Alcohol use as predictor for infertility in a representative population of Danish women

Association between tea, coffee and caffeine consumption and risk of female infertility: a cross-sectional study

OBJECTIVES

To explore the association between tea, coffee, and caffeine consumption and the risk of female infertility.

METHODS

We analyzed data from 2099 females aged 18 to 44 years, participating in the National Health and Nutrition Examination Survey (NHANES) 2013-2018. We used generalized linear models (GLM) and generalized additive model (GAM) to investigate the dose-response relationship between the tea, coffee, and caffeine consumption and infertility, adjusting for potential confounders.

RESULTS

A non-linear relationship was detected between tea consumption and infertility and the inflection point was 2 cups/day. On the right side of the inflection point, we did not detect a significant association. However, on the left side, we found a negative relationship between tea consumption and infertility (OR: 0.73; 95% CI: 0.57 to 0.93; P = 0.0122). Meanwhile, our study found no significant association between coffee (0.96, 0.81 to 1.13, P = 0.6189) or caffeine consumption (1.15, 0.93 to 1.42, P = 0.2148) and female infertility.

CONCLUSIONS

Tea consumption was non-linearly associated with infertility, whereas no significant associations were found between coffee, caffeine consumption and infertility.

Common Beverage Consumption and Benign Gynecological Conditions

The purpose of this article is to review the effects of four commonly consumed beverage types-sugar-sweetened beverages (SSBs), caffeinated beverages, green tea, and alcohol-on five common benign gynecological conditions: uterine fibroids, endometriosis, polycystic ovary syndrome (PCOS), anovulatory infertility, and primary dysmenorrhea (PD). Here we outline a plethora of research, highlighting studies that demonstrate possible associations between beverage intake and increased risk of certain gynecological conditions-such as SSBs and dysmenorrhea-as well as studies that demonstrate a possible protective effect of beverage against risk of gynecological condition-such as green tea and uterine fibroids. This review aims to help inform the diet choices of those with the aforementioned conditions and give those with uteruses autonomy over their lifestyle decisions.

Effects of physical activity on infertility in reproductive females

OBJECTIVES

To explore the relationship between different types of physical activity and female infertility.

METHODS

This study analyzed data from 2,796 female participants aged 18-44 years in the United States, obtained from the National Health and Nutrition Examination Survey (NHANES) database spanning the years 2013 to 2020. Multiple logistic regression analyses and generalized linear models were used to explore the relationship between different types of physical activity and infertility after adjusting for potential confounding factors.

RESULTS

We found a non-linear relationship between recreational activities and infertility with an inflection point of 5.83 h/week (moderate intensity), while work activities and traffic-related activities did not. On the left side of the inflection point, there was no significant association between recreational activity time and infertility (OR = 0.93, 95% CI: 0.86 to 1.02, P = 0.1146), but on the right side of the inflection point, there was a positive association between recreational activity time and the risk of infertility (OR = 1.04, 95% CI: 1.02 to 1.06, P = 0.0008).

CONCLUSIONS

The relationship between different types of physical activity and female infertility varies. We acknowledge the potential influence of confounding variables on this relationship. However, we have already adjusted for these potential variables in our analysis. Therefore, our findings suggest that appropriate recreational activity programs are essential for promoting reproductive health in women of reproductive age. Nevertheless, it is important to note that the observed association does not imply causality. Given the limitations of cross-sectional studies, further prospective cohort studies are needed to explore the causal relationship while accounting for additional confounding factors.

Impact of heavy alcohol consumption and cigarette smoking on sperm DNA integrity

The purposes of the presents study were to investigate the impact of alcohol consumption and cigarette smoking on semen parameters and sperm DNA quality, as well as to determine whether tobacco smoking, or alcohol consumption causes more deterioration of sperm quality. Two hundred and eleven semen samples of men were included in this study. Four groups were studied: heavy smokers (N = 48), heavy drinkers (N = 52), non-smokers (n = 70), and non-drinkers (n = 41). Semen parameters were determined according to WHO guidelines, protamine deficiency assessed by chromomycin (CMA3) staining, and sperm DNA fragmentation (sDF) evaluated by TUNEL assay. Sperm parameters were significantly higher in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.005). However, protamine deficiency and sDF were significantly lower in non-smokers versus smokers and in non-drinkers versus drinkers (p < 0.0001). No significant difference in the semen analysis parameters was observed between heavy smokers and heavy drinkers (semen volume: 3.20 ± 1.43 vs. 2.81 ± 1.56 ml, semen count: 65.75 ± 31.32 vs. 53.51 ± 32.67 mill/ml, total motility: 24.27 ± 8.18 vs. 23.75 ± 1.75%, sperm vitality: 36.15 ± 18.57 vs. 34.62 ± 16.65%, functional integrity: 41.56 ± 18.57 vs. 45.96 ± 17.98% and the morphologically normal spermatozoa: 28.77 ± 11.82 vs. 27.06 ± 13.13%, respectively). However, protamine deficiency was significantly higher among drinkers than smokers (37.03 ± 9.75 vs. 33.27 ± 8.56%, p = 0.020). The sDF was also significantly higher among drinkers than smokers (22.37 ± 7.60 vs. 15.55 ± 3.33%, p < 0.0001). Thus, cigarette smoking, and heavy alcohol intake can deteriorate sperm quality. However, alcohol consumption deteriorates sperm maturity and damages DNA integrity at significantly higher rates than cigarette smoking.

Optimizing natural fertility: a committee opinion

This committee opinion provides practitioners with suggestions for optimizing the likelihood of achieving pregnancy in couples or individuals attempting conception who have no evidence of infertility. This document replaces the document of the same name previously published in 2013 (Fertil Steril 2013;100:631-7).

Female Germ Cell Development, Functioning and Associated Adversities under Unfavorable Circumstances

In the present era, infertility is one of the major issues which restricts many couples to have their own children. Infertility is the inability to achieve a clinical pregnancy after regular unprotected sexual intercourse for the period of one year or more. Various factors including defective male or female germ cell development, unhealthy and improper lifestyles, diseases like cancer and associated chemo-or-radiation therapies, congenital disorders, etc., may be responsible for infertility. Therefore, it is highly important to understand the basic concepts of germ cell development including primordial germ cell (PGC) formation, specification, migration, entry to genital ridges and their molecular mechanisms, activated pathways, paracrine and autocrine signaling, along with possible alteration which can hamper germ cell development and can cause adversities like cancer progression and infertility. Knowing all these aspects in a proper way can be very much helpful in improving our understanding about gametogenesis and finding possible ways to cure related disorders. Here in this review, various aspects of gametogenesis especially female gametes and relevant factors causing functional impairment have been thoroughly discussed.

Potential causes of male and female infertility in Qatar

A steady decline in the fertility rate has been observed in Qatar during the past fifty years. Therefore, infertility is considered a national priority in Qatar, a pronatalist society. This review article summarises the potential causes of infertility that are particularly prevalent in the Qatari population. The high rate of consanguinity leading to genetic abnormalities, the high incidence of metabolic disease, environmental contamination due to the rapid urbanization and oil and natural gas extraction procedures are discussed. In addition, the particular lifestyle of the Qatari population and the influence of religion and culture on sexual and reproductive behavior in an Arab/Islamic society are considered. The active response of the state of Qatar in implementing ways to mitigate the effects of these factors to protect fertility are also presented.

Smoke, alcohol and drug addiction and female fertility

BACKGROUND

Considerable interest has been gathered on the relevant impact of preventable factors, including incorrect lifestyle and unhealthy habits, on female fertility. Smoking, alcohol and addictive drugs consumption represent a major concern, given the broad range of diseases which might be favored or exacerbated by these dependable attitudes. Despite the well-characterized effects of prenatal exposure on pregnancy outcomes and fetus health, a substantial proportion of women of reproductive age is still concerned with these habits. At present, the impact of smoke, alcohol and addictive drugs on women fertility, and, particularly, the specific targets and underlying mechanisms, are still poorly understood or debated, mainly due to the scarcity of well-designed studies, and to numerous biases.

OBJECTIVE

The current review will provide a comprehensive overview of clinical and experimental studies in humans and animals addressing the impact of smoke, alcohol and addictive drugs on female fertility, by also embracing effects on ovary, oviduct, and uterus, with particular reference to primary endpoints such as ovarian reserve, steroidogenesis, ovulation and menstrual cycle, oviduct function and uterus receptivity and implantation. A brief focus on polycystic ovary syndrome and endometriosis will be also included.

METHODS

A Pubmed literature search was performed with selected keywords; articles were individually retrieved by each author. No limitation was set for publication date. Articles in languages other than English were excluded. Additional articles were retrieved from references list of selected manuscripts.

RESULTS AND CONCLUSIONS

Currently, the most consistent evidences of a detrimental effect of smoke, alcohol and addictive drugs on specific domains of the female reproductive function are provided by experimental studies in animals. Overall, clinical studies suggest that smoking is associated to decreased fertility, although causal inference should be further demonstrated. Studies addressing the effect of alcohol consumption on female fertility provide conflicting results, although the majority reported lack of a correlation. Extremely scarce studies investigated the effects of addictive drugs on female fertility, and the specific actions of selected drugs have been difficult to address, due to multidrug consumption.

Observational Study of the Social Determinants of Health in Subfertile versus Nonsubfertile Women

CONTEXT

Subfertility affects about 15% of couples worldwide. There are several factors that affect subfertility called social determinants of health (SDH): biological factors as age, ethnic origin, and body mass index; behavioral factors as alcohol intake, smoking, coffee, dietary restriction, physical activity, and psychological state; and contextual factors as education, work activity, and income level.

AIMS

The aim of the study is to evaluate the distribution's relevance of the SDH in subfertile women versus nonsubfertile women.

SETTINGS AND DESIGN

A prospective comparative study with two groups of women recruited over 1 year at hospital consultation: one group with subfertile women excluding women without a male partner or with a previous child and another one formed by primigravidae, excluding those receiving assisted reproduction techniques to become pregnant.

SUBJECTS AND METHODS

We compare the different factors between subfertile and nonsubfertile women one by one. Second, a multivariate analysis was conducted with logistic regression. In all cases, informed consent was obtained.

RESULTS

Regular physical exercise 3-4 times/week (odds ratio [OR]: 0.33, 95% confidence interval [CI]: 0.15-0.71) or healthy food products such as fish 1-2 times/week (OR: 0.40, 95% CI: 0.17-0.95) were associated with nonsubfertile women.

CONCLUSIONS

The distribution of SDH in natural fertility is not altogether homogeneous. Weight control by means of restricting calorie intake, greater consumption of healthy foods such as fish, regular physical exercise, and lower age are positively associated with fertility. Population-level intervention is possible to improve women's health, as these are modifiable factors. Ethnic origin can be considered as a relevant factor, as it may condition the distribution of other determinants.

Diet and fertility: a review

The literature on the relationship between diet and human fertility has greatly expanded over the last decade, resulting in the identification of a few clear patterns. Intake of supplemental folic acid, particularly at doses higher than those recommended for the prevention of neural tube defects, has been consistently related to lower frequency of infertility, lower risk of pregnancy loss, and greater success in infertility treatment. On the other hand and despite promising evidence from animal models, vitamin D does not appear to exert an important role in human fertility in the absence of deficiency. Antioxidant supplementation does not appear to offer any benefits to women undergoing infertility treatment, but it appears to be beneficial when it is the male partner who is supplemented. However, the available evidence does not allow discerning which specific antioxidants, or at which doses, are responsible for this benefit. Long-chain omega-3 fatty acids appear to improve female fertility, although it remains unclear to what extent contamination of shared food sources, such as fish with high levels of environmental toxicants, can dampen this benefit. Lastly, adherence to healthy diets favoring seafood, poultry, whole grains, fruits, and vegetables are related to better fertility in women and better semen quality in men. The cumulative evidence has also piled against popular hypotheses. Dairy and soy, once proposed as reproductive toxicants, have not been consistently related to poor fertility. In fact, soy and soy supplements appear to exert a beneficial effect among women undergoing infertility treatment. Similarly, because data from large, high-quality studies continue to accumulate, the evidence of a potentially deleterious effect of moderate alcohol and caffeine intake on the ability to become pregnant seems less solid than it once did. While a complete picture of the role of nutrition on fertility is far from complete, much progress has been made. The most salient gaps in the current evidence include jointly considering female and male diets and testing the most consistent findings in randomized trials.

Female alcohol consumption and fecundability: a systematic review and dose-response meta-analysis

To what extent could alcohol consumption affects female fertility is still unclear. The aim of this study was to quantitatively summarize the dose-response relation between total and specific types of alcohol beverage (beer, wine, and spirits) consumption in female and the fecundability. Four electronic databases were searched. Observational studies (cohort and case-control) that provided female alcohol consumption and fecundity were eligible. Nineteen studies, involving 98657 women, were included in this study. Compared to non-drinkers, the combined estimate (with relative risk, RR) of alcohol consumers on fecundability was 0.87 (95% CI 0.78-0.95) for overall 19 studies. Compared to non-drinkers, the pooled estimates were 0.89 (95% CI 0.82-0.97) for light drinkers (≤12.5 g/day of ethanol) and 0.77 (95% CI 0.61-0.94) for moderate-heavy drinkers (>12.5 g/day of ethanol). Moreover, compared to non-drinkers, the corresponding estimates on fecundability were 0.98 (95% CI 0.85-1.11), 1.02 (95% CI 0.99-1.05), and 0.92 (95% CI 0.83-1.01) for studies focused on wine, beer and spirits, respectively. Dose-response meta-analysis suggested a linear association between decreased fecundability and every 12.5 g/d increasing in alcohol consumption with a RR 0.98 (95% CI 0.97-0.99). This first systematic review and meta-analysis suggested that female alcohol consumption was associated with a reduced fecundability.

Alcohol and fertility: how much is too much?

Alcohol use is prevalent in the United States. Given that a substantial portion of the drinking population is of reproductive age, it is not uncommon for couples who are attempting conception, or for women who are already pregnant, to be regularly consuming alcohol. Alcohol use is associated with multiple reproductive risks, including having a child with a Fetal Alcohol Spectrum Disorder, increased risk of fetal loss, and decreased chance of live birth. This review serves to examine the risks of alcohol in the context of reproductive health.

Fertility in Norwegian women: Results from a population-based health survey

Aims: Reproductive behaviour has changed during the most recent decades, with increased infertility and subfertility. This study evaluated fertility, estimated the prevalence of fertility problems, and assessed possible predictors for impaired fertility. Methods: Eligible subjects were 9,983 menopausal women participating in two health surveys. Data were collected by comprehensive questionnaires. Results: Of all women 89.3% were fertile, 4.8% were subfertile, 4.1% were voluntarily childless, and 1.8% were involuntaruly childless. Impaired fertility was associated with a higher level of education and excessive alcohol intake. There were significant differences in subfertility among the parous women, with increased subfertility with decreasing age. Among the nullipara, involuntary childlessness was more prevalent in the youngest age group, while voluntary childlessness increased with advancing age. Conclusions: Fertility problems were quite common, and have increased in younger age groups, though seemingly fewer women remained childless past their reproductive age in the youngest age group.

Alcohol intake, reproductive hormones, and menstrual cycle function: a prospective cohort study

BACKGROUND

Although habitual low-to-moderate alcohol intake has been linked with reduced all-cause mortality and morbidity, the effect of recent alcohol intake on female reproductive function has not been clearly established.

OBJECTIVE

We assessed the relation between acute alcohol consumption, reproductive hormones, and markers of menstrual cycle dysfunction including sporadic anovulation, irregular cycle length, luteal phase deficiency, long menses, and heavy blood loss.

DESIGN

A total of 259 healthy, premenopausal women from Western New York were followed for ≤2 menstrual cycles (2005-2007) and provided fasting blood specimens during ≤8 visits/cycle and four 24-h dietary recalls/cycle. Linear mixed models were used to estimate associations between previous day's alcohol intake and hormone concentrations, whereas Poisson regression was used to assess RR of cycle-average alcohol intake and menstrual cycle function.

RESULTS

For every alcoholic drink consumed, the geometric mean total and free estradiol, total and free testosterone, and luteinizing hormone were higher by 5.26% (95% CI: 1.27%, 9.41%), 5.82% (95% CI: 1.81%, 9.99%), 1.56% (95% CI: 0.23%, 2.90%), 1.42% (95% CI: 0.02%, 2.84%), and 6.18% (95% CI: 2.02%, 10.52%), respectively, after adjustment for age, race, percentage of body fat, perceived stress, pain-medication use, sexual activity, caffeine, and sleep. Binge compared with nonbinge drinking (defined as reporting ≥4 compared with <4 drinks/d, respectively) was associated with 64.35% (95% CI: 18.09%, 128.71%) and 63.53% (95% CI: 17.41%, 127.73%) higher total and free estradiol. No statistically significant associations were shown between cycle-average alcohol intake and menstrual cycle function.

CONCLUSION

Although recent moderate alcohol intake does not appear to have adverse short-term effects on menstrual cycle function, including sporadic anovulation, potential protective and deleterious long-term effects of alterations in reproductive hormones on other chronic diseases warrant additional investigation.

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

The impact of lifestyle modifications, diet, and vitamin supplementation on natural fertility

BACKGROUND

Infertility is a relatively common condition. When patients are confronted with this diagnosis, there are medical, psychological, and financial sequelae. Patients often wonder if there is anything they can do to optimize their natural fertility or increase the effectiveness of infertility treatments.

FINDINGS

If there is a clear impact on fertility, such as with smoking and alcohol, cessation should be advised. Similarly, weight loss should be recommended if the BMI is in the overweight and obese category, and weight gain should be recommended for an underweight BMI. The evidence surrounding other lifestyle modifications is less clear. There are conflicting data regarding an optimal fertility diet and consumption of vitamins and supplements. Antioxidants seem to improve semen parameters in men, but the effect on female fertility is less clear. If conflicting evidence exists, such as with caffeine consumption or exercise, moderation should be emphasized. Finally, the diagnosis of infertility and subsequent fertility treatments are stressful for both partners. The psychological aspects should not be ignored and methods such as yoga and cognitive behavioral therapy may be beneficial.

CONCLUSION

Continued research will determine the optimal lifestyle modifications to achieve pregnancy.

Prepregnancy Nutrition and Early Pregnancy Outcomes

Implantation failure and pregnancy loss are estimated to affect up to 75% of fertilized ova; however as of yet there is limited empirical evidence, particularly at the population level, for understanding the environmental determinants of these losses. The purpose of this review is to summarize the current knowledge on prepregnancy nutrition and early pregnancy outcomes with particular focus on the outcome of spontaneous abortion among pregnancies conceived naturally and early pregnancy end points among pregnancies conceived through in vitro fertilization. To date, there is limited evidence to support associations of prepregnancy vitamin D and caffeine intake with pregnancy loss. There is suggestive data supporting a link between a healthy diet and lower risk of pregnancy loss. High folate and minimal to no alcohol intake prior to conception have the most consistent evidence supporting an association with lower risk of pregnancy loss.

Modifiable Risk Factors and Infertility: What are the Connections?

Infertility is a relatively common condition, greatly affecting couples medically and psychologically. Although infertility treatment is safe, it can be time-intensive, expensive and increase the risk of multiple gestations. Thus, to reduce costs and risks, couples may initially consider lifestyle change to increase their fertility and chances of pregnancy. For many of the diet factors studied (for example: caffeine, soy, protein, iron), there are conflicting data. However, there are some items men and women consume that are detrimental to fertility, such as alcohol and tobacco. The data on exercise are varied but may have an effect on ovulation and fertility - positive or negative. Body mass index appears to impact fertility also, with obesity in both men and women negatively affecting pregnancy rates. In addition, there remains concern and a growing body of research on environmental toxin exposures and reproductive health. Finally, supporting patients through infertility diagnosis and treatment is critical, as psychological stress may impact conception. It is imperative that the relationship between lifestyle factors and fertility continue to be explored as to lessen the morbidity associated with infertility.

Low-to-moderate prenatal alcohol consumption and the risk of selected birth outcomes: a prospective cohort study

PURPOSE

To estimate whether low-to-moderate prenatal alcohol exposure is associated with selected birth outcomes.

METHODS

Low-to-moderate prenatal alcohol drinking and effects on low birthweight, preterm delivery, intrauterine growth restriction, and selected neonatal outcomes were evaluated among 4496 women and singleton infants. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression, controlling for confounding variables.

RESULTS

Early pregnancy drinking was associated with reduced odds of low birthweight, OR, 0.66 (95% CI, 0.46-0.96) and birth length less than 10th percentile, OR, 0.74 (95% CI, 0.56-0.97). Drinking during the first 3 months showed lower odds for birth length and head circumference less than 10th percentile, OR, 0.56 (95% CI, 0.36-0.87) and OR, 0.69 (95% CI, 0.50-0.96), respectively. Third trimester drinking was associated with lower odds for low birthweight, OR, 0.56 (95% CI, 0.34-0.94) and preterm delivery, OR, 0.60 (95% CI, 0.42-0.87).

CONCLUSIONS

Our results suggest low-to-moderate alcohol exposure during early and late gestation is not associated with increased risk of low birthweight, preterm delivery, intrauterine growth restriction, and most selected perinatal outcomes.

General aspects of fertility and infertility

Fertility rates have been declining in most Western nations over the past several decades, although it is not entirely clear if an increased rate of infertility substantially contributes to this. As compared to other species, the reproductive efficiency of humans is relatively low. Factors related to fertility include age, exposure to sexually transmitted diseases, frequency of intercourse, coital timing, as well as diet and lifestyle habits. Infertility is considered a disease due to its major disruption of major organ systems and life functions. An infertility evaluation is recommended after 12 months or more of regular, unprotected intercourse and may be considered after 6 months for those female patients over the age of 35 or with other known abnormalities. A proper infertility evaluation is a comprehensive examination of possibly identifiable infertility factors of both female and male partners, lending itself to the most appropriate and potentially effective treatment.

Has fertility declined from mid-1990s to mid-2000s?

OBJECTIVE

To assess changes in self-reported fertility from the mid-1990s to the mid-2000s.

DESIGN

The study is a retrospective population-based study.

SETTING

The study applied a dataset from two cross-sectional surveys conducted in the mid-1990s and some 10 years later, inviting all women in a county in Norway.

POPULATION

Women aged 50-59 years enrolled in either survey constituted two cohorts. Data on 4468 women in the first survey (Cohort 1940) and 4951 women in the latter survey (Cohort 1950) were collected by structured questionnaires.

MAIN OUTCOME MEASURES

Prevalence of fertility, infertility with subcategories subfertility and involuntary childlessness, as well as childlessness was estimated and compared between the surveys. Possible sociodemographic and lifestyle predictors of fertility were assessed at different points in time.

RESULTS

Fertility declined over the two successive surveys; 87.8% of the women in Cohort 1940 were fertile compared with 84.2% of the women in Cohort 1950 (p = 0.000). The prevalence of infertility increased over time due to an increase in subfertility from 7.8 to 10.6% (p = 0.000). The level of education increased with time, as did at-risk alcohol consumption and smoking, and these factors were adversely associated with fertility. The proportion of childless women increased across surveys (p = 0.004) but relatively fewer women were involuntarily childless in Cohort 1950 than in Cohort 1940 (p = 0.543).

CONCLUSION

Fertility, measured at 10-year intervals, declined significantly. The decline in fertility was related to changes in subfertility. Adjustments for sociodemographic and lifestyle factors did not fully explain the decline in fertility.

The effects of oxidative stress on female reproduction: a review

Oxidative stress (OS), a state characterized by an imbalance between pro-oxidant molecules including reactive oxygen and nitrogen species, and antioxidant defenses, has been identified to play a key role in the pathogenesis of subfertility in both males and females. The adverse effects of OS on sperm quality and functions have been well documented. In females, on the other hand, the impact of OS on oocytes and reproductive functions remains unclear. This imbalance between pro-oxidants and antioxidants can lead to a number of reproductive diseases such as endometriosis, polycystic ovary syndrome (PCOS), and unexplained infertility. Pregnancy complications such as spontaneous abortion, recurrent pregnancy loss, and preeclampsia, can also develop in response to OS. Studies have shown that extremes of body weight and lifestyle factors such as cigarette smoking, alcohol use, and recreational drug use can promote excess free radical production, which could affect fertility. Exposures to environmental pollutants are of increasing concern, as they too have been found to trigger oxidative states, possibly contributing to female infertility. This article will review the currently available literature on the roles of reactive species and OS in both normal and abnormal reproductive physiological processes. Antioxidant supplementation may be effective in controlling the production of ROS and continues to be explored as a potential strategy to overcome reproductive disorders associated with infertility. However, investigations conducted to date have been through animal or in vitro studies, which have produced largely conflicting results. The impact of OS on assisted reproductive techniques (ART) will be addressed, in addition to the possible benefits of antioxidant supplementation of ART culture media to increase the likelihood for ART success. Future randomized controlled clinical trials on humans are necessary to elucidate the precise mechanisms through which OS affects female reproductive abilities, and will facilitate further explorations of the possible benefits of antioxidants to treat infertility.

Management of the infertile couple: an evidence-based protocol

BACKGROUND

Infertility is defined as inability of a couple to conceive naturally after one year of regular unprotected sexual intercourse. It remains a major clinical and social problem, affecting perhaps one couple in six. Evaluation usually starts after 12 months; however it may be indicated earlier. The most common causes of infertility are: male factor such as sperm abnormalities, female factor such as ovulation dysfunction and tubal pathology, combined male and female factors and unexplained infertility.

OBJECTIVES

The aim of this study is to provide the healthcare professionals an evidence-based management protocol for infertile couples away from medical information overload.

METHODS

A comprehensive review where the literature was searched for "Management of infertility and/or infertile couples" at library website of University of Bristol (MetaLib) by using a cross-search of different medical databases besides the relevant printed medical journals and periodicals. Guidelines and recommendations were retrieved from the best evidence reviews such as that from the American College of Obstetricians and Gynaecologists (ACOG), American Society for Reproductive Medicine (ASRM), Canadian Fertility and Andrology Society (CFAS), and Royal College of Obstetricians and Gynaecologists (RCOG).

RESULTS

A simple guide for the clinicians to manage the infertile couples.

CONCLUSIONS

The study deploys a new strategy to translate the research findings and evidence-base recommendations into a simplified focused guide to be applied on routine daily practice. It is an approach to disseminate the recommended medical care for infertile couple to the practicing clinicians.

Impact of oxidative stress on female fertility

PURPOSE OF REVIEW

To review the role of oxidative stress in the context of female fertility.

RECENT FINDINGS

Oxidative stress is associated with decreased female fertility in animal and in-vitro models, but no studies to date have directly assessed the relationship in women. Exposures associated with oxidative stress and with evidence to influence the timing and maintenance of a viable pregnancy include pregnancy complications (e.g. preeclampsia), extremes of body weight, alcohol, tobacco, and caffeine intake. Intake of antioxidant nutrients, including use of multivitamins, impacts the generation of reactive oxygen species and may play a beneficial role in female fertility.

SUMMARY

Infertility is a significant public health problem and diagnosis and treatment are stressful, invasive, and costly. The role of oxidative stress in female fertility is an understudied and compelling area for investigation. Identifying modifiable factors to decrease oxidative stress in the gynecologic environment may be an inexpensive and noninvasive therapy for increasing fertility.

Caffeinated and alcoholic beverage intake in relation to ovulatory disorder infertility

BACKGROUND

Many studies have examined whether caffeine, alcohol, or specific beverages containing these substances affect fertility in women. However, most of these studies have retrospectively collected information on alcohol and caffeine intake, making the results susceptible to biases.

METHODS

We followed 18,555 married women without a history of infertility for 8 years as they attempted to become (or became) pregnant. Diet was measured twice during this period and prospectively related to the incidence of ovulatory disorder infertility.

RESULTS

There were 438 incident report of ovulatory disorder infertility during follow-up. Intakes of alcohol and caffeine were unrelated to the risk of ovulatory disorder infertility. Comparing the highest to lowest categories of intake, the multivariate-adjusted relative risk, was 1.11 (95% confidence interval = 0.76-1.64; P for trend 0.78) for alcohol and 0.86 (0.61-1.20; 0.44) for total caffeine. However, intake of caffeinated soft drinks was positively related to ovulatory disorder infertility. Comparing the highest to lowest categories of caffeinated soft drink consumption, the RR was 1.47 (1.09-1.98; 0.01). Similar associations were observed for noncaffeinated, sugared, diet, and total soft drinks.

CONCLUSIONS

Our findings do not support the hypothesis that alcohol and caffeine impair ovulation to the point of decreasing fertility. The association between soft drinks and ovulatory disorder infertility seems not to be attributable to their caffeine or sugar content, and deserves further investigation.

Optimizing natural fertility

This Committee Opinion provides practitioners with suggestions for optimizing the likelihood of achieving pregnancy in couples attempting conception who have no evidence of infertility.

Racial differences in self-reported infertility and risk factors for infertility in a cohort of black and white women: the CARDIA Women's Study

OBJECTIVE

To determine racial differences in self-reported infertility and in risk factors for infertility in a cohort of black and white women.

DESIGN

A cross-sectional analysis of data from the longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) Study, a prospective, epidemiologic investigation of the determinants and evolution of cardiovascular risk factors among black and white young adults and from the ancillary CARDIA Women's Study (CWS).

SETTING

Population-based sample from four US communities (Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA).

PATIENT(S)

Women aged 33-44 years who had complete data (n = 764).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Self-report of ever having unprotected sexual intercourse for at least 12 months without becoming pregnant.

RESULT(S)

Among nonsurgically sterile women, blacks had a twofold increased odds (95% confidence interval [CI] 1.3-3.1) of infertility compared with whites after adjustment for socioeconomic position (education and ability to pay for basics), correlates of pregnancy intent (marital status and hormonal contraceptive use), and risk factors for infertility (age, smoking, T, fibroid presence, and ovarian volume). The corresponding odds ratio among all women was 1.5 (95% CI 1.0-2.2). Difficulty paying for basics and ovarian volume were associated with infertility among black but not white women.

CONCLUSION(S)

In this population-based sample, black women were more likely to have experienced infertility. This disparity is not explained by common risk factors for infertility, such as smoking and obesity, and among nonsurgically sterile women, it is not explained by gynecologic risk factors such as fibroids and ovarian volume.

Problem drinking in women evaluated for infertility

Clinicians may wish to use the T-ACE, a screening instrument for prenatal risk drinking, for their infertile patients. Twenty-eight T-ACE negative and 23 T-ACE positive women presenting to an academic infertility clinic completed two interviews about their drinking. The 23 T-ACE positive participants were also randomized to receive a brief intervention. The T-ACE distinguished between heavier and lighter patterns of alcohol use in this sample. Moreover, it appeared that although the average quantity of alcohol consumed per drinking day was unchanged, the overall mean percentage of days drinking declined significantly from the time of enrollment to follow-up in all groups.

ART: iatrogenic multiple pregnancy?

Assisted reproductive technologies (ART) are now widely accepted as effective treatment for most causes of infertility. With improving success rates, attention has turned to the problem of multiple pregnancies, which are associated with a poor perinatal outcome, maternal complications and significant financial consequences. The challenge is to reduce multigestational pregnancies while maintaining good treatment outcomes. Methods to prevent multiple pregnancy include restrictive use of ART in couples with a good chance of spontaneous pregnancy, cautious use of gonadotrophins, and increased use of natural-cycle intra-uterine insemination and elective single embryo transfer in in-vitro fertilization and intracytoplasmic sperm injection. The aim of this article is to review the contribution of fertility treatment to multiple pregnancies and strategies for reducing multiples in ART.

Environmental and occupational factors affecting fertility and IVF success

Reproductive function has been shown to be sensitive to changes in the physical, psychosocial and chemical environments. Although reproductive effects of occupational exposure to hazardous chemicals have been well documented in the literature, the potential effects of chemical contaminants at levels representative of contemporary exposures in the general population are much less certain. Evidence for adverse effects of exposure to environmental contaminants is more conclusive among the lower animals than for humans where considerable controversy remains. In addition to potential reproductive hazards of exposure to environmental contaminants, there is also evidence for adverse reproductive effects of the physical and psychosocial environments. In this review we focus on the difficulties involved in linking exposure to putative hazardous substances in environmental and occupational settings to adverse reproductive outcomes, especially success of IVF procedures. We highlight the plausibility of adverse events through animal and cell studies and the application of these results to the interpretation of human data. We consider both the male and female partners since it is essentially their combined contributions of gametes which may be affected by chemicals, which lead to successful outcomes.