Paediatric and perinatal epidemiology最新文献

Background: Data on antihypertensive medication for non-severe gestational hypertension may suffer from immortal time and selection bias. Emulating target trials can prevent these biases by aligning follow-up with treatment initiation.

Objectives: We estimated the safety of antihypertensive medication initiation for the treatment of non-severe gestational hypertension on adverse birth outcomes in Botswana using sequential target trial emulation.

Methods: Data from the Tsepamo study (2014-2022), capturing birth outcomes at government delivery sites in Botswana, was used to examine antihypertensive medication initiation ≥ 24 weeks gestation for non-severe gestational hypertension (140-159 systolic or 90-109 diastolic blood pressure ≥ 20 weeks gestation without chronic hypertension). Sequential weekly target trial emulation compared initiation versus no initiation during 24-35 weeks' gestation on the risk of stillbirth and birth of infant small for gestational age (SGA), with secondary outcomes including very SGA, preterm birth, very preterm birth, neonatal death, and severe gestational hypertension. For each trial, eligible individuals were without chronic hypertension, had not previously initiated antihypertensive medication and had ≥ 2 non-severe blood pressure readings, at least one within 1 week of trial start. Log-binomial models estimated gestational week-specific and pooled risk ratios (RR) with 95% confidence intervals (CI) using bootstrapping.

Results: Of eligible individuals, there were 1676 antihypertensive initiator 'person-trials' and 5211 non-initiator 'person-trials'. In the pooled analysis, the adjusted RR for stillbirth and SGA comparing initiators to non-initiators was 0.92 (0.68, 1.19) and 1.09 (0.97, 1.23), respectively. The pooled adjusted RR for secondary outcomes were: very SGA, 1.05 (95% CI 0.88, 1.25); preterm birth, 1.09 (95% CI 0.96, 1.22); very preterm birth, 1.05 (95% CI 0.78, 1.47); neonatal death, 1.23 (95% CI 0.68, 2.24); severe gestational hypertension, 0.88 (95% CI 0.74, 1.07).

Conclusions: In this retrospective cohort study, antihypertensive medication initiation between 24 and 35 weeks' gestation for non-severe gestational hypertension was not associated with increased risk of adverse birth outcomes.

Background: As climate change worsens, instances of combined extreme heat and wildfire smoke events are becoming more frequent. Despite their increased vulnerability, investigations on the joint effect of wildfire smoke and extreme heat on children's health are limited.

Objective: To investigate the joint effects of extreme heat and wildfire smoke on paediatric acute care utilisation (ACU) in California from 2006 to 2019.

Methods: In this case-crossover analysis, we assembled a time-series dataset of warm seasons, (May-September) for 1772 ZIP Code Tabulation Areas (ZCTA) in California from 2006 to 2019 to evaluate daily ACUs in the paediatric population (0-19 years). For wildfire smoke, we identified ZCTA-days exposed using a previously developed time-series dataset. For extreme heat, we calculated the daily ZCTA-specific maximum heat index. There were four exposure types: exposed to extreme heat alone, exposed to wildfire smoke alone, exposed to both events simultaneously (compound event) and not exposed to either event. We quantified the synergistic effects by comparing a child's exposures on the day when an ACU occurred to the child's exposure during control days.

Results: We found 1100-105,788 ZCTA-days where exposure to both extreme heat and wildfire smoke events occurred across eight combinations of event definitions. The relative excess risk due to interaction (RERI) ranged up to 0.11 (95% confidence interval [CI]: 0.03, 0.19) with thresholds of the 95th percentile for extreme heat and 35 μg/m³ for wildfire PM_2.5, indicating a synergistic effect of extreme heat and wildfire smoke on paediatric ACUs. Positive RERIs were consistently observed for infectious enteritis, heat-related illness, asthma, endocrine nutritional and metabolic disease, and respiratory disease.

Conclusion: Investigating the synergistic effects of extreme heat and wildfire smoke events in paediatric populations is necessary to develop effective health protection strategies.

Background: Compared to undergoing prenatal care with a physician, care with a midwife reduces the risk of medical interventions and complications during labor and delivery among low-risk pregnant individuals. However, many analyses that assess the relationship between midwifery-led care and birth outcomes condition on live births, potentially inducing a type of collider bias.

Objective: The objective was to analyse the change in prevalence of caesarean deliveries, primary and secondary postpartum haemorrhage, obstetric trauma, and maternal infection under hypothetical scenarios where midwifery-led prenatal care was increased.

Methods: Our sample included commercially insured, midwifery-eligible pregnant people in an insurance claims data source. We used g-computation to assess the change in prevalence of caesarean deliveries, primary and secondary postpartum haemorrhage, obstetric trauma, and maternal infection if 10%, 20%, and 50% more pregnant people enrolled in prenatal care with a midwife rather than a physician, among a cohort of low-risk pregnant people with commercial insurance in the U.S. between 2004 and 2015.

Results: With a 50% increase in midwifery-led care compared with no increase, we found the prevalence of caesarean deliveries was reduced by 5.4 percentage points (95% confidence interval [CI] -5.7, -5.1) and of maternal infection decreased by 1.3 percentage points (95% CI -1.6, -1.0), while the prevalence of primary postpartum haemorrhage increased by 0.5 percentage points (95% CI 0.4, 0.6) and of secondary postpartum haemorrhage increased by 0.6 percentage points (95% CI 0.4, 0.7).

Conclusions: Increasing midwifery-led prenatal care reduced the prevalence of caesarean deliveries and maternal infections and slightly increased the prevalence of primary and secondary postpartum haemorrhage. Our results were similar to those of studies among live birth cohorts.

Background: Prior studies report associations between periconceptional exposure to natural and synthetic oestrogen and progesterone and autism spectrum disorder (ASD). Hormonal contraception contains synthetic forms of one or both hormones. Although hormonal contraception is highly effective when consistently used, unintended pregnancy can occur with irregular use. Given the popularity of hormonal contraception, foetal exposure in utero is possible, yet the potential consequences are unknown.

Objectives: We investigated the association between periconceptional hormonal contraception use and the development of ASD in offspring.

Methods: We analysed data from the Study to Explore Early Development (SEED), a population-based case-control study conducted in select US states, from 2007 to 2020. Children with and without ASD were identified from clinical/education sources and vital records, respectively, and enrolled at ages 2.5-5 years. We confirmed the ASD case status by in-person developmental assessment. We assessed hormonal contraception via a structured interview. We assessed the associations between ASD and hormonal contraception exposure separately for contraception discontinued in the 3 months prior to pregnancy and contraception continued during pregnancy using logistic models to estimate odds ratios (OR) adjusted for biological mother age, education, parity, pre-pregnancy body mass index (BMI), and presence of gynaecologic conditions and 95% confidence intervals (CI).

Results: Of 5210 participants, 9.9% reported discontinuing hormonal contraception use before pregnancy and 2.3% reported continuing use during pregnancy. A suggestive association was found between ASD and hormonal contraception use during pregnancy (aOR 1.38,95% CI 0.93, 2.05). There was no association with use prior to pregnancy (aOR 1.02, 95% CI 0.84, 1.25).

Conclusions: Discontinuation of hormonal contraception prior to conception was not associated with ASD. The prevalence of hormonal contraception use during pregnancy was low. Results were imprecise and may be impacted by recall bias and unmeasured confounding by indication and health behaviours related to planning pregnancy.

Background: Estimating the causal effect of third-stage management approaches on preventing postpartum haemorrhage (PPH) in the context of physiologic birth using observational data requires conditioning on specific variables, with selection relying on assumptions about their roles in the exposure-outcome pathway that are rarely made explicit.

Objectives: To apply the evidence synthesis for constructing DAGs approach, incorporating findings from a systematic review, to develop a causal directed acyclic graph (DAG) that clarifies these assumptions and identifies the minimum set of variables needed to reduce bias in estimating the causal effects of physiologic third-stage care versus oxytocin prophylaxis on PPH.

Data sources: MEDLINE, Embase, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials (to December 15, 2023), ClinicalTrials.gov (to July 8, 2024), and reference lists of eligible studies.

Study selection and data extraction: The systematic review included randomised and non-randomised studies involving individuals with physiologic birth or minimal obstetric interventions. Two authors independently screened studies. DAG development was based on the subset of non-randomised studies. For each, one reviewer extracted outcome, exposure, control variables and mediators.

Synthesis: Eligible studies were analysed in three stages: (i) mapping each study's saturated implied graph; (ii) translating each posited connection using causal criteria to create study-specific DAGs; (iii) synthesising individual DAGs into an integrated DAG. The assumptions underlying this process were specific to the midwifery context in Ontario, Canada and translation was guided by midwifery expertise and existing literature.

Results: Four non-randomised studies were included. Expert consultation identified 20 factors influencing third-stage management. The integrated DAG comprised 339 directed edges connecting 35 covariates, yielding four minimal sufficient adjustment sets.

Conclusions: The integrated DAG and minimal sufficient adjustment sets are valuable tools for informing future study design and analysis, helping to minimise bias in estimating the causal effect of physiologic third-stage care versus oxytocin prophylaxis on PPH in the context of physiologic birth, while also exposing the assumptions about causal relationships between variables to scrutiny.