METHODS AND FINDINGS: We searched the major electronic databases Medline, Embase, and Google Scholar (January 1990-October 2018) without language restrictions. We included cohort studies on term pregnancies that provided estimates of stillbirths or neonatal deaths by gestation week. We estimated the additional weekly risk of stillbirth in term pregnancies that continued versus delivered at various gestational ages. We compared week-specific neonatal mortality rates by gestational age at delivery. We used mixed-effects logistic regression models with random intercepts, and computed risk ratios (RRs), odds ratios (ORs), and 95% confidence intervals (CIs). Thirteen studies (15 million pregnancies, 17,830 stillbirths) were included. All studies were from high-income countries. Four studies provided the risks of stillbirth in mothers of White and Black race, 2 in mothers of White and Asian race, 5 in mothers of White race only, and 2 in mothers of Black race only. The prospective risk of stillbirth increased with gestational age from 0.11 per 1,000 pregnancies at 37 weeks (95% CI 0.07 to 0.15) to 3.18 per 1,000 at 42 weeks (95% CI 1.84 to 4.35). Neonatal mortality increased when pregnancies continued beyond 41 weeks; the risk increased significantly for deliveries at 42 versus 41 weeks gestation (RR 1.87, 95% CI 1.07 to 2.86, p = 0.012). One additional stillbirth occurred for every 1,449 (95% CI 1,237 to 1,747) pregnancies that advanced from 40 to 41 weeks. Limitations include variations in the definition of low-risk pregnancy, the wide time span of the studies, the use of registry-based data, and potential confounders affecting the outcome.

CONCLUSIONS: Our findings suggest there is a significant additional risk of stillbirth, with no corresponding reduction in neonatal mortality, when term pregnancies continue to 41 weeks compared to delivery at 40 weeks.

OBJECTIVES: The authors undertook a scoping umbrella review of the research integrity literature concerning RCTs.

SEARCH STRATEGY AND SELECTION CRITERIA: Following prospective registration (https://osf.io/3ursn), two reviewers independently searched PubMed, Scopus, The Cochrane Library, and Google Scholar, without language or time restrictions, until November 2021. The authors included systematic reviews covering any aspect of research integrity throughout the RCT lifecycle.

DATA COLLECTION AND ANALYSIS: The authors assessed methodological quality using a modified AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) tool and collated the main findings.

MAIN RESULTS: A total of 55 relevant reviews, summarizing 6001 studies (median per review, 63; range, 8-1106) from 1964 to 2021, had an overall critically low quality of 96% (53 reviews). Topics covered included general aspects (15%), design and approval (22%), conduct and monitoring (11%), reporting (38%), postpublication concerns (2%), and future research (13%). The most common integrity issues covered were ethics (18%) and transparency (18%).