Association between intrapartum fetal pulse oximetry and adverse perinatal and long-term outcomes: a systematic review and meta-analysis protocol

Background

Current methods of intrapartum fetal monitoring based on heart rate, increase the rates of operative delivery but do not prevent or accurately detect fetal hypoxic brain injury. There is a need for more accurate methods of intrapartum fetal surveillance that will decrease the incidence of adverse perinatal and long-term neurodevelopmental outcomes while maintaining the lowest possible rate of obstetric intervention. Fetal pulse oximetry (FPO) is a technology that may contribute to improved intrapartum fetal wellbeing evaluation by providing a non-invasive measurement of fetal oxygenation status.

Objective

This systematic review and meta-analysis aims to synthesise the evidence examining the association between intrapartum fetal oxygen saturation levels and adverse perinatal and long-term outcomes in the offspring.

Methods

We will include randomised control trials (RCTs), cohort, cross-sectional and case-control studies which examine the use of FPO during labour as a means of measuring intrapartum fetal oxygen saturation and assess its effectiveness at detecting adverse perinatal and long-term outcomes compared to existing intrapartum surveillance methods. A detailed systematic search of PubMed, EMBASE, CINAHL, The Cochrane Library, Web of Science, ClinicalTrials.Gov and WHO ICTRP will be conducted following a detailed search strategy until February 2024. Three authors will independently review titles, abstracts and full text of articles. Two reviewers will independently extract data using a pre-defined data extraction form and assess the quality of included studies using the Risk of Bias tool for RCTs and Newcastle-Ottawa Scale for observational studies. The grading of recommendations, assessment, development, and evaluation (GRADE) approach will be used to evaluate the certainty of the evidence. We will use random-effects meta-analysis for each exposure-outcome association to calculate pooled estimates using the generic variance method. This systematic review will follow the Preferred Reporting Items for Systematic reviews and Meta-analyses and MOOSE guidelines.

PROSPERO registration

CRD42023457368 (04/09/2023).

Maternal hypertensive disorders of pregnancy and depression or anxiety in adolescence: Findings from the Millennium Cohort Study

BACKGROUND

The short-term effects of hypertensive disorders of pregnancy (HDP) on the health of the fetus are well known; however, their impacts on the risk of mental health in the exposed offspring are not fully understood. Our aim was to examine the association between HDP and depression/anxiety at age 17 years.

METHODS

We used data from The Millennium Cohort Study, a nationally representative longitudinal study of children born in the United Kingdom. Data on HDP and potential confounders were collected when children were 9-months. Data on depression and anxiety were collected as one variable when children were aged 17 years using self-reported doctor diagnosis, and reclassified as depression/anxiety (overall), depression/anxiety with treatment, and depression/anxiety without treatment. Crude and adjusted logistic regression models were performed to examine the association between HDP and depression/anxiety, adjusting for several maternal and socio-economic factors.

RESULTS

There were 9517 singleton mother-child pairs included in the analyses. Adjusted logistic regression suggested an association between HDP and depression/anxiety (adjusted odds ratio, (aOR):1.30 [95 % CI, 1.02-1.66]) at age 17 years. A similar association was observed for HDP and depression/anxiety with treatment (aOR:1.33 [95 % CI, 1.01-1.73]) and HDP and depression/anxiety without treatment (aOR: 1.30 [95 % CI, 0.80-2.12]), although the latter did not reach statistical significance.

LIMITATIONS

Data on severity and classifications of HDP were not available.

CONCLUSION

Exposure to HDP may be associated with an increased likelihood of depression or anxiety at age 17 years. Future research should consider severity and different classifications of HDP.

The Association between Threatened Miscarriage and Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder in Offspring by Age 14 Years

OBJECTIVE

To examine the association between threatened miscarriage, and neurodevelopmental disorders, including autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in offspring by age 14 years.

METHODS

We used data from the Millennium Cohort Study, a nationally representative longitudinal study of children born in the UK. Data on threatened miscarriage and potential confounders were maternal-reported and collected at 9 months postpartum. Data on ASD and ADHD were based on maternal-reported doctor diagnoses and collected when children were aged 5, 7, 11 and 14 years. A diagnosis of ASD or ADHD was assumed if parents reported ASD or ADHD at age 5, 7, 11 or 14 years. Crude and adjusted logistic regression examined threatened miscarriage and ASD and ADHD relationship, adjusting for several sociodemographic, maternal and lifestyle factors.

RESULTS

A total of 18,294 singleton babies were included at baseline, and 1,104 (6.0%) women experienced a threatened miscarriage during their pregnancy. Adjusted results suggested an association between threatened miscarriage and ASD (OR: 1.55, 95% CI 1.15, 2.08), and ADHD (OR: 1.51, 95% CI 1.09, 2.10) by age 14 years. E-values for threatened miscarriage and ASD were 2.47, while the lower limits of the 95% CI were 1.57. E-values for threatened miscarriage and ADHD were 2.39, while the corresponding lower limits of the 95% CI were 1.40.

CONCLUSION

Threatened miscarriage was associated with an increased likelihood of ASD and ADHD by the age of 14 years, however, residual confounding cannot be ruled out. Placental pathology may be a potential mechanism for the observed associations.

Association between socioeconomic status with pregnancy and neonatal outcomes: An international multicenter cohort

INTRODUCTION

Previous evidence examining the association between socioeconomic status and pregnancy complications are conflicted and often limited to using area-based measures of socioeconomic status. In this study, we aimed to examine the association between individual-level socioeconomic factors and a wide range of adverse pregnancy and neonatal outcomes using data from the IMPROvED birth cohort conducted in Sweden, the Netherlands and Republic of Ireland.

MATERIAL AND METHODS

The study cohort consisted of women who participated in the IMPROvED birth cohort between 2013 and 2017. Data on socioeconomic factors were self-reported and obtained at 15 weeks' gestation, and included level of education, employment status, relationship status, and income. Data on pregnancy and neonatal outcomes included gestational hypertension, pre-eclampsia, gestational diabetes mellitus, emergency cesarean section, preterm birth, post term delivery, small for gestational age and Apgar score at 1 min. These data were obtained within 72 h following delivery and confirmed using medical records. Multivariable logistic regression examined the association between each socioeconomic variable and each outcome separately adjusting for maternal age, maternal body mass index, maternal smoking, maternal alcohol consumption and cohort center. We also examined the effect of exposure to any ≥2 risk factors compared to none.

RESULTS

A total of 2879 participants were included. Adjusted results suggested that those with less than third level of education had an increased odds of gestational hypertension (OR: 1.74, 95% CI: 1.23-2.46), while those on a middle level of income had a reduced odds of emergency cesarean section (OR: 0.59, 95% CI: 0.42-0.84). No significant associations were observed between socioeconomic variables and neonatal outcomes. Exposure to any ≥2 socioeconomic risk factors was associated with an increased risk of preterm birth (OR: 1.75, 95% CI: 1.06-2.89).

CONCLUSIONS

We did not find strong evidence of associations between individual-level socioeconomic factors and pregnancy and neonatal outcomes in high-income settings overall, with only few significant associations observed among pregnancy outcomes.

Pregnancy and birth complications associations with long-term adverse maternal mental health outcomes: a systematic review and meta-analysis protocol

Background

Existing studies have established an association between pregnancy, birth complications, and mental health in the first few weeks postpartum. However, there is no clear understanding of whether pregnancy and birth complications increase the risk of adverse maternal mental outcomes in the longer term. Research on maternal adverse mental health outcomes following pregnancy and birth complications beyond 12 months postpartum is scarce, and findings are inconsistent.

Objective

This systematic review and meta-analysis will examine the available evidence on the association between pregnancy and birth complications and long-term adverse maternal mental health outcomes.

Methods and analysis

We will include cohort, cross-sectional, and case-control studies in which a diagnosis of pregnancy and/or birth complication (preeclampsia, pregnancy loss, caesarean section, preterm birth, perineal laceration, neonatal intensive care unit admission, major obstetric haemorrhage, and birth injury/trauma) was reported and maternal mental disorders (depression, anxiety disorders, bipolar disorders, psychosis, and schizophrenia) after 12 months postpartum were the outcomes. A systematic search of PubMed, Embase, CINAHL, PsycINFO, and Web of Science will be conducted following a detailed search strategy until August 2022. Three authors will independently review titles and abstracts of all eligible studies, extract data using pre-defined standardised data extraction and assess the quality of each study using the Newcastle-Ottawa Scale. We will use random-effects meta-analysis for each exposure and outcome variable to calculate overall pooled estimates using the generic inverse variance method. This systematic review will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.

Ethical consideration

The proposed systematic review and meta-analysis is based on published data; ethics approval is not required. The results will be presented at scientific meetings and publish in a peer-reviewed journal.

PROSPERO registration

CRD42022359017.

Predicting perineal trauma during childbirth using data from a general obstetric population

Background

Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population.

Methods

Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation.

Results

Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance.

Conclusions

Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

Long-term cardiometabolic health in people born after assisted reproductive technology: a multi-cohort analysis

AIMS

To examine associations of assisted reproductive technology (ART) conception (vs. natural conception: NC) with offspring cardiometabolic health outcomes and whether these differ with age.

METHODS AND RESULTS

Differences in systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), lipids, and hyperglycaemic/insulin resistance markers were examined using multiple linear regression models in 14 population-based birth cohorts in Europe, Australia, and Singapore, and results were combined using meta-analysis. Change in cardiometabolic outcomes from 2 to 26 years was examined using trajectory modelling of four cohorts with repeated measures. 35 938 (654 ART) offspring were included in the meta-analysis. Mean age ranged from 13 months to 27.4 years but was <10 years in 11/14 cohorts. Meta-analysis found no statistical difference (ART minus NC) in SBP (-0.53 mmHg; 95% CI:-1.59 to 0.53), DBP (-0.24 mmHg; -0.83 to 0.35), or HR (0.02 beat/min; -0.91 to 0.94). Total cholesterol (2.59%; 0.10-5.07), HDL cholesterol (4.16%; 2.52-5.81), LDL cholesterol (4.95%; 0.47-9.43) were statistically significantly higher in ART-conceived vs. NC offspring. No statistical difference was seen for triglycerides (TG), glucose, insulin, and glycated haemoglobin. Long-term follow-up of 17 244 (244 ART) births identified statistically significant associations between ART and lower predicted SBP/DBP in childhood, and subtle trajectories to higher SBP and TG in young adulthood; however, most differences were not statistically significant.

CONCLUSION

These findings of small and statistically non-significant differences in offspring cardiometabolic outcomes should reassure people receiving ART. Longer-term follow-up is warranted to investigate changes over adulthood in the risks of hypertension, dyslipidaemia, and preclinical and clinical cardiovascular disease.

Maternal and perinatal outcomes following a diagnosis of Hodgkin lymphoma during or prior to pregnancy: A systematic review

BACKGROUND

The initial peak incidence of Hodgkin lymphoma (HL) occurs during reproductive years.

OBJECTIVES

Synthesise published literature on the relationship between HL and maternal and perinatal outcomes.

SEARCH STRATEGY

Systematic search of PubMed/Medline, Cochrane Library, Scopus, Embase and Science Direct from inception to June 2022, supplemented by hand-searching reference lists.

SELECTION CRITERIA

Two reviewers independently reviewed titles, abstracts and full-text articles. Published studies containing original data were eligible.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and appraised study quality. Outcomes for pregnant women with a previous/current diagnosis of HL were compared separately with women never diagnosed with HL. Where data permitted, meta-analyses of odds ratios and proportions were performed. Certainty of evidence was determined using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

MAIN RESULTS

Of the 5527 studies identified, 33 met the inclusion criteria. In the groups with HL before pregnancy and HL during pregnancy, adjusted odds ratios were not statistically significant for congenital malformation (aOR 1.7, 95% CI 0.9-3.1, and aOR 1.84, 95% CI 0.81-4.15, respectively), preterm birth (PTB) (aOR 0.99, 95% CI 0.65-1.51, and aOR 6.74, 95% CI 0.52-88.03, respectively) and miscarriage (aOR 0.78, 95% CI 0.55-1.10, and aOR 0.38, 95% CI 0.05-2.72, respectively). The aORs for all other outcomes were not statistically significant, except for blood transfusion (aOR 1.38, 95% CI 1.05-1.82) and venous thromboembolism (VTE) (aOR 7.93, 95% CI 2.97-21.22) in the group for HL during pregnancy. The proportion of anaemia was also increased in this group (69%, 95% CI 57%-80% vs 4%, 95% CI 4%-5%, respectively). The GRADE certainty of findings ranged from low to very low.

CONCLUSIONS

Rates of most adverse pregnancy outcomes among women with a previous/current HL diagnosis are not increased significantly compared with the general pregnant population. Women with HL diagnosed during pregnancy may have a higher PTB rate and increased likelihood of VTE, anaemia and blood transfusion; however, small study numbers and the low to very low GRADE certainty of findings preclude firm conclusions.

Heterogenous Differences in Cellular Senescent Phenotypes in Pre-Eclampsia and IUGR following Quantitative Assessment of Multiple Biomarkers of Senescence

Premature ageing of the placenta in pregnancy outcomes is associated with the persistent presence of oxidative stress and placental insufficiency reducing its functional capacity. In this study, we investigated cellular senescence phenotypes of pre-eclampsia and IUGR pregnancies by simultaneously measuring several biomarkers of senescence. Maternal plasma and placental samples were collected at term gestation from nulliparous women undergoing pre-labour elective caesarean section with pre-eclampsia without intrauterine growth restriction (PE; n = 5), pre-eclampsia associated with intrauterine growth restriction (n = 8), intrauterine growth restriction (IUGR < 10th centile; n = 6), and age-matched controls (n = 20). Placental absolute telomere length and senescence gene analysis was performed by RTqPCR. The expression of cyclin-dependent kinase inhibitors (p21 and p16) was determined by Western blot. Senescence-associated secretory phenotypes (SASPs) were evaluated in maternal plasma by multiplex ELISA assay. Placental expression of senescence-associated genes showed significant increases in CHEK1, PCNA, PTEN, CDKN2A, and CCNB-1 (p < 0.05) in pre-eclampsia, while TBX-2, PCNA, ATM, and CCNB-1 expression were evident (p < 0.05) and were significantly decreased in IUGR compared with controls. Placental p16 protein expression was significantly decreased in pre-eclampsia only compared with controls (p = 0.028). IL-6 was significantly increased in pre-eclampsia (0.54 pg/mL ± 0.271 vs. 0.3 pg/mL ± 0.102; p = 0.017) while IFN-γ was significantly increased in IUGR (4.6 pg/mL ± 2.2 vs. 2.17 pg/mL ± 0.8; p = 0.002) compared with controls. These results provide evidence of premature senescence in IUGR pregnancies, and while cell cycle checkpoint regulators are activated in pre-eclampsia, the cellular phenotype is one of cell repair and subsequent proliferation rather than progression to senescence. The heterogeneity of these cellular phenotypes highlights the complexity of characterising cellular senescence and may equally be indicative of the differing pathophysiological insults unique to each obstetric complication.

Pregnancy and birth complications associations with long-term adverse maternal mental health outcomes: a systematic review and meta-analysis protocol

Background: Existing studies have established an association between pregnancy, birth complications, and mental health in the first few weeks postpartum. However, there is no clear understanding of whether pregnancy and birth complications increase the risk of adverse maternal mental outcomes in the longer term. Research on maternal adverse mental health outcomes following pregnancy and birth complications beyond 12 months postpartum is scarce, and findings are inconsistent. Objective: This systematic review and meta-analysis will examine the available evidence on the association between pregnancy and birth complications and long-term adverse maternal mental health outcomes. Methods and analysis: We will include cohort, cross-sectional, and case-control studies in which a diagnosis of pregnancy and/or birth complication (preeclampsia, pregnancy loss, caesarean section, preterm birth, perineal laceration, neonatal intensive care unit admission, major obstetric haemorrhage, and birth injury/trauma) was reported and maternal mental disorders (depression, anxiety disorders, bipolar disorders, psychosis, and schizophrenia) after 12 months postpartum were the outcomes. A systematic search of PubMed, Embase, CINAHL, PsycINFO, and Web of Science will be conducted following a detailed search strategy until August 2022. Three authors will independently review titles and abstracts of all eligible studies, extract data using pre-defined standardised data extraction and assess the quality of each study using the Newcastle-Ottawa Scale. We will use random-effects meta-analysis for each exposure and outcome variable to calculate overall pooled estimates using the generic inverse variance method. This systematic review will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Ethical consideration: The proposed systematic review and meta-analysis is based on published data; ethics approval is not required. The results will be presented at scientific meetings and publish in a peer-reviewed journal. PROSPERO registration: CRD42022359017

Predicting perineal trauma during childbirth using data from a general obstetric population

Background: Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population. Methods: Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation. Results: Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance. Conclusions: Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

Patient-reported outcome measures evaluating postpartum maternal health and well-being: a systematic review and evaluation of measurement properties

OBJECTIVE

This study aimed to systematically review and evaluate postpartum health and well-being using patient-reported outcome measures across all domains of postpartum health using the COnsensus-based Standards for the selection of health Measurement INstruments guidelines.

DATA SOURCES

Based on a preprepared published protocol, a systematic search of PubMed, Embase, and CINAHL was undertaken to identify patient-reported outcome tools. The protocol was registered with the International Prospective Register of Systematic Reviews (registration number CRD42021283472), and this work followed the COnsensus-based Standards for the selection of health Measurement INstruments guidelines for systematic reviews.

STUDY ELIGIBILITY CRITERIA

Studies eligible for inclusion included those that assessed a patient-reported outcome measure examining postpartum women's health and well-being with no limitation on the domain. The included studies aimed to evaluate one or more measurement properties of the patient-reported outcome measure.

METHODS

Data extraction and the methodological assessment of the quality of the patient-reported outcome measure were assessed by 2 reviewers independently based on content validity, structural validity, internal consistency, cross-cultural validity or measurement invariance, reliability, measurement error, hypotheses testing for construct validity, and responsiveness, as defined by the COnsensus-based Standards for the selection of health Measurement INstruments. The standard used for content validity were the domains of importance to women in postpartum health and well-being proposed by the International Consortium for Health Outcomes Measurement. The outcome domains for patient-reported health status include mental health, health-related quality of life, incontinence, pain with intercourse, breastfeeding, and motherhood role transition. The quality of the methods was rated an overall rating of results, awarded a level of evidence, and assessed using the Grading of Recommendations, Assessment, Development, and Evaluations assessment tool, and a level of recommendation was awarded for each tool.

RESULTS

There were 10,324 studies identified in the initial search, of which 29 tools were identified from 41 eligible studies included in the review. Moreover, 21 tools were awarded an "A" grading of recommendation for use as a patient-reported outcome measure in postpartum women following the COnsensus-based Standards for the selection of health Measurement Instruments standards. Of the "A"-rated tools, 17 (80%) examined the domain of mental health, 5 examined health-related quality of life, 4 examined breastfeeding, and 6 represented role transition. No "A"-recommended tool examined postpartum incontinence or pain with intercourse. Of note, 3 tools did not cover domains as recommended by the International Consortium for Health Outcomes Measurement, and 5 tools were awarded a "B" rating, requiring more research before their recommendation for use. Here, most tools were awarded very low-moderate Recommendations, Assessment, Development, and Evaluations level of evidence. Moreover, the highest quality tool identified that covered multiple domains of postpartum health and well-being was the women's Postpartum Quality-of-Life Questionnaire.

CONCLUSION

This systematic review identified the best performing patient-reported outcome measures to assess postpartum health and well-being. No individual tool covers all 6 domains of postpartum health and well-being. Here, the highest quality tool found that covered multiple domains of postpartum health and well-being was the Postpartum Quality-of-Life Questionnaire. The Postpartum Quality-of-Life Questionnaire captures 4 of 6 domains of importance to women, with domains of incontinence and sexual health unevaluated. The domain of urinary incontinence was represented by the International Consultation on Incontinence Questionnaire Short Form, which requires further psychometric analysis before its recommended use. Postpartum sexual health, not represented by any tool, necessitates the development of a patient-reported outcome measure. A postpartum patient-reported outcome measure would be best provided by a combination of tools; however, further research is required before its implementation.

The association between hypertensive disorders of pregnancy and childhood asthma

BACKGROUND

Asthma is a chronic long-term inflammatory disease of the airways and is a major global health challenge. The primary aim of this study was to investigate the association between hypertensive disorders of pregnancy (HDP) and the risk of asthma at or before the age of seven years using the UK Millennium Cohort Study (MCS).

METHODS

Overall, 18,552 families were recruited for wave one of the MCS when the child was 9 months old, and subsequently participated in waves two, three and four when they were three, five and seven years respectively. HDP were self-reported by mothers in wave one. The primary outcome was a parent-reported diagnosis of "ever asthma" at seven years, based on responses to a validated questionnaire.

RESULTS

Following adjustment for a range of potential confounding factors, HDP was found to be associated with asthma in the offspring (adjusted odds ratio (AOR 1.35; 95% CI: 1.15-1.59)). A larger effect estimate was observed amongst children exposed to HDP and born preterm (AOR 1.81; 95% CI: 1.25-2.61) or small for gestational age (SGA) (AOR = 1.58; (95% CI: 1.15-2.18)).

CONCLUSIONS

In conclusion, children exposed to HDP may be at increased odds of asthma diagnosis by age seven, particularly if they were born preterm or SGA.

IMPACT

There is a paucity of data investigating the relationship between hypertensive disorders of pregnancy and childhood asthma, with recent studies showing conflicting results. Our study investigated this relationship using a large cohort with ample information on a wide range of confounding factors. Our study showed that individuals exposed to HDP may be at increased odds of asthma diagnosis by age seven years, particularly if they were also born SGA or preterm.

Fetal and maternal outcomes after maternal biologic use during conception and pregnancy: A systematic review and meta-analysis

Background

Biologic medications, specifically tumour necrosis factor‐α (TNF‐α) inhibitors, have become increasingly prevalent in the treatment of chronic inflammatory disease (CID) in pregnancy.

Objective

To determine pregnancy outcomes in women with CID exposed to biologics during pregnancy.

Search strategy

PubMed and EMBASE databases were searched through January 1998–July 2021.

Selection criteria

Peer‐reviewed, English‐language cohort, case–control, cross‐sectional studies, and case series that contained original data.

Data collection and analysis

Two authors independently conducted data extraction. A meta‐analysis of proportions using a random‐effects model was used to pool outcomes. Linear regression analysis was used to compare the mean of proportions of outcomes across exposure groups using the ‘treated’ group as the reference category. All studies were evaluated using an appropriate quality assessment tool. The GRADE approach was used to assess the overall certainty of evidence.

Main results

Thirty‐five studies, describing 11 172 pregnancies, were eligible for inclusion. Analysis showed pooled proportions for congenital malformations as follows: treated 0.04 (95% CI 0.03–0.04; I² = 77) versus disease‐matched 0.04 (95% CI 0.03–0.05. I² = 86; p = 0.238); preterm delivery treated 0.04 (95% CI 0.10–0.14; I² = 88) versus disease‐matched 0.10 (95% CI 0.09–0.12; I² = 87; p = 0.250); severe neonatal infection: treated 0.05 (95% CI 0.03–0.07; I² = 88) versus disease‐matched 0.05 (95% CI 0.02–0.07; I² = 94; p = 0.970); low birthweight: treated 0.10 (95% CI 0.07–0.12; I² = 93) versus disease‐matched 0.08 (95% CI 0.07–0.09; I² = 0; p = 0.241); pooled miscarriage: treated 0.13 (95% CI 0.10–0.15; I² = 77) versus disease‐matched 0.08 (95% CI 0.04–0.11; I² = 5; p = 0.078); pre‐eclampsia; treated 0.01 (95% CI 0.01–0.02; I² = 0) versus disease‐matched 0.01 (95% CI 0.00–0.01; I² = 0; p = 0.193). No statistical differences in proportions were observed. GRADE certainty of findings was low to very low.

Conclusion

We demonstrated comparable pregnancy outcomes in pregnancies exposed to biologics, disease‐matched controls and CID‐free pregnancies using the GRADE approach.

Meta‐analysis of 11 172 pregnancies exposed to biologic medications shows no evidence of harm for the fetus or the mother.

Linked article: This article is commented on by Laurine L. van der Slink, pp. 1247 in this issue. To view this minicommentary visit https://doi.org/10.1111/1471-0528.17095.

Association of Assisted Reproductive Technology With Offspring Growth and Adiposity From Infancy to Early Adulthood

Importance

People conceived using assisted reproductive technology (ART) make up an increasing proportion of the world's population.

Objective

To investigate the association of ART conception with offspring growth and adiposity from infancy to early adulthood in a large multicohort study.

Design, Setting, and Participants

This cohort study used a prespecified coordinated analysis across 26 European, Asia-Pacific, and North American population-based cohort studies that included people born between 1984 and 2018, with mean ages at assessment of growth and adiposity outcomes from 0.6 months to 27.4 years. Data were analyzed between November 2019 and February 2022.

Exposures

Conception by ART (mostly in vitro fertilization, intracytoplasmic sperm injection, and embryo transfer) vs natural conception (NC; without any medically assisted reproduction).

Main Outcomes and Measures

The main outcomes were length / height, weight, and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared). Each cohort was analyzed separately with adjustment for maternal BMI, age, smoking, education, parity, and ethnicity and offspring sex and age. Results were combined in random effects meta-analysis for 13 age groups.

Results

Up to 158 066 offspring (4329 conceived by ART) were included in each age-group meta-analysis, with between 47.6% to 60.6% females in each cohort. Compared with offspring who were NC, offspring conceived via ART were shorter, lighter, and thinner from infancy to early adolescence, with differences largest at the youngest ages and attenuating with older child age. For example, adjusted mean differences in offspring weight were -0.27 (95% CI, -0.39 to -0.16) SD units at age younger than 3 months, -0.16 (95% CI, -0.22 to -0.09) SD units at age 17 to 23 months, -0.07 (95% CI, -0.10 to -0.04) SD units at age 6 to 9 years, and -0.02 (95% CI, -0.15 to 0.12) SD units at age 14 to 17 years. Smaller offspring size was limited to individuals conceived by fresh but not frozen embryo transfer compared with those who were NC (eg, difference in weight at age 4 to 5 years was -0.14 [95% CI, -0.20 to -0.07] SD units for fresh embryo transfer vs NC and 0.00 [95% CI, -0.15 to 0.15] SD units for frozen embryo transfer vs NC). More marked differences were seen for body fat measurements, and there was imprecise evidence that offspring conceived by ART developed greater adiposity by early adulthood (eg, ART vs NC difference in fat mass index at age older than 17 years: 0.23 [95% CI, -0.04 to 0.50] SD units).

Conclusions and Relevance

These findings suggest that people conceiving or conceived by ART can be reassured that differences in early growth and adiposity are small and no longer evident by late adolescence.

Chronic kidney disease and adverse pregnancy outcomes: a systematic review and meta-analysis

OBJECTIVE

Limited evidence exists on the role that the cause of chronic kidney disease plays in determining pregnancy outcomes. The aim of this systematic review and meta-analysis was to examine the association between chronic kidney disease and adverse pregnancy outcomes by the cause and severity of chronic kidney disease where reported. The protocol was registered under the International Prospective Register of Systematic Reviews (CRD42020211925).

DATA SOURCES

PubMed, Embase, and Web of Science were searched until May 24, 2021, supplemented with reference list checking.

STUDY ELIGIBILITY CRITERIA

Studies that compared the pregnancy outcomes in women with or without chronic kidney disease were included. Two reviewers independently screened titles, abstracts, and full-text articles according to a priori defined inclusion criteria.

METHODS

Data extraction and quality appraisal were performed independently by 3 reviewers. The grading of recommendations, assessment, development, and evaluation approach was used to assess the overall certainty of the evidence. Random-effects meta-analyses were used to calculate the pooled estimates using the generic inverse variance method. The primary outcomes included preeclampsia, cesarean delivery, preterm birth (<37 weeks' gestation), and small for gestational age babies.

RESULTS

Of 4076 citations, 31 studies were included. Prepregnancy chronic kidney disease was significantly associated with a higher odds of preeclampsia (pooled crude odds ratio, 8.13; [95% confidence interval, 4.41-15], and adjusted odds ratio, 2.58; [1.33-5.01]), cesarean delivery (adjusted odds ratio, 1.65; [1.21-2.25]), preterm birth (adjusted odds ratio, 1.73; [1.31-2.27]), and small for gestational age babies (adjusted odds ratio, 1.93; [1.06-3.52]). The association with stillbirth was not statistically significant (adjusted odds ratio, 1.67; [0.96-2.92]). Subgroup analyses indicated that different causes of chronic kidney disease might confer different risks and that the severity of chronic kidney disease is associated with a risk of adverse pregnancy outcomes, as pregnancies with later stages of chronic kidney disease had higher odds of preeclampsia, preterm birth, and small for gestational age babies than those at earlier stages. The grading of recommendations, assessment, development, and evaluation certainty of the evidence overall was "very low".

CONCLUSION

This meta-analysis quantified the associations between prepregnancy chronic kidney disease and adverse pregnancy outcomes, both overall and according to the cause and severity of the disease. These findings might support the clinicians aiming to counsel women having chronic kidney disease by allowing them to tailor their advice according to cause and severity of the chronic kidney disease. We identified the gaps in the literature, and further studies examining the effect of specific kidney diseases and other clinical characteristics (eg, proteinuria, hypertension) on adverse pregnancy outcomes are warranted.

Obstetrical mode of delivery and behavioural outcomes in childhood and adolescence: findings from the Millennium Cohort Study

PURPOSE

To examine the association between mode of delivery (in particular caesarean section) and behavioural outcomes in offspring at six time-points between age 3 and 17 years.

METHODS

Similar to previous work examining the association between mode of delivery and behavioural outcomes in offspring at age 7, we used maternal-reported data from the Millennium Cohort Study. Data on mode of delivery were collected when children were 9 months and categorised as spontaneous vaginal delivery, assisted vaginal delivery, induced vaginal delivery, emergency caesarean section, planned caesarean section and caesarean section after induction of labor. Data on behavioural outcomes were collected at ages 3, 5, 7, 11, 14 and 17 years using the Strengths and Difficulties Questionnaire (SDQ). Crude and adjusted logistic regression examined mode of delivery-behavioural difficulties relationship, using validated SDQ cut-off points (total SDQ ≥ 17, emotional ≥ 5, conduct ≥ 4, hyperactivity ≥ 7, peer problems ≥ 4 and prosocial behaviour ≤ 4). Multilevel models with linear splines examined the association between mode of delivery and repeated measures of SDQ.

RESULTS

There were 18,213 singleton mother-child pairs included at baseline, 13,600 at age 3; 13,831 at age 5; 12,687 at age 7; 11,055 at age 11; 10,745 at age 14 and 8839 at age 17. Adjusted logistic regression suggested few associations between mode of delivery and behavioural outcomes at ages 3, 5, 11, 14 and 17 years using validated SDQ cut-off points. After correction for multiple testing, only the protective association between planned caesarean section-Conduct difficulties at age 5 years (OR 0.63, 95% CI 0.46, 0.85) and positive association between caesarean section after induction-Emotional difficulties at age 11 years (OR 1.57, 95% CI 1.19, 2.07) remained statistically significant. Multilevel modelling suggested mean SDQ scores were similar in each mode of delivery group at each time point.

CONCLUSIONS

Results of this study indicate that mode of delivery is unlikely to have a major impact on behavioural outcomes.

Hypertensive Disorders of Pregnancy and Behavioural Outcomes in the Offspring: Findings from the Millennium Cohort Study

BACKGROUND

The aim of this study was to examine the association between hypertensive disorders of pregnancy (HDP) and behavioural outcomes in offspring at five time-points.

METHODS

We used maternal-reported data from the Millennium Cohort Study. Data on HDP were collected when children were 9-months. Data on behavioural outcomes were collected at age 3, 5, 7, 11 and 14years using the Strengths and Difficulties Questionnaire (SDQ). Multivariate logistic regression analysis examined a HDP-behavioural difficulties relationship, using validated SDQ cut-off points. Multilevel models with linear splines examined the association between HDP and repeated measures of SDQ.

RESULTS

18,274 singleton children were included in the study at baseline, Multivariate logistic regression suggested HDP was not significantly associated with SDQ domain cut-off points at ages 3, 7 and 11years. At age 5years, HDP was associated with a 40% increased odds of behavioural difficulties based on total SDQ(≥17) (OR:1.40, 95% CI:1.03,1.91). HDP was associated with a 43% increased odds of Peer Problem difficulties at age 5 (OR:1.43, 95% CI:1.10,1.86), and a 28% increased odds of Peer Problem difficulties(≥4) at age 14 (OR:1.28, 95% CI:1.02,1.61). In the linear spline model, mean SDQ score was higher at each time-point in those exposed to HDP, although did not always reach statistical significance.

LIMITATIONS

Data on different classifications of HDP were unavailable; therefore, we could not examine the effect of gestational hypertension and preeclampsia separately.

CONCLUSIONS

While we did not find strong evidence of associations between HDP and behavioural outcomes overall, some associations between HDP and behavioural difficulties did persist at age 5 and 14years.

Puberty timing and markers of cardiovascular structure and function at 25 years: a prospective cohort study

BACKGROUND

Whether earlier onset of puberty is associated with higher cardiovascular risk in early adulthood is not well understood. Our objective was to examine the association between puberty timing and markers of cardiovascular structure and function at age 25 years.

METHODS

We conducted a prospective birth cohort study using data from the Avon Longitudinal Study of Parents and Children (ALSPAC). Participants were born between April 1, 1991, and December 31, 1992. Exposure of interest was age at peak height velocity (aPHV), an objective and validated growth-based measure of puberty onset. Outcome measures included cardiovascular structure and function at age 25 years: carotid intima-media thickness (CIMT), left ventricular mass index (LVMI) and relative wall thickness (RWT), pulse wave velocity (PWV) and systolic blood pressure (SBP). Multiple imputation was used to impute missing data on covariates and outcomes. Linear regression was used to examine the association between aPHV and each measure of cardiac structure and function, adjusting for maternal age, gestational age, household social class, maternal education, mother's partner's education, breastfeeding, parity, birthweight, maternal body mass index, maternal marital status, maternal prenatal smoking status and height and fat mass at age 9. All analyses were stratified by sex.

RESULTS

A total of 2752-4571 participants were included in the imputed analyses. A 1-year older aPHV was not strongly associated with markers of cardiac structure and function in males and females at 25 years and most results spanned the null value. In adjusted analyses, a 1-year older aPHV was associated with 0.003 mm (95% confidence interval (CI) 0.00001, 0.006) and 0.0008 mm (95% CI - 0.002, 0.003) higher CIMT; 0.02 m/s (95% CI - 0.05, 0.09) and 0.02 m/s (95% CI - 0.04, 0.09) higher PWV; and 0.003 mmHg (95% CI - 0.60, 0.60) and 0.13 mmHg (95% CI - 0.44, 0.70) higher SBP, among males and females, respectively. A 1-year older aPHV was associated with - 0.55 g/m2.7 (95% CI - 0.03, - 1.08) and - 0.89 g/m2.7 (95% CI - 0.45, - 1.34) lower LVMI and - 0.001 (95% CI - 0.006, 0.002) and - 0.002 (95% CI - 0.006, 0.002) lower RWT among males and females.

CONCLUSIONS

Earlier puberty is unlikely to have a major impact on pre-clinical cardiovascular risk in early adulthood.

Association between hypertensive disorders of pregnancy and the risk of asthma, eczema and allergies in offspring: A systematic review and meta-analysis

OBJECTIVE

Conduct a systematic review and meta-analysis examining the association between hypertensive disorders of pregnancy (HDP) and risk of asthma, eczema, food allergies and allergic rhinitis in the offspring.

DESIGN

A systematic review and random-effects meta-analyses were used to synthesize the published literature. PRISMA guidelines were followed throughout. Two independent reviewers carried out data extraction and quality assessment of included studies. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess certainty of findings.

DATA SOURCES

A systematic search of PubMed, Embase, Web of Science and CINAHL was performed from inception of databases-21 April 2020, supplemented by hand-searching reference lists of included articles.

ELIGIBILITY CRITERIA

Two reviewers independently reviewed titles, abstracts and full-text articles. English language, cohort, case-control and cross-sectional published studies examining the association between HDP (primary exposure: pre-eclampsia; secondary exposures: all other HDP) and asthma, eczema, food allergies and allergic rhinitis were included.

RESULTS

Of the 2833 studies retrieved, 14 studies met inclusion criteria. Of these, 11 studies reported evidence of association between HDP and atopic disorders. Thirteen studies reported estimates for asthma. Seven of these included adjusted estimates (including 3 645 773 participants) for a pre-eclampsia-asthma relationship resulting in a pooled odds ratio (OR) of 1.14 (95% CI: 1.04, 1.26) (I²  = 62%). However, this OR was reduced to 1.08 (95% CI: (0.78, 1.48) when the large registry-based cohort studies were excluded, and only studies using parent-reported measures to determine a diagnosis of asthma were included. Four studies included adjusted estimates (including 254 998 participants) for other HDP and asthma (pooled OR: 1.02, 95% CI: 0.96, 1.09) (I²  = 0%). Two studies provided adjusted estimates (including 1 699 663 participants) for a pre-eclampsia-eczema relationship (pooled OR: 1.06, 95% CI: 0.98, 1.14) (I²  = 0%). One study including pre-eclampsia-food allergies was identified (OR: 1.28, 95% CI: 1.11, 1.46). Three studies examined a HDP (including pre-eclampsia) and allergic rhinitis relationship, with effect estimates ranging from 1.14 to 2.10. Studies were classified as low or low-moderate risk of bias, while GRADE certainty of findings were low to very low.

CONCLUSIONS

While pre-eclampsia was associated with a possible increased risk of asthma in offspring, there was no evidence for a relationship between other HDP and asthma. There is a lack of published literature examining the association between HDP and eczema, food allergy and allergic rhinitis. Further primary research is warranted to gain a better understanding of the association between HDP and the risk of childhood atopic disease.

SYSTEMATIC REVIEW REGISTRATION

Review protocol in appendix.

Association between preeclampsia and attention-deficit hyperactivity disorder: a population-based and sibling-matched cohort study

OBJECTIVE

To examine the association between preeclampsia and attention-deficit hyperactivity disorder (ADHD), using a large Swedish-based registry cohort.

METHODS

This study comprised 2 047 619 children, with 114 934 (5.6%) cases of ADHD. Preeclampsia was based on two alternate definitions: (i) preeclampsia (using ICD-9/ICD-10) and (ii) preeclampsia and small for gestational age (SGA) combined. ADHD was determined in one of two ways: (i) if a diagnosis of ADHD was present in the National Patient Register or (ii) if an individual was in receipt of ADHD medication in the Prescribed Drug Register. Multivariate Cox proportional hazards regression analysis allowed adjustment for several perinatal/sociodemographic factors. Sibling-matched analysis further controlled for shared genetic and familial confounding.

RESULTS

In the adjusted Cox model, preeclampsia was associated with an increase in likelihood of ADHD (HR: 1.15, 95% CI: 1.12, 1.19). The HR for preeclampsia and those born SGA was 1.43 (95% CI: 1.31, 1.55) in the adjusted model, compared to those unexposed to preeclampsia/SGA. The sibling-matched analysis did not materially change these associations (HR: 1.13, 95% CI: 1.05, 1.22) and 1.55 (95% CI: 1.28, 1.88).

CONCLUSIONS

Exposure to preeclampsia or preeclampsia/SGA was associated with ADHD, independent of genetic/familial factors shared by siblings. However, it is important to note that sibling-matched analysis can only adjust for factors that are constant between pregnancies; therefore, residual confounding cannot be ruled out. Further research is needed to explore modifiable risk factors and identify those most-at-risk babies following delivery.

Association between preeclampsia and autism spectrum disorder: a population-based study

BACKGROUND

The environmental contribution of autism spectrum disorder (ASD) is approximately 17%-50%, highlighting the importance of investigating factors potentially contributing to the likelihood of its development, and of gaining a greater understanding of the pathogenesis surrounding ASD. The objective of this study was to examine the association between preeclampsia and ASD using a population-based cohort study.

METHODS

All singleton live births in Sweden from 1982 to 2010 were included, using data from Swedish National Registers. Exposures of interest included: (a) preeclampsia (classified according to ICD-8, ICD-9 and ICD-10) and (b) preeclampsia and small for gestational age (SGA) combined, used as a proxy for preeclampsia with placental dysfunction. ASD status was based on ICD-9 and ICD-10. The cohort consisted of 2,842,230 children, with 54,071 cases of ASD. Follow-up began from the child's first birthday, and data were censored at first diagnosis of ASD, death, migration or end of study period (31st December 2016). We conducted multivariate Cox proportional hazards regression analysis, adjusting for several perinatal and sociodemographic factors, selected a priori. We further controlled for shared genetic and familial confounding using sibling-matched analysis.

RESULTS

In the adjusted Cox proportional hazards regression analysis, preeclampsia was associated with a 25% increase in the likelihood of ASD (Hazard Ratio (HR): 1.25, 95% CI:1.19, 1.30) compared with those unexposed to preeclampsia, while in the sibling-matched analysis the HR was 1.17 (95% CI: 1.06, 1.28). The HR for preeclampsia and SGA combined was 1.66 (95% CI: 1.49, 1.85) in the adjusted Cox model and 1.95 (95% CI: 1.53, 2.48) in the sibling-matched analysis.

CONCLUSIONS

Exposure to preeclampsia or preeclampsia/SGA (i.e. SGA baby exposed to preeclampsia) was associated with ASD. The stronger association with preeclampsia/SGA than preeclampsia alone suggests that placental pathology may be a mechanism for the increased likelihood of ASD.

Group-based trajectory modelling for BMI trajectories in childhood: A systematic review

Childhood obesity is an important public health issue. We aimed to systematically review studies that used group-based trajectory modelling approaches to investigate body mass index (BMI) trajectories in early childhood, explore associated determinants, and the association with body composition outcomes. Five databases were searched systematically for studies using group-based trajectory modelling approaches to track BMI trajectories from birth. Fourteen studies using latent class growth analysis or growth mixture modelling to track BMI trajectories were identified. Three or four trajectories were identified in most studies. High maternal pre-pregnancy BMI was the most frequently identified risk factor for membership of a rapid gain trajectory. Significant associations between rapid weight gain and stable high trajectories and body measures at follow-up were identified by several studies. Relatively similar trajectories were identified across studies. Trajectories characterized by rapid weight gain were associated with several predictors, as well as body measures at follow-up, however not with great consistency. Similar associations with body measure outcomes were found for stable high and rapid gain trajectories, suggesting that long-term outcomes do not differ greatly between children with consistently high BMI and children with rapid increases in BMI. As the shape and timing of the trajectories differed between studies, it is difficult to draw conclusions.

A perspective on pre-eclampsia and neurodevelopmental outcomes in the offspring: Does maternal inflammation play a role?

Pre-eclampsia is a leading cause of maternal death and maternal and perinatal morbidity. Whilst the clinical manifestations of pre-eclampsia often occur in late pregnancy, the molecular events leading into the onset of this disease are thought to originate in early pregnancy and result in insufficient placentation. Although the causative molecular basis of pre-eclampsia remains poorly understood, maternal inflammation is recognised as a core clinical feature. While the adverse effects of pre-eclampsia on maternal and fetal health in pregnancy is well-recognised, the long-term impact of pre-eclampsia exposure on the risk of autism spectrum disorder (ASD) in exposed offspring is a topic of on-going debate. In particular, a recent systematic review has reported an association between exposure to pre-eclampsia and increased risk of ASD, however the molecular basis of this association is unknown. Here we review recent evidence for; 1) maternal inflammation in pre-eclampsia; 2) epidemiological evidence for alterations in neurodevelopmental outcomes in offspring exposed to pre-eclampsia; 3) long-term changes in the brains of offspring exposed to pre-eclampsia; and 4) how maternal inflammation may lead to altered neurodevelopmental outcomes in pre-eclampsia exposed offspring. Finally, we discuss the implications of this for the development of future studies in this field.

Association of Hypertensive Disorders of Pregnancy With Risk of Neurodevelopmental Disorders in Offspring: A Systematic Review and Meta-analysis

Importance

Although research suggests an association between hypertensive disorders of pregnancy (HDP) and autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and other neurodevelopmental disorders in offspring, consensus is lacking. Given the increasing prevalence of hypertension in pregnancy, it is important to examine the association of HDP with neurodevelopmental outcome.

Objective

To synthesize the published literature on the association between HDP and risk of neurodevelopmental disorders in offspring in a systematic review and meta-analysis.

Data Sources

On the basis of a preprepared protocol, a systematic search of PubMed, CINAHL, Embase, PsycINFO, and Web of Science was performed from inception through June 7, 2017, supplemented by hand searching of reference lists.

Study Selection

Two investigators independently reviewed titles, abstracts, and full-text articles. English-language cohort and case-control studies were included in which HDP and neurodevelopmental disorders were reported.

Data Extraction and Synthesis

Data extraction and quality appraisal were performed independently by 2 reviewers. Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed throughout.

Main Outcomes and Measures

Random-effects meta-analyses of estimated pooled odds ratios (ORs) for HDP and ASD and for HDP and ADHD. Stand-alone estimates were reported for all other neurodevelopmental disorders.

Results

Of 1166 studies identified, 61 unique articles met inclusion criteria. Twenty studies reported estimates for ASD. Eleven of these (including 777 518 participants) reported adjusted estimates, with a pooled adjusted OR of 1.35 (95% CI, 1.11-1.64). Ten studies reported estimates for ADHD. Six of these (including 1 395 605 participants) reported adjusted estimates, with a pooled adjusted OR of 1.29 (95% CI, 1.22-1.36). Subgroup analyses according to type of exposure (ie, preeclampsia or other HDP) showed no statistically significant differences for ASD or ADHD. Thirty-one studies met inclusion criteria for all other neurodevelopmental disorders. Individual estimates reported for these were largely inconsistent, with few patterns of association observed.

Conclusions and Relevance

Exposure to HDP may be associated with an increase in the risk of ASD and ADHD. These findings highlight the need for greater pediatric surveillance of infants exposed to HDP to allow early intervention that may improve neurodevelopmental outcome.

Hypertensive disorders of pregnancy and risk of neurodevelopmental disorders in the offspring: a systematic review and meta-analysis protocol

INTRODUCTION

Hypertensive disorders of pregnancy (HDPs), that is chronic hypertension, gestational hypertension, pre-eclampsia (de novo or superimposed on chronic hypertension) and white coat hypertension, affect approximately 5%-15% of pregnancies. HDP exposure has been linked to an increased risk of autism spectrum disorder, attention deficit/hyperactivity disorder and other neurodevelopmental disorders in children. However, findings are inconsistent, and a clear consensus on the impact of HDPs on the risk of neurodevelopmental disorders is needed. Therefore, we aim to synthesise the published literature on the relationship between HDPs and the risk of neurodevelopmental disorders in the form of a systematic review and meta-analysis.

METHODS AND ANALYSIS

We will include cohort, case-control and cross-sectional studies in which diagnosis of an HDP was reported, and neurodevelopmental disorders were the outcome of interest based on a preprepared protocol. A systematic search of PubMed, CINAHL, Embase, PsycINFO and Web of Science will be conducted in accordance with a detailed search strategy. Two authors will independently review the titles and abstracts of all studies, perform data extraction using a standardised data collection form and assess study quality using a bias classification tool. Meta-analyses will be performed to calculate overall pooled estimates using the generic inverse variance method. This systematic review will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses.

ETHICS AND DISSEMINATION

This proposed systematic review and meta-analysis is based on published data, therefore, does not require ethics approval. Findings will be presented at scientific conferences and disseminated through publication in a peer-reviewed journal.

REGISTRATION

CRD42017068258.

Relation between outer and luminal diameter in cannulated arteries

Resistance in blood vessels is directly related to the inner (luminal) diameter (ID). However, ID can be difficult to measure during physiological experiments because of poor transillumination of thick-walled or tightly constricted vessels. We investigated whether the wall cross-sectional area (WCSA) in cannulated arteries is nearly constant, allowing IDs to be calculated from outer diameters (OD) using a single determination of WCSA. With the use of image analysis, OD and ID were directly measured using either transillumination or a fluorescent marker in the lumen. IDs from a variety of vessel types were calculated from WCSA at several reference pressures. Calculated IDs at all of the reference WCSA were within 5% (mean <1%) of the corresponding measured IDs in all vessel types studied, including vessels from heterozygote elastin knockout animals. This was true over a wide range of transmural pressures, during treatment with agonists, and before and after treatment with KCN. In conclusion, WCSA remains virtually constant in cannulated vessels, allowing accurate determination of ID from OD measurement under a variety of experimental conditions.

Vascular actions of 'caged' phenylephrine analogs depend on the structure and site of attachment of the 2-nitrobenzyl group

In the experiments presented in this article, the effects of four caged analogs of the alpha 1-adrenergic agonist phenylephrine (PE) on the properties of small (100-200 microns outer diameter), isolated rat mesenteric arteries were compared. The four caged PE analogs contained either an unsubstituted (analogs I and II) or an alpha-carboxy substituted (analogs III and IV) 2-nitrobenzyl group attached to the phenolic oxygen atom (O-linked; analogs II and IV) or to the amino group (N-linked; analogs I and III) of PE. The structure of each caged PE analog was confirmed by UV, IR and 1H NMR spectral analysis. For physiological experiments, photolysis of the caged PE analogs was accomplished with a Hi-Tech Scientific flashlamp, and vascular smooth muscle contraction was measured with a computer-based image analysis system. In some experiments, the fura-2 ratiometric technique was used to examine the effects of the caged PE analogs on intracellular Ca2+ levels. At concentration < or = 10(-6) M, none of the four analogs displayed measurable intrinsic vasoconstricting activity, that is, vasoconstrictions were only observed following light flashes, consistent with the release of free PE. At concentrations > or = 10(-5) M, however, both O-linked compounds (analogs II and IV) and the alpha-carboxy substituted N-linked caged PE (analog III) produced vasoconstriction prior to photolysis. In contrast, no intrinsic vasoconstricting activity was evident with the unsubstituted N-linked caged PE (analog I) at concentrations up to 300 microM (the highest concentration tested). At concentrations > or = 10 microM, the O-linked unsubstituted caged PE (analog II) also had intrinsic vasodilating activity and markedly attenuated vasoconstrictions and increases in intracellular Ca2+ produced by high KCl. Similar effects were observed with the N-linked caged PE analogs (I and III) at > or = 100 microM, whereas no measurable relaxations were seen with the alpha-carboxy O-linked caged PE analog (i.v.) at concentrations up to 300 microM (the highest concentration tested). Taken together, the results presented here demonstrate that the N-linked unsubstituted caged PE analog (I) can be used reliably at concentrations up to 100 microM and is, therefore, the analog of choice for physiological studies of alpha 1-receptor-mediated events.

Endothelium-independent vasoconstricting and vasodilating actions of halothane on rat mesenteric resistance blood vessels

BACKGROUND

Whether volatile anesthetics produce changes in vascular resistance and blood flow because of direct effects on vascular tissue is unclear. Direct vasoconstricting and vasodilating actions have been demonstrated in isolated conductance arteries in vitro, but there is little information regarding direct effects on the small vessels that mediate resistance and flow changes in vivo.

METHODS

We investigated the actions of halothane on 50-200 microM branches of the rat mesenteric artery that were cannulated and studied in vitro. The vessels were pressurized to 60 mmHg, and vascular dimensions were continuously monitored using a computer-based real-time image analysis system. The vessel bath was perfused with HCO3(-)-buffered saline (37 degrees C) equilibrated with 95% O2/5% CO2 (+/- halothane). The vascular endothelium was mechanically removed before cannulation in some vessels.

RESULTS

In unstimulated vessels, halothane had a concentration-dependent vasoconstricting action (EC50 = 0.45 mM approximately 1.5 vol% at 37 degrees C) that was largely transient and was similar to that produced by caffeine. Both halothane and caffeine constrictions were unaffected by bath [Ca2+], nifedipine (1 microM) or Cd2+ (100 microM) and were abolished by ryanodine (10 microM). In addition, caffeine responses were attenuated by halothane in a concentration-dependent manner (EC50 = 1.6 mM). In vessels preconstricted with KCl (40 mM) or phenylephrine (10(-6) M), halothane produced transient constriction followed by concentration-dependent vasodilation. Ryanodine, which abolished halothane constrictions, had little effect on the amplitude of KCl- or phenylephrine-induced constrictions or the vasodilating action of halothane. Removal of the endothelium likewise had little effect on the vasoconstricting or the vasodilating actions of halothane in unstimulated, KCl- or phenylephrine-constricted vessels. Halothane completely relaxed KCl and phenylephrine constrictions with EC50 values of 0.36 mM (1.2% at 37 degrees C) and 0.75 mM (2.5%), respectively, in intact vessels before ryanodine; 0.25 mM (0.8%) and 0.59 mM (1.9%) in intact vessels after ryanodine; and 0.52 mM (1.7%) and 0.67 mM (2.2%) in endothelium-denuded vessels.

CONCLUSIONS

Halothane has endothelium-independent vasoconstricting and vasodilating actions in isolated mesenteric resistance blood vessels. The vasoconstricting action appears to involve halothane-induced Ca2+ release from caffeine/ryanodine-sensitive intracellular store(s). The vasodilating action in phenylephrine- or KC1-constricted vessels is independent of the Ca(2+)-releasing action and most likely involves an effect(s) on sarcolemmal-dependent Ca2+ signaling (e.g., extracellular Ca2+ influx) and/or Ca2+ activation of contractile proteins. The magnitude of both the vasoconstricting and the vasodilating actions of halothane in these vessels at clinically relevant concentrations suggests these direct actions contribute to the overall cardiovascular effects of halothane in vivo.

"Caged" phenylephrine: development and application to probe the mechanism of alpha-receptor-mediated vasoconstriction

A "caged" analogue of the alpha-adrenergic receptor agonist phenylephrine (PE) was prepared by exploiting the 2-nitrobenzyl protecting group and using a synthetic procedure developed to permit preferential derivatization at the amino group. On isolated adult rat mesenteric arterioles, caged-PE had no measurable effects at concentrations up to 100 microM; 0.5-ms light flashes in the presence of caged-PE, however, produced marked and dose-dependent vasoconstriction. Flash-induced vasoconstrictions were blocked by the alpha-receptor antagonist phentolamine and were unaffected by the beta-receptor antagonist propranolol, indicating that the light-induced responses reflect the selective activation of alpha-adrenergic receptors. After a single flash, a large transient decrease in vessel diameter was recorded, and in most vessels, this was followed by a smaller, sustained constriction. The sustained component of the contraction was selectively eliminated when Ca2+ was removed from the bath, which suggests that different mechanisms underlie the transient and the sustained responses to PE. The responses to single flashes of varying intensities occurred with a mean latency of 460 ms, which is consistent with the intermediacy of several steps between alpha-receptor activation and contraction. We anticipate that it will be possible to extend this approach to develop caged analogues of other neurotransmitters for mechanistic and kinetic studies.

Detection of antineutrophil autoantibodies by flow cytometry: use of unfixed neutrophils as antigenic targets

Antineutrophil antibodies may be found in the sera of patients with chronic neutropenia as well as in the sera of a variety of patients with neutropenia and associated autoimmune or infectious disorders. We evaluated an immunofluorescent flow cytometric technique for the measurement of antineutrophil antibodies in serum. Sera from patients with suspected immune neutropenia were studied and compared with a group of sera from normal healthy individuals, as well as with sera from patients with rheumatoid arthritis and systemic lupus erythematosus. Of 159 patients with suspected immune neutropenia and a variety of associated clinical disorders, 59 (37%) were found to have evidence for enhanced binding of IgG to normal target neutrophils, interpreted as positive for antineutrophil antibodies. Whereas 0/37 non-neutropenic patients with typical RA had positive results, 51/244 (21%) of sera from nonneutropenic patients with SLE or other collagen vascular disorders showed enhanced IgG binding to neutrophils. Living neutrophils were used to study the effects of cellular activation, and increased antibody binding was observed with certain sera that contained IgG directed against activation-dependent antigens. We found that, under controlled conditions, flow cytometry can be reliably used to detect antineutrophil autoantibodies, with unfixed, living neutrophils as antigenic targets.