World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project: V. physical examination standards in endometriosis research

OBJECTIVE

The World Endometriosis Research Foundation (WERF) established the Endometriosis Phenome and Biobanking Harmonisation Project (EPHect) to create standardized documentation tools (with common data elements) to facilitate the comparison and combination of data across different research sites and studies. In 2014, four data research standards were published: clinician-reported surgical data, patient-reported clinical data, and fluid and tissue biospecimen collection. Our current objective is to create an EPHect standard for the clinician-reported physical examination (EPHect-PE) for research studies.

DESIGN

An international consortium involving 26 clinical and academic experts and patient partners from 11 countries representing 25 institutions and organizations. Two virtual workshops, followed by the development of the physical examination standards that underwent multiple rounds of iterations and revisions.

SUBJECTS

N/A MAIN OUTCOME MEASURE(S): N/A RESULT(S): The EPHect physical examination (EPHect-PE) tool provides standardised assessment of physical examination characteristics and pain phenotyping. Data elements involve examination of a) back and pelvic girdle; b) abdomen including allodynia and trigger points; c) vulva including provoked vestibulodynia; d) pelvic floor muscle tone and tenderness; e) tenderness on unidigital pelvic exam; f) presence of pelvic nodularity; g) uterine size and mobility; h) presence of adnexal masses; i) presence of incisional masses; j) speculum examination; k) tenderness and allodynia at an extra-pelvic site (e.g. forearm); and l) recording of anthropometrics.

CONCLUSION(S)

The EPHect physical examination standards (EPHect-PE) will facilitate the standardised documentation of the physical examination, including the assessment and documentation of examination phenotyping of endometriosis-associated pelvic pain.

Validity of self-reported endometriosis: a comparison across four cohorts

STUDY QUESTION

How accurately do women report a diagnosis of endometriosis on self-administered questionnaires?

SUMMARY ANSWER

Based on the analysis of four international cohorts, women self-report endometriosis fairly accurately with a > 70% confirmation for clinical and surgical records.

WHAT IS KNOWN ALREADY

The study of complex diseases requires large, diverse population-based samples, and endometriosis is no exception. Due to the difficulty of obtaining medical records for a condition that may have been diagnosed years earlier and for which there is no standardized documentation, reliance on self-report is necessary. Only a few studies have assessed the validity of self-reported endometriosis compared with medical records, with the observed confirmation ranging from 32% to 89%.

STUDY DESIGN, SIZE, DURATION

We compared questionnaire-reported endometriosis with medical record notation among participants from the Black Women's Health Study (BWHS; 1995-2013), Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (E3N; 1990-2006), Growing Up Today Study (GUTS; 2005-2016), and Nurses' Health Study II (NHSII; 1989-1993 first wave, 1995-2007 second wave).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants who had reported endometriosis on self-administered questionnaires gave permission to procure and review their clinical, surgical, and pathology medical records, yielding records for 827 women: 225 (BWHS), 168 (E3N), 85 (GUTS), 132 (NHSII first wave), and 217 (NHSII second wave). We abstracted diagnosis confirmation as well as American Fertility Society (AFS) or revised American Society of Reproductive Medicine (rASRM) stage and visualized macro-presentation (e.g. superficial peritoneal, deep endometriosis, endometrioma). For each cohort, we calculated clinical reference to endometriosis, and surgical- and pathologic-confirmation proportions.

MAIN RESULTS AND THE ROLE OF CHANCE

Confirmation was high-84% overall when combining clinical, surgical, and pathology records (ranging from 72% for BWHS to 95% for GUTS), suggesting that women accurately report if they are told by a physician that they have endometriosis. Among women with self-reported laparoscopic confirmation of their endometriosis diagnosis, confirmation of medical records was extremely high (97% overall, ranging from 95% for NHSII second wave to 100% for NHSII first wave). Importantly, only 42% of medical records included pathology reports, among which histologic confirmation ranged from 76% (GUTS) to 100% (NHSII first wave). Documentation of visualized endometriosis presentation was often absent, and details recorded were inconsistent. AFS or rASRM stage was documented in 44% of NHSII first wave, 13% of NHSII second wave, and 24% of GUTS surgical records. The presence/absence of deep endometriosis was rarely noted in the medical records.

LIMITATIONS, REASONS FOR CAUTION

Medical record abstraction was conducted separately by cohort-specific investigators, potentially introducing misclassification due to variation in abstraction protocols and interpretation. Additionally, information on the presence/absence of AFS/rASRM stage, deep endometriosis, and histologic findings were not available for all four cohort studies.

WIDER IMPLICATIONS OF THE FINDINGS

Variation in access to care and differences in disease phenotypes and risk factor distributions among patients with endometriosis necessitates the use of large, diverse population samples to subdivide patients for risk factor, treatment response and discovery of long-term outcomes. Women self-report endometriosis with reasonable accuracy (>70%) and with exceptional accuracy when women are restricted to those who report that their endometriosis had been confirmed by laparoscopic surgery (>94%). Thus, relying on self-reported endometriosis in order to use larger sample sizes of patients with endometriosis appears to be valid, particularly when self-report of laparoscopic confirmation is used as the case definition. However, the paucity of data on histologic findings, AFS/rASRM stage, and endometriosis phenotypic characteristics suggests that a universal requirement for harmonized clinical and surgical data documentation is needed if we hope to obtain the relevant details for subgrouping patients with endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by Eunice Kennedy Shriver National Institute of Child Health and Development grants HD48544, HD52473, HD57210, and HD94842, National Cancer Institute grants CA50385, R01CA058420, UM1CA164974, and U01CA176726, and National Heart, Lung, and Blood Institute grant U01HL154386. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. AS, SM, and KT were additionally supported by the J. Willard and Alice S. Marriott Foundation. MK was supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA-2011-302078) and is grateful to the Philippe Foundation and the Bettencourt-Schueller Foundation for their financial support. Funders had no role in the study design, conduct of the study or data analysis, writing of the report, or decision to submit the article for publication. LA Wise has served as a fibroid consultant for AbbVie, Inc for the last three years and has received in-kind donations (e.g. home pregnancy tests) from Swiss Precision Diagnostics, Sandstone Diagnostics, Kindara.com, and FertilityFriend.com for the PRESTO cohort. SA Missmer serves as an advisory board member for AbbVie and a single working group service for Roche; neither are related to this study. No other authors have a conflict of interest to report. Funders had no role in the study design, conduct of the study or data analysis, writing of the report, or decision to submit the article for publication.

TRIAL REGISTRATION NUMBER

N/A.

Dairy and related nutrient intake and risk of uterine leiomyoma: a prospective cohort study

STUDY QUESTION

Is there an association between consumption of dairy foods and related nutrients and risk of uterine leiomyoma?

SUMMARY ANSWER

While dairy consumption was not consistently associated with uterine leiomyoma risk, intake of yogurt and calcium from foods may reduce risk of uterine leiomyoma.

WHAT IS KNOWN ALREADY

Two studies have examined the association between dairy intake and uterine leiomyoma risk with inconsistent results. Dairy foods have been inversely associated with inflammation and tumorigenesis, suggesting that vitamins and minerals concentrated in these dietary sources may influence uterine leiomyoma risk.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was carried out using data collected from 81 590 premenopausal women from 1991 to 2009 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Diet was assessed with a validated food frequency questionnaire every 4 years. Cases were restricted to self-reported ultrasound or hysterectomy-confirmation uterine leiomyoma. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

Eight thousand one hundred and forty-two cases of ultrasound or hysterectomy-confirmed uterine leiomyoma were diagnosed over an 18-year period. When compared to participants who consumed two servings a week of total dairy foods, participants who consumed four or more servings had a borderline significant 8% reduced risk of uterine leiomyoma (HR = 0.92, 95% CI = 0.85, 1.00; ptrend = 0.19). When the association between specific dairy foods and uterine leiomyoma was examined, the relation between dairy-food intake and uterine leiomyoma appeared to be driven primarily by yogurt consumption (HR for 2+ servings/day = 0.76; 95% CI = 0.55, 1.04 compared to <=4 servings/week; ptrend = 0.03); however, there was a small number of cases in the 2+ servings/day group (n = 39). Of the nutrients examined, the association was strongest for calcium from foods (HR fifth quintile = 0.92, 95% CI = 0.86, 0.99; ptrend = 0.04).

LIMITATIONS, REASONS FOR CAUTION

Some cases of uterine leiomyoma were likely misclassified, particularly those that were asymptomatic. It is possible that dairy product constituents reduce uterine leiomyoma symptomology rather than development, giving the appearance of a protective effect on leiomyoma development: no data on uterine leiomyoma symptomology were available. We did not have vitamin and mineral concentrations from actual blood levels. Similarly, there is the potential for misclassification of participants based on predicted 25(OH)D, and changes in vitamin D supplementation over time may have impacted prediction models for 25(OH)D. Further, some error in the self-reporting of dietary intake is expected. Given our prospective design, it is likely that these misclassifications were non-differential with respect to the outcome, likely biasing estimates toward the null.

WIDER IMPLICATIONS OF THE FINDINGS

While no clear association between overall dairy consumption and uterine leiomyoma risk was observed, our findings suggest that intake of yogurt and calcium from foods may reduce risk of uterine leiomyoma.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research grant HD081064 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The Nurses' Health Study II is supported by the Public Health Service grant UM1 CA176726 from the National Cancer Institute, NIH, U.S. Department of Health and Human Services. H.R.H. is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). There are no conflicts of interest to declare.

Genome-wide association and epidemiological analyses reveal common genetic origins between uterine leiomyomata and endometriosis

Uterine leiomyomata (UL) are the most common neoplasms of the female reproductive tract and primary cause for hysterectomy, leading to considerable morbidity and high economic burden. Here we conduct a GWAS meta-analysis in 35,474 cases and 267,505 female controls of European ancestry, identifying eight novel genome-wide significant (P < 5 × 10^-8) loci, in addition to confirming 21 previously reported loci, including multiple independent signals at 10 loci. Phenotypic stratification of UL by heavy menstrual bleeding in 3409 cases and 199,171 female controls reveals genome-wide significant associations at three of the 29 UL loci: 5p15.33 (TERT), 5q35.2 (FGFR4) and 11q22.3 (ATM). Four loci identified in the meta-analysis are also associated with endometriosis risk; an epidemiological meta-analysis across 402,868 women suggests at least a doubling of risk for UL diagnosis among those with a history of endometriosis. These findings increase our understanding of genetic contribution and biology underlying UL development, and suggest overlapping genetic origins with endometriosis.

Fruit and vegetable consumption and risk of endometriosis

STUDY QUESTION

Is there an association between intake of fruits and vegetables and risk of laparoscopically confirmed endometriosis?

SUMMARY ANSWER

Higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis.

WHAT IS KNOWN ALREADY

Two case-control studies have examined the associations between fruit and vegetable intake and endometriosis risk with contrasting results. Diets rich in fruits and vegetables include higher levels of pro-vitamin A nutrients (alpha-carotene, beta-carotene, beta-cryptoxanthin) and women with endometriosis have been reported to have lower intake of vitamin A than women without endometriosis.

STUDY DESIGN SIZE, DURATION

A prospective cohort study using data collected from 70 835 premenopausal women from 1991 to 2013 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Diet was assessed with a validated food frequency questionnaire (FFQ) every 4 years. Cases were restricted to laparoscopically confirmed endometriosis. Cox proportional hazards models were used to calculate rate ratios (RR) and 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

During 840 012 person-years of follow-up, 2609 incident cases of laparoscopically confirmed endometriosis were reported (incidence rate = 311 per 100 000 person-years). We observed a non-linear inverse association between higher fruit consumption and risk of laparoscopically confirmed endometriosis (Psignificance of the curve = 0.005). This inverse association was particularly evident for citrus fruits. Women consuming ≥1 servings of citrus fruits/day had a 22% lower endometriosis risk (95% CI = 0.69-0.89; Ptrend = 0.004) compared to those consuming <1 serving/week. No association was observed between total vegetable intake and endometriosis risk. However, women consuming ≥1 servings/day cruciferous vegetables had a 13% higher risk of endometriosis (95% CI = 0.95-1.34; Ptrend = 0.03) compared to those consuming <1 serving/week. Of the nutrients examined, only beta-cryptoxanthin intake was significantly associated with lower endometriosis risk (RR fifth quintile = 0.88; 95% CI = 0.78-1.00; Ptrend = 0.02).

LIMITATIONS REASONS FOR CAUTION

Some error in the self-reporting of dietary intake is expected, however, use of a validated FFQ and examining diet prospectively across multiple time points, make it unlikely that this non-differential misclassification strongly influenced the results.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that a higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis, and beta-cryptoxanthin in these foods may partially explain this association. In contrast to what we hypothesized, consumption of some vegetables increased endometriosis risk which may indicate a role of gastrointestinal symptoms in both the presentation and exacerbation of endometriosis-related pain; however, it is not clear what components of these foods might underlie the observed associations. Future studies examining dietary patterns that consider different combinations of food intake may help clarify these associations.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research grants HD4854, HD52473 and HD57210 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and grant P30 DK046200 from the National Institute of Diabetes and Digestive and Kidney Diseases. The Nurses' Health Study II is supported by the Public Health Service grant UM1 CA176726 from the National Cancer Institute, National Institutes of Health. HRH is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). No competing interests.

TRIAL REGISTRATION NUMBER

n/a.

Early or late pregnancy loss and development of clinical cardiovascular disease risk factors: a prospective cohort study

OBJECTIVE

To assess the association between the outcome of a woman's first pregnancy and risk of clinical cardiovascular disease risk factors.

DESIGN

Prospective cohort study.

SETTING AND POPULATION

Nurses' Health Study II.

METHODS

Multivariable-adjusted Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between first pregnancy outcome and hypertension, type 2 diabetes, and hypercholesterolemia.

MAIN OUTCOME MEASURES

Hypertension, type 2 diabetes, and hypercholesterolemia.

RESULTS

Compared to women who reported a singleton live first birth, women with early spontaneous abortion (<12 weeks) had a greater rate of type 2 diabetes (HR: 1.20; 95% CI: 1.07-1.34) and hypercholesterolemia (HR: 1.06; 95% CI: 1.02-1.10), and a marginally increased rate of hypertension (HR: 1.05, 95% CI: 1.00-1.11). Late spontaneous abortion (12-19 weeks) was associated with an increased rate of type 2 diabetes (HR: 1.38; 95% CI: 1.14-1.65), hypercholesterolemia (HR: 1.11; 95% CI: 1.03-1.19), and hypertension (HR: 1.15; 95% CI: 1.05-1.25). The rates of type 2 diabetes (HR: 1.45; 95% CI: 1.13-1.87) and hypertension (HR: 1.15; 95% CI: 1.01-1.30) were higher in women who delivered stillbirth. In contrast, women whose first pregnancy ended in an induced abortion had lower rates of hypertension (HR: 0.87; 95% CI: 0.84-0.91) and type 2 diabetes (HR: 0.89; 95% CI: 0.79-0.99) than women with a singleton live birth.

CONCLUSIONS

Several types of pregnancy loss were associated with an increased rate of hypertension, type 2 diabetes, and hypercholesterolemia, which may provide novel insight into the pathways through which pregnancy outcomes and CVD are linked.

TWEETABLE ABSTRACT

Pregnancy loss is associated with later maternal risk of hypertension, type 2 diabetes, and hypercholesterolemia.

Risk for and consequences of endometriosis: A critical epidemiologic review

Endometriosis affects approximately 10% of women of reproductive age. Characteristics robustly associated with a greater risk for endometriosis include early age at menarche, short menstrual cycle length, and lean body size, whereas greater parity has been associated with a lower risk. Relationships with other potential characteristics including physical activity, dietary factors, and lactation have been less consistent, partially because of the need for rigorous data collection and a longitudinal study design. Critical methodologic complexities include the need for a clear case definition; valid selection of comparison/control groups; and consideration of diagnostic bias and reverse causation when exploring demographic characteristics, medical history, and lifestyle factors. Reviewers and editors must demand a detailed description of rigorous methods to facilitate comparison and replication to advance our understanding of endometriosis.

Associations among body size across the life course, adult height and endometriosis

STUDY QUESTION

Are body size across the life course and adult height associated with endometriosis?

SUMMARY ANSWER

Endometriosis is associated with lean body size during childhood, adolescence and adulthood; tall total adult height; and tall sitting height.

WHAT IS KNOWN ALREADY

The literature suggests that both adult body size and height are associated with endometriosis risk, but few studies have investigated the role of body size across the life course. Additionally, no study has investigated the relationships between components of height and endometriosis.

STUDY DESIGN, SIZE, DURATION

We used a nested case-control design within E3N (Etude Epidémiologique auprès de femmes de l'Education Nationale), a prospective cohort of French women. Data were updated every 2-3 years through self-administered questionnaires. Odds ratios (ORs) and 95% CIs were computed using logistic regression models adjusted for a priori confounding factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2416 endometriosis cases were reported as surgically ascertained among the 61 208 included women.

MAIN RESULTS AND THE ROLE OF CHANCE

The odds of endometriosis were lower among women who reported having a large versus lean body size at 8 years (P for trend = 0.003), at menarche (P for trend < 0.0001) and at ages 20-25 years (P for trend < 0.0001). Women in the highest quartiles of height had statistically significantly increased odds of endometriosis compared to those in the lowest (<158 cm) (162-164 cm: OR = 1.28, 95% CI = 1.12-1.46; ≥165 cm: OR = 1.33, 95% CI = 1.18-1.49, P for trend < 0.0001). Statistically significantly increased odds were also observed among women with a taller sitting height (OR = 1.24, 95% CI = 1.05-1.47, P for trend = 0.01). Leg length was not statistically significantly associated with endometriosis.

LIMITATIONS REASONS FOR CAUTION

Endometriosis cases may be prone to misclassification; however, we restricted our case definition to surgically-confirmed cases, which showed a high validation rate. Body size is based on retrospective self-report, which may be subject to recall bias.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study suggest that endometriosis is positively associated with lean body size across the life course and total adult height. They also suggest that components of height are associated with endometriosis, which should be investigated further.

STUDY FUNDING/COMPETING INTEREST(S)

The Mutuelle Générale de l'Education Nationale (MGEN); the European Community; the French League against Cancer (LNCC); Gustave Roussy; the French Institute of Health and Medical Research (Inserm). L.V.F. was supported by a T32 grant (#HD060454) in reproductive, perinatal and pediatric epidemiology from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Cancer Institute (3R25CA057711) National Institutes of Health. M.K. was supported by a Marie Curie Fellowship within the seventh European Community Framework Programme (#PIOF-GA-2011-302078). The authors have no conflicts of interest to declare.

Responses to fertility treatment among patients with cancer: a retrospective cohort study

Background

Cancer treatments have significant negative impacts on female fertility, but the impact of cancer itself on fertility remains to be clarified. While some studies have shown that compared with healthy women, those with cancer require higher doses of gonadotropins resulting in decreased oocyte yields, others have shown comparable oocyte yields between the two groups. The purpose of this study is to evaluate whether there is an association between any cancer and/or type of cancer, and response to ovarian stimulation for egg and embryo banking.

Methods

In this retrospective cohort study, ovarian stimulation cycles performed from June 2007 through October 2014 at a single academic medical center were reviewed to identify those undertaken for women with cancer undergoing fertility preservation (n = 147) or women with no cancer undergoing their first cycle due to male factor infertility (n = 664). Of the 147 women undergoing fertility preservation, 105 had local cancer (Stage I-III solid malignancies) and 42 had systemic cancer (hematologic or Stage IV solid malignancies). Response to ovarian stimulation was compared among these two groups and women with no cancer.

Results

Adjusting for age and BMI, women with systemic cancer had lower baseline antral follicle counts (AFC) than women with no cancer or local cancer. Women with systemic cancer required higher doses of FSH than women with no cancer or local cancer, and they had higher oocyte to AFC ratios than women with no cancer or local cancer, but greater odds of cycle cancellation as compared to women with no cancer or local cancer. No significant differences were observed among the three groups for duration of stimulation, number of oocytes and mature oocytes retrieved, or number of embryos created.

Conclusions

Women with cancer achieve similar oocyte and embryo yields as women with no cancer, although those with systemic cancer require higher FSH doses and are at greater risk of cycle cancellation.

National survey on use of time-lapse imaging systems in IVF laboratories

PURPOSE

Several time-lapse imaging (TLI) systems for non-invasive continuous monitoring of developing embryos are currently available. The present study explored the prevalence, means of acquisition, and clinical application of TLI systems in USA in vitro fertilization (IVF) laboratories.

METHODS

An online cross-sectional survey of 294 USA IVF laboratory directors was conducted in February and March 2016. Those directing more than one laboratory were asked to complete the survey for their home program and for their smallest laboratory by number of IVF/intracytoplasmic sperm injection (ICSI) cycle starts. Use of TLI was analyzed using logistic regression to calculate odds ratios (OR).

RESULTS

Of 294 directors surveyed, 162 (55%) reported data on 204 laboratories. Thirty-five laboratories (17%) possessed at least one TLI system (median 2, interquartile range 1-4, total range 1-11). The more oocyte retrievals a laboratory performed annually, the more likely the laboratory was to possess a TLI system. Fifteen laboratories (43%) purchased their own systems, while others leased, loaned, or received donated systems. Twenty-five laboratories (71%) reported using TLI for embryo selection; all used TLI always, or usually, in combination with standard morphology evaluation. Twenty laboratories (80%) offered TLI to all patients. Some laboratories charged patients for TLI. Directors with TLI systems were more inclined to believe that TLI has value for embryo selection in clinical IVF.

CONCLUSIONS

TLI system possession in USA IVF laboratories is low, although positively associated with the number of retrievals performed and with directors' opinions on the technology's utility. Over 70% of laboratories with TLI systems use them clinically, and less than half purchased their systems.

Building a model to increase live birth rate through patient-specific optimization of embryo transfer day

PURPOSE

Many practices are moving away from cleavage-stage transfer in favor of blastocyst transfer. The purpose of this study is to evaluate how the overall live birth rate for fresh IVF cycles may increase by optimizing the day of transfer for each patient.

METHODS

This is a retrospective cohort study of 1225 first fresh autologous IVF cycles performed between May 2012 and November 2013. Stepwise logistic regression was used to determine characteristics associated with live birth following cleavage-stage versus blastocyst transfer. The optimal transfer day (i.e., the day that maximized the odds of live birth) was determined for each patient, and the actual live birth rate was compared with the projected rate had each patient undergone transfer on her optimal day.

RESULTS

With transfer on the optimal day for each patient, the overall birth rate would have increased from its actual value of 34.8 % to a projected 43.0 %, a 24 % increase. The majority of this increase (21 %) was due to optimization of patients who underwent cleavage-stage transfer but had a higher projected birth rate from blastocyst transfer. These patients were older (37.8 versus 36.0 years, p < 0.01) and had more follicles ≥18 mm than patients who should have remained with a cleavage-stage transfer.

CONCLUSIONS

A model can be built enabling patient-specific identification of optimal transfer day; within this discovery cohort, such optimization was estimated to increase live birth following a fresh transfer by 24 %. This study suggests blastocyst transfer should be more widely offered; however, there remain patients for whom a cleavage-stage transfer may yield better outcomes.

A prospective cohort study of endometriosis and subsequent risk of infertility

STUDY QUESTION

Is there a temporal relationship between endometriosis and infertility?

SUMMARY ANSWER

Endometriosis is associated with a higher risk of subsequent infertility, but only among women age <35 years.

WHAT IS KNOWN ALREADY

Endometriosis is the most commonly observed gynecologic pathology among infertile women undergoing laparoscopic examination. Whether endometriosis is a cause of infertility or an incidental discovery during the infertility examination is unknown.

STUDY DESIGN, SIZE, DURATION

This study included data collected from 58 427 married premenopausal female nurses <40 years of age from 1989 to 2005, who are participants of the Nurses' Health Study II prospective cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our exposure was laparoscopically confirmed endometriosis. Multivariate Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for infertility risk (defined as attempting to conceive for >12 months) among women with and without endometriosis.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified 4612 incident cases of infertility due to any cause over 362 219 person-years of follow-up. Compared with women without a history of endometriosis, women with endometriosis had an age-adjusted 2-fold increased risk of incident infertility (HR = 2.12, 95% CI = 1.76-2.56) that attenuated slightly after accounting for parity. The relationship with endometriosis was only observed among women <35 years of age (multivariate HR <35 years = 1.77, 95% CI = 1.46-2.14; multivariate HR 35-39 years = 1.20, 95% CI = 0.94-1.53; P-interaction = 0.008). Risk of primary versus secondary infertility was similar subsequent to endometriosis diagnosis. Among women with primary infertility, 50% became parous after the endometriosis diagnosis, and among all women with endometriosis, 83% were parous by age 40 years.

LIMITATIONS, REASONS FOR CAUTION

We did not have information on participants' intentions to conceive, but by restricting the analytic population to married women we increased the likelihood that pregnancies were planned (and therefore infertility would be recognized). Women in our cohort with undiagnosed asymptomatic endometriosis will be misclassified as unexposed. However, the small proportion of these women are diluted among the >50 000 women accurately classified as endometriosis-free, minimizing the impact of exposure misclassification on the effect estimates.

WIDER IMPLICATIONS OF THE FINDINGS

This study supports a temporal association between endometriosis and infertility risk. Our prospective analysis indicates a possible detection bias in previous studies, with our findings suggesting that the infertility risk posed by endometriosis is about half the estimates observed in cross-sectional analyses.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Institutes of Health (grant numbers: UM1 CA176726, HD52473, HD57210, T32DK007703, T32HD060454, K01DK103720). We have no competing interests to declare.

Adult air pollution exposure and risk of infertility in the Nurses' Health Study II

STUDY QUESTION

Is there an association between air pollution exposures and incident infertility?

SUMMARY ANSWER

Increased exposure to air pollution is associated with an increased incidence of infertility.

WHAT IS KNOWN ALREADY

Exposures to air pollution have been associated with lower conception and fertility rates. However, the impact of pollution on infertility incidence is unknown.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study using data collected from 116 430 female nurses from September 1989 to December 2003 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Infertility was defined by report of attempted conception for ≥12 months without success. Participants were able to report if evaluation was sought and if so, offer multiple clinical indications for infertility. After exclusion, 36 294 members were included in the analysis. Proximity to major roadways and ambient exposures to particulate matter less than 10 microns (PM10), between 2.5 and 10 microns (PM2.5-10), and less than 2.5 microns (PM2.5) were determined for residential addresses for the 36 294 members between the years of 1993 and 2003. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using multivariable adjusted Cox proportional hazard models with time-varying covariates.

MAIN RESULTS AND THE ROLE OF CHANCE

Over 213 416 person-years, there were 2508 incident reports of infertility. Results for overall infertility were inconsistent across exposure types. We observed a small increased risk for those living closer to compared to farther from a major road, multivariable adjusted HR = 1.11 (CI: 1.02-1.20). This was consistent for those reporting primary or secondary infertility. For women living closer to compared to farther from a major road, for primary infertility HR = 1.05 (CI: 0.94-1.17), while for secondary infertility HR = 1.21 (CI: 1.07-1.36). In addition, the HR for every 10 µg/m(3) increase in cumulative PM2.5-10 among women with primary infertility was 1.10 (CI: 0.96-1.27), and similarly was 1.10 (CI: 0.94-1.28) for those with secondary infertility.

LIMITATIONS, REASONS FOR CAUTION

Within the 2 year window of infertility diagnosis, we do not have the exact date of diagnosis or the exact timing of the start of attempting conception. As infertility status and subtypes of infertility were prospectively collected biennially, we were unable to tightly examine the timing of exposures on incidence of infertility. In terms of exposure quantification, we used ambient air pollution exposures as a proxy for personal exposures, potentially leading to exposure misclassification. However, several studies suggest that ambient measurements are an acceptable surrogate for individual level exposures in most populations.

WIDER IMPLICATIONS OF THE FINDINGS

We observed an association between all size fractions of PM exposure, as well as traffic-related air pollution, and incidence of infertility. Of note, the strongest association was observed between cumulative average exposures over the course of follow-up and the risk of infertility, suggesting that chronic exposures may be of greater importance than short-term exposures.

STUDY FUNDING/COMPETING INTERESTS

The work for this paper was supported by the following: S.M.: Reproductive Scientist Development Program HD000849, and the Building Interdisciplinary Research Careers in Women's Health HD043444, the Boston University CTSI 1UL1TR001430, and a research grant from the Boston University Department of Obstetrics and Gynecology, S.A.M.: R01HD57210 from the National Institute of Child Health and Human Development and the Massachusetts Institute of Technology Center for Environmental Health Sciences Translational Pilot Project Program, R01CA50385 from the National Cancer Institute, J.E.H. and F.L.: 5R01ES017017 from the National Institute for Environmental Health Sciences, 5 P42 ES007381 from the National Institute of Environmental Health at the National Institute of Health. L.V.F.: T32HD060454 in reproductive, perinatal, and pediatric epidemiology from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The Nurses' Health Study II is additionally supported by infrastructure grant UM1CA176726 from the National Cancer Institute, NIH, U.S. Department of Health and Human Services. The authors have no actual or potential competing financial interests to disclose.

Associations between paternal urinary phthalate metabolite concentrations and reproductive outcomes among couples seeking fertility treatment

INTRODUCTION

Limited evidence suggests that male exposure to ubiquitous environmental phthalates may result in poor reproductive outcomes among female partners.

METHODS

This analysis included male-female couples undergoing in vitro fertilization (IVF) and/or intrauterine insemination (IUI). We evaluated associations between the geometric mean of paternal specific gravity-adjusted urinary phthalate concentrations prior to the female partners' cycle and fertilization, embryo quality, implantation, and live birth using generalized linear mixed models.

RESULTS

Two-hundred eighteen couples underwent 211 IVF and 195 IUI cycles. Trends were observed between paternal urinary mono-3-carboxypropyl phthalate (MCPP; P=0.01) and mono(carboxyoctyl) phthalate (MCOP; P=0.01) and decreased odds of implantation. MCPP and MCOP were also associated with decreased odds of live birth following IVF (P=0.01 and P=0.04, respectively), and monobutyl phthalate above the first quartile was significantly associated with decreased odds of live birth following IUI (P=0.04). However, most urinary phthalate metabolites were not associated with these reproductive outcomes.

CONCLUSION

Selected phthalates were associated with decreased odds of implantation and live birth.

Dietary fat intake and risk of epithelial ovarian cancer by tumour histology

BACKGROUND

Studies of fat intake and epithelial ovarian cancer (EOC) risk have reported inconsistent findings, hence we hypothesised that associations may vary by histologic subtype.

METHODS

We evaluated fat intake in a New England case-control study including 1872 cases and 1978 population-based controls (1992-2008). Epithelial ovarian cancer risk factors and diet were assessed using a food frequency questionnaire at enrolment. Logistic regression was used to estimate associations between fat intake and EOC risk and polytomous logistic regression was used to test whether associations varied by histologic subtype.

RESULTS

We observed a decreased risk of EOC when comparing the highest vs lowest quartiles of intake of omega-3 (odds ratio (OR)=0.79, 95% confidence interval (CI) 0.66-0.96, P-trend=0.01) and omega-6 (OR=0.77, 95% CI 0.64-0.94, P-trend=0.02) and an increased risk with high consumption of trans fat (OR=1.30, 95% CI 1.08-1.57, P-trend=0.002). There was no significant heterogeneity by tumour histologic subtype; however, we observed a strong decreased risk for endometrioid invasive tumours with high intake of omega-3 (quartile (Q) 4 vs Q1, OR=0.58, 95% CI 0.41-0.82, P-trend=0.003).

CONCLUSIONS

These findings suggest that higher intake of omega-3 may be protective for EOC overall and endometrioid tumours in particular, whereas greater consumption of trans fat may increase risk of EOC overall.

Uterine length and fertility outcomes: a cohort study in the IVF population

STUDY QUESTION

What is the relationship between pre-cycle uterine length and IVF outcome (chemical pregnancy, clinical pregnancy, spontaneous abortion and live birth)?

SUMMARY ANSWER

Women at extremes of uterine length (<7.0 or >9.0 cm) were less likely to achieve live birth and women with uterine lengths <6.0 cm were also more likely to experience spontaneous abortion.

WHAT IS KNOWN ALREADY

A prospective study of 807 women published in 2000 found that implantation and clinical pregnancy rates were highest in women with uterine lengths between 7.0 and 9.0 cm, though the difference was not significant. The relationship between pre-cycle uterine length and live birth has not been evaluated.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of all cycles performed after uterine length measurement at an academic hospital IVF clinic from 2001 to 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 8981 fresh cycles were performed in 5120 adult women with normal uterine anatomy. Women with uterine anomalies (unicornuate, bicornuate, septate or uterus exposed to diethylstilbestrol) were excluded and women with fibroids were identified for subanalysis. Uterine length was measured by uterine sounding. Cycles were divided by uterine length into groups: <6.0 cm (very short, n = 76), 6.0-6.9 cm (short, n = 2014), 7.0-7.9 cm (referent, n = 4984), 8.0-8.9 cm (long, n = 1664) and ≥9 cm (very long, n = 243). Multivariate logistic regression (first-cycle analyses) and generalized estimating equations (all-cycle analyses) were adjusted for age, fibroids and ART treatment (assisted hatching, intracytoplasmic sperm injection) to generate relative risk (RR) of cycle outcomes by uterine length.

MAIN RESULTS AND THE ROLE OF CHANCE

Median uterine length in the IVF population was 7.0 cm (interquartile range 7.0-7.8) and was positively associated with BMI (P < 0.001) and fibroids (P = 0.02). Compared with the referent group, women with uterine lengths <6.0 cm were half as likely to achieve live birth (RR: 0.53; 95% confidence interval (CI): 0.35-0.81) and women with lengths of 6.0-6.9 cm were also less likely (RR: 0.91; CI: 0.85-0.98). Cubic regression spline identified a significant inverse U-shaped association whereby women with uterine lengths <7.0 or >9.0 cm were less likely to achieve live birth. Women with lengths <6.0 cm were also more likely to experience spontaneous abortion (RR: 2.16; CI: 1.23-3.78). Results remained consistent when excluding women with a uterine factor diagnosis (n = 8823), when limiting to the first cycle at our institution (n = 5120) and when further restricting to first-ever cycles (n = 3941).

LIMITATIONS, REASONS FOR CAUTION

Optimal assessment of uterine length by ultrasound was not feasible due to time and cost limitations, though uterine sounding is a clinically relevant measurement allowing for results with practical implications. Findings from our predominantly Caucasian clinic population may not be generalizable to infertile populations with different ethnic compositions.

WIDER IMPLICATIONS OF THE FINDINGS

Reproducibility of results would solidify findings and inform patient counseling in women undergoing IVF.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was sought for this investigation. MD declares relationships with UpToDate (royalties) and WINFertlity (consultant).

Twin pregnancies with a 'vanished' embryo: a higher risk multiple gestation group?

BACKGROUND

Prior studies have documented increased risks to the offspring of IVF singletons that result from a vanished twin pregnancy. We aim to investigate the effect on perinatal outcomes of having an early vanished triplet in IVF twins.

METHODS

This is a retrospective cohort study of twins from a large academic IVF practice. Multivariate analysis was performed to examine the perinatal risks--including small for gestational age (SGA), low-birthweight (LBW), preterm delivery and early preterm delivery--in twins that resulted from an early vanished triplet compared with twins without a vanished embryo.

RESULTS

Of 829 IVF twin deliveries, 59 were a result of vanished triplet pregnancies (7.1%). There was no significant increase in SGA, LBW or delivery <37 weeks in the vanished triplets compared with other twins; however, the risk of early preterm birth (<32 weeks) was significantly higher (OR 3.09, 95% CI 1.63-5.87) and the length of gestation of these pregnancies was on average 1.5 weeks shorter (P < 0.01). In addition, the unadjusted mean birthweight was lower by nearly 200 g in the vanished triplet pregnancies (P < 0.01).

CONCLUSIONS

IVF twin pregnancies with a vanished triplet are at an increased risk for early preterm birth compared with other twin pregnancies. These pregnancies should be recognized at higher risk for early preterm birth and considered for increased obstetrical monitoring. A significant limitation of this study is that the cause for preterm birth was unknown.

Maternal exposure to second-hand tobacco smoke and pregnancy outcome among couples undergoing assisted reproduction

BACKGROUND

Exposure to second-hand tobacco smoke is preventable, yet common. This study assessed relationships between maternal exposure to second-hand tobacco smoke and adverse pregnancy outcomes.

METHODS

We measured cotinine (a biomarker of tobacco smoke) in urine from 921 women undergoing assisted reproductive technologies (ARTs) between 1994 and 1998. We also collected information on self-reported exposure to second-hand smoke at home or at work, in addition to parental smoking during the women's childhood.

RESULTS

In crude analysis, creatinine-adjusted cotinine levels were associated with a slight decrease in implantation rate among non-smoking women (11.1% in the lowest cotinine quintile versus 8.2% in the highest cotinine quintile; P=0.13). However, in multivariate logistic regression, cotinine levels above the median were not associated with failed fertilization, failed implantation or spontaneous abortion, nor was there evidence of a dose-response relationship among cotinine quintiles. After excluding women in couples diagnosed with male factor infertility, there were increased odds of having a spontaneous abortion among non-smoking women who reported that both parents smoked while they were children growing up compared with women reporting that neither parent smoked [adjusted odds ratio (OR) = 4.35; 95% confidence interval (CI) = 1.04-18.1].

CONCLUSIONS

Female exposure to second-hand smoke as a child or in utero may be associated with an increased risk of spontaneous abortion in adulthood. However, this may be a chance finding due to multiple comparisons. Similar associations should be explored in additional studies with more refined estimates of childhood and in utero exposure to tobacco smoke.

Predictors of change in the functional status of children with human immunodeficiency virus infection

OBJECTIVE

The purpose of this study was to identify important clinical predictors of change in the functional status of children with perinatally acquired human immunodeficiency virus (HIV) infection.

METHODS

Children who were perinatally exposed to HIV underwent evaluation of growth, nutritional, and functional status parameters as part of a prospective study of HIV and nutrition in children. The main outcome measures for HIV-infected children were change over time in: 1) Total Health, 2) General Health, and 3) Responsiveness as measured by the Functional Status II(R) (FSII[R]). Candidate predictors included anthropometric measurements, social factors, HIV disease stage, CD4 T lymphocyte count, medications, and other clinical markers of illness.

RESULTS

The parents or legal guardians of 35 perinatally HIV-infected children completed 2 FSII(R) surveys over a mean of 16 months. Functional Status scores were significantly correlated with number of times and days hospitalized in the past 6 months and with illness at the time of baseline evaluation. Functional status declined overtime on all 3 scales; however, only the change in Total Health score was statistically significant. Total, General Health, and Responsiveness scores declined by >/=5 points in 20.0%, 17.1%, and 14.3% of children, respectively. Significant univariate predictors of change in at least 1 component of the functional status survey included race, guardianship, height z score, prescription of antiviral medications other than antiretrovirals, and illness at time of baseline evaluation. In multivariate models, adjusting for baseline score and biologic relationship of guardian completing survey, significant predictors of a decline in Total Health scores included non-white race and lower baseline height z score. The General Health score declined with lower baseline absolute CD4 count and lower baseline height z score. Finally, Responsiveness scores declined in children whose guardian was their biologic parent and in children with lower baseline height z scores.

CONCLUSION

The FSII(R) questionnaire correlates with other markers of disease severity in children with HIV infection. Growth parameters, immune status, and social factors are important predictors of functional status in HIV-infected children.