A successful implementation of e-epidemiology: the Danish pregnancy planning study 'Snart-Gravid'

Cervical intraepithelial neoplasia and fecundability: a prospective cohort study

STUDY QUESTION

Is cervical intraepithelial neoplasia (CIN) associated with reduced fecundability, defined as the probability of conceiving per menstrual cycle?

SUMMARY ANSWER

Overall, we observed no meaningful association between CIN and fecundability, regardless of surgical status, although a recent diagnosis of moderate or severe CIN might be associated with slightly reduced fecundability for 2 years after diagnosis.

WHAT IS KNOWN ALREADY

About 15% of couples experience infertility. Few studies have examined the influence of CIN on fertility, and the results have been inconsistent. No study has investigated the association between fecundability and pathologist-reported CIN diagnoses, particularly with respect to the recency of the specific CIN diagnoses.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 9586 women trying to conceive. The women were enrolled from 1 June 2007 to 3 February 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women were invited to complete a baseline questionnaire and bimonthly follow-up questionnaires for up to 12 months or until pregnancy occurred. Data on cervical cytologies and biopsies were retrieved from The National Pathology Registry (DNPR), which holds records of all cervical specimens examined in Denmark. Women were categorized based on their most severe diagnosis of CIN: no lesion, other cervical changes, mild CIN (CIN1), or moderate/severe CIN (CIN2+) with or without surgery. To investigate the association between CIN and fecundability, we computed fecundability ratios (FR) and 95% confidence intervals (CI) using a proportional probabilities regression model. We adjusted for age at study entry, partner age, body mass index, smoking status, timing of intercourse, parity, education, number of sexual partners, and household income.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with no lesion, the adjusted FRs (95% CI) for the association between CIN and fecundability were: other cervical lesions, 0.97 (0.91-1.04); CIN1, 1.04 (0.96-1.13); CIN2+ no surgery, 1.00 (0.82-1.22); and CIN2+ with surgery 0.99 (0.89-1.10). The FRs (95% CI) for a recent diagnosis (<2 years) of CIN were 0.98 (0.86-1.11) for other cervical lesions; 1.13 (0.99-1.29) for CIN1; 0.89 (0.62-1.26) for CIN2+ no surgery and 0.91 (0.75-1.10) for CIN2+ with surgery compared with the no lesion group.

LIMITATIONS, REASONS FOR CAUTION

In the analyses, we adjusted for several covariates related to the women. However, we had little information on the male partners which could lead to unmeasured confounding as fecundability is a couple-based measure of fertility. Furthermore, a CIN diagnosis may not be constant as it may regress or progress spontaneously; therefore, it is possible that we have misclassified some women, especially women categorized as having normal cells or CIN1.

WIDER IMPLICATIONS OF THE FINDINGS

Our results contribute important knowledge to women who are concerned about their future fertility after receiving a CIN diagnosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by The Danish Cancer Society (R167-A11036-17-S2). The overall cohorts were funded by the National Institute of Child Health and Human Development (R01-HD086742 and R03-HD094117). The authors report no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Preconception contraceptive use and miscarriage: prospective cohort study

Objectives

To evaluate the association between preconception contraceptive use and miscarriage.

Design

Prospective cohort study.

Setting

Residents of the United States of America or Canada, recruited from 2013 until the end of 2022.

Participants

13 460 female identified participants aged 21-45 years who were planning a pregnancy were included, of whom 8899 conceived. Participants reported data for contraceptive history, early pregnancy, miscarriage, and potential confounders during preconception and pregnancy.

Main outcome measure

Miscarriage, defined as pregnancy loss before 20 weeks of gestation.

Results

Preconception use of combined and progestin-only oral contraceptives, hormonal intrauterine devices, copper intrauterine devices, rings, implants, or natural methods was not associated with miscarriage compared with use of barrier methods. Participants who most recently used patch (incidence rate ratios 1.34 (95% confidence interval 0.81 to 2.21)) or injectable contraceptives (1.44 (0.99 to 2.12)) had higher rates of miscarriage compared with recent users of barrier methods, although results were imprecise due to the small numbers of participants who used patch and injectable contraceptives.

Conclusions

Use of most contraceptives before conception was not appreciably associated with miscarriage rate. Individuals who used patch and injectable contraceptives had higher rates of miscarriage relative to users of barrier methods, although these results were imprecise and residual confounding was possible.

Socioeconomic status and fecundability in a Danish preconception cohort

STUDY QUESTION

To what extent is socioeconomic status (SES), as measured by educational attainment and household income, associated with fecundability in a cohort of Danish couples trying to conceive?

SUMMARY ANSWER

In this preconception cohort, lower educational attainment and lower household income were associated with lower fecundability after adjusting for potential confounders.

WHAT IS KNOWN ALREADY

Approximately 15% of couples are affected by infertility. Socioeconomic disparities in health are well established. However, little is known about socioeconomic disparity and its relation to fertility.

STUDY DESIGN, SIZE, DURATION

This is a cohort study of Danish females aged 18-49 years who were trying to conceive between 2007 and 2021. Information was collected via baseline and bi-monthly follow-up questionnaires for 12 months or until reported pregnancy.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall, 10 475 participants contributed 38 629 menstrual cycles and 6554 pregnancies during a maximum of 12 cycles of follow-up. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with upper tertiary education (highest level), fecundability was substantially lower for primary and secondary school (FR: 0.73, 95% CI: 0.62-0.85), upper secondary school (FR: 0.89, 95% CI: 0.79-1.00), vocational education (FR: 0.81, 95% CI: 0.75-0.89), and lower tertiary education (FR: 0.87, 95% CI: 0.80-0.95), but not for middle tertiary education (FR: 0.98, 95% CI: 0.93-1.03). Compared with a monthly household income of >65 000 DKK, fecundability was lower for household income <25 000 DKK (FR: 0.78, 95% CI: 0.72-0.85), 25 000-39 000 DKK (FR: 0.88, 95% CI: 0.82-0.94), and 40 000-65 000 DKK (FR: 0.94, 95% CI: 0.88-0.99). The results did not change appreciably after adjustment for potential confounders.

LIMITATIONS, REASONS FOR CAUTION

We used educational attainment and household income as indicators of SES. However, SES is a complex concept, and these indicators may not reflect all aspects of SES. The study recruited couples planning to conceive, including the full spectrum of fertility from less fertile to highly fertile individuals. Our results may generalize to most couples who are trying to conceive.

WIDER IMPLICATIONS OF THE FINDINGS

Our results are consistent with the literature indicating well-documented inequities in health across socioeconomic groups. The associations for income were surprisingly strong considering the Danish welfare state. These results indicate that the redistributive welfare system in Denmark does not suffice to eradicate inequities in reproductive health.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, and the National Institute of Child Health and Human Development (RO1-HD086742, R21-HD050264, and R01-HD060680). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Glycemic Load, Dietary Fiber, Added Sugar, and Spontaneous Abortion in Two Preconception Cohorts

BACKGROUND

Spontaneous abortion (SAB)-pregnancy loss before the 20th week of gestation-has adverse psychological and physical sequelae. Some medical conditions known to affect insulin sensitivity, including polycystic ovary syndrome and diabetes, can affect the risk of SAB. No prior studies have examined glycemic load and incidence of SAB in populations without conditions known to affect insulin sensitivity.

OBJECTIVES

We prospectively evaluated the association between preconception glycemic load and intake of carbohydrates, dietary fiber, and added sugar and risk of SAB.

METHODS

During 2013-2020, we recruited pregnancy planners from Denmark (SnartForaeldre.dk; SF) and the United States and Canada (Pregnancy Study Online; PRESTO). Participants completed a baseline questionnaire and a cohort-specific FFQ evaluated for validity. We estimated preconception glycemic load and intake of carbohydrates, dietary fiber, and added sugar from individual foods and mixed recipes. We included 2238 SF and 4246 PRESTO participants who reported a pregnancy during the course of the study. SAB data were derived from questionnaires and population registries. We used Cox proportional hazards regression to estimate HRs and 95% CIs.

RESULTS

In the study population, 15% of SF participants and 22% of PRESTO participants experienced SAB. Across both cohorts, there was no appreciable association between glycemic load, carbohydrate quality, dietary fiber, or added sugar intake and SAB. Compared with daily mean glycemic load <110, the HR for women with daily mean glycemic load ≥130 was 0.76 (95% CI: 0.52, 1.10) in SF and 1.01 (95% CI: 0.86, 1.19) in PRESTO.

CONCLUSIONS

Diets with high glycemic load, carbohydrates, and added sugars were not consistently associated with risk of SAB in parallel analyses of 2 preconception cohort studies of women in North America and Denmark.

Perceived stress and semen quality

BACKGROUND

Psychological stress is prevalent among reproductive-aged men. Assessment of semen quality for epidemiological studies is challenging as data collection is expensive and cumbersome, and studies evaluating the effect of perceived stress on semen quality are inconsistent.

OBJECTIVE

To examine the association between perceived stress and semen quality.

MATERIAL AND METHODS

We analyzed baseline data on 644 men (1,159 semen samples) from two prospective preconception cohort studies during 2015-2021: 592 in Pregnancy Study Online (PRESTO) and 52 in SnartForaeldre.dk (SF). At study entry, men aged ≥21 years (PRESTO) and ≥18 years (SF) trying to conceive without fertility treatment completed a questionnaire on reproductive and medical history, socio-demographics, lifestyle, and the 10-item version of the Perceived Stress Scale (PSS; interquartile range [IQR] of scores: 0-40). After enrollment (median weeks: 2.1, IQR: 1.3-3.7), men were invited to perform in-home semen testing, twice with 7-10 days between tests, using the Trak Male Fertility Testing System. Semen quality was characterized by semen volume, sperm concentration, and total sperm count. We fit generalized estimating equation linear regression models to estimate the percent difference in mean log-transformed semen parameters by four PSS groups (<10, 10-14, 15-19, ≥20), adjusting for potential confounders.

RESULTS

The median PSS score and IQR was 15 (10-19), and 136 men (21.1%) had a PSS score ≥20. Comparing men with PSS scores ≥20 with <10, the adjusted percent difference was -2.7 (95% CI: -9.8; 5.0) for semen volume, 6.8 (95% CI: -10.9; 28.1) for sperm concentration, and 4.3 (95% CI: -13.8; 26.2) for total sperm count.

CONCLUSION

Our findings indicate that perceived stress is not materially associated with semen volume, sperm concentration, or total sperm count.

Organic food consumption and fecundability in a preconception cohort study of Danish couples trying to conceive

BACKGROUND

Little is known about potential health effects of eating organic food in relation to reproduction.

OBJECTIVE

We examined associations between organic food consumption and fecundability.

METHODS

Data were derived from a preconception cohort study of Danish couples trying to conceive (SnartForaeldre.dk, SF). Participants completed a baseline questionnaire on socio-demographics, anthropometrics and lifestyle and a validated food-frequency questionnaire, which included questions on proportions of organic food consumed within six food groups. Participants were followed up with bimonthly questionnaires for up to 12 months or until pregnancy. Analyses were restricted to 2061 participants attempting pregnancy for ≤6 cycles at enrollment and 1303 with <3 cycles. Fecundability ratios (FRs) and 95% confidence intervals (CI) were estimated by proportional probabilities regression models adjusted for potential confounders including age, lifestyle and socioeconomic factors. Associations were examined for vegetables, fruits, cereals, dairy products, eggs and meat, separately, and for the overall pattern of organic food consumption (organic sum score).

RESULTS

The final analytic sample comprised 2069 participants. In the full cohort, organic food consumption was not meaningfully associated with fecundability. Among participants <3 cycles of pregnancy attempt at study entry (n = 1303), the FR was 1.11 (95% CI 0.93, 1.33) for the category 'less than half', for 'more than half' the FR was 1.17 (95% CI 0.99, 1.38) and for 'almost everything' the FR was 1.12 (95% CI 0.97, 1.28).

CONCLUSION

Higher consumption of organic foods was not meaningfully associated with fecundability, although slightly greater fecundability was seen among participants with <3 cycles of pregnancy attempt time.

Potential of Online Recruitment Among 15-25-Year Olds: Feasibility Randomized Controlled Trial

Background

Recruiting young people for health and intervention studies by traditional methods has become increasingly challenging. The widespread access to the internet may offer new strategies for online recruitment.

Objective

This study aims to assess the feasibility of online recruitment for a randomized controlled trial evaluating the effectiveness of Mindhelper, an online national youth mental health promotion service. The target group was young Danes aged 15-25 in need of mental health promotion.

Methods

Advertisements for recruitment were set up on Facebook and Instagram. Browser history was collected for a subsample of participants. We compared basic characteristics of participants who completed the baseline survey and those who did not, as well as of participants who completed the follow-up survey and those who were lost to follow-up. The significance of these differences was tested with the Pearson chi-square test.

Results

A total of 560 Danes aged 15-25 were recruited within 1 month (ie, had completed the baseline survey). Among these participants, 356 (63.6%) were at risk of developing depression or stress. The average advertisement price per participant completing the baseline questionnaire was 31 DKK (approximately €4 [US $4.2]). The follow-up survey was sent to 545 participants, of whom 318 (58.3%) completed the survey. No statistically significant differences were observed in baseline characteristics of participants who completed the follow-up and those who were lost to follow-up in terms of gender (P=.45), age (P=.35), occupation (P=.17), cohabitation (P=.90), mental well-being (P=.26), mental illness (P=.44; impact of the illness, P=.05), or use of the internet when having a hard time (P=.92).

Conclusions

We conclude that it is feasible to recruit young Danes online for a large-scale randomized controlled trial assessing the effectiveness of Mindhelper.

Trial Registration

ClinicalTrials.gov NCT04650906; https://clinicaltrials.gov/ct2/show/NCT04650906

A snapshot of an eCohort: A comparison of the LifeGene population at baseline with the Swedish general population

AIMS

With access to technologies and internet around the globe, opportunities have been provided to contact and recruit participants at a more rapid pace, without face-to-face contact. However, 'eCohorts' may yield substantial volunteer bias. Few studies have compared eCohorts to general populations or samples where traditional research methods have been applied. To our knowledge, no prior analyses have reported on Swedish-based LifeGene eCohort, in comparison with the Swedish general population. The aim of this study was to compare the LifeGene eCohort at baseline with the Swedish general population.

METHODS

The LifeGene eCohort (n = 39,862) was compared with the general population in Sweden represented by weighted data from the Swedish Public Health agency and Statistics Sweden. LifeGene is a nationwide project with yearly data collection. Descriptive statistics were used to compare demographic characteristics, and self-reported data on diagnosis of depression.

RESULTS

The LifeGene eCohort overrepresented younger people, females, those with a higher socio-economic status, non-smokers and people with a diagnosis of depression. Surprisingly, the eCohort included a larger percentage of people born outside of Sweden compared to the general population, which is not in line with previous studies.

CONCLUSION

The results show that the participants in the LifeGene eCohort are different regarding demographic variables and some health indicators from the Swedish general population. Hence, if comparisons are made between the LifeGene eCohort and a general population it becomes important to be aware of the differences that might exist between the different cohort populations and how these might affect the estimates.

Dietary folate intake and fecundability in two preconception cohorts

STUDY QUESTION

To what extent is dietary folate intake and total folate intake (dietary and supplemental intakes) associated with fecundability, the per cycle probability of conception?

SUMMARY ANSWER

Preconception dietary folate intake was positively associated with fecundability in a monotonic pattern.

WHAT IS KNOWN ALREADY

Supplemental folic acid has been associated with improved fertility, but little is known about the relation between dietary folate and fecundability.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study including 9559 women trying to conceive without fertility treatment and enrolled in the period 2013-2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used data from two internet-based prospective cohort studies of pregnancy planners from Denmark, where folic acid fortification is not performed (SnartForældre.dk (SF); n = 3755) and North America, where the food supply is fortified with folic acid (Pregnancy Study Online (PRESTO); n = 5804). Women contributed menstrual cycles at risk until they reported conception or experienced a censoring event. We used proportional probabilities regression models to compute fecundability ratios (FRs) and 95% CI, adjusting for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with a dietary folate intake ≥400 µg/day, the adjusted FRs for women in SF were 0.92 (95% CI: 0.85-0.99) for intake 250-399 µg/day, and 0.80 (95% CI: 0.68-0.94) for intake of <250 µg/day. The corresponding FRs in PRESTO were 0.95 (95% CI: 0.89-1.01) and 0.81 (95% CI: 0.65-1.00). Compared with the highest level of total folate intake (diet folate ≥400 µg/day plus folic acid supplementation), in both cohorts fecundability was lowest among women with the lowest dietary intake <250 µg/day dietary folate and no supplementation (FR: 0.76, 95% CI: 0.59-0.98 [SF] and 0.49, 95% CI: 0.31-0.77 [PRESTO]). Further, total intake dietary folate <250 µg/day plus supplementation was associated with reduced fecundability for SF participants (FR; 0.79, 95% CI: 0.65-0.98) and for PRESTO participants (FR; 0.92, 95% CI: 0.72-1.16).

LIMITATIONS, REASONS FOR CAUTION

It is unknown whether dietary folate and folic acid intake affect fecundability on its own or if there is an interaction with other micronutrients provided in healthy diet. Thus, the observed associations may not reflect dietary folate intake alone, but overall healthy diet.

WIDER IMPLICATIONS OF THE FINDINGS

Recommendations for preconception dietary folate intake and folic acid supplementation are of importance not only to prevent neural tube defects but also to enhance fecundability.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the National Institute of Child Health and Human Development (R01-HD086742). The authors report no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Air pollution and fecundability: Results from a Danish preconception cohort study

BACKGROUND

Animal and epidemiologic studies indicate that air pollution may adversely affect fertility. Epidemiologic studies have been restricted largely to couples undergoing fertility treatment or have retrospectively ascertained time-to-pregnancy among pregnant women.

OBJECTIVES

We examined the association between residential ambient air pollution and fecundability, the per-cycle probability of conception, in a large preconception cohort of Danish pregnancy planners.

METHODS

During 2007-2018, we used the Internet to recruit and follow women who were trying to conceive without the use of fertility treatment. Participants completed an online baseline questionnaire eliciting socio-demographic characteristics, lifestyle factors, and medical and reproductive histories and follow-up questionnaires every 8 weeks to ascertain pregnancy status. We determined concentrations of ambient nitrogen oxides (NOx ), nitrogen dioxide (NO2 ), carbon monoxide (CO), ozone (O3 ), particulate matter <2.5 µm (PM2.5 ) and <10 µm (PM10 ), and sulphur dioxide (SO2 ) at each participant's residential address. We calculated average exposure during the year before baseline, during each menstrual cycle over follow-up and during the entire pregnancy attempt time. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs), adjusting for potential confounders and co-pollutants. The analysis was restricted to the 10,183 participants who were trying to conceive for <12 cycles at study entry whose addresses could be geocoded.

RESULTS

During 12 months of follow-up, 73% of participants conceived. Higher concentrations of PM2.5 and PM10 were associated with small reductions in fecundability. For example, the FRs for a one interquartile range (IQR) increase in PM2.5 (IQR = 3.2 µg/m3 ) and PM10 (IQR = 5.3 µg/m3 ) during each menstrual cycle were 0.93 (95% CI: 0.87, 0.99) and 0.91 (95% CI: 0.84, 0.99), respectively. Other air pollutants were not appreciably associated with fecundability.

CONCLUSIONS

In this preconception cohort study of Danish women, residential exposures to PM2.5 and PM10 were associated with reduced fecundability.

Accuracy of self-reported birth outcomes relative to birth certificate data in an Internet-based prospective cohort study

BACKGROUND

The accuracy of birth outcome data provided by Internet-based cohort study participants has not been well studied.

METHODS

We compared self-reported data on birth characteristics in Pregnancy Study Online (PRESTO), an Internet-based prospective cohort study of North American pregnancy planners, with birth certificate data. At enrolment, participants were aged 21-45 years, attempting conception, and not using fertility treatment. Women completed online questionnaires during preconception, early and late pregnancy, and postpartum. We requested birth certificate data during 2014-2019 from seven health departments in states with the most participants. After restricting to singleton births, we assessed specificity, sensitivity, and agreement comparing self-reported data from postpartum questionnaires with birth certificate data for gestational age at delivery (GA) and birthweight (grams). Our primary measure of self-reported GA (weeks) was calculated as [280-(due date-birth date)]/7. We used log-binomial regression to assess predictors of agreement.

RESULTS

We linked 85% (771/909) of women in selected states. Median age of women was 30 years (range: 21-42), 84% had ≥ 16 years of education, nearly 96% were married, 12% had household incomes <$50 000, 32% were parous, and 85% identified as non-Hispanic White. Median recall interval was 6 months. Among those with self-reported data, 89% reported the same GA as the birth certificate and 98% reported GA within 1 week of the birth certificate. Self-report of preterm birth (GA < 37 weeks) agreed with information from birth certificates for 100% of women; sensitivity was 100%, and specificity was 99%. Self-reported low birthweight (<2500 grams) agreed with birth certificates for 93% of women; sensitivity and specificity were 93% and ≥99%, respectively. Predictors of poorer agreement included higher parity and longer pregnancy attempt time for GA, and lower education and longer recall interval for birthweight.

CONCLUSION

Self-reported data on GA and birthweight from an Internet-based cohort showed high accuracy compared with birth certificates.

Use of a mobile app to capture supplemental health information during pregnancy: Implications for clinical research

PURPOSE

Mobile applications ("apps") may be efficient tools for improving the quality of clinical research among pregnant women, but evidence is sparse. We assess the feasibility and generalizability of a mobile app for capturing supplemental data during pregnancy.

METHODS

In 2017, we conducted a pilot study of the FDA MyStudies mobile app within a pregnant population identified through Kaiser Permanente Washington (KPWA), an integrated healthcare delivery system. We ascertained health conditions, medications, and substance use through app-based questionnaires. In a post-hoc analysis, we utilized electronic health records (EHR) to summarize sociodemographic and health characteristics of pilot participants and, for comparison, a pregnant population identified using similar methods.

RESULTS

Six percent (64/1070) of contacted women enrolled in the pilot study. Nearly half (23/53) reported taking medication for headaches and one-fourth for constipation (13/53) and nausea (12/53) each. Few instances (2/92) of over-the-counter medication use were identified in electronic dispensing records. One-quarter to one-third of participants with depression and anxiety/panic, respectively, reported recently discontinuing medications for these conditions. Eighty-eight percent of pilot participants reported White race (95%CI: 81-95%), versus 67% of the comparison population (N = 2065). More pilot participants filled ≥1 prescription for antianxiety medication (22% [95%CI: 13-35%]) and antidepressants (19% [95%CI 10-31%]) pre-pregnancy than the comparison population (10 and 9%, respectively).

CONCLUSIONS

Mobile apps may be a feasible tool for capturing health data not routinely available in EHR. Pregnant women willing to use a mobile app for research may differ from the general pregnant population, but confirmation is needed.

Pregravid contraceptive use and fecundability: prospective cohort study

OBJECTIVE

To evaluate the association between pregravid use of a variety of contraceptive methods and subsequent fecundability.

DESIGN

Prospective cohort study.

SETTING

Denmark and North America, 2007-19.

PARTICIPANTS

17 954 women who had tried to conceive for up to six menstrual cycles at study entry. At baseline, participants reported their contraceptive histories, and personal, medical, and lifestyle characteristics.

MAIN OUTCOME MEASURES

Pregnancy, determined by bimonthly follow-up questionnaires for up to 12 months.

RESULTS

Approximately 38% (n=6735) of participants had recently used oral contraceptives, 13% (n=2398) had used long acting reversible contraceptive methods, and 31% (n=5497) had used barrier methods. Women who had recently stopped using oral contraceptives, the contraceptive ring, and some long acting reversible contraceptive methods experienced short term delays in return of fertility compared with users of barrier methods. Use of injectable contraceptives was associated with decreased fecundability compared with use of barrier methods (fecundability ratio 0.65; 95% confidence interval 0.47 to 0.89). Users of injectable contraceptives had the longest delay in return of normal fertility (five to eight menstrual cycles), followed by users of patch contraceptives (four cycles), users of oral and ring contraceptives (three cycles), and users of hormonal and copper intrauterine devices and implant contraceptives (two cycles). Lifetime length of use of hormonal contraceptive methods was not associated with fecundability.

CONCLUSIONS

Use of some hormonal contraceptive methods was associated with delays in return of fertility, with injectable contraceptives showing the longest delay. The findings indicated little or no lasting effect of long term use of these methods on fecundability.

The Association between Seafood Intake and Fecundability: Analysis from Two Prospective Studies

Background: Seafood is an important source of omega-3 fatty acids, which have been associated with improved oocyte quality and embryo morphology in some studies. However, seafood is also a source of persistent organic pollutants and heavy metals, which may adversely affect fecundity. Previous studies of seafood intake and fecundity have generated inconsistent results. Methods: In two prospective cohort studies of 7836 female pregnancy planners from Denmark (Snart Foraeldre, n = 2709) and North America (PRESTO, n = 5127), we evaluated the association of dietary intake of total seafood and marine-sourced long-chain omega-3 fatty acids (eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid) with fecundability. Participants completed a baseline questionnaire on sociodemographics, behavioral factors, anthropometrics, and medical history, and a food frequency questionnaire. Pregnancy status was updated bimonthly for up to 12 months or until reported conception. We estimated fecundability ratios (FRs) and 95% confidence intervals (CIs) using proportional probabilities regression models, adjusted for energy intake and other potential confounders. We restricted analyses to women with ≤6 menstrual cycles of attempt time at enrollment. Results: Intake of total seafood or marine-sourced long-chain omega-3 fatty acids was not appreciably associated with fecundability in either cohort (≥200 vs. <50 g/week total seafood: FR = 0.94, 95% CI: 0.79–1.10 in Snart Foraeldre; FR = 1.00, 95% CI: 0.90–1.13 in PRESTO; marine fatty acids: ≥90th vs. <25th percentile: FR = 1.00, 95% CI: 0.85–1.18 in Snart Foraeldre; FR = 0.97, 95% CI: 0.86–1.09 in PRESTO). In PRESTO, where we collected additional data on seafood preparation, we observed an inverse association between fecundability and fried shellfish (≥10 g/week vs. none: FR = 0.77, 95% CI: 0.61–0.98), but not unfried shellfish (≥20 g/week vs. none: FR = 0.98, 95% CI: 0.89–1.07); in Snart Foraeldre, there was no association with total shellfish intake. Conclusions: We found little association between seafood intake and fecundability overall, but greater intake of fried shellfish was associated with reduced fecundability among North American participants.

Glycemic load, dietary fiber, and added sugar and fecundability in 2 preconception cohorts

BACKGROUND

Glycemic load (GL) reflects the quantity and quality of carbohydrates in the diet; dietary fiber and added sugar are components of GL. Few epidemiologic studies have assessed the association between these dietary factors and fecundability.

OBJECTIVE

We prospectively evaluated the associations of GL, total carbohydrates, dietary fiber, and added sugar with fecundability.

METHODS

Snart Foraeldre (SF) and Pregnancy Study Online (PRESTO) are parallel web-based prospective preconception cohorts of couples attempting to conceive in Denmark and North America. At baseline, female participants completed a web-based questionnaire on demographic and lifestyle factors and a validated FFQ. We calculated GL, total carbohydrate intake, total dietary fiber, carbohydrate-to-fiber ratio, and added sugar based on reported frequencies for individual foods, standard recipes for mixed foods, and average serving sizes. The analysis included 2709 SF participants and 4268 PRESTO participants. We used proportional probabilities regression models to estimate fecundability ratios (FR) and 95% CIs.

RESULTS

Compared with an average daily GL of ≤100, FRs for an average daily GL of ≥141 were 0.89 (95% CI: 0.73, 1.08) in SF and 0.87 (95% CI: 0.77, 0.98) in PRESTO participants. Compared with consuming ≤16 g/d of dietary fiber, FRs for consuming ≥25 g/d were 0.99 (95% CI: 0.81, 1.22) in SF and 1.06 (95% CI: 0.94, 1.20) in PRESTO. Compared with a carbohydrate-to-fiber ratio of ≤8, FRs for a ratio of ≥13 were 0.86 (95% CI: 0.73, 1.01) in SF and 0.87 (95% CI: 0.78, 0.98) in PRESTO. Compared with ≤27 g/d of added sugar, FRs for ≥72 g/d were 0.87 (95% CI: 0.68, 1.10) in SF and 0.86 (95% CI: 0.75, 0.99) in PRESTO participants.

CONCLUSIONS

Among women attempting to conceive in Denmark and North America, diets high in GL, carbohydrate-to-fiber ratio, and added sugar were associated with modestly reduced fecundability.

Online Consent Enables a Randomized, Controlled Trial Testing a Patient-Centered Online Decision-Aid for Medicare Beneficiaries to Meet Recruitment Goal in Short Time Frame

Online consenting allows potential participants of research projects to deliberate their participation at their own pace and may be more cost-effective than conventional approaches. Yet, online consenting is not widespread in health services research due partly to concerns about security, confidentiality, and lack of established processes. We report our use of online consenting to successfully enroll over 1185 Medicare beneficiaries in a short 9-week time frame for a research study.

Iron Consumption Is Not Consistently Associated with Fecundability among North American and Danish Pregnancy Planners

BACKGROUND

Infertility is an important public health problem with few known modifiable risk factors. Dietary factors including folic acid have been associated with improved fertility, but the association between iron and fertility is understudied. One study among US nurses found a 40% lower risk of ovulatory infertility with higher intake of nonheme iron and iron supplements.

OBJECTIVES

The aim of this study was to determine the extent to which iron intake from diet and supplements reported on structured questionnaires is associated with fecundability.

METHODS

We conducted parallel analyses that used data from 2 prospective cohort studies of pregnancy planners from Denmark (Snart Foraeldre; n = 1693) and North America (PRESTO; n = 2969) during 2013-2018. Follow-up comprised menstrual cycles at risk until pregnancy or censoring for fertility treatment, stopped trying to conceive, withdrawal, loss to follow-up, or 12 cycles of attempt. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs, adjusting for confounders.

RESULTS

We found little association between dietary heme iron intake and fecundability in either cohort. The FR for nonheme iron intake (≥11 mg/d compared with <9 mg/day) was 1.11 for Snart Foraeldre participants (95% CI: 0.92, 1.34) and 1.01 for PRESTO participants (95% CI: 0.89, 1.14). The FR for iron-containing supplements was 1.01 in Snart Foraeldre (95% CI: 0.90, 1.13) and 1.19 in PRESTO (95% CI: 1.03, 1.38). In PRESTO, but not Snart Foraeldre, stronger positive associations were found for nonheme iron intake and iron supplement use among women with heavy menses or short menstrual cycles.

CONCLUSIONS

Overall, dietary intake of iron was not consistently associated with fecundability, although there was some evidence for a positive association among women with risk factors for iron deficiency. We also found a small positive association between supplemental iron intake and fecundability among North American, but not Danish, pregnancy planners.

Design and Preliminary Findings From a New Electronic Cohort Embedded in the Framingham Heart Study

Background

New models of scalable population-based data collection that integrate digital and mobile health (mHealth) data are necessary.

Objective

The aim of this study was to describe a cardiovascular digital and mHealth electronic cohort (e-cohort) embedded in a traditional longitudinal cohort study, the Framingham Heart Study (FHS).

Methods

We invited eligible and consenting FHS Generation 3 and Omni participants to download the electronic Framingham Heart Study (eFHS) app onto their mobile phones and co-deployed a digital blood pressure (BP) cuff. Thereafter, participants were also offered a smartwatch (Apple Watch). Participants are invited to complete surveys through the eFHS app, to perform weekly BP measurements, and to wear the smartwatch daily.

Results

Up to July 2017, we enrolled 790 eFHS participants, representing 76% (790/1044) of potentially eligible FHS participants. eFHS participants were, on average, 53±8 years of age and 57% were women. A total of 85% (675/790) of eFHS participants completed all of the baseline survey and 59% (470/790) completed the 3-month survey. A total of 42% (241/573) and 76% (306/405) of eFHS participants adhered to weekly digital BP and heart rate (HR) uploads, respectively, over 12 weeks.

Conclusions

We have designed an e-cohort focused on identifying novel cardiovascular disease risk factors using a new smartphone app, a digital BP cuff, and a smartwatch. Despite minimal training and support, preliminary findings over a 3-month follow-up period show that uptake is high and adherence to periodic app-based surveys, weekly digital BP assessments, and smartwatch HR measures is acceptable.

Obtaining contextually relevant geographic data using Facebook recruitment in public health studies

INTRODUCTION

Online participant recruitment for public health research studies has increased dramatically in recent years, particularly as traditional recruitment strategies have waned in efficiency. The emergence of e-epidemiology offers possibilities for reaching understudied populations as well as conducting large-scale studies.

METHODS

We conducted a cross-sectional survey focused on self-reported neighborhood characteristics, perceived stress, and feasibility of obtaining work/residential addresses via online recruitment in St. Louis, Missouri, USA from February 2017 to December 2017. We report the process of using Facebook recruitment and demonstrate how this strategy can enhance collection of geospatial data to better understand context and spatial patterns of disease.

RESULTS

A total of 425 participants were recruited via Facebook advertisements. All participants reported their residential and work ZIP codes, though only 64.7% and 45.6% provided their complete residential and work street addresses, respectively. Those who reported their complete residential street addresses were more likely to be female (69.8% vs. 56.1% of males, χ² = 7.89, 1 df, p = 0.005), though no differences were observed by race, age, or employment status.

DISCUSSION

These findings indicate that valuable location data can be successfully collected via Facebook recruitment - data that could potentially include residential history or prospective follow-up time or be combined with other emerging technologies for geographic data in order to better understand the context and the effects of place on health outcomes.

CONCLUSIONS

Facebook recruitment may be an underutilized resource for obtaining accurate geospatial and contextually relevant health data and should be considered as a means for finding participants due to the cost-effectiveness, efficiency and flexibility of this recruitment approach.

Trial exclusion criteria and their impact on the estimation of antipsychotic drugs effect: A case study using the SOHO database

OBJECTIVES

To explore the impact upon estimation of drug effect as a result of applying exclusion criteria in randomized-controlled trials (RCT) measuring the efficacy of antipsychotics (AP) in schizophrenia.

METHODS

Three characteristics which may act as effect-modifiers of AP, while also common exclusion criteria in RCTs, were identified through literature review: schizophrenia duration, substance use disorder and poor adherence. The SOHO cohort was used to estimate the effect of initiating antipsychotic drugs "A", "B" or "C" (pooled) upon symptom evolution at 3months from baseline (CGI-S scale). "Estimated effectiveness" and "estimated efficacy" were drawn from the "SOHO" and "RCT-like" (patients with none of the above-listed exclusion criteria) samples, respectively. Effect-modification and impact of each exclusion criterion on AP effect estimates were explored using non-adjusted statistics.

RESULTS

The "SOHO sample" included 8250 patients initiating drug A, B or C at baseline, whose AP "estimated effectiveness" was ΔCGI-S=-0.78 (95% CI=-0.80, -0.76). The "RCT-like" sub-sample included 5348 (65%) patients whose AP "estimated efficacy" was ΔCGI-S=-0.73 (95% CI=-0.75, -0.70). Patients with short illness duration (≤3years since first AP; n=2436) experienced significant symptom improvement (ΔCGI-S=-0.89; 95%CI=-0.93, -0.85) compared to patients with duration >3years (mean ΔCGI-S=-0.73; 95%CI=-0.76, -0.71). Excluding patients with short illness duration led to a change in AP effect estimates but this was not the case for substance use disorder or poor adherence.

CONCLUSION

Using certain exclusion criteria in RCTs may impact the drug's effect estimate, particularly when exclusion criteria are AP effect-modifiers representing frequent characteristics among patients with schizophrenia.

Is human fecundity changing? A discussion of research and data gaps precluding us from having an answer

Fecundity, the biologic capacity to reproduce, is essential for the health of individuals and is, therefore, fundamental for understanding human health at the population level. Given the absence of a population (bio)marker, fecundity is assessed indirectly by various individual-based (e.g. semen quality, ovulation) or couple-based (e.g. time-to-pregnancy) endpoints. Population monitoring of fecundity is challenging, and often defaults to relying on rates of births (fertility) or adverse outcomes such as genitourinary malformations and reproductive site cancers. In light of reported declines in semen quality and fertility rates in some global regions among other changes, the question as to whether human fecundity is changing needs investigation. We review existing data and novel methodological approaches aimed at answering this question from a transdisciplinary perspective. The existing literature is insufficient for answering this question; we provide an overview of currently available resources and novel methods suitable for delineating temporal patterns in human fecundity in future research.

Dietary Fat Intake and Fecundability in 2 Preconception Cohort Studies

The association between dietary fat and fertility is not well studied. We evaluated intakes of total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, trans fatty acids (TFA), ω-3 fatty acids, and ω-6 fatty acids in relation to fecundability in Danish and North American preconception cohort studies. Women who were attempting to become pregnant completed a validated food frequency questionnaire at baseline. Pregnancy status was updated bimonthly for 12 months or until pregnancy. Fecundability ratios (FR) and 95% confidence intervals were estimated using multivariable proportional probabilities regression. Intakes of total fat and saturated, monounsaturated, polyunsaturated, and ω-6 fatty acids were not appreciably associated with fecundability. TFA intake was associated with reduced fecundability in North American women (for the fourth quartile vs. the first, FR = 0.86, 95% confidence interval (CI): 0.71, 1.04) but not Danish women (for the fourth quartile vs. the first, FR = 1.04, 95% CI: 0.86, 1.25), though intake among Danish women was low. In North America, ω-3 fatty acid intake was associated with higher fecundability, but there was no dose-response relationship (among persons who did not use fish oil supplements: for the fourth quartile vs. the first, FR = 1.40, 95% CI: 1.13, 1.73); no association was found in Danish women, among whom low intake was rare. In the present study, high TFA intake and low ω-3 fatty acid intake were associated with reduced fecundity.

The use of random-effects models to identify health care center-related characteristics modifying the effect of antipsychotic drugs

Purpose

A case study was conducted, exploring methods to identify drugs effects modifiers, at a health care center level.

Patients and methods

Data were drawn from the Schizophrenia Outpatient Health Outcome cohort, including hierarchical information on 6641 patients, recruited from 899 health care centers from across ten European countries. Center-level characteristics included the following: psychiatrist’s gender, age, length of practice experience, practice setting and type, countries’ Healthcare System Efficiency score, and psychiatrist density in the country. Mixed multivariable linear regression models were used: 1) to estimate antipsychotic drugs’ effectiveness (defined as the association between patients’ outcome at 3 months – dependent variable, continuous – and antipsychotic drug initiation at baseline – drug A vs other antipsychotic drug); 2) to estimate the similarity between clustered data (using the intra-cluster correlation coefficient); and 3) to explore antipsychotic drug effects modification by center-related characteristics (using the addition of an interaction term).

Results

About 23% of the variance found for patients’ outcome was explained by unmeasured confounding at a center level. Psychiatrists’ practice experience was found to be associated with patient outcomes (p=0.04) and modified the relative effect of “drug A” (p<0.001), independent of center- or patient-related characteristics.

Conclusion

Mixed models may be useful to explore how center-related characteristics modify drugs’ effect estimates, but require numerous assumptions.

Sick leave and medication use in pregnancy: a European web-based study

BACKGROUND AND OBJECTIVE

A comparison of sick leave in pregnancy between countries is difficult as most studies have been conducted in single countries in Scandinavia. The objective of this study was to explore patterns of and reasons for sick leave during pregnancy on a multinational level, focusing on medication use but also differences in sick leave policies.

DESIGN AND SETTING

Cross-sectional, web-based study in 12 European countries from October 2011 to February 2012. Data were collected via an electronic questionnaire.

PARTICIPANTS

Pregnant women and mothers of children under the age of 1 year.

PRIMARY OUTCOME MEASURE

Sick leave prevalence in pregnancy.

RESULTS

Of 6686 women included, 3385 (50.6%) had been on sick leave during pregnancy. The rates of sick leave varied across countries, ranging from 31.7%-34.8% in Sweden and the UK to 62.4%-71.3% in Norway, Serbia, Croatia and Poland. The most common reasons for being on sick leave were pregnancy complications (26.5%); pain in the neck, back or pelvic girdle (16.2%); and nausea and vomiting (NVP, 16.0%). Women using medications for acute illnesses were more likely to be on sick leave than their non-medicated counterparts, while an opposite trend was observed for women with chronic disorders, where non-medicated women were more likely to be on sick leave. Women from countries with 'low' sick leave policies were less likely to have extensions of sick leaves compared with women from countries with 'medium' policies (adjusted OR 0.63, 95% CI 0.49 to 0.82).

CONCLUSION

The rates of sick leave in pregnancy vary greatly across European countries. Women using medications were more likely to be on sick leave, especially for acute illnesses. The differences in sick leave patterns across countries only partially reflected differences in sick leave policies, which implies that sick leave in pregnancy is also affected by other national differences.

Volunteer Participation in the Health eHeart Study: A Comparison with the US Population

Direct volunteer "eCohort" recruitment can be an efficient way of recruiting large numbers of participants, but there is potential for volunteer bias. We compared self-selected participants in the Health eHeart Study to participants in the National Health And Nutrition Examination Survey (NHANES) 2013-14, a cross-sectional survey of the US population. Compared with the US population (represented by 5,769 NHANES participants), the 12,280 Health eHeart participants with complete survey data were more likely to be female (adjusted odds ratio (ORadj) = 3.1; 95% confidence interval (CI) 2.9-3.5); less likely to be Black, Hispanic, or Asian versus White/non-Hispanic (ORadj's = 0.4-0.6, p < 0.01); more likely to be college-educated (ORadj = 15.8 (13-19) versus ≤high school); more likely to have cardiovascular diseases and risk factors (ORadj's = 1.1-2.8, p < 0.05) except diabetes (ORadj = 0.8 (0.7-0.9); more likely to be in excellent general health (ORadj = 0.6 (0.5-0.8) for "Good" versus "Excellent"); and less likely to be current smokers (ORadj = 0.3 (0.3-0.4)). While most self-selection patterns held for Health eHeart users of Bluetooth blood pressure cuff technology, there were some striking differences; for example, the gender ratio was reversed (ORadj = 0.6 (0.4-0.7) for female gender). Volunteer participation in this cardiovascular health-focused eCohort was not uniform among US adults nor for different components of the study.

Exposure to multiple chemicals in a cohort of reproductive-aged Danish women

BACKGROUND

Current exposure assessment research does not sufficiently address multi-pollutant exposure and their correlations in human media. Understanding the extent of chemical exposure in reproductive-aged women is of particular concern due to the potential for in utero exposure and fetal susceptibility.

OBJECTIVES

The objectives of this study were to characterize concentrations of chemical biomarkers during preconception and examine correlations between and within chemical classes.

METHODS

We examined concentrations of 135 biomarkers from 16 chemical classes in blood and urine from 73 women aged 18-40 enrolled in Snart Foraeldre/Milieu, a prospective cohort study of pregnancy planners in Denmark (2011-2014). We compared biomarker concentrations with United States similarly-aged, non-pregnant women who participated in the National Health and Nutrition Environmental Survey (NHANES) and with other international biomonitoring studies. We performed principal component analysis to examine biomarker correlations.

RESULTS

The mean number of biomarkers detected in the population was 92 (range: 60-108). The most commonly detected chemical classes were phthalates, metals, phytoestrogens and polycyclic aromatic hydrocarbons. Except blood mercury, urinary barium and enterolactone, geometric means were higher in women from NHANES. Chemical classes measured in urine generally did not load on a single component, suggesting high between-class correlation among urinary biomarkers, while there is high within-class correlation for biomarkers measured in serum and blood.

CONCLUSIONS

We identified ubiquitous exposure to multiple chemical classes in reproductive-aged Danish women, supporting the need for more research on chemical mixtures during preconception and early pregnancy. Inter- and intra-class correlation between measured biomarkers may reflect common exposure sources, specific lifestyle factors or shared metabolism pathways.

Online Recruitment: Feasibility, Cost, and Representativeness in a Study of Postpartum Women

Background

Online recruitment is feasible, low-cost, and can provide high-quality epidemiological data. However, little is known about the feasibility of recruiting postpartum women online, or sample representativeness.

Objective

The current study investigates the feasibility of recruiting a population of postpartum women online for health research and examines sample representativeness.

Methods

Two samples of postpartum women were compared: those recruited online as participants in a brief survey of new mothers (n=1083) and those recruited face-to-face as part of a nationally representative study (n=579). Sociodemographic, general health, and mental health characteristics were compared between the two samples.

Results

Obtaining a sample of postpartum women online for health research was highly efficient and low-cost. The online sample over-represented those who were younger (aged 25-29 years), were in a de facto relationship, had higher levels of education, spoke only English at home, and were first-time mothers. Members of the online sample were significantly more likely to have poor self-rated health and poor mental health than the nationally representative sample. Health differences remained after adjusting for sociodemographic differences.

Conclusions

Potential exists for feasible and low-cost e-epidemiological research with postpartum populations; however, researchers should consider the potential influence of sample nonrepresentativeness.

Costs and Efficiency of Online and Offline Recruitment Methods: A Web-Based Cohort Study

BACKGROUND

The Internet is widely used to conduct research studies on health issues. Many different methods are used to recruit participants for such studies, but little is known about how various recruitment methods compare in terms of efficiency and costs.

OBJECTIVE

The aim of our study was to compare online and offline recruitment methods for Internet-based studies in terms of efficiency (number of recruited participants) and costs per participant.

METHODS

We employed several online and offline recruitment methods to enroll 18- to 45-year-old women in an Internet-based Danish prospective cohort study on fertility. Offline methods included press releases, posters, and flyers. Online methods comprised advertisements placed on five different websites, including Facebook and Netdoktor.dk. We defined seven categories of mutually exclusive recruitment methods and used electronic tracking via unique Uniform Resource Locator (URL) and self-reported data to identify the recruitment method for each participant. For each method, we calculated the average cost per participant and efficiency, that is, the total number of recruited participants.

RESULTS

We recruited 8252 study participants. Of these, 534 were excluded as they could not be assigned to a specific recruitment method. The final study population included 7724 participants, of whom 803 (10.4%) were recruited by offline methods, 3985 (51.6%) by online methods, 2382 (30.8%) by online methods not initiated by us, and 554 (7.2%) by other methods. Overall, the average cost per participant was €6.22 for online methods initiated by us versus €9.06 for offline methods. Costs per participant ranged from €2.74 to €105.53 for online methods and from €0 to €67.50 for offline methods. Lowest average costs per participant were for those recruited from Netdoktor.dk (€2.99) and from Facebook (€3.44).

CONCLUSIONS

In our Internet-based cohort study, online recruitment methods were superior to offline methods in terms of efficiency (total number of participants enrolled). The average cost per recruited participant was also lower for online than for offline methods, although costs varied greatly among both online and offline recruitment methods. We observed a decrease in the efficiency of some online recruitment methods over time, suggesting that it may be optimal to adopt multiple online methods.

Dairy intake and fecundability in 2 preconception cohort studies

BACKGROUND

Animal studies have shown that a high intake of galactose, a breakdown product of lactose, increases ovarian toxicity. Few epidemiologic studies, to our knowledge, have examined the association between dairy intake and fertility, and they have had conflicting findings.

OBJECTIVE

We prospectively evaluated dairy intake in relation to fecundability among women who were planning for pregnancy.

DESIGN

Data were derived from preconception cohort studies in Denmark (Snart Foraeldre) and North America [PRESTO (Pregnancy Study Online)] in which women completed a validated food-frequency questionnaire 10 d after enrollment. The dietary intake of dairy foods and their constituents was calculated based on reported frequencies, mean serving sizes, and standard recipes for mixed foods. Outcome data were updated every 8 wk for 12 mo or until reported conception. Analyses were restricted to 2426 women attempting pregnancy for ≤6 cycles at study entry. Fecundability ratios (FRs) and 95% CIs were estimated with the use of proportional probabilities regression models adjusted for potential confounders.

RESULTS

FRs for total dairy intake (≥18 compared with <7 servings/wk) were 1.37 (95% CI: 1.05, 1.78) among 1126 Snart Foraeldre participants and 1.04 (95% CI: 0.78, 1.38) among 1300 PRESTO participants (pooled FR: 1.11; 95% CI: 0.94, 1.31). The elevated FR for total dairy intake among Snart Foraeldre participants was limited to milk consumption and found only among women aged <30 y. There was no clear association between low- or high-fat dairy intake and fecundability in either cohort. Although there was little evidence of an association between dietary intake of calcium, potassium, magnesium, or vitamin D and fecundability, a greater consumption of phosphorus and lactose was associated with slightly higher fecundability in both cohorts.

CONCLUSIONS

Associations between dairy intake and fecundability were generally small and inconsistent across cohorts. Our findings do not support the hypotheses that a greater consumption of high-fat dairy improves fertility or that a greater consumption of lactose or low-fat dairy harms fertility.

Lessons Learned From Methodological Validation Research in E-Epidemiology

Background

Traditional epidemiological research methods exhibit limitations leading to high logistics, human, and financial burden. The continued development of innovative digital tools has the potential to overcome many of the existing methodological issues. Nonetheless, Web-based studies remain relatively uncommon, partly due to persistent concerns about validity and generalizability.

Objective

The objective of this viewpoint is to summarize findings from methodological studies carried out in the NutriNet-Santé study, a French Web-based cohort study.

Methods

On the basis of the previous findings from the NutriNet-Santé e-cohort (>150,000 participants are currently included), we synthesized e-epidemiological knowledge on sample representativeness, advantageous recruitment strategies, and data quality.

Results

Overall, the reported findings support the usefulness of Web-based studies in overcoming common methodological deficiencies in epidemiological research, in particular with regard to data quality (eg, the concordance for body mass index [BMI] classification was 93%), reduced social desirability bias, and access to a wide range of participant profiles, including the hard-to-reach subgroups such as young (12.30% [15,118/122,912], <25 years) and old people (6.60% [8112/122,912], ≥65 years), unemployed or homemaker (12.60% [15,487/122,912]), and low educated (38.50% [47,312/122,912]) people. However, some selection bias remained (78.00% (95,871/122,912) of the participants were women, and 61.50% (75,590/122,912) had postsecondary education), which is an inherent aspect of cohort study inclusion; other specific types of bias may also have occurred.

Conclusions

Given the rapidly growing access to the Internet across social strata, the recruitment of participants with diverse socioeconomic profiles and health risk exposures was highly feasible. Continued efforts concerning the identification of specific biases in e-cohorts and the collection of comprehensive and valid data are still needed. This summary of methodological findings from the NutriNet-Santé cohort may help researchers in the development of the next generation of high-quality Web-based epidemiological studies.

Evaluation of Selection Bias in an Internet-based Study of Pregnancy Planners

Selection bias is a potential concern in all epidemiologic studies, but it is usually difficult to assess. Recently, concerns have been raised that internet-based prospective cohort studies may be particularly prone to selection bias. Although use of the internet is efficient and facilitates recruitment of subjects that are otherwise difficult to enroll, any compromise in internal validity would be of great concern. Few studies have evaluated selection bias in internet-based prospective cohort studies. Using data from the Danish Medical Birth Registry from 2008 to 2012, we compared six well-known perinatal associations (e.g., smoking and birth weight) in an internet-based preconception cohort (Snart Gravid n = 4,801) with the total population of singleton live births in the registry (n = 239,791). We used log-binomial models to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for each association. We found that most results in both populations were very similar. For example, maternal obesity was associated with an increased risk of delivering a macrosomic infant in Snart Gravid (RR = 1.5; 95% CI: 1.2, 1.7) and the total population (RR = 1.5; 95% CI: 1.45, 1.53), and maternal smoking of >10 cigarettes per day was associated with a higher risk of low birth weight (RR = 2.7; 95% CI: 1.2, 5.9 vs. RR = 2.9; 95% CI: 2.6, 3.1) in Snart Gravid and the total population, respectively. We cannot be certain that our results would apply to other associations or different populations. Nevertheless, our results suggest that recruitment of reproductive aged women via the internet may be no more prone to selection bias than traditional methods of recruitment.

Identifying Complementary and Alternative Medicine Usage Information from Internet Resources. A Systematic Review

OBJECTIVES

Identify and highlight research issues and methods used in studying Complementary and Alternative Medicine (CAM) information needs, access, and exchange over the Internet.

METHODS

A literature search was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines from PubMed to identify articles that have studied Internet use in the CAM context. Additional searches were conducted at Nature.com and Google Scholar.

RESULTS

The Internet provides a major medium for attaining CAM information and can also serve as an avenue for conducting CAM related surveys. Based on the literature analyzed in this review, there seems to be significant interest in developing methodologies for identifying CAM treatments, including the analysis of search query data and social media platform discussions. Several studies have also underscored the challenges in developing approaches for identifying the reliability of CAM-related information on the Internet, which may not be supported with reliable sources. The overall findings of this review suggest that there are opportunities for developing approaches for making available accurate information and developing ways to restrict the spread and sale of potentially harmful CAM products and information.

CONCLUSIONS

Advances in Internet research are yet to be used in context of understanding CAM prevalence and perspectives. Such approaches may provide valuable insights into the current trends and needs in context of CAM use and spread.

Following young people with perinatal HIV infection from adolescence into adulthood: the protocol for PHACS AMP Up, a prospective cohort study

INTRODUCTION

The first generation of adolescents born with HIV infection has reached young adulthood due to advances in treatment. It is important to continue follow-up of these individuals to assess their long-term medical, behavioural and mental health and ability to successfully transition to adulthood while coping with a chronic, potentially stigmatising condition. To accomplish this, and to maintain their interest in long-term research participation, we need to accommodate the changing lifestyles and interests of young adult study participants while ensuring valid data collection. We report the protocol for Pediatric HIV/AIDS Cohort Study (PHACS) Adolescent Master Protocol (AMP) Up, a prospective cohort study enrolling young adult participants for long-term follow-up.

METHODS AND ANALYSIS

AMP Up is recruiting 850 young men and women 18 years of age and older-600 perinatally HIV-infected and a comparison group of 250 perinatally HIV-exposed, uninfected-at 14 clinical research sites in the USA and Puerto Rico. Recruitment began in April 2014 and is ongoing, with 305 participants currently enrolled. Planned follow-up is ≥6 years. Data are collected with a flexible hybrid of online and in-person methods. Outcomes include: transition to adult clinical care and retention in care; end-organ diseases; malignancies; metabolic complications; sexually transmitted infections; reproductive health; mental health and neurocognitive functioning; adherence to antiretroviral treatment; sexual behaviour and substance use; hearing and language impairments; and employment and educational achievement.

ETHICS AND DISSEMINATION

The study received ethical approval from the Harvard T.H. Chan School of Public Health's institutional review board (IRB), and from the IRBs of each clinical research site. All participants provide written informed consent; for cognitively impaired individuals with legally authorised representatives, legal guardian permission and participant assent is obtained. Findings will be disseminated through peer-reviewed journals, conference presentations and participant summaries.

An International Study of the Ability and Cost-Effectiveness of Advertising Methods to Facilitate Study Participant Self-Enrolment Into a Pilot Pharmacovigilance Study During Early Pregnancy

Background

Knowledge of the fetal effects of maternal medication use in pregnancy is often inadequate and current pregnancy pharmacovigilance (PV) surveillance methods have important limitations. Patient self-reporting may be able to mitigate some of these limitations, providing an adequately sized study sample can be recruited.

Objective

To compare the ability and cost-effectiveness of several direct-to-participant advertising methods for the recruitment of pregnant participants into a study of self-reported gestational exposures and pregnancy outcomes.

Methods

The Pharmacoepidemiological Research on Outcomes of Therapeutics by a European Consortium (PROTECT) pregnancy study is a non-interventional, prospective pilot study of self-reported medication use and obstetric outcomes provided by a cohort of pregnant women that was conducted in Denmark, the Netherlands, Poland, and the United Kingdom. Direct-to-participant advertisements were provided via websites, emails, leaflets, television, and social media platforms.

Results

Over a 70-week recruitment period direct-to-participant advertisements engaged 43,234 individuals with the study website or telephone system; 4.78% (2065/43,234) of which were successfully enrolled and provided study data. Of these 90.4% (1867/2065) were recruited via paid advertising methods, 23.0% (475/2065) of whom were in the first trimester of pregnancy. The overall costs per active recruited participant were lowest for email (€23.24) and website (€24.41) advertisements and highest for leaflet (€83.14) and television (€100.89). Website adverts were substantially superior in their ability to recruit participants during their first trimester of pregnancy (317/668, 47.5%) in comparison with other advertising methods (P<.001). However, we identified international variations in both the cost-effectiveness of the various advertisement methods used and in their ability to recruit participants in early pregnancy.

Conclusions

Recruitment of a pregnant cohort using direct-to-participant advertisement methods is feasible, but the total costs incurred are not insubstantial. Future research is needed to identify advertising strategies capable of recruiting large numbers of demographically representative pregnant women, preferentially in early pregnancy.

Treatment of nausea in pregnancy: a cross-sectional multinational web-based study of pregnant women and new mothers

BACKGROUND

The factors related to the treatment of nausea during pregnancy have not yet been investigated in several countries simultaneously. The present study aimed to describe differences in self-reported nausea during pregnancy and the patterns of use for both conventional and herbal medicines across countries. The factors related to nausea and its treatment and the relationships between different self-reported co-morbidities and nausea were also investigated.

METHODS

This cross-sectional study used data collected by a web-based questionnaire distributed between October 2011 and February 2012 in several countries within five regions: Western, Northern, and Eastern Europe, North America, and Australia. Women who were pregnant or had a child less than one year old were eligible to participate.

RESULTS

A total of 9113 women were included in the study, whereof 6701 (73.5%) had experienced nausea during pregnancy. Among respondents with nausea, conventional medicines were used by 1201 (17.9%) women and herbal medicines by 556 (8.3%) women. The extent of self-reported nausea and its treatment varied by country. Education, working status, and folic acid use were significantly associated with the use of conventional medicines against nausea. Respondents who had nausea also had a high burden of co-morbidity.

CONCLUSION

The prevalence of nausea was high across all participating countries but its treatment varied, possibly due to cultural differences and differences in attitudes towards medicines. A high degree of co-morbidity was found among respondents with nausea.

Impact of preconception enrollment on birth enrollment and timing of exposure assessment in the initial vanguard cohort of the U.S. National Children's Study

Background

The initial vanguard cohort of the U.S. National Children’s Study was a pregnancy and birth cohort study that sought to enroll some women prior to pregnancy, and to assess exposures early in pregnancy.

Methods

During the recruitment phase (2009–2010), geographically based sampling was used to recruit women early in pregnancy and women not currently pregnant, not using contraception and heterosexually active. We assessed the following outcomes for women enrolled preconception and early in pregnancy: yield of births; demographic characteristics of births for different enrollment groups; time to pregnancy for preconception women; and the timing of study visits for exposure assessment.

Results

1399 women were recruited into the initial vanguard cohort: 429 preconception (198 trying for pregnancy, and 231 not trying) and 970 already pregnant. There were 1135 pregnancies (81 % of women) and 922 newborns enrolled (81 % of pregnancies) through September 2012. Preconception women represented 30.6 % of women enrolled, and contributed 14.5 % of births. Among women who gave birth, and who had enrolled preconception trying for pregnancy, 67.3 % were white non-Hispanic, compared to 50.0 % of preconception women not trying for pregnancy, and 61.5 % of pregnant women. Women enrolled preconception who were trying for pregnancy had higher cumulative probability of pregnancy at one year compared to women not trying (adjusted 86 % versus 56 %). Of 165 women enrolled preconception who became pregnant, 19 % had a study visit within 30 days of conception. By 10.5 weeks after conception, 75 % of women enrolled preconception had completed a pregnancy study visit; for women enrolled pregnant, the 75 % threshold was reached at 28.4 weeks.

Conclusions

There were demographic differences in births from women enrolled preconception trying for pregnancy, preconception not trying for pregnancy, or during pregnancy. Time to pregnancy was shorter for women actively trying for pregnancy. Most women enrolled preconception did not have exposure assessment within 30 days of conception, but they did have exposure assessment much earlier during pregnancy than women who enrolled during pregnancy.

History of oral contraceptive use and risk of spontaneous abortion

PURPOSE

To examine the association between pregravid oral contraceptive (OC) use and spontaneous abortion (SAB).

METHODS

In an Internet-based preconception cohort study of 4862 Danish pregnancy planners, we used Cox proportional hazards models to estimate adjusted hazard ratios and 95% confidence intervals (CIs) for the association between OC use and SAB. We controlled for maternal age, physical activity, parity, education, alcohol and caffeine consumption, body mass index, and smoking.

RESULTS

Compared with women who discontinued OCs >1 year before conception, HRs were 0.95 (95% confidence interval (CI) = 0.77-1.17), 0.99 (95% CI = 0.82-1.19), and 0.80 (95% CI = 0.60-1.06) for women who discontinued OCs 7-12, 2-6, and 0-1 months before conception, respectively. Compared with less than 4 years of OC use, HRs for 4-7, 8-11, and 12 years or more of OC use were 1.05 (95% CI = 0.80-1.37), 0.92 (95% CI = 0.71-1.19), and 0.88 (95% CI = 0.65-1.19), respectively. Dose of estrogen and generation of progestin were not materially associated with SAB risk.

CONCLUSIONS

We found no evidence that pregravid OC use is associated with an increase in SAB. Use within 1 month of conception was associated with a slightly lower risk of SAB, but this may be due to increased reproductive fitness in women who conceive quickly after discontinuation of OCs.

Comparison of web versus interview participants in a case-control study

PURPOSE

To evaluate whether selection bias might be introduced because of differential self-selection into an internet-based case-control study.

METHODS

We compared sociodemographic factors and behavioral factors for cases and controls who opted for their first entrée into the study be via the internet (Web group) versus the telephone (Phone group), using data from a study on clubfoot.

RESULTS

Overall, 200 of 1,825 mothers were in the Web group and were more likely to be non-Hispanic White, nonsmokers, more educated, wealthier, and took ≥7 medications/vitamins in pregnancy. These differences were greater for case mothers, introducing the potential for selection bias. Maternal smoking is an established risk factor for clubfoot and was confirmed in the Phone group (OR = 1.61) but was not observed in the Web group (OR = 1.15).

CONCLUSION

Our results suggest there is potential for selection bias if enrollment is solely internet based for a case-control study.

Relative validity of a semi-quantitative, web-based FFQ used in the 'Snart Forældre' cohort - a Danish study of diet and fertility

OBJECTIVE

To assess the relative validity of a semi-quantitative, web-based FFQ completed by female pregnancy planners in the Danish 'Snart Forældre' study.

DESIGN

We validated a web-based FFQ based on the FFQ used in the Danish National Birth Cohort against a 4 d food diary (FD) and assessed the relative validity of intakes of foods and nutrients. We compared means and medians of intakes, and calculated Pearson correlation coefficients and de-attenuated coefficients to assess agreement between the two methods. We also calculated the proportion correctly classified based on the same or adjacent quintile of intake and the proportion of grossly misclassified (extreme quintiles).

SETTING

Participants (n 128) in the 'Snart Forældre' study who had completed the web-based FFQ were invited to participate in the validation study.

SUBJECTS

Participants in the 'Snart Forældre' study, in total ninety-seven women aged 20-42 years.

RESULTS

Reported intakes of dairy products, vegetables and potatoes were higher in the FFQ compared with the FD, whereas reported intakes of fruit, meat, sugar and beverages were lower in the FFQ than in the FD. Overall the de-attenuated correlation coefficients were acceptable, ranging from 0·33 for energy to 0·93 for vitamin D. The majority of the women were classified in the same or adjacent quintile and few women were misclassified (extreme quintiles).

CONCLUSION

The web-based FFQ performs well for ranking women of reproductive age according to high or low intake of foods and nutrients and, thus, provides a solid basis for investigating associations between diet and fertility.

Design and Conduct of an Internet-Based Preconception Cohort Study in North America: Pregnancy Study Online

BACKGROUND

We launched the Boston University Pregnancy Study Online (PRESTO) to assess the feasibility of carrying out an Internet-based preconception cohort study in the US and Canada.

METHODS

We recruited female participants age 21-45 and their male partners through Internet advertisements, word of mouth, and flyers. Female participants were randomised with 50% probability to receive a subscription to FertilityFriend.com (FF), a web-based programme that collects real-time data on menstrual characteristics. We compared recruitment methods within PRESTO, assessed the cost-efficiency of PRESTO relative to its Danish counterpart (Snart-Gravid), and validated retrospectively reported date of last menstrual period (LMP) against the FF data.

RESULTS

After 99 weeks of recruitment (2013-15), 2421 women enrolled; 1384 (57%) invited their male partners to participate, of whom 693 (50%) enrolled. Baseline characteristics were balanced across randomisation groups. Cohort retention was similar among those randomised vs. not randomised to FF (84% vs. 81%). At study enrollment, 56%, 22%, and 22% couples had been trying to conceive for < 3, 3-5, and ≥ 6 months, respectively. The cost per subject enrolled was $146 (2013 US$), which was similar to our companion Danish study and half that of a traditional cohort study. Among FF users who conceived, > 97% reported their LMP on the PRESTO questionnaire within 1 day of the LMP recorded via FF.

CONCLUSIONS

Use of the Internet as a method of recruitment and follow-up in a North American preconception cohort study was feasible and cost-effective.

Folic acid supplementation and fecundability: a Danish prospective cohort study

BACKGROUND/OBJECTIVES

Periconceptional folic acid (FA) supplementation reduces the risk of neural tube defects and has been associated with ovulatory function. However, only two studies have associated supplementation with multivitamins (MVs) that contained FA with increased pregnancy rates. We aimed to examine the association between FA supplementation (obtained either through single FA tablets or through MVs) and fecundability.

SUBJECTS/METHODS

A prospective cohort study of 3895 Danish women who were planning a pregnancy between 2007 and 2011. We estimated fecundability ratios (FRs) and 95% confidence intervals (CIs) in relation to FA supplementation (either through single FA tablets or MV) using a proportional probabilities regression model, with adjustment for potential socio-demographic, reproductive and lifestyle confounders. In stratified analyses, we also estimated FR with 95% CI in relation to FA supplementation for women with regular and irregular cycles, respectively, and for women with short (<27 days), medium (27-29 days) and long cycles (⩾30 days), respectively.

RESULTS

FA supplementation was associated with increased fecundability (FR=1.15, 95% CI=1.06-1.25), compared with non-use. The adjusted FRs for FA supplement use relative to non-use were 1.35 (95% CI=1.12-1.65) and 1.11 (95% CI=1.01-1.22) for women with irregular and regular cycles, respectively, and 1.36 (95% CI=0.95-1.95), 1.10 (95% CI=0.98-1.22) and 1.24 (95% CI=1.10-1.41) for women with short (<27 days), medium (27-29 days) and long cycles (⩾30 days), respectively.

CONCLUSIONS

FA supplementation was associated with increased fecundability, and this association appeared to be stronger among women with irregular cycles and among women with either short or long cycle length.

Folic acid supplement use and menstrual cycle characteristics: a cross-sectional study of Danish pregnancy planners

PURPOSE

To examine the association between folic acid (FA) supplementation obtained through either single FA tablets or multivitamins (MVs) and menstrual cycle characteristics among 5386 women aged 18-40 years, enrolled in an Internet-based study of Danish women attempting pregnancy during 2007-2011.

METHODS

In a cross-sectional study, we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of FA supplementation with menstrual cycle regularity; short (<27 days), long (30-33 days), and very long (≥34 days) cycle lengths; and duration and intensity of menstrual bleeding.

RESULTS

Compared with nonuse, FA supplementation was associated with reduced odds of short cycle length (OR = 0.80, 95% CI: 0.68-0.94) and a trend toward increased odds of very long cycle length (OR = 1.21, 95% CI: 0.87-1.68) compared with cycle length of 27-29 days. The inverse association with short cycle length was stronger among 18- to 30-year-old women (OR = 0.68, 95% CI: 0.53-0.87), nulliparous women (OR = 0.66, 95% CI: 0.52-0.84), and women who used both FA and MVs (OR = 0.75, 95% CI: 0.60-0.95). We found no clear association between FA supplementation and cycle regularity and duration and intensity of menstrual bleeding.

CONCLUSIONS

FA supplementation was inversely associated with short menstrual cycle length. This association was strongest among women aged 18-30 years, nulliparous women, and women who used both FA and MVs.

Next steps for birth defects research and prevention: The birth defects study to evaluate pregnancy exposures (BD-STEPS)

BACKGROUND

The Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS) is a population-based, multi-Center case-control study of modifiable risk factors for selected birth defects in the United States. BD-STEPS is the second major research effort of the Centers for Birth Defects Research and Prevention, which extends and expands the initial research effort, the National Birth Defects Prevention Study (NBDPS).

METHODS

BD-STEPS focuses on 17 categories of structural birth defects selected based on severity, prevalence, consistent ascertainment, and previous findings that warrant additional research. Cases are identified through existing birth defects surveillance programs; controls are from vital records or birth hospital logs from the same catchment area. BD-STEPS uses a standardized computer-assisted telephone interview to collect information from case and control mothers on topics including demographics, health conditions, and medication use. Following the maternal interview, selected Centers request permission to sample residual newborn screening blood spots from state repositories for genetic analyses. New components planned for BD-STEPS include linkages with external datasets and use of online questionnaires to collect in-depth information on selected exposures.

RESULTS

BD-STEPS extends NBDPS by continuing to collect data on many exposures that were assessed in NBDPS, allowing data from both studies to be combined and providing an unprecedented sample size to analyze rare exposures. BD-STEPS expands upon NBDPS by collecting more detailed information on existing exposures as well as new exposures.

CONCLUSION

The goal of BD-STEPS is to provide women and healthcare providers with information they need to make decisions to promote the healthiest pregnancy possible.

Caffeine and caffeinated beverage consumption and risk of spontaneous abortion

STUDY QUESTION

Is caffeine and caffeinated beverage consumption associated with the risk of spontaneous abortion (SAB)?

SUMMARY ANSWER

While preconceptional caffeine consumption was not materially associated with an increased risk of SAB, consumption during early pregnancy was associated with a small increased risk of SAB, although the relation was not linear.

WHAT IS KNOWN ALREADY

Caffeine has been hypothesized as a risk factor for SAB since the 1980s; however, results from previous studies have been conflicting.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 5132 Danish women planning pregnancy and enrolled from 2007 to 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were women who conceived after entry into the Snart-Gravid cohort and who were aged 18-40, in a stable relationship with a male partner, and did not use fertility treatments to conceive. Women reported their daily caffeine and caffeinated beverage consumption on questionnaires before conception and during early pregnancy. All exposure measurements were prospective with respect to outcome ascertainment. We estimated hazard ratios (HRs) of SAB for categories of caffeine consumption in milligrams (mg) per day and the corresponding 95% confidence intervals (CIs) using Cox proportional hazards regression models with gestational weeks as the time scale.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 732 women (14.3%) who were identified as having a SAB. In the preconceptional period, caffeine consumption was not materially associated with SAB risk (HR comparing ≥300 with <100 mg/day: 1.09; 95% CI: 0.89, 1.33). In early pregnancy, the HRs for 100-199, 200-299 and ≥300 mg/day of caffeine consumption were 1.62 (95% CI: 1.19, 2.22), 1.48 (95% CI: 1.03, 2.13) and 1.23 (95% CI: 0.61, 2.46), respectively, compared with that for <100 mg/day.

LIMITATIONS, REASONS FOR CAUTION

The observed results may be affected by non-differential exposure misclassification, reverse causation and residual confounding.

WIDER IMPLICATIONS OF THE FINDINGS

This is the largest study to date of prospectively measured, preconception caffeine consumption and risk of SAB. We were able to reduce the likelihood of differential left truncation bias and recall bias present in other analyses.

STUDY FUNDING/COMPETING INTERESTS

Snart-Gravid was funded by the NICHD (R21-050264). Dr. Hahn's work was funded in part by the BU Reproductive, Perinatal, and Pediatric Epidemiology Training Grant NIH #T32HD052458. There are no competing interests.

Recruitment for longitudinal, randomised pregnancy trials initiated preconception: lessons from the effects of aspirin in gestation and reproduction trial

BACKGROUND

Recruitment into large, preconception randomised clinical trials (RCT) is challenging. We describe clinic and community-based preconception recruitment strategies for the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial and highlight approaches that were and were not successful. This longitudinal RCT was conducted at four major sites in the US. Eligible women had one to two prior pregnancy losses and were actively trying to become pregnant.

METHODS

Provider/clinic and community-based outreach strategies were utilised, and the recruitment rate and costs of methods were assessed.

RESULTS

A screening questionnaire was completed by 5485 women; 42.4% (n = 2323) screened were initially eligible, of whom 50.7% (n = 1228) were randomised. Provider/clinic-based recruitment yielded the highest number eligible of those screened (30.1%) and also the most randomised participants overall (40.3%). The next highest yield came from direct mail and brochures/flyers at 13.1% and 12.5% of women randomised, respectively. However, direct mailings cost $720 per participant randomised. Other than word of mouth, provider/clinic-based recruitment was the most cost effective method, costing an average of $60 per randomised participant. Web-based recruitment yielded 4.7% of participants at a cost of $278 per randomised participant.

CONCLUSIONS

Provider and clinic-based recruitment was the most effective and cost-efficient method of recruitment in a preconception intervention study of reproduction among women.