Key Points Question Are maternal prepregnancy weight and gestational weight gain associated with childhood allergies? Findings In this cross-sectional study evaluating 8877 children, excessive gestational weight gain was associated with a risk of asthma and/or wheezing, allergic rhinitis, eczema, and food and/or drug allergy, and this risk appeared to be higher when coexisting with maternal prepregnancy overweight or obesity. Low gestational weight gain was associated with a reduced risk of allergies in children of women with low or normal prepregnancy weight, while there was no association in women who were overweight or obese. Meaning The findings of this study suggest that, to meet the challenge of increasing childhood allergies, the management of prepregnancy weight and gestational weight gain must be considered.

The COVID-19 pandemic has been a global threat. Through rapid and effective surveillance and control, the newly confirmed patients have been fluctuated at a very low level and imported case explained most of them through March, 2020 to the present, indicating China's response has achieved a stage victory. By contrast, the epidemic of COVID-19 in other countries out of China is bursting. Different countries are adopting varied response strategy in terms of their public health system to prevent the spread. Herd immunity has been a hot topic since the outbreak of COVID-19 pandemic. Can it be a possible strategy to combat COVID-19? To fully interpret the knowledge regarding the term upon the background of COVID-19-related health crisis, we aim to systematically review the definition, describe the effective measures of acquiring herd immunity, and discuss its feasibility in COVID-19 prevention. Findings from this review would promote and strengthen the international cooperation and joint efforts when confronting with COVID-19.

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Has your child ever been diagnosed with asthma? □ yes □ no 2.Has your child experienced any wheezing, breathing difficulties, or whistling in the chest in the last 12 months? □ yes □ no 3.Has your child ever been diagnosed with allergic rhinitis? □ yes □ no 4.Has your child ever sneezing, runny nose, stuffy, or itchy in the last 12 months not due to having a cold or flu? □ yes □ no 5.Has your child had repeated skin itching or a rash on the bent side of the elbow or knee joint in the last 12 months? □ yes □ no 6.Has your child ever been diagnosed with eczema? □ yes □ no 7.Has your child had a history of food allergies (redness, swelling, rash, abdominal pain, etc. within 2 hours after eating)? □ yes □ no 8.Has your child ever been diagnosed by a doctor with a drug allergy? □ yes □ no * All questions were translated into Chinese when used.# Diagnosed asthma with current symptoms was determined by both positive answers to two questions: "Has your child ever been diagnosed with asthma?" and "Has your child experienced any wheezing, breathing difficulties or whistling in the chest in the last 12 months?". Questions utilized to identify allergic rhinitis with current symptoms were: "Has your child ever been diagnosed with allergic rhinitis?" and "Has your child ever sneezing, runny nose, stuffy, itchy in the last 12 months not due to having a cold or flu?". Diagnosed eczema with current symptom was confirmed by questions: "Has your child ever been diagnosed with eczema?" and "Has your child had repeated itching or rash on the bent side of the elbow or knee joint in the last 12 months?". Food allergy was ascertained by the positive answer to question: "Does your child have a history of food allergies (redness, swelling, rash, abdominal pain, etc. within 2 hours after eating)?". Drug allergy was determined by question: "Has your child ever been diagnosed by a doctor with a drug allergy?" Children who were screened out one of any diagnosed and current symptom were involved in non-allergic group.

Background: Animal studies suggested that maternal sleep during pregnancy was associated with sleep pattern in offspring; however, it has not been clear in human populations. Aim: Our study discusses the relationships of maternal sleep duration with sleep characteristics in their offspring through an epidemiological study. Methods: A retrospective cross-sectional study including 6236 mother-child dyads was conducted in 31 preschools in May 2019, in Shanghai, China. Information regarding maternal sleep duration in three trimesters of pregnancy was collected retrospectively. Children's current sleep characteristics were evaluated through the Children's Sleep Habits Questionnaire (CSHQ). Linear regressions and logistic regression models were applied to estimate β and adjusted odds ratios with 95% confidence intervals (95% CI). Results: Maternal sleep duration was positively associated with childhood sleep duration, which was shown in the first (β=0.113), second (β=0.131), and third trimesters (β=0.088). Meanwhile, insufficient maternal sleep duration could increase the risk of children's short sleep duration (first trimester: AOR=1.25; second trimester: AOR=1.33; third trimester: AOR=1.33). Maternal sleep duration was also associated with childhood CSHQ score: β= −0.308, −0.392, and −0.300 for the first, second, and third trimesters, respectively. Similarly, insufficient maternal sleep duration could predict childhood sleep disturbance as AOR=1.28 in the second trimester and AOR=1.26 in the third trimester. Conclusion: Our findings established a relationship between maternal sleep during pregnancy and their children's sleep pattern through a population-based epidemiology study. Poor childhood sleep was found when their mother experienced less sleep duration during pregnancy, especially in the second and third trimesters.