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REPRODUCTIONRESEARCH Semen quality trends in French regions are consistent with a global change in environmental exposure Joe¨lle Le Moal, Matthieu Rolland, Sarah Goria, Ve´re`ne Wagner, Perrine De Crouy-Chanel, Annabel Rigou, Jacques De Mouzon1,2 and Dominique Roye`re1 Environmental Health Department, Institut de Veille Sanitaire, 12 Rue du Val d’Osne, 94415 Saint Maurice, France, 1Fivnat, Reproductive Biology Unit, CHU Bretonnneau, 37000 Tours, France and 2Inserm, Reproductive Medicine Unit, Paris-Descartes University, CHU Cochin-Port Royal, 7414 Paris, France Correspondence should be addressed to J Le Moal; Email: [email protected] Abstract A retrospective study carried out recently in a large sample of men, close to the general population, has reported a significant and strong decline in sperm concentration and morphology in the whole of France between 1989 and 2005. We studied these trends within each region of France. Data were obtained from the Fivnat database. The study sample comprised male partners of sterile women in whom both tubes were absent or blocked. They were located at the assisted reproductive technology center. A Bayesian spatio-temporal model with parametric time trends, adjusted for age, was used to model overall time trends for each region. The results show that sperm concentration decreased in almost all regions of France. Among them, Aquitaine showed the highest decrease and Midi-Pyre´ne´es had the lowest average for the whole period. Regarding total motility, most regions showed a slight increase while Bourgogne showed a steep and significant decrease. While considering sperm morphology, there was a decrease in most of the regions. The decrease in Aquitaine and Midi-Pyre´ne´es was stronger when compared with the overall trend. In conclusion, a decrease in sperm concentration and morphology, already shown at the French metropolitan territory level, was observed in most regions of France. This is consistent with a global change in environmental exposure, according to the endocrine disruptor hypothesis especially. Indeed, ubiquitary exposure to chemicals has been growing in the general population of France since the 1950s, and the results do not appear to support the lifestyle hypothesis. The highest decreases and lowest values are consistently observed in two proximate regions that are both highly agricultural and densely populated. Reproduction (2014) 147 567–574 Introduction 26 609 men from the whole metropolitan country between 1989 and 2005. No decrease in motility was Temporal trends in human semen quality have been observed (Rolland et al. 2013). This sample of men discussed for a long time, partly due to spatial close to the general population is, to date, the largest heterogeneity (Jorgensen et al. 2001) and methodo- sample that has ever been used to study semen quality logical issues (Fisch 2008). trends. Recently in France, an overall decrease in sperm These results were consistent with the past studies in concentration and morphology has been observed in France (Auger et al. 1995) and in other countries (Carlsen et al. 1992, Swan et al. 1997) where decreasing temporal This paper forms part of a special issue of Reproduction on Endocrine trends have been observed. These robust results Disrupters. This article was presented at the 7th Copenhagen Workshop regarding temporal trends constitute a serious public on Endocrine Disrupters, 28–31 May 2013. The meeting was supported health warning. The endocrine disruptor hypothesis, by the Danish Ministry of the Environment – Environmental Protection strengthened by accumulating evidence lately (Bergman Agency as an activity under the Danish Centre on Endocrine Disrupters. Publication of this special issue has been supported by the Society for et al. 2012), may partly explain such trends. Changes in Reproduction and Fertility. The opinions or views expressed in this lifestyle are other identified factors (Sharpe 2010). special issue are those of the authors, and do not necessarily reflect In the previous study, the trends were calculated at the the opinions or recommendations of the Danish Ministry of the level of the whole country, and did not take into account Environment – Environmental Protection Agency or the Society for a possible spatial heterogeneity. Spatial heterogeneity Reproduction and Fertility. The Guest Editors for this special issue were Anna-Maria Andersson, Hanne Frederiksen, Niels Erik Skakkebæk, has previously been observed in France in limited Rigshospitalet, Denmark, Kenneth M Grigor, Western General Hospital, samples (Auger & Jouannet 1997), as well as in Europe Edinburgh, UK and Jorma Toppari, University of Turku, Finland. (Jorgensen et al. 2001) or in USA (Swan et al. 2003), but q 2014 Society for Reproduction and Fertility DOI: 10.1530/REP-13-0499 ISSN 1470–1626 (paper) 1741–7899 (online) Online version via www.reproduction-online.org Downloaded from Bioscientifica.com at 10/02/2021 02:24:39PM via free access 568 J Le Moal and others little is known about the causal factors. The present study spermiogram was studied. The methods used for the measure- aims to analyze spatial patterns in France between 1989 ment of each sperm indicator were not available in the Fivnat and 2005, using the same sample in which the global database. For sperm concentration and motility, French experts trends were calculated, in order to generate possible confirmed that the methods have not changed noticeably consistent hypotheses. during the study period (Rolland et al. 2013). Regarding morphology classification, a majority of the laboratories used David’s classification during the study period (Blanchard et al. 2011). Materials and methods Source and study population Men’s location Data were obtained from the Fivnat database, a national The Fivnat database did not register the couples’ addresses, registry that recorded most of the French-assisted reproductive so the men were located using the address of the ART center technology (ART) attempts during the study period. The study where the attempt was performed. For this reason, the French sample comprised partners of totally infertile women whose metropolitan regions were chosen as the geographical scale for both tubes were either blocked or absent. They had to be the spatio-temporal analyses. We assumed that couples were involved in the first attempt of a standard IVF or ICSI program more likely to attempt ARTs within the regions where they lived. carried out in metropolitan France and registered between 1st In order to check this assumption, we looked at the national January 1989 and 31st December 2005 (Rolland et al. 2013). hospital database in which oocyte retrievals were recorded They also had to provide freshly ejaculated sperm. since 2010. This enabled us to compare the women’s dwelling In theory, couples all over France had equal access to ARTs, locations and the locations of the fertility clinics they attended. as the first four attempts were fully covered by the Health Insurance, and Fivnat centers were set up all over the country (Fig. 1). The attempts were covered identically in public or Statistical analysis private ART centers. We studied the indicators of semen quality that were defined in the national study: concentration, motility, and morphology Measurement methods (Rolland et al. 2013). A Box–Cox transform (Box & Cox 1964) was applied to sperm concentration for the residuals of the Three indicators of semen quality were registered in the Fivnat model to be normally distributed. Data for the three indicators database: sperm concentration (in millions of sperm per of semen quality were aggregated by region and by month. milliliter), total motility (in percentage of motile sperm) and A Gaussian observation model for each semen quality indicator morphology (in percentage of sperm with normal forms). Two was defined. spermiograms per individual were available: the check-up We used the spatio-temporal model introduced by Bernardi- spermiogram, carried out mostly in a town laboratory prior nelli et al.(Bernardinelli et al. 1995, Schro¨dle & Held 2011). To to the attempt, and the attempt spermiogram, carried out in the model data in space and time, a Bayesian model with ART center the day of the attempt. The date for the check-up parametric time trends was proposed. The linear predictor is spermiogram was not available, so only the attempt decomposed additively into components depending on space, time or both. A main linear time trend and a differential time Fivnat centers location trend for each region are added to the spatial component. The age effect was taken into account. The main objective of this Nord-Pas- spatio-temporal model is to show how the slopes are positioned de-Calais in between the regions. Additional details on the model are Haute- Normandie Picardie provided in Supplementary Methods, see section on supple- Basse- mentary data given at the end of this article. The inla program Normandie Lorraine Alsace lle-de- Champagne- and the R package INLA were used (Martino & Rue 2010). Bretagne France Ardenne The slopes and credible intervals for the 21 French Centre Bourgogne metropolitan regions were compared with a null trend and Pays de Franche- la Loire Comté the estimated overall linear trend. In a Bayesian analysis, a 95% Poitou- Limousin credible interval means that the probability of the parameter Charentes Rhône- Alpes to belong to it is 0.95. The slopes were mapped in order to Fivnat centers Auvergne Regional boundaries visualize possible spatial trends. Maps were drawn using Aquitaine Provence- ESRI Basic ArcGIS for Desktop 10.0. Finally, for each indicator, Midi-Pyrénées Alpes-Côte d'Azur the estimated linear trends for the 21 regions were shown to Languedoc- analyze together the slopes and the variations of the values. Roussillon Corse N INSTITUT Km DE VEILLE SANITAIRE Source: IGN-GéoFLA, 2008; FIVNAT, 1989–2005; InVS, 2013. 0 80 160 320 Results Figure 1 Location of Fivnat centers in metropolitan France that provided The number of men included in the study was generally data between 1989 and 2005.