Measures of fetal growth and preterm birth and risk of endometriosis and adenomyosis in adult life: a systematic review and meta-analysis.

INTRODUCTION: Exposures in utero are suggested to play a role in the etiology of endometriosis and adenomyosis, although the current evidence is inconclusive. Knowledge about potential prenatal programming and early life exposures that may affect this risk is of high importance, to focus potential preventive strategies for the diseases already during pregnancy. The aim of this study was to review systematically the literature of the association between measures of fetal growth and preterm birth and endometriosis and adenomyosis in adult life. MATERIAL AND METHODS: A systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and by search on PubMed and EMBASE was carried out. We included published case-control and cohort studies. We excluded studies without a reference group, eg case series, case reports as well as commentaries, letters and editorials. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Meta-analyses using a random-effect inverse variance weighted model were performed. PROSPERO registration number is CRD42021249322. RESULTS: A total of 11 studies were included. In general, the quality scores of the studies were moderate. We found that the risk of endometriosis was 26% higher in women born with a birthweight <2.5 kg (pooled odds ratio [pOR] 1.26, 95% confidence interval [CI] 1.05-1.52) and 32% higher in women born preterm (pOR 1.32, 95% CI 1.01-1.72) than in the reference groups. The studies on adenomyosis pointed towards no association, but a meta-analysis was unfeasible due to the small number of studies. CONCLUSIONS: This systematic review and meta-analysis found that low birthweight and being born preterm were associated with endometriosis in adult life, but the results must be interpreted cautiously. No solid conclusion could be made regarding adenomyosis due to a limited number of published studies, but the studies included found no association. The results support the hypothesis of a potential early programming effect of endometriosis. However, the body of evidence is sparse and this hypothesis needs to be investigated further.

Randomized Trial of 2 Versus 1 Dose of Measles Vaccine: Effect on Hospital Admission of Children After 9 Months of Age.

BACKGROUND: Two doses of measles vaccine (MV) might reduce the nonmeasles mortality rate more than 1 dose of MV does. The effect of 2 versus 1 dose on morbidity has not been examined. Within a randomized trial of the effect of 2 doses versus 1 dose of MV on mortality in Guinea-Bissau, we investigated the effect on hospital admissions. METHODS: Children were randomly assigned 1:2 to receive MV at 4.5 and 9 months of age or the currently recommended dose at 9 months. We compared hospital admission rates among children between 9 and 18 months of age in a Cox regression model with age as the underlying time scale. Half of the children had received neonatal vitamin A supplementation (NVAS) in another trial. The beneficial effect of MV at 4.5 and 9 months on mortality was limited to children who had not received NVAS; therefore, we investigated the interaction of MV with NVAS on admission rates. RESULTS: Among 5626 children (2 doses of MV, 1960 children; 1 dose of MV, 3666), we identified 311 hospital admissions of children between 9 and 18 months of age. Overall, compared to 1 dose of MV, 2 doses reduced the risk of hospital admission for children who had not received NVAS (hazard ratio [HR], 0.66 [95% confidence interval (CI), 0.47-0.93]), but we found no effect among NVAS recipients (HR, 1.16 [95% CI, 0.82-1.63]) (P = .02 for interaction). CONCLUSIONS: The benefit of 2 doses of MV was limited to children who had not received NVAS. NVAS is not generally recommended; hence, an early 2-dose measles vaccination policy might reduce hospital admissions more than the current policy of providing the first MV at 9 months of age. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00168558.