The BISTIM study: a randomized controlled trial comparing dual ovarian stimulation (duostim) with two conventional ovarian stimulations in poor ovarian responders undergoing IVF

STUDY QUESTION

Is the total number of oocytes retrieved with dual ovarian stimulation in the same cycle (duostim) higher than with two consecutive antagonist cycles in poor responders?

SUMMARY ANSWER

Based on the number of total and mature oocytes retrieved in women with poor ovarian response (POR), there is no benefit of duostim versus two consecutive antagonist cycles.

WHAT IS KNOWN ALREADY

Recent studies have shown the ability to obtain oocytes with equivalent quality from the follicular and the luteal phase, and a higher number of oocytes within one cycle when using duostim. If during follicular stimulation smaller follicles are sensitized and recruited, this may increase the number of follicles selected in the consecutive luteal phase stimulation, as shown in non-randomized controlled trials (RCT). This could be particularly relevant for women with POR.

STUDY DESIGN, SIZE, DURATION

This is a multicentre, open-labelled RCT, performed in four IVF centres from September 2018 to March 2021. The primary outcome was the number of oocytes retrieved over the two cycles. The primary objective was to demonstrate in women with POR that two ovarian stimulations within the same cycle (first in the follicular phase, followed by a second in the luteal phase) led to the retrieval of 1.5 (2) more oocytes than the cumulative number of oocytes from two consecutive conventional stimulations with an antagonist protocol. In a superiority hypothesis, with power 0.8 alpha-risk 0.05 and a 35% cancellation rate, 44 patients were needed in each group. Patients were randomized by computer allocation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eighty-eight women with POR, defined using adjusted Bologna criteria (antral follicle count ≤5 and/or anti-Müllerian hormone ≤1.2 ng/ml) were randomized, 44 in the duostim group and 44 in the conventional (control) group. HMG 300 IU/day with flexible antagonist protocol was used for ovarian stimulation, except in luteal phase stimulation of the duostim group. In the duostim group, oocytes were pooled and inseminated after the second retrieval, with a freeze-all protocol. Fresh transfers were performed in the control group, frozen embryo transfers were performed in both control and duostim groups in natural cycles. Data underwent intention-to-treat and per-protocol analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no difference between the groups regarding demographics, ovarian reserve markers, and stimulation parameters. The mean (SD) cumulative number of oocytes retrieved from two ovarian stimulations was not statistically different between the control and duostim groups, respectively, 4.6 (3.4) and 5.0 (3.4) [mean difference (MD) [95% CI] +0.4 [-1.1; 1.9], P = 0.56]. The mean cumulative numbersof mature oocytes and total embryos obtained were not significantly different between groups. The total number of embryos transferred by patient was significantly higher in the control group 1.5 (1.1) versus the duostim group 0.9 (1.1) (P = 0.03). After two cumulative cycles, 78% of women in the control group and 53.8% in the duostim group had at least one embryo transfer (P = 0.02). There was no statistical difference in the mean number of total and mature oocytes retrieved per cycle comparing Cycle 1 versus Cycle 2, both in control and duostim groups. The time to the second oocyte retrieval was significantly longer in controls, at 2.8 (1.3) months compared to 0.3 (0.5) months in the duostim group (P < 0.001). The implantation rate was similar between groups. The cumulative live birth rate was not statistically different, comparing controls versus the duostim group, 34.1% versus 17.9%, respectively (P = 0.08). The time to transfer resulting in an ongoing pregnancy did not differ in controls 1.7 (1.5) months versus the duostim group, 3.0 (1.6) (P = 0.08). No serious adverse events were reported.

LIMITATIONS, REASONS FOR CAUTION

The RCT was impacted by the coronavirus disease 2019 pandemic and the halt in IVF activities for 10 weeks. Delays were recalculated to exclude this period; however, one woman in the duostim group could not have the luteal stimulation. We also faced unexpected good ovarian responses and pregnancies after the first oocyte retrieval in both groups, with a higher incidence in the control group. However, our hypothesis was based on 1.5 more oocytes in the luteal than the follicular phase in the duostim group, and the number of patients to treat was reached in this group (N = 28). This study was only powered for cumulative number of oocytes retrieved.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT comparing the outcome of two consecutive cycles, either in the same menstrual cycle or in two consecutive menstrual cycles. In routine practice, the benefit of duostim in patients with POR regarding fresh embryo transfer is not confirmed in this RCT: first, because this study demonstrates no improvement in the number of oocytes retrieved in the luteal phase after follicular phase stimulation, in contrast to previous non-randomized studies, and second, because the freeze-all strategy avoids a pregnancy with fresh embryo transfer after the first cycle. However, duostim appears to be safe for women. In duostim, the two consecutive processes of freezing/thawing are mandatory and increase the risk of wastage of oocytes/embryos. The only benefit of duostim is to shorten the time to a second retrieval by 2 weeks if accumulation of oocytes/embryos is needed.

STUDY FUNDING/COMPETING INTERESTS

This is an investigator-initiated study supported by a research Grant from IBSA Pharma. N.M. declares grants paid to their institution from MSD (Organon France); consulting fees from MSD (Organon France), Ferring, and Merck KGaA; honoraria from Merck KGaA, General Electrics, Genevrier (IBSA Pharma), and Theramex; support for travel and meetings from Theramex, Merck KGaG, and Gedeon Richter; and equipment paid to their institution from Goodlife Pharma. I.A. declares honoraria from GISKIT and support for travel and meetings from GISKIT. G.P.-B. declares Consulting fees from Ferring and Merck KGaA; honoraria from Theramex, Gedeon Richter, and Ferring; payment for expert testimony from Ferring, Merck KGaA, and Gedeon Richter; and support for travel and meetings from Ferring, Theramex, and Gedeon Richter. N.C. declares grants from IBSA pharma, Merck KGaA, Ferring, and Gedeon Richter; support for travel and meetings from IBSA pharma, Merck KGaG, MSD (Organon France), Gedeon Richter, and Theramex; and participation on advisory board from Merck KGaA. E.D. declares support for travel and meetings from IBSA pharma, Merck KGaG, MSD (Organon France), Ferring, Gedeon Richter, Theramex, and General Electrics. C.P.-V. declares support for travel and meetings from IBSA Pharma, Merck KGaA, Ferring, Gedeon Richter, and Theramex. M.Pi. declares support for travel and meetings from Ferring, Gedeon Richetr, and Merck KGaA. M.Pa. declares honoraria from Merck KGaA, Theramex, and Gedeon Richter; support for travel and meetings from Merck KGaA, IBSA Pharma, Theramex, Ferring, Gedeon Richter, and MSD (Organon France). H.B.-G. declares honoraria from Merck KGaA, and Gedeon Richter and support for travel and meetings from Ferring, Merck KGaA, IBSA Pharma, MSD (Organon France), Theramex, and Gedeon Richter. S.G. and M.B. have nothing to declare.

TRIAL REGISTRATION NUMBER

Registration number EudraCT: 2017-003223-30. ClinicalTrials.gov identifier: NCT03803228.

TRIAL REGISTRATION DATE

EudraCT: 28 July 2017. ClinicalTrials.gov: 14 January 2019.

DATE OF FIRST PATIENT’S ENROLMENT

3 September 2018.

O-068 The BISTIM study: first RCT comparing dual ovarian stimulation on the same cycle (duostim) vs 2 conventional ovarian stimulations in poor ovarian responders undergoing IVF

Study question

Is the number of cumulated oocytes with dual ovarian stimulation on the same cycle (duostim) higher compared to 2 consecutive antagonist cycles in poor responders?

Summary answer

Considering the number of total and mature oocytes collected in poor ovarian responders, there is no benefit of duostim vs two consecutive antagonist cycles.

What is known already

Several waves of follicular development exist on the same cycle. Recent studies have shown the ability to obtain oocytes with equivalent quality in the luteal phase, even after a previous ovarian stimulation in the follicular phase. During stimulation, smaller follicles are recruited and sensitized, which may increase the selection of follicles available on the second stimulation. In poor ovarian responders (POR) this potentialization may have a great interest, as 2 stimulations on the same cycle could give a higher number of oocytes compared to two conventional stimulations. However, these preliminary data need to be confirmed with a randomized controlled trial.

Study design, size, duration

This is a multicenter, open-labeled randomized control trial (2018, september – 2021, march). The primary objective was to demonstrate that two ovarian stimulations within the same cycle (first in the follicular phase, followed by a second in the luteal phase) lead to the retrevial of 1.5 more oocytes than the cumulative number of oocytes from two consecutive conventional stimulation, in POR women. According to this hypothesis, 44 patients were needed in each group.

Participants/materials, setting, methods

88 POR women, defined with Bologna criteria (AFC≤5 and/or AMH≤1.2ng/ml and ≤3 oocytes if previous IVF) were randomized, 44 in duostim group (D) and 44 in conventional group (C). FertistartKit® 300IU/day with antagonist protocol was used except in luteal phase stimulation of group D. In group D, oocytes were pooled and inseminated after the second retrieval, with freeze all embryos. Fresh transfer was performed in group C. The analysis is presented in intention to treat.

Main results and the role of chance

There was no difference between the groups regarding demographics, ovarian reserve markers (AFC, AMH) and stimulation parameters. The mean number of cumulated oocytes retrieved with 2 ovarian stimulation was not statistically different in group D and C, respectively 5.0+/-3.4 and 4.6+/-3.4 (p = 0.56). The mean number of cumulated mature oocytes was not statistically different, 3.7+/-3.3 in group D vs 3.1+/-3.0 in group C (p = 0.38). The mean number of embryos was significantly lower in the group D, 0.8+/-1.3 vs group C 1.6+/-1.3 (p &lt; 0.01). There was no statistical difference of the mean number of oocytes retrieved per cycle in cycle 1 vs cycle 2 in both group D and C. The delay, between the first and the second day 1 of stimulation was statistically different in group D 14.4 days (10-19) vs group C 90.6 (28-232). The ongoing pregnancy rate in group D 17.9% (7/39) was not statistically different with group C 29.3% (12/41), (p = 0.23). And the mean time to ongoing pregnancy tends to be longer in group D (144 days) vs group C (115 days) but was not statistically different (p = 0.21).

Limitations, reasons for caution

The RCT was impacted by Covid pandemia and stop of IVF activities for 10 weeks. Delays were recalculated to exclude this period, however one women in group D cannot have the luteal stimulation. We also faced unexpected good ovarian responses and pregnancies after the first oocyte pick-up in group C.

Wider implications of the findings

In routine practice, the benefit of duostim in patients with POR is not confirmed. Firstly, because there is no potentialization on the number of oocyte retrieved in luteal phase after follicular phase stimulation. Secondly, because the freeze all strategy avoids a pregnancy with fresh embryo transfer after the first cycle.

Trial registration number

2017-A00498-45

[Dydrogesterone versus micronized vaginal progesterone as luteal phase support after fresh embryo transfer in IVF]

OBJECTIVES

The objective of the study was to compare the live birth rate and miscarriage rate after fresh embryo transfer (Fresh ET) when patients are treated either with oral dydrogesterone or micronized vaginal progesterone (MVP) as luteal phase support (LPS). The vaginal route is still preferred, despite the discomfort for the patients and recent RCTs showing similar results for dydrogesterone and MVP.

METHODS

All 556 consecutive Fresh ET after autologous IVF procedure, from December 2011 to March 2013 in one centre in France were included. Patients were treated either with dydrogesterone 10mg every 12hours (n=267) or MVP 200mg every 12hours (n=289), the physician's arbitrary choice on the day of the oocyte aspiration procedure.

RESULTS

The groups were comparable regarding the demographic data and stimulation protocols, except for the rank of the oocyte pickup procedure [1.54±0.80 vs. 1.74±0.96, (P=0.01)], with no significant difference in live birth rates (22.4% vs. 23.8%, P=0.77) and miscarriage rates (4.1% vs. 5.5%, P=0.55) for dydrogesterone vs. MVP respectively. The results were similar in a good prognosis patients' subgroup.

CONCLUSIONS

LPS with either dydrogesterone or MVP after Fresh ET showed similar live birth rates and miscarriage rates. The benefits of the oral over vaginal route might be higher tolerance and possibly better compliance. Dydrogesterone seems to be a safe treatment, but its long-term innocuity needs to be further proven.

Impact of endometrial preparation on early pregnancy loss and live birth rate after frozen embryo transfer: a large multicenter cohort study (14,421 frozen cycles)

STUDY QUESTION

Does the endometrial preparation protocol (artificial cycle (AC) vs natural cycle (NC) vs stimulated cycle (SC)) impact the risk of early pregnancy loss and live birth rate after frozen/thawed embryo transfer (FET)?

SUMMARY ANSWER

In FET, ACs were significantly associated with a higher pregnancy loss rate and a lower live birth rate compared with SC or NC.

WHAT IS KNOWN ALREADY

To date, there is no consensus on the optimal endometrial preparation in terms of outcomes. Although some studies have reported a higher pregnancy loss rate using AC compared with NC or SC, no significant difference was found concerning the pregnancy rate or live birth rate. Furthermore, no study has compared the three protocols in a large population.

STUDY DESIGN, SIZE, DURATION

A multicenter retrospective cohort study was conducted in nine reproductive health units in France using the same software to record medical files between 1 January 2012 and 31 December 2016. FET using endometrial preparation by AC, modified NC or SC were included. The primary outcome was the pregnancy loss rate at 10 weeks of gestation. The sample size required was calculated to detect an increase of 5% in the pregnancy loss rate (21–26%), with an alpha risk of 0.5 and a power of 0.8. We calculated that 1126 pregnancies were needed in each group, i.e. 3378 in total.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were collected by automatic extraction using the same protocol. All consecutive autologous FET cycles were included: 14 421 cycles (AC: n = 8139; NC: n = 3126; SC: n = 3156) corresponding to 3844 pregnancies (hCG > 100 IU/l) (AC: n = 2214; NC: n = 812; SC: n = 818). Each center completed an online questionnaire describing its routine practice for FET, particularly the reason for choosing one protocol over another.

MAIN RESULTS AND THE ROLE OF CHANCE

AC represented 56.5% of FET cycles. Mean age of women was 33.5 (SD ± 4.3) years. The mean number of embryos transferred was 1.5 (±0.5). Groups were comparable, except for history of ovulation disorders (P = 0.01) and prior delivery (P = 0.03), which were significantly higher with AC. Overall, the early pregnancy loss rate was 31.5% (AC: 36.5%; NC: 25.6%; SC: 23.6%). Univariable analysis showed a significant association between early pregnancy loss rate and age >38 years, history of early pregnancy loss, ovulation disorders and duration of cryopreservation >6 months. After adjustment (multivariable regression), the early pregnancy loss rate remained significantly higher in AC vs NC (odds ratio (OR) 1.63 (95% CI) [1.35–1.97]; P < 0.0001) and in AC vs SC (OR 1.87 [1.55–2.26]; P < 0.0001). The biochemical pregnancy rate (hCG > 10 and lower than 100 IU/l) was comparable between the three protocols: 10.7% per transfer.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by its retrospective design that generates missing data. Routine practice within centers was heterogeneous. However, luteal phase support and timing of embryo transfer were similar in AC. Univariable analysis showed no difference between centers. Moreover, a large number of parameters were included in the analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study shows a significant increase in early pregnancy loss when using AC for endometrial preparation before FET. These results suggest either a larger use of NC or SC, or an improvement of AC by individualizing hormone replacement therapy for patients in order to avoid an excess of pregnancy losses.

STUDY FUNDING/COMPETING INTEREST(S)

The authors declare no conflicts of interest in relation to this work. G.P.-B. declares consulting fees from Ferring, Gedeon-Richter, Merck KGaA, Theramex, Teva; Speaker’s fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter, Theramex, Teva. N.C. declares consulting fees from Ferring, Merck KGaA, Theramex, Teva; Speaker’s fees or equivalent from Merck KGaA, Ferring. C.R. declares a research grant from Ferring, Gedeon-Richter; consulting fees from Gedeon-Richter, Merck KGaA; Speaker’s fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter; E.M.d’A. declares Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Theramex, Teva. I.C-D. declares Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, IBSA. N.M. declares a research grant from Merck KGaA, MSD, IBSA; consulting fees from MSD, Ferring, Gedeon-Richter, Merck KGaA; Speaker’s fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Teva, Goodlife, General Electrics.

TRIAL REGISTRATION NUMBER

N/A.

Random antral follicle count performed on any day of the menstrual cycle has the same predictive value as AMH for good ovarian response in IVF cycles

OBJECTIVE

To determine whether the predictive value of AFC for ovarian response to stimulation for IVF depends on the day of the menstrual cycle when ultrasound is performed.

METHODS

410 women undergoing their first IVF cycle were included. All the women had AFC performed twice. The first measurement, random AFC (r-AFC), was performed during the fertility workup whatever the day of their menstrual cycle. Three groups were constituted according to the period of ultrasound performance: at early follicular phase i.e., day 1 to day 6 (eFP-AFC); at mid follicular phase i.e., day 7 to 12 (mFP-AFC) and at luteal phase i.e., day 13 or after (LP-AFC). A second AFC measurement was performed before the start of the ovarian stimulation (SD1-AFC). AMH dosing was done in the early follicular phase.

RESULTS

Random AFC (r-AFC) was correlated to AMH (r = 0.69; p<0.001), SD1-AFC (r = 0.75; p<0.001) and number of oocytes retrieved (r = 0.49; p<0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was 0.65, 0.66 and 0.85 for the eFP-AFC, the mFP-AFC and the LP-AFC respectively (all p were <0.001). The ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively; p = 0.28). The AUC of r-AFC (0.76) were similar to those of AMH (0.74) and SD1-AFC (0.74) (p = 0.21 and 0.92 respectively).

CONCLUSION

AFC is strongly correlated with AMH and highly predictive of good ovarian response during the whole menstrual cycle.

P–599 random antral follicle count, performed at any day of the menstrual cycle, demonstrates the same predictive value for ovarian response in in vitro fertilization cycles

Study question

Does antral follicle count (AFC) retains its predictive value for ovarian response to stimulation for in vitro fertilization (IVF) throughout the whole menstrual cycle?

Summary answer

AFC is strongly correlated to anti-mullerian hormone (AMH) and highly predictive of good ovarian response whatever the day of cycle the ultrasound is performed.

What is known already

Usually performed in the early follicular phase (at day 2–3 of the menstrual cycle), AFC and AMH are the most accurate markers of ovarian reserve. They are routinely used to predict ovarian response to ovarian stimulation for IVF and eventually to individualize the gonadotropin starting dose.

Study design, size, duration

Retrospective cohort study performed between January, 2017 and December, 2019.

Participants/materials, setting, methods

410 consecutive women aged 20 to 42 years were included. Random AFC (r-AFC) was performed during the fertility workup whatever the day of their menstrual cycle was: early follicular phase i.e. day 1 to day 6 (eFP-AFC), mid follicular phase i.e. day 7 to 12 (mFP-AFC) and luteal phase i.e. day 13 or after (LP-AFC). A second AFC was performed before the start of the stimulation (SD1-AFC). AMH was measured in the early follicular phase.

Main results and the role of chance

Random AFC (r-AFC) was correlated to AMH (r = 0.692; p &lt; 0.001), SD1-AFC (r = 0.756; p &lt; 0.001) and number of oocytes retrieved (r = 0.491; p &lt; 0.001). When regarding AFC depending on the cycle day group, the correlation with AMH was significantly higher for the LP-AFC, (LP-AFC) (r = 0.853) than for the eFP-AFC (r = 0.657; p &lt; 0.001) and for the mFP-AFC (r = 0.668). The correlation with SD1-AFC was similar regardless of the time of performance of r-AFC (r = 0.739, 0.783, 0.733, respectively for eFP, mFP and LP-AFC). Moreover, the ROC analysis showed the same predictive value for good ovarian response (more than 6 oocytes retrieved) for the eFP-AFC, mFP-AFC and LP-AFC (AUC 0.73, 0.75 and 0.84 respectively) as well as for AMH and SD1-AFC (AUC 0.74 and 0.74, respectively).

Limitations, reasons for caution

This is a retrospective analysis, however data were prospectively collected and the method for ultrasound acquisition of AFC was standardized.

Wider implications of the findings: The absence of significant variation of AFC across the menstrual cycle allows to its random performance. Ultrasound performed besides early follicular phase discloses informations on ovaries, the uterus and the endometrium. It is more comfortable and convenient for women and physicians by limiting targeted appointment during menstruation and reiterated examination.

Trial registration number

Not applicable

P–730 “Fertility Check Up”: A proposal for assessment of women’s fertility potential. Analysis and evaluation of the first 200 women

Study question

Is there an interest in offering a fertility assessment to all women, with or without proven infertility, whatever their personal situation or parental project ?

Summary answer

Assessing the fertility of all women allows us to inform and advise them, in order to optimize their chances to achieve their parenting project.

What is known already

In a society where the age of childbearing is increasing and where women want to be able to postpone their pregnancies and to plan their parenting plan, there is no medical recommendation to assess fertility of women who are single or who do not have proven infertility.

Study design, size, duration

We implemented a new proposal in our reproductive medicine department, the “Fertility Check Up” (FCU), allowing any woman, whatever her personal situation or parental project, to benefit from an evaluation of her fertility, as well as personalized information and advice, to optimize the realization of her life plan.

Participants/materials, setting, methods

The FCU is carried out on female volunteers who do not need to be referred by a doctor. The fertility evaluation is performed by a self-questionnaire and an “all-in-one” ultrasound examination (Fertiliscan) including a complete pelvic ultrasound with a hysterosalpingo-foam-sonography (Hyfosy); this examination allows an anatomical and functional evaluation of the female reproductive system, in one step. Women then benefit from a personalized interview with a fertility specialist.

Main results and the role of chance

In the first year, 200 women aged 24 to 48 years old benefited from this examination, 56% of whom had never attempted to conceive. Anomalies found included: tubal diseases (29%), congenital or acquired uterine anomalies (11,5%), and endometriosis (6,5%). We concluded to a low ovarian reserve for age in 14% of cases. 84% of women say they felt little or no discomfort during the Fertiliscan. A questionnaire was sent to women 6 months after the FCU: among the 85 women with a desire for pregnancy at the time of the FCU, 29.1% obtained a pregnancy, and 36% began ART procedures. Among the women who had no plans for pregnancy, 50% stated that the completion of the FCU had modified their personal or professional plans regarding a possible desire for future pregnancy.

Limitations, reasons for caution

Women are informed that the FCU gives them indications about their theoretical chances of pregnancy, but that there is no way to be sure that a woman will ever bear a child, as 10% of infertilities remain idiopathic.

Wider implications of the findings: The proposal of fertility assessment for women, whether infertile or not, with or without immediate pregnancy plans, allows for information, advice and treatment if necessary. Women are better informed about their own fertility, and can get the best chances to achieve their parental project, with, or ideally without, assisted-reproductive-techniques.

Trial registration number

Not applicable

A large observational data study supporting the PROsPeR score classification in poor ovarian responders according to live birth outcome

STUDY QUESTION

Can the Poor Responder Outcome Prediction (PROsPeR) score identify live birth outcomes in subpopulations of patients with poor ovarian response (POR) defined according to the ESHRE Bologna criteria (female age, anti-Müllerian hormone (AMH), number of oocytes retrieved during the previous cycle (PNO) after treatment with originator recombinant human follitropin alfa?

SUMMARY ANSWER

The PROsPeR score discriminated the probability of live birth in patients with POR using observational data with fair discrimination (AUC ≅ 70%) and calibration, and the AUC losing less than 5% precision compared with a model developed using the observational data.

WHAT IS KNOWN ALREADY

Although scoring systems for the likelihood of live birth after ART have been developed, their accuracy may be insufficient, as they have generally been developed in the general population with infertility and were not validated for patients with POR. The PROsPeR score was developed using data from the follitropin alfa (GONAL-f; Merck KGaA, Darmstadt, Germany) arm of the Efficacy and Safety of Pergoveris in Assisted Reproductive Technology (ESPART) randomized controlled trial (RCT) and classifies women with POR as mild, moderate or severe, based upon three variables: female age, serum AMH level and number of oocytes retrieved during the previous cycle (PNO).

STUDY DESIGN, SIZE, DURATION

The external validation of the PROsPeR score was completed using data derived from eight different centres in France. In addition, the follitropin alfa data from the ESPART RCT, originally used to develop the PROsPeR score, were used as reference cohort. The external validation of the PROsPeR score l was assessed using AUC. A predetermined non-inferiority limit of 0.10 compared with a reference sample and calibration (Hosmer-Lemeshow test) were the two conditions required for evaluation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The observational cohort included data from 8085 ART treatment cycles performed with follitropin alfa in patients with POR defined according to the ESHRE Bologna criteria (17.6% of the initial data set). The ESPART cohort included 477 ART treatment cycles with ovarian stimulation performed with follitropin alfa in patients with POR.

MAIN RESULTS AND THE ROLE OF CHANCE

The external validation of the PROsPeR score to identify subpopulations of women with POR with different live birth outcomes was shown in the observational cohort (AUC = 0.688; 95% CI: 0.662, 0.714) compared with the ESPART cohort (AUC = 0.695; 95% CI: 0.623, 0.767). The AUC difference was -0.0074 (95% CI: -0.083, 0.0689). This provided evidence, with 97.5% one-sided confidence, that there was a maximum estimated loss of 8.4% in discrimination between the observational cohort and the ESPART cohort, which was below the predetermined margin of 10%. The Hosmer-Lemeshow test did not reject the calibration when comparing observed and predicted data (Hosmer-Lemeshow test = 1.266688; P = 0.260).

LIMITATIONS, REASONS FOR CAUTION

The study was based on secondary use of data that had not been collected specifically for the analysis reported here and the number of characteristics used to classify women with POR was limited to the available data. The data were from a limited number of ART centres in a single country, which may present a bias risk; however, baseline patient data were similar to other POR studies.

WIDER IMPLICATIONS OF THE FINDINGS

This evaluation of the PROsPeR score using observational data supports the notion that the likelihood of live birth may be calculated with reasonable precision using three readily available pieces of data (female age, serum AMH and PNO). The PROsPeR score has potential to be used to discriminate expected probability of live birth according to the degree of POR (mild, moderate, severe) after treatment with follitropin alfa, enabling comparison of performance at one centre over time and the comparison between centres.

STUDY FUNDING/COMPETING INTEREST(S)

This analysis was funded by Merck KGaA, Darmstadt, Germany. P.L. received grants from Merck KGaA, outside of the submitted work. N.M. reports grants, personal fees and non-financial support from Merck KGaA outside the submitted work. T.D.H. is Vice President and Head of Global Medical Affairs Fertility, Research and Development at Merck KGaA, Darmstadt, Germany. P.A. has received personal fees from Merck KGaA, Darmstadt, Germany, outside the submitted work. C.R. has received grants and personal fees from Gedeon Richter and Merck Serono S.A.S., France, an affiliate of Merck KGaA, Darmstadt, Germany, outside the submitted work. P.S. reports congress support from Merck Serono S.A.S., France (an affiliate of Merck KGaA, Darmstadt, Germany), Gedeon Richter, TEVA and MDS outside the submitted work. C.A., J.P., G.P. and R.W. declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Under-estimation of self-reported occupational exposure by questionnaire in hospital workers

OBJECTIVES

The aim of the study was to determine whether self-reported occupational exposure to cleaning/disinfecting agents in hospital workers is accurate, in comparison to expert assessment, taken to be the gold standard.

METHODS

In the Epidemiological Study of the Genetics and Environment of Asthma (EGEA), participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardised procedure to estimate intensity, frequency and probability of exposure for each job. The present analysis focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. Agreement and differences between self-reported and expert estimates were studied by kappa and phi coefficients and McNemar tests, respectively.

RESULTS

In the survey of 1571 adults, 176 ever hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5% vs 32.7%, p=0.01), ammonia (7.4% vs 18.8%, p<0.0001), alcohol (64.9% vs 93.0%, p<0.0001) and quaternary ammonium components (16.6% vs 70.9%, p<0.0001), compared to expert assessment.

CONCLUSION

Occupational exposure to disinfecting/cleaning agents is common and high in hospitals. A large underestimation of self-reported exposure and a lack of knowledge of product components was observed. Our results show the relevance of expert assessment in epidemiological studies to limit measurement bias. This work underlines the need for health education programmes on the occupational risks induced by these types of products.

Evaluation of different markers of the ovarian reserve in patients presenting with premature ovarian failure

Premature ovarian failure (POF) is a heterogeneous syndrome, possibly due to mutations of genes involved in the normal development of the ovary and/or the follicles. Based essentially on animal models, these mutations are associated with various ovarian histological phenotypes, from a complete absence of to a partial follicular maturation. The aims of our work were in one hand to determine if ovarian histology, compared to pelvic ultrasonography, would be helpful either in identifying which patients display an impaired follicular growth or in the orientation of the POF etiology; on the other hand, since developing follicles up to the antral stage are reported in POF and that Anti-Müllerian hormone (AMH) might be a good indicator of follicular presence, we decided to determine whether AMH should be a better marker to determine the presence of an ovarian reserve in POF patients. To try to answer to the first question, we studied first 166 patients suffering from POF with a normal karyotype. Vaginal ultrasonography (US) was performed in 134 patients and an ovarian biopsy was obtained in 67 women. The presence of follicles suggested at US was confirmed at histology in only 56% of the patients. Ovarian histology led to the distinction of two phenotypes (a) small-sized ovaries, deprived of follicles, and (b) normal-sized ovaries with partial follicular maturation. To confirm the value of ovarian biopsies, samples from 20 normal women have been studied, confirming that ovarian biopsy at random allow reliable assessment of follicular activity. To try to answer to the second question of our work, a cross sectional study analyzing serum AMH, ovarian histology and AMH immunoexpression in 48 POF patients, was performed. Serum AMH was significantly higher in women with more than 5 follicles at ovarian histology. Ovarian AMH immunostaining revealed a normal AMH expression in POF preantral follicles but a decrease expression at the early antral stages. In conclusion, ovarian histology appears to be a reliable tool to appreciate the follicular reserve, and helpful and complementary to clinical and hormonal phenotyping in order to orient the search for various genetic causes of POF syndrome. Finally, AMH levels in POF patients could identify women with persistent follicles.

Respiratory symptoms and bronchial responsiveness among cleaning and disinfecting workers in the food industry

OBJECTIVES

To measure the levels of exposure to nitrogen trichloride (NCl3) and aldehydes among cleaning and disinfecting workers in the atmosphere of food industry plants during cleaning and disinfecting operations, and to examine how they relate to irritant and chronic respiratory symptoms-which are indices of pulmonary function-and bronchial hyperresponsiveness (BHR) to methacholine.

METHODS

175 exposed workers (M = 149; F = 26) recruited from 17 enterprises of the food industry (8 cattle, pig, and ovine slaughterhouses, 8 fowl slaughterhouses, and 1 catering firm) and 70 non-exposed workers (M = 52; F = 18) were examined. Concentration levels of NCl3 and aldhehydes were measured by personal sampling. Symptoms were assessed by means of a questionnaire and the methacholine bronchial challenge (MBC) test using an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered.

RESULTS

277 air samples were taken in the 17 food industry plants. For a given plant and in a given workshop, the actual concentrations of chloramines, aldehydes, and quaternary ammonium compounds were measured with personal samplers during the different steps of the procedures. For each cleaner, a total exposure index Sigma was calculated. A statistically significant concentration-response relationship was found between eye, nasal, and throat symptoms of irritation--but not chronic respiratory symptoms--and exposure levels or exposure duration. No relation was found between BHR and exposure.

CONCLUSIONS

These data show that cleaning and disinfecting workers in the food industry are at risk of developing eye, nasal, and throat irritation symptoms. Although NCl3 exposure does not seem to carry a risk of developing permanent BHR, the possibility of transient BHR cannot be ruled out entirely.

Serum anti-Müllerian hormone expression in women with premature ovarian failure

BACKGROUND

Premature ovarian failure (POF) is generally irreversible. However, developing follicles up to the antral stage are reported in POF and anti-Müllerian hormone (AMH) might be a good indicator of follicular presence. This study analysed serum AMH, ovarian histology and AMH immunoexpression in POF patients.

METHODS

A cross-sectional study of 48 POF patients in an Endocrinology Department setting. Patients had an ovarian biopsy simultaneously with serum AMH sampling and/or ovarian AMH immunostaining.

RESULTS

Mean serum AMH was 1.04 +/- 1.66 ng/ml. Serum AMH was significantly higher in women with 15 or more follicles at ovarian histology (P = 0.001). Comparison of ovarian AMH immunostaining from POF patients and 10 normal controls revealed a normal AMH expression in POF pre-antral follicles, but a decreased expression at the early antral stages. Serum AMH was undetectable in 77% of the patients with 0-5 AMH immunopositive follicles and detectable in 100% of the patients with more than 15 AMH immunopositive follicles.

CONCLUSIONS

AMH levels in POF patients could identify women with persistent follicles. The decrease of AMH immunoexpression in POF antral follicles could suggest a defect of antral development.

Timing of FSH administration for ovarian stimulation in normo-ovulatory women: comparison of an early or a mid follicular phase initiation of a short-term treatment

BACKGROUND

In normo-ovulatory infertile women undergoing mild ovarian stimulation out of IVF, FSH stimulation regimen must be carefully adjusted to control the number of recruited follicles and to prevent multiple pregnancies. The aim of this prospective study was to assess the effect of the timing of FSH administration (fixed dose and duration) on the number of large follicles.

METHODS

Women were prospectively randomized by means of sealed envelopes to receive daily 112.5 IU recombinant FSH (rFSH), either from cycle day (CD) 2-6 (Group A) or from CD 7-11 (Group B). Hormonal measurements and follicular ultrasound assessments were performed on CD 2, 7 and 12.

RESULTS

On CD 12, the development rate of exactly two follicles >or=14 mm in diameter was significantly lower in Group A than in Group B (4% of women versus 42%, P = 0.002). Although the pattern of serum estradiol (E(2)) concentrations in Group A displayed a plateau from CD 7, the cancellation rate for overstimulation (more than three follicles >or=14 mm in diameter) was significantly increased (P = 0.009).

CONCLUSIONS

Preventing the closure of the FSH window by mid to late follicular phase FSH administration better fulfils the objective of obtaining a limited number of large follicles than surpassing the FSH threshold by an early administration.

Mortality among Paris sewage workers

OBJECTIVES

To describe the mortality of Paris sewage workers.

METHODS

A cohort of all Paris sewage workers since 1970 was established and followed up in mortality until 1999. The causes of death were determined by matching with a national database. The mortality rates were compared to the rates of a local reference population.

RESULTS

A large excess in mortality (standardised mortality ratio (SMR) = 1.25; 530 cases, 95% CI 1.15 to 1.36) and in particular mortality from cancer (SMR = 1.37, 235 cases) was detected which was particularly important in the subgroup of subjects who had left employment because they resigned or were laid off (SMR = 1.77; 50 cases). The excess mortality is to a large extent due to alcohol related diseases (SMR = 1.65, 122 cases) especially malignant (SMR = 1.85, 16 cases) and non-malignant (SMR = 1.68, 38 cases) liver diseases, lung cancer (SMR = 1.47, 68 cases), and infectious diseases (SMR = 1.86, 25 cases). The SMRs for some diseases (all cancers, cancers of the oesophagus and lung, all alcohol related diseases) seem to increase with duration of employment as a sewage worker. Other than lung cancer, smoking related diseases were not in excess.

CONCLUSION

The increased mortality by both malignant and non-malignant liver diseases is probably due to excessive alcohol consumption, but could be partially the result of occupational exposure to chemical and infectious agents and interactions of these factors. The excess lung cancer is unlikely to be due to an increased smoking prevalence.

Idiopathic Premature Ovarian Failure in 63 Young Women

BACKGROUND

Premature ovarian failure (POF) in adolescents is defined as primary or secondary amenorrhea associated with high follicle-stimulating hormone (FSH) levels. In normal 46,XX patients, its etiology is most often unknown. We have evaluated the clinical, hormonal and ovarian phenotypes in patients with a normal karyotype who were diagnosed with POF before the age of 18.

METHODS

Sixty-three patients were included in this retrospective study.

RESULTS

The mean patient age was 20.4 years. The patients presented with three clinical patterns: lack of pubertal development (n = 23), primary amenorrhea with interrupted puberty (n = 18), and secondary amenorrhea with normal puberty (n = 22). Ten patients had a familial history of POF and 6 presented with hypothyroidism. The FSH, estradiol and inhibin B levels were not statistically different in the three clinical groups. Fifty percent of the patients presented small ovaries (length <2 cm) at ultrasonography. The presence of follicles was found at histology in only 7 of the 27 patients who underwent an ovarian biopsy.

CONCLUSION

46,XX patients presenting with early POF rarely presented a specific, identifiable disorder. We discuss the clinical management and different diagnosis strategies to improve our current knowledge of this syndrome.

Effects of transdermal testosterone application on the ovarian response to FSH in poor responders undergoing assisted reproduction technique—a prospective, randomized, double-blind study

BACKGROUND

In primates, androgens can play a synergistic role with FSH in promoting the early follicular recruitment, which is critical in assisted reproduction technique programmes.

OBJECTIVE

To assess whether poor responders can benefit from androgen application.

METHODS

Inclusion criteria were a previous poor ovarian response to controlled ovarian stimulation and a decreased hormonal ovarian reserve. Selected women were randomized to receive either transdermal application of testosterone (n = 24) or placebo (n = 25) gel for 15 days before FSH treatment for a second IVF cycle. Similar GnRH analogue and equivalent FSH daily doses were used in both cycles. The primary outcome was the total number of oocytes retrieved.

RESULTS

Testosterone gel application resulted in a significant increase in plasma testosterone levels but did not significantly improve the antral follicle count. Furthermore, after gel application, the main parameters of the ovarian response (numbers of pre-ovulatory follicles, total and mature oocytes and embryos) did not significantly differ between testosterone and placebo-treated patients.

CONCLUSION

No significant beneficial effects of androgen administration on the ovarian response to FSH could be demonstrated. However, subsequent clinical trials are needed to determine whether an optimal dose and/or a longer duration of testosterone administration may be helpful.

[Intrauterine insemination: spontaneous or medically-assisted ovulation?]

Intrauterine insemination (i.u.i.) is usually proposed as the first-line therapy for infertility related to cervical factor, male and unexplained infertility. The overall success rate of i.u.i. is about 10-20% clinical pregnancies per cycle. i.u.i. may be performed in patients with or without prior controlled ovarian hyperstimulation (COH). The aim of COH is to closely monitor follicular growth in order to achieve a timely triggering of ovulation and i.u.i. Additionally, ovarian stimulation allows to increase the number of developing follicles. According to the review of previous prospective randomized studies and meta-analyses, it seems that: (i) when a cervical factor is involved, the advantage of COH in conjunction with i.u.i. is likely but has to be confirmed; (ii) in male infertility, COH with gonadotropins in conjunction with i.u.i. increases the clinical pregnancy rate by two. In this situation, the better the sperm parameters are, the more advantageous COH is; (iii) in unexplained infertility, COH in addition to i.u.i. improves the pregnancy rate but stimulation with clomifene citrate appears to be less effective than gonadotropins administration. Beside the sperm parameters, the success rate depends on both woman's age and degree of ovarian stimulation. Meanwhile, ovarian hyperstimulation exposes to the risk of multiple pregnancy and hyperstimulation syndrome. Increasing the number of preovulatory follicles from one to two allows to approximately double the pregnancy rate. However, there is clear evidence that getting three or more than three follicles exposes to a worrying risk of multiple pregnancy. At the present time, the successful outcome of i.u.i. should not be assessed by the clinical pregnancy rate any longer but by the singleton birth rate. Our therapeutic strategy for COH prior to i.u.i. should take into account woman's age, infertility duration and associated infertility factors. The objective in terms of preovulatory follicle number must be determined prior to the stimulation in order to optimise the cycle outcome with a singleton birth.

Significance of ovarian histology in the management of patients presenting a premature ovarian failure

BACKGROUND

Premature ovarian failure (POF) is a heterogeneous syndrome, possibly due to mutations of genes involved in the normal development of the ovary and/or follicles. Based essentially on animal models, these mutations are associated with various ovarian phenotypes, from a complete absence of follicles to a partial follicular maturation. The aim of the present study was to determine whether ovarian histology, compared to pelvic ultrasonography, would be helpful in identifying which patients display an impaired follicular reserve and/or growth, and in orientating the search for POF aetiology.

METHODS AND RESULTS

We studied a cohort of 61 patients suffering from POF with a normal karyotype. Their median age (range) at diagnosis was 26 years (15-39). The FSH plasma level was high, 67.0 IU/l (13-155). Estradiol and inhibin B plasma levels were low: 18.5 pmol/l (18.5-555) and 5 pg/ml (5-105) respectively. Both pelvic ultrasonography and ovarian biopsies were performed in each patient. The presence of follicles suggested at ultrasonography was confirmed at histology in 56% of the patients. Ovarian histology led to the distinction of two phenotypes: (i) small-sized ovaries, deprived of follicles; and (ii) normal-sized ovaries with partial follicular maturation. To confirm the value of ovarian biopsies, samples from 20 normal women were studied. These demonstrated that ovarian biopsy at random enables reliable assessment of follicular presence, especially when their size is <2 mm.

CONCLUSION

Ovarian histology appears to be a reliable tool in evaluating the follicular reserve, and helpful and complementary to clinical and hormonal phenotyping in orienting the search for the various genetic causes of POF syndrome.

Recombinant human LH supplementation during GnRH antagonist administration in IVF/ICSI cycles: a prospective randomized study

BACKGROUND

When administered in the late follicular phase to prevent an LH surge, GnRH antagonists induce a sharp decrease in serum LH levels that may be detrimental for assisted reproductive technology cycle outcome. Therefore, a prospective study was designed to assess the effects of recombinant human (r)LH supplementation during GnRH antagonist (cetrorelix) administration.

METHODS

The protocol consisted of cycle programming with oral contraceptive pill, ovarian stimulation with rFSH and flexible administration of a single dose of cetrorelix (3 mg). A total of 218 patients from three IVF centres were randomized (by sealed envelopes or according to woman's birth date) to receive (n = 114) or not (n = 104) a daily injection of rLH 75 IU from GnRH antagonist initiation to hCG injection.

RESULTS

The only significant difference was a higher serum peak E2 level in patients treated with rLH (1476 +/- 787 versus 1012 +/- 659 pg/ml, P < 0.001) whereas the numbers of oocytes and embryos as well as the delivery rate (25.2 versus 24%) and the implantation rate per embryo (19.1 versus 17.4%) were similar in both groups.

CONCLUSIONS

These results show that in an unselected group of patients, there is no evident benefit to supplement GnRH antagonist-treated cycles with rLH.

[Should infertile women with polycystic ovarian syndrome be treated with metformine?]

Polycystic ovary syndrome is a frequent endocrine disorder often associated with insulin resistance and hyperinsulinaemia which may play a role in hyperandrogenism and anovulation. The use of "insulin sensitizing" agents has been suggested to reduce insulin resistance and hyperandrogenism. In that respect, the use of metformin in polycystic ovary syndrome is reviewed. Although its mechanism of action is still unclear, metformin proved to be effective to restore cyclicity and spontaneous ovulation. The synergistic effect of clomiphene citrate and metformin was demonstrated in some studies, suggesting that metformin could be helpful for women with clomiphene citrate resistance. However, the potential effect of metformin administration for reducing hyperstimulation in women treated with exogenous FSH, or for preventing early miscarriages has to be confirmed. Here, we propose a guideline for the use of metformin, as an adjuvant therapy, to restore cyclicity and ovulation in women with polycystic ovary syndrome.

Beneficial effects of GnRH agonist administration prior to ovarian stimulation for patients with a short follicular phase

A short follicular phase is an early clinical feature of declining reproductive competence. The shortening of the follicular phase length is related to both advanced recruitment and selection of the dominant follicle secondary to an earlier and higher FSH rise during the luteal-follicular transition, while the late follicular growth is normal. As a short follicular phase may be detrimental for reproduction, it was postulated that increasing the duration of follicular phase could improve conception rate. For that purpose, gonadotrophin-releasing hormone agonist minidoses were administered in the mid-luteal phase to prevent the intercycle FSH rise before tailoring follicular growth by controlled exogenous FSH administration. This regimen, applied to 69 infertile ovulatory women with a short follicular phase (9.6 +/- 1.2 days) actually lengthened the follicular phase by about 3 days. It proved to be effective in 179 cycles to induce paucifollicular development (1.8 +/- 0.9 follicles) with a low cancellation rate (4%) and a moderate requirement for gonadotrophins [13.3 +/- 6.3 ampoules (75 IU)]. In those women with a high frequency (80%) of elevated basal FSH or oestradiol concentrations, the pregnancy rate reached 15.1%/cycle but the miscarriage rate remained high (44%). Thus, increasing the follicular phase length in patients with a short follicular phase may partially restore fecundity.

An epidemiological study of the respiratory health of workers in the European refractory ceramic fibre industry

OBJECTIVES

To investigate possible relations between respiratory health and past airborne exposure to refractory ceramic fibres (RCFs) and respirable dust in workers at six European factories, studied previously in 1987.

METHODS

The target population comprised all current workers associated with RCF production, plus others who had participated in 1987 "leavers". Information was collected on personal characteristics, chest radiographs, lung function, respiratory symptoms, smoking, and full occupational history. Regression analysis was used to study relations between indices of health of individual workers and of cumulative exposure to airborne dust and fibres, and likely past exposure to asbestos.

RESULTS AND DISCUSSION

774 workers participated (90% of current workers, 37% of leavers). Profusion of small opacities in exposed workers (51% 0/1+; 8% 1/0+) was similar to that among an unexposed control group but higher than in new readings of the 1987 study films (11% 0/1+, 2% 1/0+). The large difference between 1987 and recent films may be, at least in part, a reading artefact associated with film appearance. Small opacities of International Labour Organisation (ILO) category 1/0+ were not associated with exposure. An association of borderline significance overall between 0/1+ opacities and exposure to respirable fibres was found for some exposure periods only, the time related pattern being biologically implausible. Pleural changes were related to age and exposure to asbestos, and findings were consistent with an effect of time since first exposure to RCFs. Among men, forced expired volume in 1 second (FEV(1)) and forced vital capacity (FVC) were inversely related to exposure to fibres, in current smokers only. FEV(1)/ FVC ratio and transfer factor (TL(CO)) were not related to exposures. The estimated restrictive effect was on average mild. Prevalence of respiratory symptoms was low. Chronic bronchitis and its associated symptoms (cough, phlegm) showed some association with recent exposure to respirable fibres. This could be due to an irritant effect of RCFs.

Overexpression of copper zinc superoxide dismutase impairs human trophoblast cell fusion and differentiation

The syncytiotrophoblast is the major component of the human placenta, involved in feto-maternal exchanges and secretion of pregnancy-specific hormones. Multinucleated syncytiotrophoblast arises from fusion of mononuclear cytotrophoblast cells. In trisomy 21-affected placentas, we recently have shown that there is a defect in syncytiotrophoblast formation and a decrease in the production of pregnancy-specific hormones. Due to the role of oxygen free radicals in trophoblast cell differentiation, we investigated the role of the key antioxidant enzyme, copper/zinc superoxide dismutase, encoded by chromosome 21 in in vitro trophoblast differentiation. We first observed that overexpression of superoxide dismutase in normal cytotrophoblasts impaired syncytiotrophoblast formation. This was associated with a significant decrease in mRNA transcript levels and secretion of hCG and other hormonal markers of syncytiotrophoblast. We confirmed abnormal cell fusion by overexpression of green fluorescence protein-tagged superoxide dismutase in cytotrophoblasts. In addition, a significant decrease in syncytin transcript levels was observed in superoxide dismutase-transfected cells. We then examined superoxide dismutase expression and activity in isolated trophoblast cells from trisomy 21-affected placentas. Superoxide dismutase mRNA expression (P < 0.05), protein levels (P < 0.01), and activity (P < 0.05) were significantly higher in trophoblast cells isolated from trisomy 21-affected placentas than in those from normal placentas. These results suggest that superoxide dismutase overexpression may directly impair trophoblast cell differentiation and fusion, and superoxide dismutase overexpression in Down's syndrome may be responsible at least in part for the failure of syncytiotrophoblast formation observed in trisomy 21-affected placentas.

Vibrotactile perception thresholds in four non-exposed populations of working age

The purpose of this study was to establish a basis for the use of a device for measuring vibrotactile perception thresholds for epidemiological purposes on a series of non-exposed populations. Vibrotactile perception thresholds (VPTs) were measured with a vibrometer in 218 men and 160 women belonging to two non-exposed male blue collar populations, one white-collar population and one age and gender stratified sample of the general population. VPTs were measured on the middle and the little finger of the dominant hand at 31.5 and 125 Hz. The VPTs were expressed in dB and the effect of a series of factors including the population, age, gender and digital temperature was assessed in a regression analysis weighted by the inverse variance of the measurements. Adjusted for age, no significant difference between the VPTs in the four male populations was observed. At frequency 125 Hz, the effect of age (0.3 dB per year) was more important than at frequency 31.5 Hz (0.2 dB per year). In the two female populations, the results were less stable than among males and the VPTs were higher than among males. However, the age-dependence was similar among males and females. The within-test variance is a valuable indicator of the quality of the VPT measurements. Weighting by its inverse improved the fit of the regression models. Normal values for VPTs in non-exposed populations were obtained, which were reproducible in four separate populations.

Defect of syncytiotrophoblast formation and human chorionic gonadotropin expression in Down's syndrome

The syncytiotrophoblast (ST) is a major component of the human placenta as it is involved in feto-maternal exchanges and the secretion of pregnancy-specific hormones. We have studied the formation and function of the ST in normal and trisomy 21 (T21)-affected placenta using the in vitro model of cytotrophoblast differentiation into ST. Cytotrophoblast cells were isolated from first trimester, second trimester and term placentae. In vitro cytotrophoblast cells isolated from normal placenta fused to form the ST. This was associated with an increase in the transcript levels and the secretion of human chorionic gonadotropin (hCG). However, the secretion of hCG decreased through pregnancy. In T21-affected placentae, we observed a defect (or a delay) in ST formation and a dramatic decrease in the synthesis and secretion of this hormone compared with cultured cells isolated from control age-matched placentae. These results were confirmed by a significant (P < 0.05) decrease in transcript levels of alpha and beta subunits of hCG in total homogenates of T21-affected placentae compared with controls. These results suggest a decrease in functional mass of ST in T21 placenta, and therefore a decrease in production of placental pregnancy-specific polypeptide hormones.

Symptoms, airway responsiveness, and exposure to dust in beech and oak wood workers

OBJECTIVES

To investigate the relation between levels of cumulative exposure to wood dust and respiratory symptoms and the occurrence of bronchial hyperresponsiveness among beech and oak workers.

METHODS

114 Male woodworkers from five furniture factories and 13 male unexposed controls were examined. The unexposed control group was supplemented by 200 male historical controls. Statistical analyses were performed excluding and including the historical controls. Dust concentration was measured by personal sampling methods. Cumulative exposure to dust was calculated for each woodworker by multiplying the duration of the work by the intensity of exposure (years. mg/m(3)). Bronchial hyperresponsiveness was assessed by the methacholine bronchial challenge test. Subjects were labelled methacholine bronchial challenge positive if forced expiratory volume in 1 second (FEV(1)) fell by >/=20%. The linear dose-response slope was calculated as the last dose divided by the total dose given.

RESULTS

443 Dust samples were collected. The median cumulative exposure to dust was 110 years.mg/m(3) with lower and upper quartiles at 70 and 160 years.mg/m(3) Overall, no declines in FEV(1) and forced vital capacity (FVC) were found with increasing exposures. A dose-response relation was found between intensity of exposure on the one hand, and sore throat, increased prevalence of positive methacholine bronchial challenge tests, and steeper dose-response slope, on the other.

CONCLUSION

Exposure to oak and beech dust may lead to the development of sore throat and bronchial hyperresponsiveness.

On planning the number of controls in cross-sectional studies using previous studies: an application in occupational epidemiology

BACKGROUND

In occupational epidemiology, it is common to use cross-sectional studies comparing exposed with matched non-exposed populations. When several such past studies are available within a relatively short time frame, it may be possible to use their control groups to reduce the number of controls in a new study and thus reduce its cost.

METHODS

We compare existing non-exposed populations within a standard random-effects model, to explore the natural between population variability and to compute the power increase when including these populations. An example is given from respiratory epidemiology, with the forced expiratory volume in 1 s as the outcome, using 13 previously-collected control populations obtained in recent studies.

RESULTS

We show that the reduction in the number of controls needed for a new study is equal to the ratio of the between subjects and the between group variance, observed in controls in previous studies. In the present example, the reduction in the number of controls needed for a new study was found to be 18. An optimal allocation of resources is obtained in this framework.

CONCLUSIONS

The use of past available control groups provides a significant reduction in cost only if they are very homogeneous, compared to the between-subject variance.

Pleural mesothelioma: dose-response relation at low levels of asbestos exposure in a French population-based case-control study

A hospital-based case-control study of the association between past occupational exposure to asbestos and pleural mesothelioma was carried out in five regions of France. Between 1987 and 1993, 405 cases and 387 controls were interviewed. The job histories of these subjects were evaluated by a group of experts for exposure to asbestos fibers according to probability, intensity, and frequency. A cumulative exposure index was calculated as the product of these three parameters and the duration of the exposed job, summed over the entire working life. Among men, the odds ratio increased with the probability of exposure and was 1.2 (95% confidence interval (CI) 0.8-1.9) for possible exposure and 3.6 (95% CI 2.4-5.3) for definite exposure. A dose-response relation was observed with the cumulative exposure index: The odds ratio increased from 1.2 (95% CI 0.8-1.8) for the lowest exposure category to 8.7 (95% CI 4.1-18.5) for the highest. Among women, the odds ratio for possible or definite exposure was 18.8 (95% CI 4.1-86.2). We found a clear dose-response relation between cumulative asbestos exposure and pleural mesothelioma in a population-based case-control study with retrospective assessment of exposure. A significant excess of mesothelioma was observed for levels of cumulative exposure that were probably far below the limits adopted in most industrial countries during the 1980s.

Sick-building symptoms in office workers in northeastern France: a pilot study

STUDY OBJECTIVES

To verify that sick building symptoms are present in north-eastern France office workers; to try to identify new confounding factors.

METHODS

The design was that of a cross-sectional study with control group. We studied with the same methods the personnel of an air-conditioned building (n=425), and of a naturally ventilated building (n=351). Air temperature and humidity, bacterial and fungal densities were measured by the same technical staff in the two buildings. A standard questionnaire on irritative and respiratory symptoms, personal and family history, and lifestyle was completed by the participants.

RESULTS

In univariate analysis, exposure to air-conditioning was associated with an increased prevalence of symptoms (odds ratios-OR-between 1.54 and 2.84). A significant increase in sickness absence was also found among subjects working in air-conditioned offices. As a series of factors were suspected to interfere with these associations, logistic regression was applied. This method confirmed exposure to be an independent determinant of 7 symptoms, and also identified two determinants not previously described: a family history of respiratory diseases and "do-it-yourself' activities.

IN CONCLUSION

we found the sick building symptoms to be present in a group of French office workers exposed to air-conditioning. We confirmed the influence of a number of confounding factors and described two further confounders - do-it-yourself activities at home and a history of familial respiratory disease.

Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools

OBJECTIVES

To measure the levels of exposure to nitrogen trichloride (NCl3) in the atmosphere of indoor swimming pools and to examine how they relate to irritant and chronic respiratory symptoms, indices of pulmonary function, and bronchial hyperresponsiveness to methacholine in lifeguards working in the pools.

METHOD

334 lifeguards (256 men; 78 women) recruited from 46 public swimming pools (n = 228) and 17 leisure centre swimming pools (n = 106) were examined. Concentrations of NCl3 were measured with area samplers. Symptoms were assessed by questionnaire and methacholine bronchial challenge (MBC) test by an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given.

RESULTS

1262 samples were taken in the 63 pools. Mean NCl3 concentrations were greater in leisure than in public pools. A significant concentration-response relation was found between irritant eye, nasal, and throat symptoms-but not chronic respiratory symptoms-and exposure concentrations. Among women, the prevalence of MBC+ was twice as great as in men. Overall, no relation was found between bronchial hyperresponsiveness and exposure.

CONCLUSIONS

The data show that lifeguards exposed to NCl3 in indoor swimming pools are at risk of developing irritant eye, nasal, and throat symptoms. Exposure to NCl3 does not seem to carry the risk of developing permanent bronchial hyperresponsiveness, but this association might have been influenced by self selection. The possibility that subjects exposed to NCl3 are at risk of developing transient bronchial hyperresponsiveness cannot be confidently ruled out.

[Normal coronary angiography. Have the indications changed during the 1980's?]

If the indications of coronary angiography are well chosen, the percentage of normal coronary angiographies should decrease. The authors analysed 7858 primary coronary angiographies performed between 1981 and 1990 in patients without valvular or congenital heart disease. The second 5 years were compared to the first. The percentage of primary coronary angiographies decreased (63% vs 75%; p < 0.01), the percentage of women increased (21.7% vs 18.4%; p < 0.001), and the mean age increased (58.5 +/- 0.3 vs 53.9 +/- 0.3; p < 10(-9)). The lesions were less extensive: 16.3% triple vessel disease versus 24.2% (p < 0.001); 31.3% double vessel disease versus 28.1% (p < 0.02); 49.1% single vessel disease versus 44.2% (p < 0.001). The percentage of normal coronary angiographies remained constant: 20.2% in the second five years versus 19.9% in the first. Over the 10 year period, there was no significant difference one year from another. The percentage of normal investigations remained the same in men (15.7%), decreased in women (34.7 vs 40.1%, p < 0.04), remained constant in patients under 60 years of age (24.5 vs 23.8%), but increased in the more elderly (14.9 vs 10.2%; p < 0.001). The percentage remained unchanged in stable angina (19.6 vs 19.8%) and in unstable angina (12.3 vs 11.2%): it increased in cases of atypical chest pain (72.2 vs 54.3%; p < 0.01). Although, globally, the number of normal coronary angiographies was unchanged at 20%, the indications of this investigation were more selective in the younger patients, especially women, in the second five years, but coronary angiography was more commonly performed in elderly patients because of the possibility of benefiting from coronary angioplasty.

Airway responsiveness, respiratory symptoms, and exposures to soluble oil mist in mechanical workers

OBJECTIVES

To assess the relation between measured levels of exposure to soluble oil mists in a plant manufacturing ball bearings, and both respiratory symptoms and airway responsiveness in the workforce.

METHODS

114 male workers exposed to oil mist and 55 unexposed male controls from nearby factories were studied. Soluble oil mist concentrations were measured with area samplers. Respiratory symptoms were assessed by questionnaire and measurement of airway responsiveness to methacholine with an abbreviated method. Subjects were labelled positive to methacholine airway challenge (MAC+) if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given.

RESULTS

Geometric mean concentrations of oil mists ranged from 0.65 mg/m3 (GSD 1.29) to 2.20 mg/m3 (GSD 1.55) based on 92 measurements obtained from 1979-93. The prevalence of chronic cough or phlegm, bouts of bronchitis, and dyspnoea was greater among exposed workers than among controls (odds ratio (OR) 4.64, P = 0.002 for chronic cough and phlegm). After adjustment for smoking and age, dyspnoea was significantly related to an index of cumulative exposure to oil mist (OR 1.44, P = 0.006/10 y.mg/m3). The proportion of MAC+ subjects was similar in the two groups. However, after adjustment for baseline FEV1 and age, the dose-response slope was significantly steeper among exposed workers than among controls (P = 0.01), a finding indicating airway hyperresponsiveness in the exposed workers. Furthermore, the dose-response slope was significantly related to baseline FEV1, age, and, after adjustment for FEV1, the index of cumulative exposure to oil (P = 0.004).

CONCLUSION

Subjects with exposure to soluble oil mist in the metal industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.

Airflow obstruction in chalkpowder and sugar workers

Our aim was to investigate the relationship between suspected occupational hazards and airflow obstruction in industrial workers. The study was a cross-sectional survey of 314 male workers from a chalkpowder plant (n = 158) and from a sugar refinery (n = 156). Occupational exposure to chalkpowder and sugar dust was assessed by individual job classification. Outcome variables included respiratory symptoms and routine spirometric parameters. Statistical analysis was done for each industry separately. Overall, mean pulmonary function parameters fell either within or above the normal range in both industries. However, analysis by job classification showed that in the chalkpowder plant, all indices of airway obstruction declined significantly with increasing dustiness. Additionally, workers in the dustiest workplace (chalk sacking) had significantly lower airflow parameters than workers from other workstations. In the sugar refinery, workers exposed to sugar dust in the sugar cube manufacture workstation had significantly lower forced expiratory volume in 1 s (FEV1) (p = 0.02) than the non-exposed ones. For both industries, the proportion of subjects complaining of cough and/or phlegm was greater among the most exposed subgroups than among the remaining workers but the differences were not statistically significant. In conclusion, coupling spirometry to job classification proved useful in disclosing a relationship between airflow obstruction and exposure to either chalkpowder or sugar dust in industrial workers.

Altered partition of T cell subsets in the peripheral blood of healthy workers exposed to flour dust

Occupational exposure to organic compounds can induce obvious immunological disorders or more subtle modifications. We investigated peripheral blood lymphocyte subsets in 34 bakers and 82 millers exposed to wheat flour dust, and 51 salt factory workers. Significantly decreased levels of CD4+, CD8+, CD57+ and CD8+/57+ cells were noted in mill workers, and of CD57+ cells in bakers. CD29+ and CD4+/CD29+ cells were significantly lower in millers, CD4+/CD45RA+ cells higher in all exposed workers. The lower numbers of positive cells noted in millers appeared associated to significantly higher (p < 0.001) levels of CD29 and CD45RA expression as measured by fluorescence intensity. These data are opposite to those previously reported in asthmatic workers exposed to flour dust. Since the individuals tested here were clinically healthy, the alterations of T-cell subsets observed could be interpreted as a successful attempt at immunoregulation maintaining homeostasis.

Airway responsiveness to methacholine, respiratory symptoms, and dust exposure levels in grain and flour mill workers in eastern France

Our goal was to assess the relation between dust exposure levels and the respiratory health status of workers in grain and flour mills in eastern France. We studied 118 male workers from 11 mills and 164 unexposed male controls. Dust concentration was measured by personal sampling methods. Outcome variables included respiratory symptoms, routine pulmonary function tests, and indices of airway responsiveness to methacholine. A great within- and between-area variability of inhalable dust concentration was found in all mills. A dose-response relationship was observed between dust exposure levels and chronic respiratory symptoms, suggesting that exposure to grain and flour dust may lead to chronic bronchitis. A significant relation was found between dust exposure and airway hyper-responsiveness; this finding is important since it has been hypothesized that the latter abnormality may lead to or be a predisposing factor in subsequent chronic, irreversible airflow obstruction.

Humoral immune responses of workers occupationally exposed to wheat flour

Wheat flour is a complex organic dust likely to induce immune responses when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA to both antigens were significantly higher (p < 0.0001) in occupationally exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of salivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data suggest that occupational exposure to wheat flour triggers specific immune responses, most likely through stimulation of the mucosal immune system. The presence of significant levels of serum antibodies, however, indicates that a systemic immunologic response is also present among exposed individuals.

Tracheal wheezes during methacholine airway challenge (MAC) in workers exposed to occupational hazards

Methacholine airway challenge (MAC) is a simple and useful means to assess bronchial hyperreactivity in workers exposed to various occupational hazards. Recently, wheeze detection by tracheal auscultation has been proposed as an indicator of bronchial responsiveness during bronchial provocation test in children. Our aim was to examine the relationship between the appearance of wheezes and the concurrent changes in forced expiratory volume in one second (FEV1) observed during MAC test in adults. Three cumulative doses of a methacholine solution (100 micrograms, 500 micrograms and 1500 micrograms) were inhaled by 45 workers with occupational exposure to flour dust. Spirometry was done using an electronic spirometer. Tracheal sounds were recorded with an electronic stethoscope placed over the anterior cervical triangle, 2 cm above the sternal notch. The amplified sounds were stored on magnetic tape, band-pass filtered (50-2000 Hz), and digitized at a sampling rate of 4096 Hz into a GenRad Vibration Control System. Wheezes were detected by fast Fourier transform (FFT) analysis and their presence compared to a 20% fall in FEV1. A positive MAC test by spirometry was found in 12 subjects whereas wheezes were identified in 14 subjects. Among the wheezing subjects, nine had a positive MAC test (range of fall in FEV1 = 20.6 to 42.3%) and five had a negative one (range of fall in FEV1 = 3.6 to 16.9%). Moreover, no wheezes were found in the remaining three subjects with a positive MAC test (range of fall in FEV1 = 20.7 to 27.4%). Taking a 20% fall in FEV1 as reference, wheezes were 75% sensitive and 84.8% specific to detect airflow obstruction. In conclusion, since it carries a significant although small false-negative rate, the acoustic technique based upon wheeze detection cannot, at the present time, fully replace spirometry during airway challenge testing in subjects with suspected asthma.

Respiratory symptoms and airway responsiveness in apparently healthy workers exposed to flour dust

Our aim was to measure the levels of exposure to wheat flour dust in a modern industrial bakery, and to assess the relationship between respiratory symptoms, sensitization to wheat flour antigens and airway responsiveness in the workforce. Forty four flour-exposed male workers and 164 unexposed controls were examined. Inspirable dust concentrations were measured using personal samplers. Respiratory symptoms were assessed by questionnaire, sensitization to wheat flour antigens by skin-prick tests, and methacholine airway challenge (MAC) test using an abbreviated method. Subjects were labelled MAC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered. Inspirable dust concentrations were within acceptable limits in all working areas but one. The proportion of subjects with one or more symptoms and with airway hyperresponsiveness was significantly greater among flour-exposed workers than among controls. Using logistic or linear regression analysis, airway responsiveness was found to be strongly related to working at the bakery and to the baseline level of lung function. A positive skin-prick test was found in only 11% of flour-exposed workers and 6% of controls. In conclusion, our data show that despite exposure to relatively low concentration levels of inspirable flour dust, subjects working in the baking industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.

Respiratory symptoms and airway responsiveness in apparently healthy workers exposed to flour dust

Our aim was to measure the levels of exposure to wheat flour dust in a modern industrial bakery, and to assess the relationship between respiratory symptoms, sensitization to wheat flour antigens and airway responsiveness in the workforce. Forty four flour-exposed male workers and 164 unexposed controls were examined. Inspirable dust concentrations were measured using personal samplers. Respiratory symptoms were assessed by questionnaire, sensitization to wheat flour antigens by skin-prick tests, and methacholine airway challenge (MAC) test using an abbreviated method. Subjects were labelled MAC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered. Inspirable dust concentrations were within acceptable limits in all working areas but one. The proportion of subjects with one or more symptoms and with airway hyperresponsiveness was significantly greater among flour-exposed workers than among controls. Using logistic or linear regression analysis, airway responsiveness was found to be strongly related to working at the bakery and to the baseline level of lung function. A positive skin-prick test was found in only 11% of flour-exposed workers and 6% of controls. In conclusion, our data show that despite exposure to relatively low concentration levels of inspirable flour dust, subjects working in the baking industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.