Changes in Births by Month: United States, January 2019–June 2021

This report presents provisional 2021 and final 2020 and 2019 data on changes in the number of U.S. births by race and Hispanic origin of mother and by month of birth and state for January through June of 2020 and 2021.

Season of birth is associated with multiple sclerosis and disease severity

Background The latitude gradient in multiple sclerosis incidence indicates that low sun exposure and therefore vitamin D deficiency is associated with multiple sclerosis risk. Objective Investigation of the effect of month of birth, which influences postnatal vitamin D levels, on multiple sclerosis risk and severity in Sweden. Methods Patients and population-based controls were included from three nationwide cohorts. Differences in month of birth between cases and controls were analyzed using logistic regression and examined for effect modification by calendar year and geographic region at birth. Results Males had a reduced risk of multiple sclerosis if born in the winter and increased risk if born in the early fall. Individuals born before 1960 had an increased risk if born in summer or fall. Being born in late summer and early fall was associated with more severe disease. Conclusions We identified a birth cohort effect on the association between the month of birth and multiple sclerosis, with a more significant effects for births before 1960. This coincides with a period of lower breastfeeding rates, recommended intake of vitamin D, and sun exposure, resulting in a lower vitamin D exposure during the fall/winter season for infants born in the summer.

Broad phenotypic impact of the effects of transgenerational heat stress in dairy cattle: a study of four consecutive generations

Background Global warming has increased the frequency of heat stress in livestock. Although heat stress directly leads to negative effects on production and reproduction traits in dairy cattle, the transgenerational transition of these changes is poorly understood. We hypothesized that heat stress in pregnant cows might induce epigenetic modifications in the developing embryo germ cells, which, in turn, might lead to phenotypic effects in the offspring. Here, we examined whether transgenerational effects of heat stress contribute to the phenotypic expression of economic traits in Israel dairy cattle. Since heat stress in Israel occurs specifically between June and October, first we examined the association of the month of birth of F1 cows (pregnancy of the F0 dam) with the performance of the F2 and F3 female offspring. Then, we calculated an annual heat stress index and examined the association of the heat stress index during the pregnancy of the F0 dam with the performance of her F2 and F3 offspring. Finally, we examined intergenerational interactions of heat stress by comparing the performance of F3 cows according to the pregnancy seasons of the F0 and F1 animals. Results We found a significant association of the month of birth, season of pregnancy, and heat stress index of F0 females, with the performance of their F2 and F3 progenies, which suggests a true transgenerational effect. The most significant transgenerational effects were on fat yield and concentration, dystocia, still-birth, and maturation. Conclusions These findings suggest that heat stress during pregnancy affects the performance of offspring, regardless of life circumstances in at least the last three generations. Therefore, heat stress can reduce selection efficiency in breeding programs and may have economic significance in livestock.

Mother-to-infant transmission of the carcinogenic colibactin-producing bacteria

Background The Escherichia coli strain that is known to produce the genotoxic secondary metabolite colibactin is linked to colorectal oncogenesis. Therefore, understanding the properties of such colibactin-positive E. coli and the molecular mechanism of oncogenesis by colibactin may provide us with opportunities for early diagnosis or prevention of colorectal oncogenesis. While there have been major advances in the characterization of colibactin-positive E. coli and the toxin it produces, the infection route of the clb + strain remains poorly characterized. Results We examined infants and their treatments during and post-birth periods to examine potential transmission of colibactin-positive E. coli to infants. Here, analysis of fecal samples of infants over the first month of birth for the presence of a colibactin biosynthetic gene revealed that the bacterium may be transmitted from mother to infant through intimate contacts, such as natural childbirth and breastfeeding, but not through food intake. Conclusions Our finding suggests that transmission of colibactin-positive E. coli appears to be occurring at the very early stage of life of the newborn and hints at the possibility of developing early preventive measures against colorectal cancer.

Changes in HMO Concentrations throughout Lactation: Influencing Factors, Health Effects and Opportunities

Human milk oligosaccharides (HMOs) are important functional biomolecules in human breast milk. Understanding the factors influencing differences in HMO composition and changes in their concentration over lactation can help to design feeding strategies that are well-adapted to infant’s needs. This review summarises the total and individual concentration of HMOs from data published from 1999 to 2019. Studies show that the HMO concentrations are highest in colostrum (average 9–22 g/L), followed by slightly lower concentrations in transitional milk (average 8–19 g/L), with a gradual decline in mature milk as lactation progresses, from 6–15 g/L in breast milk collected within one month of birth, to 4–6 g/L after 6 months. Significant differences in HMO composition have been described between countries. Different HMOs were shown to be predominant over the course of lactation, e.g., 3-fucosyllactose increased over lactation, whereas 2′-fucosyllactose decreased. Recent clinical studies on infant formula supplemented with 2′-fucosyllactose in combination with other oligosaccharides showed its limited beneficial effect on infant health.

Evaluation of Month of Birth in Neuromyelitis Optica Spectrum Disorders (NMSOD) and Multiple Sclerosis (MS)

Introduction. Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMO) are chronic immune-mediated diseases in the central nervous system (CNS). Environmental factors such as month of birth can be a trigger for these diseases. Therefore, we conducted this study to compare the months of birth in MS and NMOSD patients with the control group. Methods. In this cross-sectional study, 2345 patients with MS, 220 NMOSD patients, and 2174 healthy subjects were enrolled. Demographic information such as age, sex, month of birth, and education in three groups was extracted from the database. The associations between month of birth and MS were studied by binary logistic regression with adjusting for the year of birth. Results. There was a reduced birth rate in September-October in NMOSD ( OR = 0.309 , 95% CI: 0.150-0.636; p < 0.001 ) and MS patients ( OR = 0.470 , 95% CI: 0.374-0.591; p < 0.001 ) compared to the general population. The birth rate in March-April in MS was higher than the control group ( OR = 1.613 , 95% CI: 1.324-1.964; p < 0.001 ). There was no difference in the birth month distribution between the NMOSD and MS patients. No significant difference in MOB among different MS types was found. Conclusion. Our findings showed a decreasing risk of NMOSD and MS in individuals born in the autumn months and an increasing MS risk in spring. More studies are required to elucidate the association between the month of birth and risk of MS and NMOSD and the seasonality factors.

Declines in Births by Month: United States, 2020

This report presents provisional 2020 and final 2019 and 2018 data on changes in the number of U.S. births by race and Hispanic origin of mother and by month of birth and state.