Association between cigarette smoking and ovarian reserve among women seeking fertility care

Sex-Specific Risk of Smoking for Abdominal Aortic Aneurysm and Exploration of Potential Mechanism: Meta-Analysis and Prospective Cohort Study

BACKGROUND

Smoking is the strongest modifiable risk factor for the development of abdominal aortic aneurysm (AAA). This study aims to confirm whether smoking is a stronger risk factor in women than men and identify contributory reasons, including inflammation, for any sex-specific difference observed.

METHODS

Systematic review and meta-analysis, conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. Data sources were Medline, Embase, and Cochrane Central Register of Controlled Trials. Population-based studies reporting the risk of AAA, adjusted for age and cardiovascular risk factors, for women versus men, were included. These were complemented by data from UK Biobank, which also were assessed for sex-specific effects of smoking on incident atherosclerotic cardiovascular disease.

RESULTS

Meta-analysis of 6 studies (including UK Biobank, 2001-2024) showed that the relative risk ratio of current versus never smokers for incident AAA in women versus men was 1.78 (95% CI, 1.32-2.38). In the UK Biobank cohort, the sex-specific relative risks of current smoking risks were higher for AAA than for atherosclerotic cardiovascular disease; hazard ratio, 1.74 and 1.29, respectively: analysis by cigarettes per day echoed these findings, but pack-year history had lesser association. The proportionately lower AAA incidence rate in exsmokers (versus current smokers) was more marked in women. Sex-specific risks of current smoking for incident AAA were not significantly modified by CRP (C-reactive protein), white blood cell count, or other inflammatory markers.

CONCLUSIONS

The relative risk of developing AAA by current smokers is almost twice as high in women versus men, but no strong association with inflammation was observed. Other reasons, including smoking intensity, must be sought.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD2024586609.

Role of inflammatory blood parameters from complete blood count in predicting ovarian follicular density in cancer patients undergoing ovarian tissue cryopreservation

BACKGROUND

Inflammation is a key feature of neoplastic diseases, especially cancer. Predicting follicular density (FD) in ovarian cortical tissue is essential for evaluating ovarian tissue cryopreservation (OTC) outcomes in fertility preservation. However, to date, no studies have explored the role of inflammatory markers in predicting FD in OTC patients. This study aims to investigate the relationship between blood inflammatory parameters and FD in this population.

METHODS

We conducted a retrospective observational study on 101 OTC patients. The primary goal was to assess whether parameters from Complete Blood Count (CBC) that include White Blood Cells (WBC), absolute neutrophil count, absolute lymphocyte count, Neutrophil/Lymphocyte Ratio (NLR), Mean Platelet Volume (MPV), Platelet Count (PC), MPV/PC and the Platelet/Lymphocyte Ratio (PLR) could predict FD. We also evaluated the impact of factors such as oncological diagnosis, smoking, Body Mass Index (BMI), and germline BRCA mutations. Spearman's correlation coefficient and the Mann-Whitney test were used for analysis.

RESULTS

Significant correlations were found in patients aged between 27 and 31. In this group, NLR was inversely correlated with FD (Rho = -0.374, p = 0.032), while lymphocyte count (Rho = 0.371, p = 0.034) and MPV/PC (Rho = 0.365, p = 0.037) were positively correlated with FD. An inverse correlation was also found between PLR and FD (Rho = -0.38, p = 0.028).

CONCLUSIONS

Our findings suggest that NLR, lymphocyte count, MPV/PC and PLR may be useful in predicting FD in a subgroup of OTC patients. Larger studies are needed to confirm these results.

Association between sleep quality and ovarian reserve in women of reproductive age: a cross-sectional study

OBJECTIVE

To evaluate the association between sleep quality and ovarian reserve among women of reproductive age.

DESIGN

Cross-sectional study.

SUBJECTS

A total of 1,070 female participants aged 20-40 years enrolled from February 2023 to January 2024.

EXPOSURE

Not applicable.

MAIN OUTCOME MEASURES

A questionnaire was administered to the participants to collect baseline information related to reproductive and lifestyle factors. Pittsburgh Sleep Quality Index (PSQI) was used to measure sleep quality. The assessment was conducted on ovarian reserve, including total antral follicle count (AFC), antimüllerian hormone (AMH) level, and basal sex hormone level.

RESULTS

The study sample of 1,070 women had a mean age of 31.67 ± 4.41 years. A total of 314 participants (29.35%) were classified under the poor sleep group (PSQI score >5). Significant differences were observed in the follicle-stimulating hormone (FSH), luteinizing hormone, estradiol, testosterone, AFC, and AMH between the two groups. The poor sleep group exhibited significantly lower levels of AMH and AFC. The FSH levels in the poor sleep group were higher. After the adjustment for confounding factors, multivariate regression analysis results indicated that the per unit increase in PSQI score was associated with increased odds of diminished ovarian reserve (adjusted odds ratio [AOR] of 1.28 for AMH <1.1 ng/mL; 95% confidence interval [CI], 1.20-1.37; AFC <7; AOR, 1.34; 95% CI, 1.25-1.43; FSH ≥10 mIU/mL; AOR, 1.16; 95% CI, 1.08-1.25; AMH <1.1 ng/mL or AFC <7 or FSH ≥10 mIU/mL; AOR, 1.29; 95% CI, 1.22-1.37). Compared with the PSQI ≤5 group, subjects with PSQI >5 had increased odds of diminished ovarian reserve (odds ratio, 3.80; 95% CI, 2.82-5.13; AOR, 4.43; 95% CI, 3.22-6.14). After stratification by age and body mass index, compared with the PSQI ≤5 group, all subgroups of the PSQI >5 group had increased odds of diminished ovarian reserve, especially <35-year-old and body mass index ≤18.4 kg/m2 subgroups.

CONCLUSION

Poor sleep quality is associated with diminished ovarian reserve in women of reproductive age.

Effects of Smoking on In Vitro Fertilization Cycle Characteristics and Outcomes in Women with Infertility Aged Under 35 Years

The increasing incidence of infertility has increased the cost of assisted reproductive techniques and raised serious concerns on fertilization worldwide. Age and smoking adversely affect the reproductive system. This study aimed to assess the in vitro fertilization (IVF) cycle characteristics and outcomes of smoking women ages over 35 years. The data of 329 women ages 20-35 who underwent frozen embryo transfer in IVF treatment were used in the study. The M2 number, pregnancy outcome, live birth rate, and embryo transfer day showed statistically significant differences according to age group. The 2PN rate, pregnancy outcome, and live birth rate were significantly higher in nonsmoking women with infertility than in smoking women. The effects of these factors, especially smoking behavior, which can potentially be modified to increase the chance of IVF success, on IVF cycle characteristics should be explained to patients.

The Concentration of Follistatin and Activin A in Serum and Selected Biochemical Parameters in Women with Polycystic Ovary Syndrome: Stratification by Tobacco Smoke Exposure, Insulin Resistance, and Overweight/Obesity

Background/Objectives: The aim of the study was to investigate the concentrations of follistatin and activin A in the serum of women with polycystic ovary syndrome (PCOS) and to assess their relationship with selected biochemical parameters, specifically stratifying the analysis based on tobacco smoke, insulin resistance, and abnormal weight. Methods: The research was carried out within a cohort of 88 women (60 women with and 28 without PCOS). Results: We observed significant differences (p < 0.05) in follistatin concentrations between women with PCOS stratified by homeostatic model assessment for insulin resistance (HOMA-IR) values. These differences were consistent across both smoking and non-smoking subgroups with PCOS. Similar results were observed when comparing normal-weight women with PCOS to those with overweight or obesity. Additionally, activin A concentrations were significantly increased by higher body mass index (BMI) and HOMA-IR values in non-smoking women with PCOS. Moreover, we identified a negative correlation (r = -0.30; p < 0.023) between cotinine levels and Anti-Müllerian hormone. Among smoking women with PCOS, we noted decreased concentrations of sex hormone-binding globulin and high-density lipoproteins, alongside increased fasting glucose, insulin, HOMA-IR, and free androgen index values. Conclusions: Our findings suggest that activin A and follistatin concentrations are more strongly influenced by disruptions in glucose metabolism and BMI than by tobacco smoke exposure. The observed changes were more pronounced in follistatin than in activin A level.

Effect of systemic lupus erythematosus on the ovarian reserve: A systematic review and meta-analysis

OBJECTIVE

Systemic Lupus Erythematosus (SLE) is an autoimmune disease that occurs at higher rates in young women. Evidence suggests that SLE may be associated with ovarian dysfunction. Therefore, it is crucial to investigate the possible effects of SLE on ovarian reserve function.

METHODS

PubMed, Embase, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov databases were searched from inception to July 2023 to identify studies that compared ovarian reserve in patients with SLE to that of healthy individuals. The study examined anti-müllerian hormone (AMH), antral follicle count (AFC), and follicle-stimulating hormone (FSH) as outcomes.

RESULTS

Thirteen studies (n=1017) were eligible for meta-analysis. Females with SLE had significantly lower levels of AMH (weighted mean difference [WMD]: -1.07, 95% confidence interval [CI]: -1.37 to -0.76, P<0.001) and AFC (WMD: -3.46, 95% CI: -4.57 to -2.34, P<0.001). There was no significant difference in FSH levels. Subgroup analyses by age of onset revealed that SLE patients with adult-onset had significantly lower AMH levels (WMD: -1.44, 95% CI: -1.71 to -1.18, P<0.001), lower AFCs (WMD: -3.11, 95% CI: -3.60 to -2.61, P<0.001) and higher FSH levels (WMD: 0.60, 95% CI: 0.15 to 1.05, P<0.01). However, SLE patients with juvenile-onset did not exhibit significant differences in their AMH and FSH levels, except for AFCs (WMD: -7.27, 95% CI: -12.39 to -2.14, P<0.01).

CONCLUSION

The impact of SLE on ovarian reserve is significant, and the effect may be particularly severe in cases of adult-onset SLE.

A systematic review of the association between modifiable lifestyle factors and circulating anti-Müllerian hormone

BACKGROUND

Levels of anti-Müllerian hormone (AMH) are known to be associated with lifestyle determinants such as smoking and oral contraception (OC) use. When measuring AMH in clinical practice, it is essential to know which factors may influence circulating levels or ovarian reserve in general.

OBJECTIVE AND RATIONALE

To date, there is no systematic review or summarizing consensus of the nature and magnitude of the relation between AMH and modifiable lifestyle factors. The purpose of this review was to systematically assess the evidence on association of lifestyle behaviors with circulating AMH levels.

SEARCH METHODS

We performed a pre-registered systematic review of publications in Embase and PubMed on the lifestyle factors BMI, smoking, OC use, alcohol consumption, caffeine consumption, physical activity, and waist-hip ratio (WHR) in relation to circulating AMH levels up to 1 November 2023. The search strategy included terms such as 'Anti-Mullerian hormone', 'lifestyle', and 'women'. Studies were considered eligible if the association between at least one of the lifestyle factors of interest and AMH was assessed in adult women. The quality of included studies was assessed using the Study Quality Assessment Tools of the National Heart, Lung, and Blood Institute. The results were presented as ranges of the most frequently used association measure for studies that found a significant association in the same direction.

OUTCOMES

A total of 15 072 records were identified, of which 65 studies were eligible for inclusion, and 66.2% of the studies used a cross-sectional design. The majority of studies investigating BMI, smoking, OC use, and physical activity reported significant inverse associations with AMH levels. For WHR, alcohol, and caffeine use, the majority of studies did not find an association with AMH. For all determinants, the effect measures of the reported associations were heterogeneous. The mean difference in AMH levels per unit increase in BMI ranged from -0.015 to -0.2 ng/ml in studies that found a significant inverse association. The mean difference in AMH levels for current smokers versus non-smokers ranged from -0.4 to -1.1 ng/ml, and -4% to -44%, respectively. For current OC use, results included a range in relative mean differences in AMH levels of -17% to -31.1%, in addition to a decrease of 11 age-standardized percentiles, and an average decrease of 1.97 ng/ml after 9 weeks of OC use. Exercise interventions led to a decrease in AMH levels of 2.8 pmol/l to 13.2 pmol/l after 12 weeks in women with polycystic ovary syndrome or a sedentary lifestyle.

WIDER IMPLICATIONS

Lifestyle factors are associated with differences in AMH levels and thus should be taken into account when interpreting individual AMH measurements. Furthermore, AMH levels can be influenced by the alteration of lifestyle behaviors. While this can be a helpful tool for clinical and lifestyle counseling, the nature of the relation between the observed differences in AMH and the true ovarian reserve remains to be assessed.

REGISTRATION NUMBER

PROSPERO registration ID: CRD42022322575.

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).

Unraveling the link: environmental tobacco smoke exposure and its impact on infertility among American women (18-50 years)

Purpose

The detrimental effects of environmental tobacco smoke (ETS) on women's reproductive health have been widely recognized. However, the detailed association between exposure to environmental tobacco smoke and the incidence of infertility remains under-explored. This investigation focuses on exploring this potential connection.

Methods

For this analysis, we extracted data from the US National Health and Nutrition Examination Survey (NHANES) database, covering the years 2013 to 2018, focusing on individuals with recorded serum cotinine levels and infertility information. ETS exposure and fertility status were analyzed as independent and dependent variables, respectively. We applied weighted multivariate logistic regression method to evaluate the impact of ETS on infertility, including subgroup analyses for more detailed insights.

Results

The study encompassed 3,343 participants. Logistic regression analysis revealed a notable positive correlation between ETS exposure and infertility, with an odds ratio (OR) of 1.64 (95% Confidence Interval [CI]: 1.14-2.36). We observed a non-linear relationship between ETS exposure and infertility risk. Notably, infertility risk increased by 64% in serum cotinine levels above 0.136 compared to that in serum cotinine levels below 0.011. Further, subgroup analysis and interaction tests showed consistent results across different segments, underscoring the robustness of the ETS-infertility link.

Conclusion

Our findings suggest that environmental tobacco smoke exposure may be a contributing factor to infertility. These results reinforce the recommendation for women in their reproductive years to avoid ETS exposure, especially when planning for pregnancy.

Anti-Mullerian Hormone and Fertility Treatment Decisions in Polycystic Ovary Syndrome: A Literature Review

Anti-Mullerian hormone is a robust marker of ovarian reserve and ovarian response in in vitro fertilisation (IVF). However, its role extends beyond improving the safety of IVF by aiding in choosing appropriate protocols and dosing. This review looks at the value of pre-treatment anti-Mullerian hormone (AMH) value in choosing the appropriate modality of treatment and its predictive ability for the outcomes of such treatment. It briefly addresses the factors that may modulate AMH levels and make clinical decision-making challenging.

Iron intake in relation to ovarian reserve among women seeking infertility treatment

STUDY QUESTION

Is there an association between iron intake and ovarian reserve among women seeking fertility care?

SUMMARY ANSWER

Supplemental iron intake above 45 mg/day is associated with lower ovarian reserve among women seeking fertility care.

WHAT IS KNOWN ALREADY

Although the literature regarding iron intake in relation to ovarian reserve is scant and inconsistent, some evidence suggests that iron may have gonadotoxic effects.

STUDY DESIGN, SIZE, DURATION

This observational study included 582 female participants attending the Massachusetts General Hospital Fertility Center (2007-2019) enrolled in the Environment and Reproductive Health (EARTH) Study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Iron intake was estimated using a validated food frequency questionnaire. Markers of ovarian reserve included antral follicle count (AFC) (assessed via transvaginal ultrasound) and Day 3 FSH, both obtained during the course of an infertility evaluation.

MAIN RESULTS AND THE ROLE OF CHANCE

Participants had a median age of 35 years and median total iron intake of 29 mg/day. Total iron intake was inversely related to AFC and this association was driven by intake of supplemental iron. Compared to women with a supplemental iron intake of ≤20 mg/day, women consuming 45-64 mg/day of supplemental iron had a 17% (-35%, 0.3%) lower AFC and women consuming ≥65 mg/day of supplemental iron had a 32% (-54%, -11%) lower AFC after adjusting for potential confounders (P, linear trend = 0.003). Similarly, in a multivariable-adjusted analysis, Day 3 FSH levels were 0.9 (0.5, 1.3) IU/ml higher among women with a supplemental iron intake of ≥65 mg/day when compared to women with a supplemental iron intake of ≤20 mg/day (P, linear trend = 0.02).

LIMITATIONS, REASONS FOR CAUTION

Iron intake was estimated using a method that relies on self-report and we had no biomarkers of iron status in our participants; only 36 women consumed ≥45 mg/day of supplemental iron.

WIDER IMPLICATIONS OF THE FINDINGS

Since all study participants were seeking fertility treatment, our findings may not apply to women in the general population. Although our findings are consistent with studies of women with iron overload, given the paucity of literature on this topic, it is essential that this question is revisited in studies designed to better understand the dose-response relation of this association across the entire distribution of ovarian reserve and the risk-benefit balance of pre-conceptional iron supplementation given its many positive effects on pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by Grants R01ES022955, R01ES033651, R01ES009718, P30ES000002, and P30DK046200 from the National Institutes of Health. N.J.-C. was supported by a Fulbright Scholarship. N.J.-C., M.M., L.M.-A., E.O.-P., S.W., I.S., and J.E.C. declare no conflict of interest related to the work in the manuscript. R.H. has received grants from the National Institute of Environmental Health Sciences.

TRIAL REGISTRATION NUMBER

N/A.