Moderate alcohol consumption and waiting time to pregnancy

Fertility of Women Treated during Childhood with Triptorelin (Depot Formulation) for Central Precocious Puberty: The PREFER Study

BACKGROUND

Gonadotropin-releasing hormone analogues (GnRHa) administered as depot formulations are the standard of care for children with central precocious puberty (CPP). Puberty resumes after treatment discontinuation, but little is known concerning fertility in women who have been treated with GnRHa for CPP during childhood.

METHODS

The PREFER (PREcocious puberty, FERtility) study prospectively analysed fertility, via a series of questionnaires, in women treated during childhood with triptorelin (depot formulation) for CPP. Co-primary endpoints were the proportion of women wanting a pregnancy any time before study inclusion and during the follow-up period but not pregnant 6 and 12 months after stopping contraception and the waiting time to pregnancy (WTP).

RESULTS

A total of 574 women were identified, and 194 women were included in the analysis. Although there were not enough data for primary endpoint assessment, few women (1.7%) reported issues with fertility or were unable to become pregnant despite trying to conceive. Most pregnancies (84.4%, 95% CI [67.2-94.7%]) occurred within 1 year of trying to conceive, in line with the WTP for women without previous CPP.

CONCLUSION

The results, based on a limited sample of patients, suggest that CPP treated with triptorelin does not negatively impact women's fertility in adulthood. These results need to be consolidated with a subsequent study performed when these women will have reached their mid-thirties.

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.

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.

Information bias in epidemiological studies with a special focus on obstetrics and gynecology

Information bias occurs when any information used in a study is either measured or recorded inaccurately. This paper describes some of the most common types of information bias, using examples from obstetrics and gynecology, and describes how information bias may affect results of observational studies. Non-differential misclassification occurs when the degree of misclassification of exposure status among those with and those without the disease is the same; in cohort studies, this type of bias is most likely and will bias estimates toward no association when exposure is dichotomized. Non-differential underreporting of an exposure with more than two categories may mask a true threshold effect as a dose-response relation and, if a true threshold effect exists, the threshold will be set at too low a level, if the exposure is underreported. Differential misclassification may cause bias in either direction and is particularly likely, when exposure status is reported after the outcome occurred. Misclassification of confounders is an issue that needs special attention by researchers, as failure to measure accurately one or more (strong) confounders may seriously bias the observed results. Misclassification of disease status may also cause bias of estimates of association in either direction. Information bias is probably best prevented during planning of data collection, as there are few and insufficient methods available for correcting inaccurate information.

The impact of maternal lifestyle factors on periconception outcomes: a systematic review of observational studies

The main risk factors for important reproductive health issues such as subfertility and perinatal mortality largely originate in the periconception period. To evaluate associations between modifiable maternal lifestyle factors and periconception outcomes, a systematic search was conducted for relevant studies published from 1990 to February 2017 on Embase, Medline, Web of Science, Cochrane database, PubMed and Google Scholar. The initial search identified 6166 articles, of which 49 studies were eligible for inclusion. Fecundity (the capacity to have a live birth) showed significant inverse associations with smoking, alcohol use and poor diet. Studies regarding time to pregnancy showed a decline in fecundity ratios (the monthly conception rate among exposed relative to unexposed couples) with increasing body mass index (BMI). Furthermore, risk of first-trimester miscarriage was found to be increased in smokers, alcohol and caffeine consumers, and with increasing BMI. Vitamin supplement use showed a decrease in this risk. This review demonstrates that maternal modifiable lifestyle factors affect periconception outcomes. If couples planning a pregnancy are more aware and supported to adopt healthy lifestyles during the periconceptional 'window of opportunity', short-term reproductive health as well as health in later life and even of future generations can be further improved.

Caffeine, alcohol, smoking, and reproductive outcomes among couples undergoing assisted reproductive technology treatments

During the past decade, as the use of assisted reproductive technologies (ART) has continued to increase worldwide, research investigating whether modifiable lifestyle factors, such as alcohol, caffeine, and smoking, may affect ART outcomes has grown. Despite the vast literature, there is still uncertainty regarding the effects of some of these exposures on ART outcomes. The objective of this review is to summarize the epidemiologic literature on intakes of caffeine and alcohol, smoking, and reproductive outcomes among women undergoing ART. Of the five epidemiologic studies on caffeine intake and ART outcomes, only one found a significant negative effect of caffeine intake on live birth following ART. There have been six epidemiologic studies exploring whether alcohol intake is associated with fertility outcomes among women undergoing ART. Three studies assessed current alcohol consumption and observed a negative effect on outcomes such as fertilization, embryo quality, and implantation. When alcohol intake in the year before treatment was assessed, no relationships were observed with clinical outcomes following ART. Finally, numerous epidemiologic studies and a handful of meta-analyses have confirmed that female current smokers have worse ART outcomes compared with nonsmokers. Although former smokers tend to have better ART outcomes than current smokers, very few individual studies have investigated the influence of smoking cessation on ART outcomes. Literature on male smoking, drinking, and caffeine habits in relation to ART outcomes is even sparser and inconsistent, making it difficult to draw strong conclusions on that topic. In summary, there is little evidence supporting a detrimental effect of moderate caffeine intake on ART outcomes. Current consumption of alcohol may have a negative effect on ART outcomes, but at present the evidence is limited. Women who currently smoke cigarettes have been consistently found to have poorer ART outcomes, including reduced live birth rates, but a quantification of the benefits of smoking cessation is lacking.

The association between pre-treatment maternal alcohol and caffeine intake and outcomes of assisted reproduction in a prospectively followed cohort

STUDY QUESTION

Is pre-treatment alcohol and caffeine intake associated with infertility treatment outcomes among women undergoing ART?

SUMMARY ANSWER

Low to moderate alcohol and caffeine intakes in the year prior to infertility treatment were not related to ART outcomes.

WHAT IS KNOWN ALREADY

Alcohol and caffeine intake have been found to be associated with infertility in some studies. Nevertheless, data on their relation with outcomes of infertility treatments are scarce and inconsistent.

STUDY DESIGN, SIZE, DURATION

We included 300 women (493 ART cycles) from the Environment and Reproductive Health Study, an ongoing cohort study (2006-2016).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pre-treatment intakes of alcohol and caffeine were assessed retrospectively using a validated food frequency questionnaire. Intermediate and clinical endpoints of ART were abstracted from electronic medical records. Generalized linear mixed models with random intercepts to account for multiple ART cycles per woman were used to evaluate the association with ART outcomes adjusting for age, BMI, smoking status, infertility diagnosis, protocol type, race, dietary patterns, and calories, vitamin B12 and folate intake.

MAIN RESULTS AND THE ROLE OF CHANCE

Median (range) pre-treatment alcohol and caffeine intakes were 5.6 (0.0-85.8) g/day and 124.9 (0.3-642.2) mg/day, respectively. The adjusted percentage of initiated cycles resulting in live birth (95% CI) for women in increasing categories of pre-treatment alcohol intake was 34% (20, 52%) for non-consumers, 46% (36, 57%) for 0.1-6 g/day, 41% (29, 53%) for 6.1-12 g/day, 42% (31, 55%) for 12.1-24 g/day, and 41% (22, 63%) for >24 g/day (P, trend = 0.87). The adjusted percentage of cycles resulting in live birth (95% CI) for women in increasing categories of caffeine intake was 46% (36-57%) for <50 mg/day, 44% (29, 60%) for 50.1-100 mg/day, 42% (31, 53%) for 100.1-200 mg/day, 40% (28, 53%) for 200.1-300 mg/day and 40% (21, 63%) for >300 mg/day (P, trend = 0.34). When specific types of alcoholic and caffeinated beverages were evaluated, no relations with ART treatment outcomes were observed.

LIMITATIONS, REASONS FOR CAUTION

Residual confounding by other diet and lifestyle factors cannot be ruled out owing to the observational nature of this study. It is also unclear how generalizable these results are to women who are conceiving without the assistance of ART.

WIDER IMPLICATIONS OF THE FINDINGS

Our results provide reassurance that low to moderate intakes of alcohol (e.g. ≤12 g/day) and caffeine (e.g. <200 mg/day) in the year prior to infertility treatment initiation do not have an adverse effect on intermediate or clinical outcomes of ART.

STUDY FUNDING/COMPETING INTEREST(S)

The authors are supported by National Institutes of Health (NIH) grants ES022955, R01ES009718, R01ES000002, P30DK46200 and L50-HD085359. No conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT00011713.

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 consumption and fecundability: prospective Danish cohort study

OBJECTIVE

 To investigate to what extent alcohol consumption affects female fecundability.

DESIGN

 Prospective cohort study.

SETTING

 Denmark, 1 June 2007 to 5 January 2016.

PARTICIPANTS

 6120 female Danish residents, aged 21-45 years, in a stable relationship with a male partner, who were trying to conceive and not receiving fertility treatment.

MAIN OUTCOME MEASURES

 Alcohol consumption was self reported as beer (330 mL bottles), red or white wine (120 mL glasses), dessert wine (50 mL glasses), and spirits (20 mL) and categorized in standard servings per week (none, 1-3, 4-7, 8-13, and ≥14). Participants contributed menstrual cycles at risk until the report of pregnancy, start of fertility treatment, loss to follow-up, or end of observation (maximum 12 menstrual cycles). A proportional probability regression model was used to estimate fecundability ratios (cycle specific probability of conception among exposed women divided by that among unexposed women).

RESULTS

 4210 (69%) participants achieved a pregnancy during follow-up. Median alcohol intake was 2.0 (interquartile range 0-3.5) servings per week. Compared with no alcohol consumption, the adjusted fecundability ratios for alcohol consumption of 1-3, 4-7, 8-13, and 14 or more servings per week were 0.97 (95% confidence interval 0.91 to 1.03), 1.01 (0.93 to 1.10), 1.01 (0.87 to 1.16) and 0.82 (0.60 to 1.12), respectively. Compared with no alcohol intake, the adjusted fecundability ratios for women who consumed only wine (≥3 servings), beer (≥3 servings), or spirits (≥2 servings) were 1.05 (0.91 to1.21), 0.92 (0.65 to 1.29), and 0.85 (0.61 to 1.17), respectively. The data did not distinguish between regular and binge drinking, which may be important if large amounts of alcohol are consumed during the fertile window.

CONCLUSION

 Consumption of less than 14 servings of alcohol per week seemed to have no discernible effect on fertility. No appreciable difference in fecundability was observed by level of consumption of beer and wine.

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.

Consumption and drinking frequency of alcoholic beverage among women in Ghana: a cross-sectional study

Background

The consumption and drinking frequency of alcoholic beverage are identified with various individual factors. The aim of this study was to identify background characteristics of women associated with the consumption and drinking frequency of alcoholic beverage.

Methods

Data was extracted from the 2008 Ghana Demographic and Health Survey. The data consisted of women’s (aged 15–49 years) background characteristics and their reported history of consumption and drinking frequency of alcoholic beverage. A weighted sample size of 4916 women was used in the present study. Binary logistic regression and multinomial logistic regression were applied to examine the independent association between the covariates and the consumption and drinking frequency of alcoholic beverage respectively.

Results

Out of the 4916 women that were included in the study, 17.5% consumed alcoholic beverage in the past week. Factors that were found to be associated with women who consumed alcoholic beverage in a binary logistic regression model were age (15–19 years up to 45–49 years), region (Central, Greater Accra, Volta, Ashanti, Northern, Upper East, and Upper West), ethnicity (Ga or Dangme, Mole-Dagbani, Grussi, Gruma or Mande), wealth quintile (middle), and employment status [past 12 months] (those employed). In the multinomial logistic regression model, drinking frequency of alcoholic beverage was associated with women in the Central (none), Greater Accra Region (none and 4 or more times), Eastern (none and 2–3 times), Brong Ahafo (none), Upper East (none), those who attained primary education (4 or more times), Ga/Dangme ethnic group (none), those of middle wealth quintile (none), and those employed (4 or more times).

Conclusions

In the country, about 2 in 10 women consume alcoholic beverage and the drinking frequency of alcoholic beverage varied among women in the country. Hence, the maintenance of moderate alcoholic beverage consumption among women, where applicable, should be encouraged.

Effect of alcohol consumption on in vitro fertilization

OBJECTIVE

To estimate whether alcohol use at the initiation of an in vitro fertilization (IVF) cycle is associated with IVF outcomes.

METHODS

In this prospective cohort study, men and women completed a self-administered questionnaire before their first IVF cycle. Participants reported alcohol type, amount, and frequency consumed. Discrete survival analysis was applied to calculate the odds ratio (OR) and 95% confidence interval (CI) for live birth-the primary outcome. Secondary outcomes were cycle characteristics and points of failure in the IVF process (cycle cancellation, failed fertilization, implantation failure, and spontaneous abortion). We conducted multicycle analyses with final models adjusted for potential confounders that included cycle number, cigarette use, body mass index, and age.

RESULTS

A total of 2,545 couples contributed 4,729 cycles. Forty-one percent of women and 58% of men drank one to six drinks per week. Women drinking at least four drinks per week had 16% less odds of a live birth rate compared with those who drank fewer than four drinks per week (OR 0.84, CI 0.71-0.99). For couples in which both partners drank at least four drinks per week, the odds of live birth were 21% lower compared with couples in which both drank fewer than four drinks per week (OR 0.79; CI 0.66-0.96).

CONCLUSION

Consumption of as few as four alcoholic drinks per week is associated with a decrease in IVF live birth rate.

LEVEL OF EVIDENCE

II.

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.

Predictors of preconceptional folic acid or multivitamin supplement use: a cross-sectional study of Danish pregnancy planners

Purpose

Compliance with the Danish preconceptional folic acid (FA) recommendation – a daily supplement of 400 μg – is reported to be poor. Uncertainty remains, however, about the prevalence of compliers and health-related predictors of compliance in the preconceptional period.

Methods

We used self-reported baseline data from 5383 women, aged 18–40 years, enrolled in an Internet-based prospective cohort study of Danish pregnancy planners during 2007–2011. We estimated the prevalence proportions of FA or multivitamin (MV) use in relation to selected sociodemographic, lifestyle, reproductive, and medical characteristics. Multivariate binomial regression was used to obtain prevalence proportion differences with 95% confidence intervals for each level of study predictors, adjusted for all other predictors.

Results

Overall, 7.7% of women used FA supplements, 20.4% used MV supplements, 34.0% used both, 1.5% used other single vitamins or minerals, and 36.4% did not use any dietary supplements. The prevalence of FA or MV supplement use was higher among older women, women with higher education and income, and women with healthy lifestyle factors such as being a nonsmoker, nondrinker, physically active, maintaining a normal body mass index and having regular pap smears. Greater intercourse frequency and a history of spontaneous abortion were also positively associated with FA or MV supplement use. We found no clear association between use of FA or MV supplements and a diagnosis of hypertension, diabetes, thyroid disease, pelvic inflammatory disease, or chlamydia.

Conclusion

A large proportion of pregnancy planners do not use FA or MV supplements. Pregnancy planners with generally risky lifestyle behaviors are less likely to comply with the FA recommendation.

The influence of maternal and paternal factors on time to pregnancy--a Dutch population-based birth-cohort study: the GECKO Drenthe study

BACKGROUND

Both maternal and paternal factors have been suggested to influence a couple's fecundity. To investigate this, we examined the role of several maternal and paternal lifestyle and socio-demographic factors as determinants of time to pregnancy (TTP) in a Dutch birth-cohort.

METHODS

Groningen Expert Center for Kids with Obesity (GECKO) Drenthe is a population-based birth-cohort study of children born between April 2006 and April 2007 in Drenthe, a province of The Netherlands. Both partners received extensive questionnaires during pregnancy. Univariable and multivariable Cox regression analyses were used to determine the impact of the investigated factors on TTP.

RESULTS

A total of 4778 children were born, and the parents of 2997 children (63%) gave their consent to participate. After excluding unintended pregnancies and pregnancies as a result of fertility treatment, the data of 1924 couples were available for analysis. Hazards ratios and 95% confidence intervals of factors influencing TTP in multivariable Cox regression analysis were: maternal age 1.23 (0.98-1.54) for age <25 years, 1.17 (1.03-1.32) for age 25-30 years and 0.72 (0.61-0.85) for age >35 years (reference category: 30-35 years); paternal age: 1.31 (0.94-1.82) for age <25 years, 1.11 (0.97-1.28) for age 25-30 years and 0.91 (0.80-1.04 for age >35 years (reference category: 30-35 years); nulliparity: 0.76 (0.68-0.85) versus multiparity; menstrual cycle length: 1.12 (0.95-1.30) for 3 weeks, 0.72 (0.62-0.83) for 4-6 weeks, 0.68 (0.40-1.16) for >6 weeks and 0.66 (0.54-0.81) for irregular cycle (reference category: 4 weeks); prior contraceptive use: 0.78 (0.67-0.91) for no contraception, 1.68 (1.45-1.95) for condom use, 1.08 (0.89-1.33) for condom use combined with oral contraception, 1.40 (1.16-1.70) for intrauterine device and 0.50 (0.25-1.01) for contraceptive injection (reference category: oral contraception); and maternal educational level 0.75 (0.62-0.92) for low education level and 0.81 (0.73-0.90) for medium educational level (reference category: high educational level).

CONCLUSIONS

This population-based birth-cohort study performed in fertile couples who had conceived revealed neither maternal nor paternal modifiable lifestyle factors were significantly associated with TTP after adjustment for confounding by socio-demographic factors. In contrast, several non-modifiable maternal socio-demographic factors are significant predictors of a couple's fecundity.

Lifestyle factors in people seeking infertility treatment - A review

BACKGROUND

Clinical infertility is a prevalent problem with significant financial and psychosocial costs. Modifiable lifestyle factors exist that may affect a person's time to conception and their chance of having a healthy, live birth. However, no guideline delineates what preconception advice should be offered to people presenting for infertility treatment.

AIM

The aim of this article is to review the literature regarding modifiable lifestyle factors in people seeking infertility treatment.

RESULTS

A person's time to pregnancy and their chance of having a healthy, live birth may be affected by factors such as weight, vitamin and iodine intake, alcohol and caffeine consumption, smoking, substance abuse, stress, environmental pollutants, vaccinations and oxidative stress.

CONCLUSIONS

Advice on modifiable lifestyle factors should be given to people presenting for infertility treatment to help them make positive changes that may improve their chances of pregnancy and delivering a healthy, live baby. Developing a guideline for this would be a prudent step towards helping clinicians to implement this aspect of preconception care.

Health and life style among infertile men and women

OBJECTIVE

Lifetime prevalence of infertility among couples is approximately 10-15%, but studies addressing their health behavior are few. Our aim was to describe health and life style of Finnish men and women who had experienced infertility.

DESIGN

Cross-sectional survey.

SETTING

Finland.

POPULATION AND METHODS

Data from a population-based survey (n=7021) was utilized. Life style of infertile men (n=289) and women (n=155) were compared to other men and fertile women.

MAIN OUTCOME MEASURES

Life style (dietary factors, use of alcohol, physical activity), reproductive factors, other diseases and symptoms.

RESULTS

After adjusting for age, area and education, infertile women under 50 years consumed more polyunsaturated fat (OR 1.23, 95% CI 1.03-1.46), less saturated fat (OR 0.83, 95% CI 0.74-0.92) and had experienced more hangovers during previous year (OR 1.02, 95% CI 1.00-1.05) than fertile women. Infertile men under 50 years consumed more total fat (OR 1.06, 95% CI 1.03-1.10), polyunsaturated fat (OR 1.20, 95% CI 1.05-1.37) and monounsaturated fat (OR 1.17, 95% CI 1.06-1.28) compared to other men. Infertile men did not consume more alcohol nor smoke more cigarettes but reported more often allergies than fertile men. Infertile women also had Chlamydia trachomatis infection, benign tumor in their uterus and intestinal disease more often than fertile women. Infertile women over 50 years were more often current smokers than fertile women, but the differences in other age-groups were not significant.

CONCLUSIONS

Women with infertility experience reported more diseases and less use of oral contraceptives than other women, possibly reflecting reasons to infertility. Since both infertility and unhealthy use of alcohol are an increasing public health issues in western societies, more attention should be paid towards life style, especially alcohol use of infertile women.

Current Medical Research Winter 2008–Spring 2009

Note that the “Current Medical Research” feature focuses on issues relevant to natural family planning and the beginning of life. This piece is complemented by medical reviews published in The National Catholic Bioethics Quarterly, which focus more on other areas of general medical interest including end-of-life issues.—Ed.

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.

Women's compliance with nutrition and lifestyle recommendations before pregnancy: general population cohort study

OBJECTIVE

To examine the extent to which women planning a pregnancy comply with recommendations for nutrition and lifestyle.

DESIGN

Prospective cohort study.

SETTING

Southampton, United Kingdom.

PARTICIPANTS

12 445 non-pregnant women aged 20-34 recruited to the Southampton Women's Survey through general practices, 238 of whom became pregnant within three months of being interviewed.

MAIN OUTCOME MEASURES

Folic acid supplement intake, alcohol consumption, smoking, diet, and physical activity before pregnancy.

RESULTS

The 238 women who became pregnant within three months of the interview were only marginally more likely to comply with recommendations for those planning a pregnancy than those who did not become pregnant in this period. Among those who became pregnant, 2.9% (95% confidence interval 1.2% to 6.0%) were taking 400 microg or more of folic acid supplements a day and drinking four or fewer units of alcohol a week, compared with 0.66% (0.52% to 0.82%) of those who did not become pregnant. 74% of those who became pregnant were non-smokers compared with 69% of those who did not become pregnant (P=0.08). Women in both groups were equally likely to consume five or more portions of fruit and vegetables a day (53% in each group, P=1.0), but only 57% of those who became pregnant had taken any strenuous exercise in the past three months compared with 64% in those who did not become pregnant (P=0.03).

CONCLUSION

Only a small proportion of women planning a pregnancy follow the recommendations for nutrition and lifestyle. Greater publicity for the recommendations is needed, but as many pregnancies are unplanned, improved nutrition and lifestyles of women of childbearing age is also required.

Oxidative stress and antioxidants: exposure and impact on female fertility

BACKGROUND

Reproductive failure is a significant public health concern. Although relatively little is known about factors affecting fertility and early pregnancy loss, a growing body of literature suggests that environmental and lifestyle factors play an important role. There is sufficient evidence to hypothesize that diet, particularly its constituent antioxidants, and oxidative stress (OS) may influence the timing and maintenance of a viable pregnancy. We hypothesize that conditions leading to OS in the female affect time-to-pregnancy and early pregnancy loss.

METHODS

We review the epidemiology of female infertility related to antioxidant defenses and oxidation and examine potential sources of OS from the ovarian germ cell through the stages of human pregnancy and pregnancy complications related to infertility. Articles were identified through a search of the PubMed database.

RESULTS

Female OS is a likely mediator of conception and threshold levels for OS exist, dependent on anatomic location and stage of preconception.

CONCLUSIONS

Prospective pregnancy studies with dietary assessment and collection of biological samples prior to conception with endpoints of time-to-pregnancy and early pregnancy loss are needed.

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.

Tracking binge drinking among U.S. childbearing-age women

OBJECTIVE

The purpose of this analysis was to track the estimated prevalence of binge drinking for the years 2001-2003 among U.S. women of childbearing age in order to inform ongoing efforts to prevent alcohol-exposed pregnancies.

METHOD

A total of 58,431, 64,181, and 65,678 women aged 18-44 for the years 2001, 2002, and 2003, respectively, participated in the Centers for Disease Control and Prevention's (CDC) Behavioral Risk Factor Surveillance System (BRFSS) survey. The estimated binge drinking prevalence for each survey year and changes in these estimates for the entire survey period were calculated for these women.

RESULTS

The estimated binge drinking prevalence among childbearing-age women 18-44 years for the years 2001, 2002, and 2003 was 11.9%, 12.4%, and 13.0%, respectively. The estimated number of childbearing-age women who engaged in binge drinking rose from 6.2 million in 2001 to 7.1 million in 2003, an increase of 0.9 million.

CONCLUSION

The results of this analysis provide support for enhancing efforts among healthcare providers to identify and intervene with childbearing-age women who engage in alcohol use that can increase their risks for various health problems, including an alcohol-exposed pregnancy.

Lifestyle choices, diet, and insulin sensitizers in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is significantly affected by environmental regulators impacting on genetic predisposition. Lifestyle changes can significantly modulate the phenotype of this disease. Diet, exercise, smoking, stress, and other factors adversely affect reproductive outcomes in PCOS. These influences can be modulated by structure change in an individual or group. Lifestyle choices should be discussed in this group of patients. The role of insulin sensitizers, including metformin, has still to be determined in this condition.

Factors affecting time to pregnancy

BACKGROUND

Both lifestyle factors and occupational and environmental factors have been suggested to affect the female reproductive system. In the present study, the separate and joint effects of several such factors are investigated.

METHODS

Information on time to pregnancy (TTP) was available for 1578 women randomly selected from the general Swedish population. The information was collected retrospectively by using self-administered questionnaires. By means of logistic regression of survival data, fecundability odds ratios were determined for many factors. Multivariate models were used to determine which factors had the most impact on TTP.

RESULTS

Several lifestyle factors were found to associate with TTP. However, only use of oral contraceptives prior to attempting to conceive, menstrual cycle length, age at conception and parity remained in the multivariate models. Together, these factors explained 14% of the variance in TTP. Excluding first and second month conceptions, only age at conception and menstrual cycle length remained in the multivariate models, together explaining only 8% of the variance in TTP.

CONCLUSIONS

Although information on several factors was available, the multivariate model explained only a small fraction of the variation in the observed time to pregnancies. Furthermore, female biological factors seemed more important predictors of TTP than lifestyle factors.

Time to first pregnancy among women working in agricultural production

OBJECTIVES

This study explores several factors potentially associated with reduced fecundability among women working in cut flowers production.

METHODS

A cross-sectional study of first pregnancies was undertaken in 47 Colombian floriculture companies. Two thousand and eighty-five women were interviewed regarding potential reproductive, lifestyle and work history predictors of time-to-pregnancy (TTP), measured in months. Fecundability odds ratios (fOR) were estimated using a discrete time analogue of Cox's proportional hazard model.

RESULTS

Associated with longer TTP were: irregular relationships with her partner (fOR 0.82, 95% CI 0.73-0.91), illness in the year prior to pregnancy (fOR 0.78, 95% CI 0.62-0.98), smoking tobacco (fOR 0.71, 95% CI 0.59-0.85), and work in flower production, less than 24 months (fOR 0.86 95% CI 0.75-0.98) or 2 years or more (fOR 0.73, 95% CI 0.63-0.84).

CONCLUSIONS

Work in flower production, irregular relationship, illness and tobacco exposure would be associated with impaired fecundability.

Shift work and subfecundity: a causal link or an artefact?

AIMS

The Danish National Birth Cohort (DNBC) was used to examine whether shift work is associated with reduced fecundity as estimated by time to pregnancy (TTP).

METHODS

From 1 March 1998 to 1 May 2000, 39 913 pregnant women were enrolled in the DNBC. Data on job characteristics and TTP (0-2, 3-5, 6-12, and >12 months) were used for 17 531 daytime workers and 3907 shift workers who had planned the pregnancy. Fecundity odds ratios (ORs) were calculated with 95% confidence intervals using the discrete time survival analysis techniques performed by logistic regression. An OR above 1 expresses a shorter TTP and then a higher fecundity. Potential confounders, such as age at conception, gravidity, prepregnant body mass index, smoking, and alcohol consumption, as well as occupational characteristics, were also included in the model.

RESULTS

Fixed evening workers and fixed night workers had a longer TTP. Compared with daytime workers, the adjusted ORs were 0.80 (95% CI 0.70 to 0.92) for fixed evening workers, 0.80 (95% CI 0.63 to 1.00) for fixed night workers, 0.99 (95% CI 0.91 to 1.07) for rotating shift (without night) workers, and 1.05 (95% CI 0.97 to 1.14) for rotating shift (with night) workers. When analysis was restricted to nulliparous women, the estimates remained unchanged. The proportions of unplanned pregnancies and contraceptive failures were higher among fixed evening and fixed night workers.

CONCLUSIONS

There was no unequivocal evidence of a causal association between shift work and subfecundity. The slightly reduced fecundity among fixed evening workers and fixed night workers may be mediated by pregnancy planning bias or differential options for sexual contacts.

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

BACKGROUND

Our aim was to examine the association between use of alcohol and subsequent incidence of primary infertility.

METHODS

The study subjects were chosen from a population-based cohort of Danish women aged 20-29 years. Eligible women were nulliparous and not pregnant (n = 7760). Information on alcohol intake and potential confounders (age, education, marital status, diseases in the reproductive organs, and cigarette smoking) was assessed at enrollment. The incidence of fertility problems during follow-up was obtained by record linkage with the Danish Hospital Discharge Register and the Danish Infertility Cohort Register. Main outcome measures were hazard ratios of infertility according to alcohol intake at baseline estimated in a multivariate Cox proportional hazards model.

RESULTS

During a mean follow-up of 4.9 years, 368 women had experienced infertility. Alcohol intake at baseline was unassociated with infertility among younger women, but was a significant predictor for infertility among women above age 30. In this age group, the adjusted hazard ratio for consuming seven or more drinks per week was 2.26 (95% confidence interval: 1.19-4.32) compared with women consuming less than one drink per week.

CONCLUSIONS

These findings suggest that alcohol intake is a predictor for infertility problems among women in the later reproductive age group.

Semen quality of male smokers and nonsmokers in infertile couples

OBJECTIVE

To investigate the effect of cigarette smoking on main sperm variables.

DESIGN

Cohort study.

SETTING

Men attending the andrology laboratory in the context of infertility investigation in the couple.

PATIENT(S)

Eight hundred thirty-nine smokers and 1,266 non-smokers were enrolled; 655 smokers and 1,131 nonsmokers fulfilled the inclusion criteria and were compared. Standard clinical analysis of semen.

RESULT(S)

Cigarette smoking was associated with a significant decrease in sperm density (-15.3%), total sperm count (-17.5%), total number of motile sperm (-16.6%), and citrate concentration (-22.4%). The percentage of normal forms was significantly reduced in smokers, and sperm vitality, ejaculate volume, and fructose concentration were slightly but nonsignificantly affected.

CONCLUSION(S)

Cigarette smoking is associated with reduced semen quality.