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.

Feasibility of mail-based biospecimen collection in an online preconception cohort study.

Background: Prospective cohort studies that enroll participants before conception are crucial for deepening scientific understanding of how the preconception environment influences reproductive outcomes. While web-based research methods provide efficient and effective strategies to collect questionnaire-based data, few of these studies incorporate biospecimen collection, which can enhance the validity of exposure assessment. There is limited literature on the feasibility and cost-effectiveness of collecting biospecimens in web-based preconception cohort studies. Methods: We evaluated the feasibility and cost-effectiveness of in-clinic and mail-based biospecimen collection in Pregnancy Study Online (PRESTO), a North American web-based preconception cohort study. Both members of the couple were eligible to participate if their conception attempt time was ≤3 months at enrollment. We invited study participants from the Boston, MA and Detroit, MI metropolitan areas to attend a study visit and provide urine and blood (hereafter "in-clinic protocol"). We invited all other participants to complete mail-based collection of urine and blood spots (hereafter "mail-based protocol"). We compared overall consent and protocol completion rates, demographic characteristics of those who consented and completed either of the protocols, and costs between mail-based and in-clinic protocols for biospecimen collection. Finally, we described logistical challenges pertaining to reliance on mail-based delivery of time-sensitive biospecimens compared with in-clinic methods. Results: During January 2022-July 2022, 69% of female participants (134/195) and 42% of male participants (31/74) consented to participate in the mail-based protocol. Consent rates for the in-clinic protocol were 39% for female participants (289/739 during March 2014-July 2022) and 25% for male participants (40/157 during March 2017-July 2022). Participants who consented to participate were generally of higher socioeconomic position than non-participants. Deviations from the protocol occurred more frequently within the mail-based protocol but were easily corrected. The cost per participant enrolled was similar across protocols (mail-based: $276.14 vs. in-clinic: $270.38). Conclusions: Our results indicate that mail-based collection of biospecimens may create opportunities to recruit a larger and more geographically diverse participant population at a comparable cost-per-participant enrolled to in-clinic methods.