphoma (NHL) treatment, but few studies have addressed this issue considering specific treatments. DESIGN AND METHODS: We estimated risk by standardized incidence ratios (SIR) and absolute excess risk (AER) based on general population rates (European Network of Cancer Registries) in 748 patients (aged 15-82 years) treated for aggressive NHL in four successive EORTC (European Organization for Research on Treatment of Cancer) trials. RESULTS: All patients received fully-dosed CHOP-like chemotherapy, 65% received involved-field radiotherapy and 14% high-dose treatment. Half of the patients needed salvage treatment and 37% were followed for more than 10 years. The cause of death was NHL in 79% of the patients; 4% died of second cancer (median survival 8.9 (0.8- 20.5) years). Cumulative incidences (death from any cause being a competing event) were 5% and 11% for solid cancer and 1% and 3% for acute myeloid leukemia/myelodysplastic syndrome at 10 and 15 years, respectively. Cancer risk appeared age-related: in young patients high risks were observed for leukemia (SIR 16.7,95% CI 1.4-93.1,AER 5.0), Hodgkin's lymphoma (SIR 60.1,95% CI 12.4-175.2, AER 15.7), colorectal cancer (SIR 12.5, 95% CI 2.6-36.5, AER 14.7) and lung cancer (SIR 15.4; 95% CI 4.2-39.4, AER 19.8), while risk in patients older than 45 years matched than that in the normal population. The risk of cancer was significantly raised by smoking and salvage treatment. INTERPRETATION AND CONCLUSIONS: Half of the patients die of aggressive NHL before living long enough to experience second cancer. Only young patients have a high risk of second cancer during follow-up beyond 10 years.

Adolescent↗
PubMed2006

Normal values for morphological abnormalities in school children.

Clinical morphology has proven to be a strong tool in the delineation of many syndromes and a helpful instrument in molecular studies. Numerous studies have been performed investigating the prevalence of minor anomalies in various disorders; all concluding that minor anomalies can well be utilized as indicators of altered embryonic differentiation. However, for adequate evaluation, normal values for phenotypic abnormalities are essential. So far, only few studies on the frequency of phenotypic abnormalities in the normal population have been done having one thing in common: all were performed in newborn infants. We studied morphological characteristics in a group of 1,007 school children, representative for the Dutch population, through a body surface examination using detailed definitions for all morphological findings. The region of study and distribution of children over various school types was chosen in such a way that it represented the general Dutch population. The median age of the studied children was 11 years (range 8-14 years), sex ratio (M:F) was 0.93. Nine hundred twenty-three children were of Caucasian descent, 84 others of mixed ethnic backgrounds. The reliability of the examinations was tested by independent scoring of 111 children by two observers, showing a kappa score of 0.85. Normal values for the morphological findings are presented together with their age-adjusted classification. These normal values provide a valuable source for validation of classifications of phenotypic abnormalities, especially those that are depending on frequency, that is, minor anomalies and common variants. Furthermore, they will allow a proper evaluation of patterns of phenotypic abnormalities found in patient groups with specific disorders.

Adolescent↗
PubMed2006

Cause-specific mortality in long-term survivors of breast cancer: A 25-year follow-up study.

PURPOSE: To assess long-term cause-specific mortality in breast cancer patients. PATIENTS AND METHODS: We studied mortality in 7425 patients treated for early breast cancer between 1970 and 1986. Follow-up was 94% complete until January 2000. Treatment-specific mortality was evaluated by calculating standardized mortality ratios (SMRs) based on comparison with general population rates and by using Cox proportional hazards regression. RESULTS: After a median follow-up of 13.8 years, 4160 deaths were observed, of which 76% were due to breast cancer. Second malignancies showed a slightly increased SMR of 1.2 (95% confidence interval [CI], 1.0-1.3). Radiotherapy (RT) as compared with surgery was associated with a 1.7-fold (95% CI, 1.2-2.5) increased mortality from cardiovascular disease (CVD). After postlumpectomy RT, no increased mortality from CVD was observed (hazard ratio, 1.0; 95% CI, 0.5-1.9). Postmastectomy RT administered before 1979 and between 1979 and 1986 was associated with a 2-fold (95% CI, 1.2-3.4) and 1.5-fold (95% CI, 0.9-2.7) increase, respectively. Patients treated before age 45 experienced a higher SMR (2.0) for both solid tumors (95% CI, 1.6-2.7) and CVD (95% CI, 1.3-3.1). CONCLUSION: Currently, a large population of breast cancer survivors is at increased risk of death from CVDs and second cancers, especially when treated with RT at a young age. Patients irradiated after 1979 experience low (postmastectomy RT) or no (postlumpectomy RT) excess mortality from CVD.

Adult↗
PubMed2006

Long-term risk of cardiovascular disease in 5-year survivors of testicular cancer.

PURPOSE: To evaluate the long-term risk of cardiovascular disease (CVD) in survivors of testicular cancer (TC). PATIENTS AND METHODS: We compared CVD incidence in 2,512 5-year survivors of TC, who were treated between 1965 and 1995, with general population rates. Treatment effects on CVD risk were quantified in multivariate Cox regression analysis. RESULTS: After a median follow-up of 18.4 years, 694 cardiovascular events occurred, including 141 acute myocardial infarctions (MIs). The standardized incidence ratio (SIR) for coronary heart disease was 1.17 (95% CI, 1.04 to 1.31), with 14 excess cases per 10,000 person-years. The SIR for MI was significantly increased in nonseminoma survivors with attained ages of less than 45 (SIR = 2.06) and 45 to 54 years (SIR = 1.86) but significantly decreased for survivors with attained ages of 55 years or older (SIR = 0.53). In Cox analysis, mediastinal irradiation was associated with a 3.7-fold (95% CI, 2.2- to 6.2-fold) increased MI risk compared with surgery alone, whereas infradiaphragmatic irradiation was not associated with an increased MI risk. Cisplatin, vinblastine, and bleomycin (PVB) chemotherapy (CT) was associated with a 1.9-fold (95% CI, 1.7- to 2.0-fold) increased MI risk, and bleomycin, etoposide, and cisplatin (BEP) CT was associated with a 1.5-fold (95% CI, 1.0- to 2.2-fold) increased CVD risk and was not associated with increased MI risk (hazard ratio = 1.2; 95% CI, 0.7 to 2.1). Recent smoking was associated with a 2.6-fold (95% CI, 1.8- to 3.9-fold) increased MI risk. CONCLUSION: Nonseminomatous TC survivors experience a moderately increased MI risk at young ages. Physicians should be aware of excess CVD risk associated with mediastinal radiotherapy, PVB CT, and recent smoking. Intervention in modifiable cardiovascular risk factors is especially important in TC survivors. Whether BEP treatment increases CVD risk should be evaluated after more prolonged follow-up.

Adult↗
PubMed2005

Long-term risk of cardiovascular disease after treatment for aggressive non-Hodgkin lymphoma.

Cardiovascular disease frequently occurs after lymphoma therapy, but it is common in the general population too. Therefore, risk estimation requires comparison to population-based rates. We calculated risk by standardized incidence ratios (SIRs) and absolute excess risks (AERs) per 10,000 person-years based on general population rates (Continuous Morbidity Registry Nijmegen) in 476 (Dutch and Belgian) patients with aggressive non-Hodgkin lymphoma (NHL) treated with at least 6 cycles of doxorubicin-based chemotherapy in 4 European Organization for Research on Treatment of Cancer (EORTC) trials (1980-1999). Cumulative incidence of cardiovascular disease, estimated in a competing risk model, was 12% at 5 years and 22% at 10 years (median follow-up, 8.4 years). Risk of chronic heart failure appeared markedly increased (SIR, 5.4; 95% CI, 4.1-6.9) with an AER of 208 excess cases per 10 000 person-years, whereas risk of coronary artery disease matched the general population (SIR, 1.2; 95% CI, 0.8-1.8; AER, 8 per 10 000 person-years). Risk of stroke was raised (SIR, 1.8; 95% CI, 1.1-2.4; AER, 15 per 10 000 person-years), especially after additional radiotherapy (> 40 Gy). Preexisting hypertension, NHL at young age, and salvage treatment increased risk of all cardiovascular events; the effect of radiotherapy was dose dependent. In conclusion, patients are at long-term high risk of chronic heart failure after NHL treatment and need therefore life-long monitoring. In contrast, risk of coronary artery disease appeared more age dependent than treatment related.

Cardiovascular Diseases↗
PubMed2005

Incidence of cancer in the area around Amsterdam Airport Schiphol in 1988-2003: a population-based ecological study.

BACKGROUND: Amsterdam Airport Schiphol is a major source of complaints about aircraft noise, safety risks and concerns about long term adverse health effects, including cancer. We investigated whether residents of the area around Schiphol are at higher risk of developing cancer than the general Dutch population. METHODS: In a population-based study using the regional cancer registry, we estimated the cancer incidence during 1988-2003 in residents of the area surrounding Schiphol. We defined a study area based on aircraft noise contours and 4-digit postal code areas, since historical data on ambient air pollution were not available and recent emission data did not differ from the background urban air quality. RESULTS: In residents of the study area 13 207 cancer cases were diagnosed, which was close to the expected number, using national incidence rates as a reference (standardized incidence ratio [SIR] 1.02). We found a statistically significantly increased incidence of hematological malignancies (SIR 1.12, 95% confidence interval [CI]: 1.05, 1.19), mainly due to high rates for non-Hodgkin lymphoma (SIR 1.22, 95% CI: 1.12, 1.33) and acute lymphoblastic leukemia (SIR 1.34, 95% CI: 0.95, 1.83). The incidence of cancer of the respiratory system was statistically significantly decreased (SIR 0.94, 95% CI: 0.90, 0.99), due to the low rate in males (SIR 0.89). In the core zone of the study area, cancer incidence was slightly higher than in the remaining ring zone (rate ratio of the core zone compared to the ring zone 1.05, 95% CI 1.01, 1.10). This was caused by the higher incidence of cancer of the respiratory system, prostate and the female genital organs in the core zone in comparison to the ring zone. CONCLUSION: The overall cancer incidence in the Schiphol area was similar to the national incidence. The moderately increased risk of hematological malignancies could not be explained by higher levels of ambient air pollution in the Schiphol area. This observation warrants further research, for example in a study with focus on substances in urban ambient air pollution, as similar findings were observed in Greater Amsterdam.

Adolescent↗
PubMed2005

Cumulative absolute breast cancer risk for young women treated for Hodgkin lymphoma.

BACKGROUND: Many women develop breast cancer after treatment for Hodgkin lymphoma (HL) at a young age. We estimated this future risk, taking into account age and calendar year of HL diagnosis, HL treatment information, population breast cancer incidence rates, and competing causes of death. METHODS: Relative risks of breast cancer for categories defined by radiation dose to the chest (0, 20- < 40 Gy, or > or = 40 Gy) and use of alkylating agents (yes or no) were estimated from a case-control study conducted within an international population-based cohort of 3817 female 1-year survivors of HL diagnosed at age 30 years or younger from January 1, 1965, through December 31, 1994. To compute cumulative absolute risks of breast cancer, we used modified standardized incidence ratios to relate cohort breast cancer risks to those in the general population, enabling application of population-based breast cancer rates, and we allowed for competing risks by using population-based mortality rates in female HL survivors. RESULTS: Cumulative absolute risks of breast cancer increased with age at end of follow-up, time since HL diagnosis, and radiation dose. For an HL survivor who was treated at age 25 years with a chest radiation dose of at least 40 Gy without alkylating agents, estimated cumulative absolute risks of breast cancer by age 35, 45, and 55 years were 1.4% (95% confidence interval [CI] = 0.9% to 2.1%), 11.1% (95% CI = 7.4% to 16.3%), and 29.0% (95% CI = 20.2% to 40.1%), respectively. Cumulative absolute risks were lower in women treated with alkylating agents. CONCLUSIONS: Breast cancer projections varied considerably by type of HL therapy, time since HL diagnosis, and age at end of follow-up. These estimates are applicable to HL survivors treated with regimens of the past and can be used to counsel such patients and plan management and preventive strategies. Projections should be used with caution, however, in patients treated with more recent approaches, including limited-field radiotherapy and/or ovary-sparing chemotherapy.

Adult↗
PubMed2005

Are cause of subfertility and in vitro fertilization treatment risk factors for an earlier start of menopause?

OBJECTIVE: To study whether women diagnosed with unexplained subfertility reach the menopause transition and natural menopause earlier than women with tubal subfertility, in an in vitro fertilization (IVF)-treated population, and to examine the influence of the number of IVF cycles on the occurrence of an early menopause transition and natural menopause. DESIGN: This retrospective cohort study included 12 IVF clinics in the Netherlands. A nationwide retrospective cohort study was conducted among women whose first IVF cycle was stimulated with gonadotrophins in the Netherlands between 1983 and 1995 (n = 7,842). Most of the women were in their late 30s at the end of the follow-up period (range 24-55 y). The main outcome measures were the relative risk (RR) of having reached natural menopause and the risks (RR) of having entered the menopause transition or natural menopause according to the cause of subfertility and the number of IVF cycles. RESULTS: Women with unexplained subfertility did not have an increased risk of entering the menopause transition or natural menopause (adjusted RR = 0.5; 95% CI, 0.2-1.5; and RR = 0.8; 95% CI, 0.6-1.1). After a 5-year follow-up period, we found no increased risk for entering the menopause transition or natural menopause among women who had undergone six or more IVF cycles when compared with women who had undergone only one IVF cycle (adjusted RR = 0.4; 95% CI, 0.1-1.7; and RR = 0.9; 95% CI, 0.6-1.6). CONCLUSIONS: Underlying causes of unexplained subfertility do not predispose women to an early start of menopause. Although the number of IVF cycles was not associated with early menopause, longer follow-up is needed.

Adult↗
PubMed2005

Breast cancer risk following radiotherapy for Hodgkin lymphoma: modification by other risk factors.

The importance of genetic and other risk factors in the development of breast cancer after radiotherapy (RT) for Hodgkin lymphoma (HL) has not been determined. We analyzed data from a breast cancer case-control study (105 patients, 266 control subjects) conducted among 3 817 survivors of HL diagnosed at age 30 years or younger in 6 population-based cancer registries. Odds ratios (ORs) and excess relative risks (ERRs) were calculated using conditional regression. Women who received RT exposure (> or = 5 Gy radiation dose to the breast) had a 2.7-fold increased breast cancer risk (95% confidence interval (CI) 1.4-5.2), compared with those given less than 5 Gy. RT exposure (> or = 5 Gy) was associated with an OR of 0.8 (95% CI, 0.2-3.4) among women with a first- or second-degree family history of breast or ovarian cancer, and 5.8 (95% CI, 2.1-16.3) among all other women (interaction P = .03). History of a live birth appeared to increase the breast cancer risk associated with RT among women not treated with ovarian-damaging therapies. Breast cancer risk following RT varied little according to other factors. The additional increased relative risk of breast cancer after RT for HL is unlikely to be larger among women with a family history of breast or ovarian cancer than among other women.

Adult↗
PubMed2005

Validity of self-reported causes of subfertility.

The authors assessed the accuracy of cause(s) of subfertility as reported by women in a self-administered questionnaire in comparison with medical record information, in a nationwide cohort study of women receiving in vitro fertilization treatment in the Netherlands (n = 9,164) between 1983 and 1995. Validity was expressed as sensitivity and specificity, and reliability was expressed by the kappa statistic and overall agreement between self-reports and medical records for various subfertility categories. The sensitivity for subfertility attributed to tubal, male, hormonal, cervical, uterine, and idiopathic factors and for endometriosis was 84%, 78%, 65%, 40%, 46%, 59%, and 83%, respectively. The corresponding kappas were 0.79, 0.71, 0.38, 0.34, 0.13, 0.50, and 0.52, respectively. For 54% of all women who reported two or more causes of subfertility, the medical record revealed only one major factor. Conversely, for 43% of all women whose subfertility was attributed to two or more major factors in the record, only one factor was reported by the women. Older age at the time of filling out the questionnaire, low educational level, long duration of subfertility, and pre-in vitro fertilization treatment were associated with less accurate reporting. The results indicate that the validity of self-reports for tubal and male subfertility is satisfactory. For unexplained subfertility, the validity is moderate; for other causes of subfertility and when two causes of subfertility play a role, the validity is low.

Adult↗
PubMed2005

Risk of morbidity and mortality from cardiovascular disease following radiotherapy for childhood cancer: a systematic review.

PURPOSE: To evaluate the existing evidence regarding the long-term risk of cardiovascular disease (CVD) after radiotherapy for childhood cancer. PATIENTS AND METHODS: MEDLINE and EMBASE were searched for articles reporting on radiation-induced CVD after childhood cancer published between 1966 and October 2002. Information about study design, population, treatment, outcome and risk factors were abstracted and the quality of each study was assessed. RESULTS: Fourteen articles met all the eligibility criteria. Ten studies evaluated clinical cardiovascular events (CVE) and 11 cardiovascular mortality (CVM) after cardiac irradiation for childhood cancer. Four studies, all in survivors of Hodgkin's disease, showed a significantly increased standardised mortality ratio; a 22- to 68-fold increase compared to the general population. No study compared the risk of CVE with the general population. Three studies examined the risk of CVD (both CVM and CVE) after radiotherapy compared to an unexposed control group, and two showed a significantly increased relative risk. Many studies had important methodological limitations, related to completeness of follow-up, adjustment for other risk factors and outcome assessment in CVE studies. CONCLUSIONS: This systematic review demonstrates that the risk of CVM after cardiac irradiation for childhood cancer is increased compared to the general population and to unexposed patients. The risk of developing clinical CVE and the precise risk factors for developing CVE or CVM after radiotherapy remain unclear. New well-designed studies are needed to reliably evaluate the long-term risk of CVD following radiotherapy and associated risk factors.

Cardiovascular Diseases↗
PubMed2004

The number of retrieved oocytes does not decrease during consecutive gonadotrophin-stimulated IVF cycles.

BACKGROUND: Our aim was to study whether there is a decreasing trend in the number of retrieved oocytes in women who had all undergone at least seven consecutive IVF cycles. METHODS: A nationwide retrospective cohort study was conducted among women whose first IVF cycle was stimulated with gonadotrophins in The Netherlands between 1983 and 1995. Among these eligible women, we identified all women who had received at least seven consecutive IVF cycles (n = 330). Poisson regression analysis was used to assess the trend in the number of retrieved oocytes over the first six IVF cycles. RESULTS: The unadjusted results showed a slight but non-significant decrease in the number of retrieved oocytes over six IVF cycles. The change in cycle 6 compared with cycle 1 was -0.06 oocytes (5.8% decrease) (P = 0.21). When adjusting for the number of ampoules and the stimulation protocol (fertility drug used combined with use of GnRH agonists), there was a considerable and highly significant decrease from cycle 1 to cycle 6 [change in cycle 6 compared with cycle 1: -0.19 oocytes (17.4% decrease), (P < 0.0001)]. However, when adjusting for age of the women, this decrease almost completely disappeared [change in cycle 6 compared with cycle 1: -0.05 oocytes (5% decrease), (P = 0.50)]. CONCLUSION: The results suggest that there is no decrease in the number of retrieved oocytes over subsequent cycles when simultaneously accounting for the increasing age of the women, differences in the number of ampoules of gonadotrophins used, type of stimulation protocol and year of IVF treatment.

Cohort Studies↗