Effects of cigarette smoking and age on the maturation of human oocytes

Consumption of hookahs, e-cigarettes, and classic cigarettes and the impact on medically assisted reproduction treatment

Smoking of classic cigarettes has been well-established as a health risk factor, including cardiovascular, neurological, and pulmonary diseases. Adverse effects on human reproduction have also been shown. Smokers are assumed to have a significantly lower chance of pregnancy, however, the impact of smoking on medically assisted reproduction (MAR) treatment outcomes is controversial. Moreover, smoking habits have changed during the last decades since e-cigarettes and hookahs, or water pipes, have become very popular, yet little is known regarding vaping or hookah-smoking patients undergoing MAR treatments. This prospective study aimed to examine the presence of benzo[a]pyrene, nicotine, and its main metabolite, cotinine, in human follicular fluid (FF) in non-smoking, smoking, and vaping/hookah-smoking patients and to evaluate the impact on female fertility. Human FF samples were collected from 320 women subjected to intracytoplasmic sperm injection (ICSI) cycles due to male subfertility. Gas chromatography combined with mass spectrometry was used to analyse the presence of benzo[a]pyrene, nicotine, and cotinine. A questionnaire was provided to assess patient consumption behaviour and to identify (1) non-smoking patients, (2) patients who consumed cigarettes, and (3) patients with exclusive consumption of e-cigarettes or hookahs. Data were analysed using linear and logistic regression, Fisher's exact test, and the Mann-Whitney U Test. Nicotine was present in 22 (6.8%) and cotinine in 65 (20.3%) of the 320 samples. The nicotine and cotinine concentrations per sample ranged from 0 to 26.3 ng/ml and 0-363.0 ng/ml, respectively. Benzo[a]pyrene was not detectable in any of the samples analysed. Nicotine and cotinine were also present in the FF of patients with exclusive consumption of e-cigarettes or hookahs. The clinical pregnancy rate, fertilization and maturation rates, and number of oocytes per oocyte pick-up were not statistically significantly different between non-smoking, smoking, or vaping/hookah-smoking patients. Smoking and the accumulation of smoking toxins in the FF have no impact on the outcome of MAR treatments-neither the clinical pregnancy rate, maturation and fertilization rates, nor the number of retrieved oocytes were affected. For the first time, nicotine and cotinine were quantified in the FF of patients exclusively vaping e-cigarettes or smoking hookahs. Since vaping liquids and hookah tobaccos contain potentially harmful substances, other adverse effects cannot be excluded.Trial registration ClinicalTrials.gov Identifier: NCT03414567.

Tobacco or marijuana use and infertility: a committee opinion

In the United States, approximately 21% of adults report some form of tobacco use, although 18% report marijuana use. Although the negative impact of tobacco use in pregnancy is well documented, the impact of tobacco and marijuana on fertility and reproduction is less clear. This committee opinion reviews the potential deleterious effects of tobacco, nicotine, and marijuana use on conception, ovarian follicular dynamics, sperm parameters, gamete mutations, early pregnancy, and assisted reproductive technology outcomes. It also reviews the current status of tobacco smoking cessation strategies. This document replaces the 2018 American Society for Reproductive Medicine Practice Committee document entitled Smoking and Infertility: a committee opinion (Fertil Steril 2018).

Preconception Evaluation Before In Vitro Fertilization

Importance

Infertility poses a substantial public health problem for women of reproductive age, in the United States and globally. Infertility can be overcome with a variety of emerging assisted reproductive technologies (ARTs). In vitro fertilization (IVF) currently represents the most commonly utilized method of ART and is typically associated with the highest clinical pregnancy rate and live birth rate compared with other infertility treatment options. However, proper preconception evaluation and counseling is paramount for optimizing IVF and pregnancy outcomes.

Objective

This article aims to outline current guidelines and recommendations for comprehensive preconception evaluation before initiation of IVF.

Evidence Acquisition

Articles were obtained from PubMed, ACOG committee opinions 781 and 762, and relevant textbook chapters.

Results

A variety of recommendations and best practices exist for optimally managing patients seeking IVF. Special attention must be paid to the workup of certain patient populations, such as those with age older than 35 years, uterine abnormalities, comorbidities (especially hypertension, diabetes, and thrombophilias), and obesity. In addition, many lifestyle factors must be addressed before IVF initiation, such as smoking, illicit drug use, and inadequate nutrition. Preconception counseling and expectation management is key to optimizing pregnancy outcome.

Conclusion and Relevance

A myriad of patient and environmental factors impact the potential success rates of IVF in treating infertility. Providers must be equipped to provide data-driven, patient-centered counseling before initiation of IVF.

Electronic Cigarettes and Fecundability: Results From a Prospective Preconception Cohort Study

Although electronic cigarette (e-cigarette) aerosol contains similar toxicants to combustible cigarettes, few studies have examined their influence on fecundability. We assessed the association between e-cigarette use and fecundability, overall and according to combustible cigarette smoking history, in a cohort of 4,586 North American women (aged 21-45 years) enrolled during 2017-2020 in Pregnancy Study Online, a Web-based prospective preconception study. Women reported current and former e-cigarette use on baseline and follow-up questionnaires, and they completed bimonthly follow-up questionnaires until self-reported pregnancy or censoring. Fecundability ratios and 95% confidence intervals were calculated using proportional probabilities models, controlling for potential confounders. Overall, 17% of women had ever used e-cigarettes and 4% were current users. Compared with never use of e-cigarettes, current e-cigarette use was associated with slightly lower fecundability (fecundability ratio = 0.84, 95% confidence interval (CI): 0.67, 1.06). Compared with current nonusers of e-cigarettes and combustible cigarettes, fecundability ratios were 0.83 (95% CI: 0.54, 1.29) for current dual users of e-cigarettes and combustible cigarettes, 0.91 (95% CI: 0.70, 1.18) for current e-cigarette users who were nonsmokers of combustible cigarettes, and 1.01 (95% CI: 0.85, 1.20) for nonusers of e-cigarettes who were current smokers of combustible cigarettes. Current e-cigarette use was associated with slightly reduced fecundability, but estimates of its independent and joint associations with combustible cigarette smoking were inconsistent and imprecise.

Perturbation of Nuclear Hormone Receptors by Endocrine Disrupting Chemicals: Mechanisms and Pathological Consequences of Exposure

Much of the early work on Nuclear Hormone Receptors (NHRs) focused on their essential roles as mediators of sex steroid hormone signaling in reproductive development and function, and thyroid hormone-dependent formation of the central nervous system. However, as NHRs display tissue-specific distributions and activities, it is not surprising that they are involved and vital in numerous aspects of human development and essential for homeostasis of all organ systems. Much attention has recently been focused on the role of NHRs in energy balance, metabolism, and lipid homeostasis. Dysregulation of NHR function has been implicated in numerous pathologies including cancers, metabolic obesity and syndrome, Type II diabetes mellitus, cardiovascular disease, hyperlipidemia, male and female infertility and other reproductive disorders. This review will discuss the dysregulation of NHR function by environmental endocrine disrupting chemicals (EDCs), and the associated pathological consequences of exposure in numerous tissues and organ systems, as revealed by experimental, clinical, and epidemiological studies.

Evaluation of the association between exosomal levels and female reproductive system and fertility outcome during aging: a systematic review protocol

BACKGROUND

Exosomes may have critical roles in the maternal-embryo cross-talk for the recognition and maintenance of pregnancy during maternal aging. Exosomes have the capability to carry developmental signaling molecules with the ability to modulate gene expressions and affect growth and regulation of embryo during pregnancy. Systematic review aims to evaluate age-related alterations in the exosomal content and functions that can influence the reproductive performance in human and animal models as conveyors of senescence signals.

METHODS

A literature search of electronic databases including MEDLINE (PubMed), Embase, ProQuest, Scopus, Google Scholar, WHO, SID, MAGIRAN, and Barakat will be conducted. Following the online search, articles will be screened by two independent reviewers according to inclusion and exclusion criteria. Eligible studies will be critically appraised by reviewers at the study level for methodological quality using Joanna Briggs Institute's standardized critical appraisal tools. The extracted data from selected studies will cover the study populations, methods, current evidence about the physiological role of extracellular vesicles and exosomes in reproductive system, relevant outcomes, and possible conclusions about the effectiveness of exposure.

DISCUSSION

Regarding the role of exosomes and their cargoes in the function of reproductive tract, the possible beneficial or adverse effects following exosomal administration from younger women to older women will be evaluated in the systematic review. As a result, exosome therapy could be suggested as a novel therapeutic agent if the favorable results are identified.

Supplementation of maturation medium with CoQ10 enhances developmental competence of ovine oocytes through improvement of mitochondrial function

In vitro maturation (IVM) can impair the balance between antioxidant capacity and oxidative stress, and jeopardize embryo development by increasing oxidative stress, reducing energy metabolism, and causing improper meiotic segregation. Balancing the energy production and reduction of oxidative stress can be achieved by supplementation with coenzyme Q10 (CoQ10), an electron transporter in the mitochondrial inner membrane. To improve the in vitro production of ovine embryos, we studied the effect of CoQ10 supplementation during the maturation of sheep oocytes. A minimum of 100 cumulus-oocyte complexes (COCs) were matured in the presence of 15, 30, or 50 μM CoQ10 in three to five replicates; next, in vitro fertilization and culture in a subset of oocytes were done. Our data revealed that compared to control oocytes or other concentrations of CoQ10, supplementation with 30 µM CoQ10 resulted in a significant increase in blastocyst formation and hatching rates, improved the distribution, relative mass and potential membrane of mitochondria, decreased the levels of reactive oxygen species and glutathione and lessened the percentage of oocytes with misaligned chromosomes after spindle assembly. The relative expression levels of apoptosis markers CASPASE3 and BAX were significantly reduced in CoQ10-treated oocytes and cumulus cells whereas the relative expression level of GDF9, an oocyte-specific growth factor, significantly increased. In conclusion, supplementation with CoQ10 improves the quality of COCs and the subsequent developmental competence of the embryo.

Ovarian response is associated with anogenital distance in patients undergoing controlled ovarian stimulation for IVF

STUDY QUESTION

Is the length of the anogenital distance (AGD) a biomarker of ovarian reserve and response to controlled ovarian stimulation (COS)?

SUMMARY ANSWER

Shorter AGD is associated with presence of poor ovarian response.

WHAT IS KNOWN ALREADY

Organ development during prenatal life is influenced by the prevailing intrauterine environment, and it has been suggested that nutritional, environmental and toxic factors could affect ovarian reserve set prenatally. AGD is a biomarker of prenatal-hormonal environment and observational studies have shown an association between its length and reproductive parameters in both sexes.

STUDY DESIGN, SIZE, DURATION

This was a prospective cohort study of 437 women treated with IVF/ICSI conducted in a tertiary-care university hospital between January and December 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All women underwent their first COS for IVF/ICSI and reached criteria for oocyte retrieval. Based on the number of oocytes obtained, patients were divided into three groups: poor responders (≤3 oocytes) (n = 50), normoresponders (4-15 oocytes) (n = 332) and high responders (>15 oocytes) (n = 55). Before retrieval, the following patient data were recorded: age, body mass index (BMI), ovarian reserve markers (anti-Müllerian hormone [AMH], antral follicle count [AFC] and follicular stimulation hormone [FSH]), cause of infertility, total doses of gonadotropins used and ovarian sensitivity index (OSI). Patients with previous pregnancies, polycystic ovary syndrome (PCOS), endometriosis and previous ovarian or genital surgery were excluded. Anthropometric biomarkers of AGDAC (anus-clitoris) and AGDAF (anus-fourchette) were measured in all patients under sedation on the day of retrieval and before proceeding to oocyte pick-up. Multiple linear regression analyses were used to examine the association between both AGD and ovarian reserve markers, the total units of gonadotropins used, the number of oocytes obtained and the OSI. Logistic regression was used to predict poor response in COS for IVF/ICSI, while accounting for confounders such as age and BMI.

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline FSH, AMH, AFC and age were significantly different among the three groups of ovarian response, as were the units of gonadotropin used, and the ovarian sensitivity index (OSI) (P < 0.001). Both AGDAC and AGDAF measurements were positively correlated with AMH levels (r = 0.38 and r = 0.21; P < 0.05), AFC (r = 0.41 and r = 0.20; P < 0.05), the OSI (r = 0.24 and r = 0.19; P < 0.05) and the number of oocytes retrieved (r = 0.29 and r = 0.28, respectively; P < 0.05). Conversely, there was a negative correlation between both AGD measurements and the doses of gonadotropins used (r= -0.19 and r= -0.15; P < 0.05). The area under the curve (AUC) for prediction of poor response of AGDAC was 0.70 (95% CI 0.66, 0.75), which was comparable to the classic ovarian reserve markers, such as AFC and AMH. AGDAF showed a significantly worse predictive capacity for poor ovarian response (AUC 0.60 [95% CI 0.55, 0.60]) than AMH and AFC.

LIMITATIONS, REASONS FOR CAUTION

The population used for the study was a highly selected group of infertile women who underwent COS for IVF, so the findings of this research may not be applicable for general population. Besides, measurement or selection biases might have been possible and must be considered.

WIDER IMPLICATIONS OF THE FINDINGS

The findings of this study suggest that in utero exposure to certain hormonal environments could affect the ovarian reserve set prenatally.

STUDY FUNDING/COMPETING INTEREST(S)

None. The authors have no competing interests to declare.

Ovotoxicity of cigarette smoke: A systematic review of the literature

This study reviews the scientific literature on the noxious effects of cigarette smoke on the ovarian follicle, and the cumulative data on the impact of smoking on in vitro fertilization (IVF) cycle outcome. There is a close association between tobacco smoke and accelerated follicle loss, abnormal follicle growth and impairment of oocyte morphology and maturation. There is an increasing amount of evidence indicating that smoke can directly derange folliculogenesis. Increased cellular apoptosis or autophagy, DNA damage and abnormal crosstalk between oocyte and granulosa cells have been implicated in the demise of ovarian follicles. It becomes increasingly clear that maternal smoking can exert multigenerational effects on the ovarian function of the progeny. Growing evidence suggests that cigarette smoke is associated with decreased results after IVF. Further research is needed to better define the molecular mechanisms behind smoking-induced ovarian disruption.

Loss of Centromere Cohesion in Aneuploid Human Oocytes Correlates with Decreased Kinetochore Localization of the Sac Proteins Bub1 and Bubr1

In human eggs, aneuploidy increases with age and can result in infertility and genetic diseases. Studies in mouse oocytes suggest that reduced centromere cohesion and spindle assembly checkpoint (SAC) activity could be at the origin of chromosome missegregation. Little is known about these two features in humans. Here, we show that in human eggs, inter-kinetochore distances of bivalent chromosomes strongly increase with age. This results in the formation of univalent chromosomes during metaphase I (MI) and of single chromatids in metaphase II (MII). We also investigated SAC activity by checking the localization of BUB1 and BUBR1. We found that they localize at the kinetochore with a similar temporal timing than in mitotic cells and in a MPS1-dependent manner, suggesting that the SAC signalling pathway is active in human oocytes. Moreover, our data also suggest that this checkpoint is inactivated when centromere cohesion is lost in MI and consequently cannot inhibit premature sister chromatid separation. Finally, we show that the kinetochore localization of BUB1 and BUBR1 decreases with the age of the oocyte donors. This could contribute to oocyte aneuploidy.

The prevalence of positive urinary cotinine tests in Korean infertile couples and the effect of smoking on assisted conception outcomes

OBJECTIVE

Smoking has been reported to harm nearly every organ of the body, but conflicting results have been reported regarding the effects of smoking on assisted conception. In this prospective cohort study, we aimed to investigate the prevalence of positive urinary cotinine tests in infertile couples and whether cotinine positivity was associated with infertility treatment outcomes.

METHODS

A qualitative urinary cotinine test was administered to 127 couples who underwent in vitro fertilization (IVF, n=92) or intrauterine insemination (IUI, n=35).

RESULTS

The overall prevalence of positive urinary cotinine test was 43.3% (55/127) in the male partners and 10.2% (13/127) in the female partners with similar prevalence rates in both genders in the IUI and IVF groups. Semen characteristics, serum markers of ovarian reserve, and number of retrieved oocytes were comparable among cotinine-positive and cotinine-negative men or women (with the exception of sperm count, which was higher among cotinine-positive men). The results of urinary cotinine tests in infertile couples were not associated with IVF and IUI outcomes.

CONCLUSION

The presence of cotinine in the system, as indicated by a positive urinary cotinine test, was not associated with poorer outcomes of infertility treatment.

Cigarette smoke exposure triggers the autophagic cascade via activation of the AMPK pathway in mice

We previously demonstrated that cigarette smoke (CS) exposure decreases primordial follicle counts and induces autophagy in ovarian granulosa cells in preference to apoptosis. Therefore, the objective of this study was to investigate molecular targets underlying smoke-induced activation of the reparative autophagy pathway in the ovary. Briefly, ovarian homogenates were prepared from adult female mice exposed to mainstream CS twice daily for 8 wk, using a whole-body exposure system. A gene array revealed that CS exposure induced a greater than 2-fold significant increase in the expression of proautophagic genes Cdkn1b, Map1lc3a, Bad, and Sqstm1/p62. A significant increase in Prkaa2, Pik3c3, and Maplc31b expression, as well as a significant decrease in Akt1 and Mtor expression, was detected by quantitative PCR. The 5'-AMP-activated protein kinase catalytic subunit (AMPK) alpha1 + alpha2 and ATG7 protein expression was significantly increased, whereas AKT1, mTOR, CDKN1B/p27, and CXCR4 proteins were significantly decreased in CS exposed versus control ovaries. Up-regulation of AMPK alpha1 + alpha2, a known initiator of autophagic signaling, and ATG7 further suggests activation of the autophagy cascade. Two prosurvival factors, AKT and mTOR, were decreased in expression, an outcome that favors induction of the autophagy pathway, whereas decreased levels of CDKN1B is suggestive of cell cycle dysregulation. In summary, our data suggest that CS exposure induces ovarian follicle loss through induction of the autophagic cascade via the AMPK pathway together with inhibition of antiautophagic markers AKT and mTOR. We further postulate that toxicant-induced dysregulation of reparative autophagy is a novel pathway central to impaired follicle development and subfertility.

In vivo exposure to benzo(a)pyrene induces significant DNA damage in mouse oocytes and cumulus cells

STUDY QUESTION

Does in vivo exposure to benzo(a)pyrene (BaP) induce DNA damage in oocytes and cumulus cells (CCs) in mice?

SUMMARY ANSWER

Significant increases in DNA strand breaks in oocytes and CCs and in BaP-induced DNA adducts in CCs were detected in exposed mice compared with controls.

WHAT IS KNOWN ALREADY

BaP has well-known mutagenic and carcinogenic effects on somatic cells, and is also registered as potential reproductive toxicant by several environmental protection agencies. It has been shown to cause a significant increase in DNA adducts in ovarian tissues; however, to our knowledge, the genotoxic effects of BaP on oocytes and CCs have not been studied to date.

STUDY DESIGN, SIZE, DURATION

Female CD1 mice were exposed to BaP via the oral administration of a single dose of 13 mg/kg body weight (bw); matched controls were exposed to the vehicle only (soya oil). A total of 15 groups of 6 mice (exposed or controls) were sacrificed 2, 4, 6, 15 or 22 days after BaP exposure, and after collection of oviducts, the oocyte-CC complexes (COC) were released.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The alkaline comet assay was used to quantify the DNA breaks in oocytes and CCs; DNA damage was expressed as the Olive Tail Moment (OTM). Immunofluorescent staining was used to quantify BaP-induced DNA adducts in CCs. Fluorescence was expressed as the average grey value (AGVA; arbitrary units). The differences between the exposed and control groups were assessed using analysis of variance (ANOVA) and the non-parametric Mann-Whitney test.

MAIN RESULTS AND THE ROLE OF CHANCE

Higher levels of DNA damage were observed in the oocytes and CCs of BaP-exposed mice than in those of vehicle controls. Significant increases in OTM (mean ± SE) were detected in (i) oocytes from females exposed for 4 (10.5 ± 0.9 versus 3.1 ± 0.4, P < 0.0001) or 6 days before collection (15.6 ± 2.0 versus 3.6 ± 0.9, P < 0.0001) and (ii) CCs from females exposed 2 (6.4 ± 0.6 versus 2.1 ± 0.2, P < 0.0001), 4 (7.8 ± 0.4 versus 2.4 ± 0.1, P < 0.0001) or 6 days before collection (7.3 ± 0.3 versus 3.2 ± 0.5, P < 0.0001) compared with controls. A significant increase in benzo(a)pyrene-7,8-9,10 diol epoxide (BPDE)-DNA adducts and higher AGVA (mean ± SE) scores were observed in CCs from females exposed 2 (6.1 ± 0.3 versus 3.6 ± 0.5, P < 0.0001), 4 (7.5 ± 0.1 versus 3.4 ± 0.1, P < 0.0001) or 6 days before collection (11.6 ± 0.4 versus 3.7 ± 0.1, P < 0.0001) compared with control mice.

LIMITATIONS, REASONS FOR CAUTION

Mice were given one treatment via the oral route because this dose and mode of administration have been shown to induce detectable BPDE-DNA adduct levels in mouse organs and sperm cells. Additional data are needed to assess DNA damage in oocytes and CCs after chronic exposure to BaP in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first study examining the in vivo genotoxicity of BaP in oocytes and CCs. We observed significant DNA damage in the oocytes and CCs of mice after acute BaP exposure. BPDE-DNA adducts result directly from BaP metabolism while DNA breaks could result mainly from BPDE-DNA adduct excision and repair and/or through direct genotoxicity from increased reactive oxygen species. These results add new and important insights regarding the recently suggested toxicity of chronic BaP exposure in the ovary.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a grant (93-CPQ 2012-05) from the DIRRECTE, Provence Alpes Côte d'Azur, France. None of the authors have any conflict of interest to declare.

Cigarette smoke impairs granulosa cell proliferation and oocyte growth after exposure cessation in young Swiss mice: an experimental study

Background

Cigarette smoke is associated with decreased female fertility, causing damage to ovarian function and disturbing follicle development. However, the effects of cigarette toxicants on ovarian function depend on duration and intensity of exposure. The aim of this study was to assess the effects of brief, intense exposure to tobacco smoke on granulosa cell number, oocyte growth, and follicle size during puberty in female Swiss mice.

Methods

Ten female Swiss mice aged 35 days were exposed to tobacco smoke from 3R4F reference research cigarettes. They were exposed to an automatic smoking machine 8 h/day, 7 days/week for 15 days. Ten age-matched controls were kept in a different room and exposed to ambient air. At the end of 15 days, five mice in each group were euthanized and the ovaries were analyzed for follicular morphometry and granulosa cell count. The remaining animals were kept for an additional 30 days for further analysis as an ex-smoker group and control group. Comparison between the two groups was evaluated by the Student’s t-test or a two-way ANOVA followed by Bonferroni post-test was applied for multiple comparisons.

Results

We found that cigarette smoke impaired antral follicular growth even after exposure cessation (p < 0.001). Both smoking and ex-smoking groups exhibited similar follicle diameter. However, at the same follicular stage, the number of granulosa cells was smaller in the ex-smoking group compared to smoking animals (p < 0.001). This was associated with increased oocyte diameter in ex-smoking animals compared to smoking animals (p < 0.01).

Conclusions

The negative effects of cigarette smoking seem to last even after exposure has been interrupted. Moreover, brief exposure during puberty may induce silent oocyte disruption, which could in turn lead to decreased fecundity rates.

Ovarian cancer: etiology, risk factors, and epidemiology

Little is known regarding the early aspects of ovarian carcinogenesis. As a consequence, the identification of women at risk for the disease is based primarily on clinical grounds, with family history being the most important risk factor. In this review, we will discuss the various hypotheses regarding ovarian etiology and pathogenesis. In addition, we will discuss the epidemiology of ovarian cancer, including hereditary, reproductive, hormonal, inflammatory, dietary, surgical, and geographic factors that influence ovarian cancer risk.

[Pregnancy predictive factors in case of double embryo transfer during "Top Quality" attempts]

OBJECTIVES

To identify IVF±ICSI pregnancy predictive factors during "Top Quality" attempts in case of double embryo transfer.

PATIENTS AND METHODS

Three years retrospective study (2007, 2008 and 2009) on parameters and results obtained during IVF±ICSI defined as "Top Quality" attempts: first or second attempts on less than 35years old women (age inferior or equal to) with one or two "Top Quality" embryo transfer.

RESULTS

In case of double embryo transfer, pregnancy predictive factors are (OR [IC 95%], P): average endometrial thickness on start (4.6 [2.9-5.5], P<0.01), women smoking (4.2 [3.5-4.9], P<0.01), average stimulation duration (3.4 [2.7-3.9], P<0.01), average men age (2.2 [1.7-2.5], P<0.05), gonadotrophins total dose (2.1 [1.1-3.2], P<0.05) and first rank's attempts (1.6 [1.2-2.5], P<0.05).

DISCUSSION AND CONCLUSION

Age patient, rank attempts and quality embryo are criteria, which used to guide to a single embryo transfer. Our results incite us to consider other parameters, in particular men age and women smoking status.

Increased zona pellucida thickness and meiotic spindle disruption in oocytes from cigarette smoking mice

BACKGROUND The precise effects of cigarette smoking on female fertility have not yet been clearly defined. We have used a mouse model that mimics human smoking and is able to control for variables that may confound clinical studies to assess the impact of chronic smoking on the quality of mouse oocytes. METHODS Mice received cigarette smoke directly to their lungs for 12 weeks. Lung tissue was analyzed for emphysematous changes and cumulus enclosed oocytes (CEOs) were recovered to study their quality. CEOs were in vitro matured, fixed and stained for chromatin and tubulin. Meiotic spindles, chromatin and the zona pellucida were all examined using confocal microscopy. RESULTS After 12 weeks of cigarette smoking, mice developed alveolar tissue damage that was determined by an increase in destructive index of the lung parenchyma. The numbers of oocytes recovered and the rates of oocyte maturation were not significantly different from non-smoking mice. However, oocytes from smoking mice had a significantly thicker zona pellucida along with shorter and wider meiotic spindles. Furthermore in total, almost a quarter of oocytes from smoking mice were abnormal as assessed by either errors in chromosomal congression or spindle shape. CONCLUSIONS We have used a novel model of inhalational cigarette smoking to show that chronic smoking has a detrimental effect on oocyte quality, and this can be observed even though oocytes are removed from the ovary and cultured in vitro.

Effects of cigarette smoking on reproduction

BACKGROUND Cigarette smoking is associated with lower fecundity rates, adverse reproductive outcomes and a higher risk of IVF failures. Over the last few decades, prevalence of smoking among women of reproductive age has increased. This review focuses on current knowledge of the potential effects of smoke toxicants on all reproductive stages and the consequences of smoke exposure on reproductive functions. METHODS We conducted a systematic review of the scientific literature on the impact of cigarette smoking and smoke constituents on the different stages of reproductive function, including epidemiological, clinical and experimental studies. We attempted to create hypotheses and find explanations for the deleterious effects of cigarette smoke observed in experimental studies. RESULTS Cigarette smoke contains several thousand components (e.g. nicotine, polycyclic aromatic hydrocarbons and cadmium) with diverse effects. Each stage of reproductive function, folliculogenesis, steroidogenesis, embryo transport, endometrial receptivity, endometrial angiogenesis, uterine blood flow and uterine myometrium is a target for cigarette smoke components. The effects of cigarette smoke are dose-dependent and are influenced by the presence of other toxic substances and hormonal status. Individual sensitivity, dose, time and type of exposure also play a role in the impact of smoke constituents on human fertility. CONCLUSIONS All stages of reproductive functions are targets of cigarette smoke toxicants. Further studies are necessary to better understand the deleterious effects of cigarette smoke compounds on the reproductive system in order to improve health care, help to reduce cigarette smoking and provide a better knowledge of the molecular mechanisms involved in reproductive toxicology.

Effects of cigarette smoke on fertilization and embryo development in vivo

OBJECTIVE

To determine the effects of smoking on eggs and subsequent embryo development by maternal exposure to cigarette smoke.

DESIGN

Mice were exposed to cigarette smoke or cigarette smoke condensate (CSC) for 4 weeks and then examined for development and telomere function of embryos in vitro after fertilization. In addition, the effects of continuous smoke on embryo development and telomere length were determined by treating mice for 4 weeks, followed by continuous exposure to cigarette smoke or CSC after fertilization.

SETTING

Laboratory study.

ANIMAL(S)

CD1 mice.

INTERVENTION(S)

Mice were exposed to cigarette smoke or CSC.

MAIN OUTCOME MEASURE(S)

The percentage (rate) of blastocyst development, quality of embryos assessed by total cell number, apoptosis, Oct4 expression (a molecular marker of embryonic stem cells), telomere length and loss, and chromosomal instability were compared between smoke- and CSC- treated mice and sham-treated mice.

RESULT(S)

Mice exposed to cigarette smoke or CSC for 4 weeks exhibited increased egg fragmentation or delayed fertilization, thus reducing development to blastocysts in vitro. Fragmented eggs showed increased reactive oxygen species. Mice exposed to smoke or CSC showed increased apoptosis and altered expression of Oct4 in developed embryos. The effects of smoke or CSC on embryo development showed a dose-dependent relationship to exposure time. Exposure to smoke or CSC beginning 4 weeks before fertilization altered expression of Oct4 and increased apoptosis in blastocysts. Notably, the rate of abnormal embryos significantly increased in the smoke and CSC groups. Smoke and CSC shortened telomeres in embryos, but their telomere shortening was not enough to induce major chromosome abnormalities in mice, which have unusually long telomeres.

CONCLUSION(S)

Together, the whole animal exposure model shows that cigarette smoke induces oxidative stress, telomere shortening, and apoptosis, and compromises embryo development in vivo.

Smoking and infertility

Approximately 30% of reproductive age women and 35% of reproductive age men in the United States smoke cigarettes. Substantial harmful effects of cigarette smoke on fecundity and reproduction have become apparent but are not generally appreciated.

Recent cigarette smoking and assisted reproductive technologies outcome

OBJECTIVE

To assess the association between recent cigarette smoking (CS) in female and male partners and assisted reproduction technology (ART) outcomes.

DESIGN

Cohort prospective study.

SETTING

University ART program in Chile.

PATIENT(S)

One hundred sixty-six couples seeking pregnancy through ART.

INTERVENTION(S)

Follicular fluid (FF) and serum cotinine concentrations were measured in female partners. Self-reported CS data were collected through personal interviews.

MAIN OUTCOME MEASURE(S)

The association between female recent smoking, assessed by FF and serum cotinine concentrations, and ART outcomes, such as number of ova retrieved and implantation rates, and the association between self-reported male recent smoking and live birth rates.

RESULT(S)

A significant age-adjusted association between increased FF cotinine level and decreased number of ova retrieved was found. The male partner's smoking habit significantly decreased the live birth rate from 21.1% to 7.8%. Serum cotinine concentrations paralleled those of FF.

CONCLUSION(S)

The hypothesis of a detrimental effect of recent female smoking over implantation rates is rejected. However, recent male smoking is associated with significantly decreased live birth rates even after adjusting for confounders. Female recent smoking was significantly associated with decreased number of retrieved ova.

Effects of cigarette smoking upon clinical outcomes of assisted reproduction: a meta-analysis

BACKGROUND

The aim of this meta-analysis was to investigate whether any difference exists in success rate of clinical outcomes of assisted reproductive technologies (ART) between women who actively smoke cigarettes at the time of treatment and those who do not.

METHODS

An intensive computerized search was conducted on published literature from eight databases, using search terms related to smoking, assisted reproduction and outcome measures. Eligible studies compared outcomes of ART between cigarette smoking patients and a control group of non-smoking patients and reported on live birth rate per cycle, clinical pregnancy rate per cycle, ectopic pregnancy rate per pregnancy or spontaneous miscarriage rate per pregnancy, and 21 studies were included in the meta-analyses. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated for the data, and statistical heterogeneity was tested for using chi(2) and I(2) values. A systematic review examined the effect of smoking upon fertilization rates across 17 studies.

RESULTS

Smoking patients demonstrated significantly lower odds of live birth per cycle (OR 0.54, 95% CI 0.30-0.99), significantly lower odds of clinical pregnancy per cycle (OR 0.56, 95% CI 0.43-0.73), significantly higher odds of spontaneous miscarriage (OR 2.65, 95% CI 1.33-5.30) and significantly higher odds of ectopic pregnancy (OR 15.69, 95% CI 2.87-85.76). A systematic literature review revealed that fertilization rates were not significantly different between smoking and non-smoking groups in most studies.

CONCLUSIONS

This meta-analysis provides compelling evidence for a significant negative effect of cigarette smoking upon clinical outcomes of ART and should be presented to infertility patients who smoke cigarettes in order to optimize success rates.

Effect of a woman's smoking status on oocyte, zygote, and day 3 pre-embryo quality in in vitro fertilization and embryo transfer program

In the present study we investigated the effect of a woman's smoking status on the quality of the oocyte, zygote, and on day 3 pre-embryo, as well as the likelihood of achieving an ongoing pregnancy at 8 weeks. Smokers presented a higher number of nonfertilized oocytes than nonsmokers (20.1% vs. 10.8% of fertilization failure), by comparable clinical pregnancy rate for smokers (40.8%; 28/72) and for nonsmokers (39.2%; 23/58).

Cigarette smoking and reproductive function

PURPOSE OF REVIEW

To perform a systematic review of the literature on the relationship between cigarette smoking and reproductive function. Whenever possible, this review is focused on the most recently published studies (mainly the past 2 years). Nevertheless, in many instances older literature was too relevant not to be taken into account.

RECENT FINDINGS

Tobacco compounds exert a deleterious effect on the process of ovarian follicle maturation. This effect is expressed by worse in-vitro fertilization parameters in cycles performed on women with smoking habits. Also, uterine receptiveness is significantly altered by the smoking habit. In men, cigarette smoking reduces sperm production, increases oxidative stress, and DNA damage. Spermatozoa from smokers have reduced fertilizing capacity, and embryos display lower implantation rates. Even in-utero exposition to tobacco constituents leads to reduced sperm count in adult life.

SUMMARY

A strong body of evidence indicates that the negative effect of cigarette smoking on fertility comprises fairly every system involved in the reproductive process. Couples in reproductive age should be strongly discouraged to smoke.

Environmental contaminants and human infertility: hypothesis or cause for concern?

Throughout the 1980s and 1990s the crude human birth rate (live births per 1000 population) declined, indicating reduced fertility and suggesting a potential decline in fecundity (the potential to conceive). Detection of environmental contaminants in human tissues, together with reports of a global decline in semen quality, further fueled speculation that human infertility rates are increasing and environmental toxicants are potentially important causal agents associated with this change. However, there is little compelling evidence to suggest that infertility rates amongst the general population have changed over time. Moreover, recent studies suggest a rise in the fertility rates. While several studies documented increased time to pregnancy (TTP) in exposed study populations, other investigators were not able to replicate these findings. Nevertheless, studies involving occupational exposure together with results from animal experiments lend support to the conclusion that environmental contaminants potentially adversely affect fertility. Consequently, the impact of exposure to environmental contaminants on human fertility remains controversial. To test the hypothesis that environmental contaminant exposure was associated with enhanced risk of infertility, data concerning trends in fertility and infertility rates were examined to assess the impact of exposure of developing gametes to environmental contaminants. The relationship between exposure and reproductive outcomes was then examined to illustrate the range of adverse effects for reproductive toxicants with data sets of divergent depth and reliability. Data showed that only a weak association between exposure to environmental contaminants and adverse effects on human fertility exists. However, it is postulated that evidence of chemical exposure and potential health consequences of these exposures highlight the need for further research in this area.

Risk factors for ovarian cancer: an overview with emphasis on hormonal factors

Ovarian cancer is the fifth most frequently occurring cancer among women and leading cause of gynecological cancer deaths in North America. Although the etiology of ovarian cancer is not clear, certain factors are implicated in the etiology of this disease, such as ovulation, gonadotropic and steroid hormones, germ cell depletion, oncogenes and tumor suppressor genes, growth factors, cytokines, and environmental agents. Family history of breast or ovarian cancer is a prominent risk factor for ovarian cancer, with 5-10% of ovarian cancers due to heritable risk. Reproductive factors such as age at menopause and infertility contribute to greater risk of ovarian cancer, whereas pregnancy, tubal ligation, and hysterectomy reduce risk. Oral contraceptive (OC) use has clearly been shown to be protective against ovarian cancer. In contrast, large epidemiologic studies found hormone replacement therapy (HRT) to be a greater risk factor for ovarian cancer. The marked influence of hormones and reproductive factors on ovarian cancer suggests that endocrine disrupters may impact risk; however, there is a notable lack of research in this area. Lifestyle factors such as cigarette smoking, obesity, and diet may affect ovarian cancer risk. Exposure to certain environmental agents such as talc, pesticides, and herbicides may increase risk of ovarian cancer; however, these studies are limited. Further research is needed to strengthen the database of information from which an assessment of environmental and toxicological risk factors for ovarian cancer can be made.

Effects of age on follicle and hormone dynamics during the oestrous cycle in mares

The effects of age (young: 5–6 years; intermediate: 10–14 years; old: ≥18 years) on follicle and hormone dynamics during an interovulatory interval (IOI; n = 46) and on preovulatory oocytes and concentrations of follicular fluid factors (n = 44) were studied in mares. Old mares were not approaching senescence, as indicated by regular lengths of the IOI (19–27 days) during the period May–October. The IOI was 1 day longer (P < 0.05) in the old group than in the two younger groups and was associated with a slower (P < 0.05) growth rate of the ovulatory follicle. The old group had diminished follicle activity, as indicated by significantly smaller and fewer follicles. Concentrations of FSH did not differ among age groups, except that the maximum concentration was greater (P < 0.05) in the old group. Concentrations of LH were greater (age × day interaction; P < 0.03) in the young group throughout the ovulatory LH surge and may have played a role in a shorter (P < 0.05) interval from maximum diameter of the preovulatory follicle to ovulation. Maximum circulating concentrations of oestradiol during the preovulatory surge were greatest (P < 0.05) in the young group. No effects of age were detected on oocyte morphology. Concentrations of ovarian steroids in preovulatory follicular fluid were not affected by the age of the mares, but concentrations of free insulin-like growth factor-1 were greater (P < 0.05) in the old group. The results indicate the importance of considering the potential confounding effects of age in experimental protocols and for considering age in the development of theriogenology programmes.

Effect of nicotine on in vitro maturation of bovine oocytes

The putative effect of nicotine on maturation and the chromosomal complement of bovine oocytes were investigated in the present study. Cumulus-enclosed oocytes were incubated in maturation medium with 0, 0.5, 1.0, 2.5, 5.0, and 10.0 mmol concentrations of nicotine. The results indicated that: (1) nicotine affected cumulus cell expansion in a dose-dependent manner and the perivitelline space failed to form when concentrations were equal to or greater than 5.0 mmol; (2) oocytes treated with 0.5 and 1.0 mmol nicotine concentrations resulted in maturation rates (83.3% and 85.9%, respectively) which was similar to the control (86.2%), whereas treatment with 2.5 and 5.0 mmol concentrations significantly decreased maturation rates to 70.2% and 26.7%, respectively; (3) nicotine at or over 2.5 mmol caused extremely irregular meiotic spindles and interrupted microfilament organization; (4) chromosomal analyses of oocytes with PB1 showed that oocytes derived from 0.5 and 1.0 mmol nicotine groups had haploid complements similar to the control (87-90%), but when the concentrations were increased to 2.5 and 5.0 mmol the haploid state was significantly reduced to around 70%; (5) oocytes at GVBD (germinal vesicle breakdown) and metaphase I stages were less affected by nicotine at 5.0 and 10.0 mmol concentrations than GV-stage oocytes; (6) maturation rates of the short-term nicotine-treated oocytes could be improved when subsequently incubated in normal maturation medium. Prolonged culture of nicotine-pretreated oocytes resulted in self-activation and some oocytes formed 1 or 2 pronuclei. In conclusion, nicotine affects bovine oocyte cumulus cell expansion, maturation rate, and chromosomal complement in a dose-dependent and an oocyte-stage-dependent manner.

Nicotine alters bovine oocyte meiosis and affects subsequent embryonic development

The effects of nicotine on nuclear maturation and meiotic spindle dynamics of bovine oocytes and subsequent embryonic development were investigated. Maturation rates (85%-94%) derived from nicotine treatments at 0.01 to 1.0 mM were similar to the control (86%), but significantly decreased at 2.0 to 6.0 mM. Haploid complements of metaphase II oocytes in 0.01 to 1.0 mM nicotine (approximately 90%) were similar to the control, while lower (ranged from 63% to 76%, P < 0.05 or P < 0.01) haploid oocytes were observed in the 2.0 to 6.0 mM nicotine groups. The majority of the PB1-free oocytes derived from 3.0 to 6.0 mM nicotine treatments were diploidy (2n = 60). Spindle microtubules changed from characteristically being asymmetrical in the controls to being equally distributed into two separate chromosome groups in the nicotine treatments. Nicotine disorganized the microfilament organization and inhibited the movement of anaphase or telophase chromosomes to the cortical area. The inhibited two chromosome groups became two spindles that either moved close in proximity or merged entirely together resulting in diploidy within the affected oocyte. Nicotine treatment significantly reduced the rate of cleavage and blastocyst development after parthenogenetic activation. Diploidy and cell number were drastically reduced in the resultant blastocysts. In conclusion, nicotine can alter the normal process of bovine oocyte meiosis and affects subsequent embryonic development.

Gender effects on the incidence of aneuploidy in mammalian germ cells

Aneuploidy occurs in 0.3% of newborns, 4% of stillbirths, and more than 35% of all human spontaneous abortions. Human gametogenesis is uniquely and gender-specific susceptible to errors in chromosome segregation. Overall, between 1% and 4% of sperm and as many as 20% of human oocytes have been estimated by molecular cytogenetic analysis to be aneuploid. Maternal age remains the paramount aetiological factor associated with human aneuploidy. The majority of extra chromosomes in trisomic offspring appears to be of maternal origin resulting from nondisjunction of homologous chromosomes during the first meiotic division. Differences in the recombination patterns between male and female meiosis may partly account for the striking gender- and chromosome-specific differences in the genesis of human aneuploidy, especially in aged oocytes. Nondisjunction of entire chromosomes during meiosis I as well as premature separation of sister chromatids or homologues prior to meiotic anaphase can contribute to aneuploidy. During meiosis, checkpoints at meiotic prophase and the spindle checkpoint at M-phase can induce meiotic arrest and/or cell death in case of disturbances in pairing/recombination or spindle attachment of chromosomes. It has been suggested that gender differences in aneuploidy may result from more permissive checkpoints in females than males. Furthermore, age-related loss of chromosome cohesion in oocytes as a cause of aneuploidy may be female-specific. Comparative data about the susceptibility of human male and female germ cells to aneuploidy-causing chemicals is lacking. Increases of aneuploidy frequency in sperm have been shown after exposure to therapeutic drugs, occupational agents and lifestyle factors. Conversely, data on oocyte aneuploidy caused by exogenous agents is limited because of the small numbers of oocytes available for analysis combined with potential maternal age effects. The vast majority of animal studies on aneuploidy induction in germ cells represent cause and effect data. Specific studies designed to evaluate possible gender differences in induction of germ cell aneuploidy have not been found. However, the comparison of rodent data available from different laboratories suggests that oocytes are more sensitive than male germ cells when exposed to chemicals that effect the meiotic spindle. Only recently, in vitro experiments, analyses of transgenic animals and knockdown of expression of meiotic genes have started to address the molecular mechanisms underlying chromosome missegregation in mammalian germ cells whereby striking differences between genders could be shown. Such information is needed to clarify the extent and the mechanisms of gender effects, including possible differential susceptibility to environmental agents.

Follicle growth is inhibited by benzo-[a]-pyrene, at concentrations representative of human exposure, in an isolated rat follicle culture assay

BACKGROUND

The adverse effects of cigarette smoking on human fertility have been well documented. However, the mechanism(s) underlying the detrimental effects of cigarette smoking are unknown. Using a novel isolated rat follicle culture assay, we tested the hypothesis that benzo-[a]-pyrene (B[a]P), a constituent of cigarette smoke, can inhibit follicle growth.

METHODS

B[a]P levels were quantified in the serum and follicular fluid (FF) of women undergoing in vitro fertilization (IVF) treatment exposed to mainstream smoke (n = 19) and non-smokers (n = 10) by gas chromatography mass spectrometry. Isolated rat follicles were cultured with increasing concentrations of B[a]P (1.5-300 ng ml(-1)) and follicle diameter was measured daily.

RESULTS

Mean ( +/- Standard error of the mean) B[a]P) was quantified in the serum (0.40 +/- 0.13 ng ml(-1)) and FF (1.32 +/- 0.68 ng ml(-1)) of women who smoke. IVF stimulation and outcome measures were similar between female smokers and non-smokers with the exception of implantation rate and pregnancy rate, which were both significantly lower (P < 0.05) in the MS group. B[a]P treatment significantly reduced rat follicle diameter and attenuated FSH stimulated growth in a dose-dependent manner, beginning at 1.5 ng ml(-1).

CONCLUSIONS

Our data suggest that B[a]P, at levels representative of those measured in human FF, may adversely affect follicle development and be an ovarian toxicant.

Smoking and infertility

Approximately 30% of reproductive age women and 35% of reproductive age men in the United States smoke cigarettes. Substantial harmful effects of cigarette smoke on fecundity and reproduction have become apparent but are not generally appreciated.

Fécondation in vitro et tabac: intérêt de la cotininurie et de l'analyseur de monoxyde de carbone expiré

OBJECTIVE

To study the correlation between expired air carbon (EACO) and urinary cotinine, and to determine the impact of tobacco smoking on in vitro fertilization (IVF) results.

PATIENTS AND METHODS

We studied prospectively 221 patients in our ART center from October 2002 to October 2004: 51 active smokers, 85 passive smokers, and 85 non-smokers. Patients were classified into active, passive smokers, or non-smokers, based on a questionnaire. We measured urinary cotinine and EACO on the embryo transfer day and we recorded the IVF parameters.

RESULTS

Two hundred and twenty-one patients were included. We observed a 17.2% reduction of estradiolemy (P=0.05), a 1.5% reduction of pregnancies (NS), a 7.8% reduction of infants born alive (NS), a 28.5% reduction of twin pregnancies (P=0.06), as well as a 10% increase of miscarriages (NS) in the active smokers in comparison with non-smokers (the same trends were observed between active and passive smokers). EACO and urinary cotinine were well correlated. There was a negative correlation between estradiolemy and urinary cotinine (R=-0.15, P=0.02).

DISCUSSION AND CONCLUSION

Tobacco smoking intensity may be dilatory on IVF results. There is a high correlation between EACO and urinary cotinine. Other larger studies would probably obtain results more statistically significant.

Tabac et fertilité chez la femme et l'homme

Cigarette smoking consequences on female and male reproduction have been evaluated for twenty years only and thus poorly spread in the general population. However, several studies have noticed noxious effects of tobacco before and after conception, in both women and men, from smokers gametes to their offspring. This negative impact occurs in spontaneous as well as in assisted reproduction (ART). For women, pregnancy rate is decreased, early spontaneous abortions are increased and ovarian reserve is altered. For men, standard sperm parameters are modified and spermatozoon nuclear quality is compromised. One of the mechanisms involved in those anomalies could be the oxidative stress produced by some cigarette smoking components. The consequences on smokers offspring are hardly evaluated yet: pathologies of the respiratory system, decrease of fecundity and cancers outcomes. In conclusion, it seems obvious that smokers - men as women - have to quit smoking before having a parental project.

Smoking impairs angiogenesis during maturation of human oocytes

OBJECTIVE

This study determines whether smoking influences ovarian vascularization which thus may impair follicular development.

DESIGN

Prospective laboratory study of follicular fluids and granulosa cells from patients undergoing in vitro fertilization.

SETTING

University Hospital Aachen, Germany.

PATIENT(S)

Fifty smoking women and 50 nonsmoking women.

INTERVENTION(S)

Cultivation of human granulosa cells. Cultivation of human umbilical vein endothelial cells (HUVECs) with either granulosa cell-conditioned medium or follicular fluid. Determination of clinical parameters.

MAIN OUTCOME MEASURE(S)

Quantification of soluble vascular endothelial growth factor receptor 1 (sVEGFR-1) and cotinine.

RESULT(S)

Mean sVEGFR-1 concentration in follicular fluid of smokers was 499.6 pg/mL compared with 159.2 pg/mL in nonsmokers. Correspondingly, supernatant of HUVECs cultured with follicular fluid from smoking and nonsmoking women showed, respectively, 1,174.1 pg/mL versus 794.2 pg/mL sVEGFR-1. The HUVECs incubated with conditioned medium from smokers' granulosa cells at culturing days 5, 9, 13, and 17 secreted, respectively, 1,712.4, 1,560.6, 1,619.0, and 1,635.0 pg/mL sVEGFR-1, whereas nonsmokers showed, respectively, 1,147.6, 1,067.2, 1,135.9, and 1,206.3 pg/mL sVEGFR-1. Mean cotinine concentration in smoking women was 83.9 ng/mL and in nonsmoking was 2.8 ng/mL. In all four comparisons, differences between groups reached statistical significance.

CONCLUSION(S)

This study showed that smokers secrete significantly higher amounts of sVEGFR-1 than nonsmokers, which may result in decreased ovarian vascularization and reduced oocyte maturation.

The effect of HMG and recombinant human FSH on oocyte quality: a randomized single-blind clinical trial

OBJECTIVE

To compare the effect of HMG and rhFSH on oocyte quality in ICSI cycle.

SETTING

Vali-e-Asr university teaching hospital.

METHOD

Prospective single-blind randomized clinical trial.

SUBJECTS

Sixty women undergoing ovarian stimulation for ICSI were randomized to receive a standard protocol of either HMG or rhFSH in down-regulation cycles.

INTERVENTIONS

Prior to microinjection, each oocyte was assessed regarding the nuclear maturity, morphology of zona plucida, cytoplasmic appearance and polar body morphology. Fertilization rate was followed.

MAIN OUTCOME

The percentage of metaphase II oocytes in HMG and rhFSH groups.

STATISTICAL ANALYSIS

Statistical analyses were carried out by the Mann-Whitney, Fisher's exact, chi2 tests and Student's t-test.

RESULTS

No significant differences were found between two groups in regard to the demographic data, the ovarian response and pregnancy/implantation rates (P>0.05). The percentage of metaphase II oocytes in HMG and rhFSH groups were 81.3% versus 80.6%, respectively.

CONCLUSIONS

There were no significant differences between parameters such as, oocyte quality and percentage of metaphase II oocytes between these two groups.

Decreased fertility in mice exposed to environmental air pollution in the city of Sao Paulo

It has largely been shown that air pollution can affect human health. Effects on human fertility have been shown mainly in males by a decrease in semen quality. Few studies have focused on the environmental effects on female fertility. The aim of the present study was to analyze the effects of air pollution in the city of Sao Paulo on mouse female fertility. Four groups of female Balb/c mice were placed in two chambers 10 days (newborn) or 10 weeks (adults) after birth. Mice were maintained in the chambers 24 h a day, 7 days a week, for 4 months. The first chamber received air that had passed through an air filter (clean chamber) and the second received ambient air (polluted chamber). We measured PM10 and NO2 inside both chambers. Mice belonging to the adult groups were bred to male mice after living for 3 months inside the chambers. The newborn groups mated after reaching reproductive age (12 weeks). After 19 days of pregnancy the numbers of live-born pups, reabsorptions, fetal deaths, corpora lutea, and implantation failures were determined. PM10 and NO2 concentrations in the clean chamber were 50% and 77.5% lower than in the polluted chamber, respectively. Differences in fertility parameters between groups were observed only in animals exposed to air pollution at an early age (10 days after birth). We observed a higher number of live-born pups per animal in the clean chamber than per animal from the polluted chamber (median=6.0 and 4.0, respectively; P=0.037). There was a higher incidence of implantation failures in the polluted group than in the clean group (median=3.5 and 2.0, respectively; P=0.048). There were no significant differences in the other reproductive parameters between groups. These results support the concept that female reproductive health represents a target of air pollutants.

Female and male lifestyle habits and IVF: what is known and unknown

There is no greater tribute to the importance and efficacy of IVF than the fact that >1 x 10(6) babies have been born to infertile couples since its clinical introduction in 1978. Despite enormous advances regarding the technical aspects of the IVF procedure, the parents' contribution has virtually been ignored when considering aspects that influence success rates. This systematic review focuses on the effects of female and male lifestyle habits (specifically: smoking, alcohol and caffeine use, and psychological stress) on the reproductive endpoints of IVF (i.e. oocyte aspiration, fertilization, embryo transfer, achievement of a pregnancy, live birth delivery, and perinatal outcomes, e.g. low birthweight, multiple gestations). What is currently known in the field of lifestyle habits and IVF? There is compelling evidence that smoking has a negative influence on IVF outcomes, whereas for stress, the evidence is suggestive but insufficient due to the heterogeneity of studies. The evidence for the effects of alcohol and caffeine on IVF is inadequate, and therefore unknown, due to the scarcity of studies.