High birth weight and risk of multiple sclerosis: A multicentre study in Argentina

Maternal and neonatal outcomes in pregnant women with multiple sclerosis disease: A systematic review and meta-analysis

OBJECTIVES

Little is known regarding the impact of multiple sclerosis (MS) on maternal and neonatal outcomes. Consequently, this systematic review and meta-analysis aimed to study the impacts of MS on maternal and neonatal outcomes in pregnant women with a history of MS.

METHODS

This review was designed in line with the PRISMA guidelines. Two researchers conducted independent reviews of the literature without time restrictions until January 2023 using international databases, including PubMed, Web of Science, CINAHL Plus, Embase, Scopus, Science Direct, and Google Scholar. A random-effect meta-analysis, using the db metan command in Stata 17.2, was used to calculate the pooled measure of association.

RESULTS

The meta-analysis identified 15 studies involving 33,174,541 pregnant women (32,191 with MS and 33,142,350 as controls). The findings indicate that women with a history of MS are at an increased risk of cesarean delivery (OR=1.28, 95% Confidence Intervals [CI]: 1.14-1.45, p-value: 0.042). Also, these women are at higher risk of neonatal outcomes, such as preterm birth (OR= 1.39, 95% CI: 1.08-1.78, p-value: 0.02), congenital malformations (OR=1.32, 95%CI: 1.16-1.50, p-value: 0.031), Apgar score <7 (OR=2.13, 95% CI: 1.19-3.79, p-value: 0.03), and small for gestational age (OR=1.27, 95% CI: 1.08-1.51, p-value: 0.040).

CONCLUSION

Pregnant women with MS have a greater chance of adverse pregnancy results than pregnant women without MS. Consequently, pregnant women with MS should create detailed before and after pregnancy plans, in consultation with their doctors, spouses, families, and friends, regarding the necessary care and supplements. Future studies applying a prospective cohort design that control for potential confounders are needed to further validate the findings.

Childhood and adolescence factors and multiple sclerosis: results from the German National Cohort (NAKO)

BACKGROUND

Multiple Sclerosis (MS) represents the most common inflammatory neurological disease causing disability in early adulthood. Childhood and adolescence factors might be of relevance in the development of MS. We aimed to investigate the association between various factors (e.g., prematurity, breastfeeding, daycare attendance, weight history) and MS risk.

METHODS

Data from the baseline assessment of the German National Cohort (NAKO) were used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the association between childhood and adolescence factors and risk of MS. Analyses stratified by sex were conducted.

RESULTS

Among a total of 204,273 participants, 858 reported an MS diagnosis. Male sex was associated with a decreased MS risk (HR 0.48; 95% CI 0.41-0.56), while overweight (HR 2.03; 95% CI 1.41-2.94) and obesity (HR 1.89; 95% CI 1.02-3.48) at 18 years of age compared to normal weight were associated with increased MS risk. Having been breastfed for ≤ 4 months was associated with a decreased MS risk in men (HR 0.59; 95% CI 0.40-0.86) compared to no breastfeeding. No association with MS risk was observed for the remaining factors.

CONCLUSIONS

Apart from overweight and obesity at the age of 18 years, we did not observe considerable associations with MS risk. The proportion of cases that can be explained by childhood and adolescence factors examined in this study was low. Further investigations of the association between the onset of overweight and obesity in childhood and adolescence and its interaction with physical activity and MS risk seem worthwhile.

Partitioning genetic effects on birthweight at classical human leukocyte antigen loci into maternal and fetal components, using structural equation modelling

BACKGROUND

Single nucleotide polymorphisms in the human leukocyte antigen (HLA) region in both maternal and fetal genomes have been robustly associated with birthweight (BW) in previous genetic association studies. However, no study to date has partitioned the association between BW and classical HLA alleles into maternal and fetal components.

METHODS

We used structural equation modelling (SEM) to estimate the maternal and fetal effects of classical HLA alleles on BW. Our SEM leverages the data structure of the UK Biobank (UKB), which includes ∼270 000 participants' own BW and/or the BW of their firstborn child.

RESULTS

We show via simulation that our model yields asymptotically unbiased estimates of the maternal and fetal allelic effects on BW and appropriate type I error rates, in contrast to simple regression models. Asymptotic power calculations show that we have sufficient power to detect moderate-sized maternal or fetal allelic effects of common HLA alleles on BW in the UKB. Applying our SEM to imputed classical HLA alleles and own and offspring BW from the UKB replicated the previously reported association at the HLA-C locus and revealed strong evidence for maternal (HLA-A*03:01, B*35:01, B*39:06, P <0.001) and fetal allelic effects (HLA-B*39:06, P <0.001) of non-HLA-C alleles on BW.

CONCLUSIONS

Our model yields asymptotically unbiased estimates, appropriate type I error rates and appreciable power to estimate maternal and fetal effects on BW. These novel allelic associations between BW and classical HLA alleles provide insight into the immunogenetics of fetal growth in utero.

Causal effects of time-varying body size on selected autoimmune disorders: a life course Mendelian randomisation study

BACKGROUND

Based on Barker's hypothesis, some studies investigated the associations between birth weight and several disorders. Apart from issues with statistical power and well-known shortcomings of the observational study design, there are no studies accounting for changes in weight-related body size over the life course regarding rheumatoid arthritis, psoriasis, psoriatic arthritis and multiple sclerosis.

METHODS

Using genetic information of up to 806 834 participants, this study investigated the associations between time-varying weight-related body size from birth to adulthood and the mentioned autoimmune diseases. Performing Mendelian randomisation (MR), the radial inverse-variance weighted approach was used iteratively in primary analyses. Robustness of the results was confirmed in several sensitivity analyses. Potential time-dependent mediation mechanisms were identified through network-clustering and assessed using multivariable MR.

RESULTS

Genetically predicted birth weight (fetal effect) was positively associated with rheumatoid arthritis (OR 1.44; 95% CI 1.17 to 1.77; Padj =0.005) but not with psoriasis, psoriatic arthritis or multiple sclerosis. This association was found to be mediated by body mass index (BMI) in adulthood (OR 1.45; 95% CI 1.14 to 1.84; Padj =0.019) rather than childhood. The direct effect of birth weight attenuated (OR 1.19; 95% CI 0.88 to 1.62); Padj =1) after adjustment for time-varying BMI.

CONCLUSION

Increased birth weight appears to be a risk factor for later manifestation of rheumatoid arthritis due to both fetal genetic components and high BMI persisting into adulthood. Approaches to prevent and minimise the risk of rheumatoid arthritis could include preventing obesity in adults with high birth weight.

Birthweight and subsequent risk for thyroid and autoimmune conditions in postmenopausal women

The objective of this study was to determine the association between birthweight and risk of thyroid and autoimmune conditions in a large sample of postmenopausal women. Baseline data from the Women's Health Initiative (n = 80,806) were used to examine the associations between birthweight category (<6 lbs., 6-7 lbs. 15 oz, 8-9 lbs. 15 oz, and ≥10 lbs.) and prevalent thyroid (underactive and overactive thyroid and goiter) and autoimmune (lupus, rheumatoid arthritis (RA), multiple sclerosis, ulcerative colitis/Crohn's disease) conditions. Follow-up questionnaire data were used to examine the associations between birthweight and incident underactive and overactive thyroid, lupus, and RA. Logistic and Cox proportional hazards regression models were used to estimate crude and adjusted odds (OR) and hazards ratios (HR), respectively. Overall, women born weighing ≥10 lbs. had an increased risk for underactive thyroid [OR 1.14 (95% CI 1.02, 1.28)] and incident lupus [HR 1.51 (95% CI 1.12, 2.03)] and a decreased risk for overactive thyroid [OR 0.67 (95% CI 0.50, 0.92)] compared to women born weighing 6-7.99 lbs., after adjustment for adult BMI, demographic variables, and lifestyle factors. Further, women born weighing <6 lbs. were at increased risk for underactive thyroid [OR 1.13 (95% CI 1.04, 1.22)]. Birthweight was not associated with other thyroid or autoimmune disorders. High birthweight was associated with later-life thyroid and autoimmune conditions while low birthweight was associated with underactive thyroid. Preconception and prenatal interventions aimed at reducing the risk of both high and low birthweights may reduce the burden of later-life thyroid and autoimmune conditions.

The Combined Effect of Birth Weight and Lifestyle on Clustered Cardio-Metabolic Risk Factors in Children and Adolescents: A National School-Based Cross-Sectional Survey

Background: Due to the adverse effects of cardio-metabolic risk factors (CMRFs) in children and adolescents on their current and later life health, and the growing evidence that birth weight and lifestyle have on CMRFs, we aimed to estimate the combined effect of birth weight and lifestyle on clustered CMRFs in children and adolescents. Methods: We enrolled 11,509 participants aged 7–18 years old in a national school-based cross-sectional study in seven provinces in China in 2013. Information on CMRFs was collected through anthropometric measurements and blood sample testing. Information on birth weight, lifestyle and other basic information were investigated through children and adolescents’ as well as parents’ questionnaires. The generalized linear mixed model was applied to estimate the odd ratio (OR) and 95% confidence interval (95% CI) for the associations between CMRFs, clustered CMRFs and birth weight, lifestyle, and the combinations of birth weight and lifestyle. Results: Overall, the prevalence of clustered CMRFs was 3.6% in children and adolescents aged 7–18 years, higher in boys (4.4%) than girls (2.9%). The combination of LBW/ideal lifestyle (OR = 2.00, 95% CI: 1.07–3.72) was associated with higher risk of clustered CMRFs, as well as in adolescents aged 13–18 years and in boys. The combination of HBW/poor lifestyle (OR = 1.74, 95% CI: 1.13–2.68) was related to elevated risk of clustered CMRFs, especially in children aged 7–12 years. Conclusions: CMRFs in Chinese children and adolescents is concerning, ideal lifestyle could weaken the association of birth weight with clustered CMRFs, especially in younger age, indicating that programs to prevent abnormal birth weight or poor lifestyle or both among children and adolescents may reduce CMRFs in China.

Risk Factors from Pregnancy to Adulthood in Multiple Sclerosis Outcome

Multiple sclerosis (MS) is an autoimmune disease characterized by a robust inflammatory response against myelin sheath antigens, which causes astrocyte and microglial activation and demyelination of the central nervous system (CNS). Multiple genetic predispositions and environmental factors are known to influence the immune response in autoimmune diseases, such as MS, and in the experimental autoimmune encephalomyelitis (EAE) model. Although the predisposition to suffer from MS seems to be a multifactorial process, a highly sensitive period is pregnancy due to factors that alter the development and differentiation of the CNS and the immune system, which increases the offspring’s susceptibility to develop MS. In this regard, there is evidence that thyroid hormone deficiency during gestation, such as hypothyroidism or hypothyroxinemia, may increase susceptibility to autoimmune diseases such as MS. In this review, we discuss the relevance of the gestational period for the development of MS in adulthood.