Background: Vitamin D deficiency during pregnancy or infancy is associated with adverse growth in children. No systematic review has been conducted to summarize available evidence on the effect of vitamin D supplementation in pregnancy and infancy on growth and body composition in children. Objective: We aim to summarize the available evidence on the effect of vitamin D supplementation in pregnancy and infancy on child growth and body composition. Method: A systematic review and meta-analysis were performed on the effects of vitamin D supplementation during early life on children’s growth and body composition (bone, lean and fat). A literature search of randomized controlled trials (RCTs) was conducted to identify relevant studies on the effects of vitamin D supplementation during pregnancy and infancy on children’s body composition (bone, lean and fat) in PubMed, EMBASE and Cochrane Library from inception to 31 December 2020. A Cochrane Risk Assessment Tool was used for quality assessment. The comparison was vitamin D supplementation vs. placebo or standard care. Random-effects and fixed-effect meta-analyses were conducted. The effects are presented as mean differences (MDs) or risk ratios (RRs) with 95% confidence intervals (CIs). Results: A total of 3960 participants from eleven randomized controlled trials were eligible for inclusion. Vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) (MD 0.33, 95% CI, 0.12, 0.54; I² = 34%) in neonates. Vitamin D supplementation during pregnancy or infancy was associated with significantly increased length for age z-score in infants at 1 year of age (MD 0.29, 95% CI, 0.03, 0.54; I² = 0%), and was associated with lower body mass index (BMI) (kg/m²) (MD −0.19, 95% CI −0.34, −0.04; I² = 0%) and body mass index z-score (BMIZ) (MD −0.12, 95% CI −0.21, −0.04; I² = 0%) in offspring at 3–6 years of age. Vitamin D supplementation during early life was not observed to be associated with children’s bone, lean or fat mass. Conclusion: Vitamin D supplementation during pregnancy or infancy may be associated with reduced adiposity in childhood. Further large clinical trials of the effects of vitamin D supplementation on childhood body composition are warranted.

Objective: To assess the effect of periodontal treatment during pregnancy on maternal, fetal and neonatal outcomes. Methods: This is a systematic review and meta-analysis of randomized controlled trials that evaluated the effect of treatment of periodontal diseases on pregnancy outcomes. Primary outcome was perinatal mortality. Secondary outcomes were maternal and neonatal morbidity. Outcomes were pooled using fix-effect or random effects models and presented as risk ratio (RR), or mean difference (MD), and 95% confidence interval (CI). Results: Twenty randomized controlled trials involving 8171 participants were included in this study. Periodontal treatment during pregnancy was associated with significantly decreased risk of perinatal mortality [N = 5942; RR = 0.53 (0.30–0.93); p = .03; heterogeneity (I²) = 0%, Number needed to treat (NNT): 162]. Periodontal treatment during pregnancy reduced risks of preterm birth [N = 7335; RR = 0.78 (0.62–0.98); p = .03; I² = 72%, NNT = 37]. Periodontal treatment during pregnancy significantly increased birthweight (gram) [N = 4708; MD = 200.79 (63.34–337.24); p = .004; I² = 93%]. Periodontal treatment during pregnancy was not associated with preeclampsia, gestational diabetes, cesarean section, small for gestational age, or congenital malformations. Conclusion: Periodontal treatment during pregnancy reduces the risks of perinatal mortality and preterm birth, and improves birth weight.

STUDY QUESTION: Do children whose mothers have polycystic ovary syndrome (PCOS) have an increased risk of morbidity? SUMMARY ANSWER: Maternal PCOS is associated with an increased risk of infection, allergy and other childhood morbidity. WHAT IS KNOWN ALREADY: PCOS is associated with higher rates of gestational diabetes, pre-eclampsia and preterm delivery, but the long-term impact on child health is poorly understood. STUDY DESIGN, SIZE, DURATION: We conducted a retrospective longitudinal cohort study of 1 038 375 children in Quebec between 2006 and 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included 7160 children whose mothers had PCOS and 1 031 215 unexposed children. Outcomes included child hospitalization for infectious, allergic, malignant and other diseases before 13 years of age. We estimated hazard ratios (HRs) and 95% CI for the association of PCOS with childhood morbidity in adjusted Cox proportional hazards regression models. MAIN RESULTS AND THE ROLE OF CHANCE: Children exposed to PCOS were hospitalized at a rate of 68.9 (95% CI 66.2–71.8) per 1000 person-years, whereas unexposed children were hospitalized at a rate of 45.3 (95% CI 45.1–45.5) per 1000 person-years. Compared with no exposure, maternal PCOS was associated with 1.32 times the risk of any childhood hospitalization (95% CI 1.26–1.40), 1.31 times the risk of infectious disease hospitalization (95% CI 1.25–1.38) and 1.47 times the risk of allergy-related hospitalization (95% CI 1.31–1.66). Risk of hospitalization was also elevated for childhood metabolic (HR 1.59, 95% CI 1.16–2.18), gastrointestinal (HR 1.72, 95% CI 1.53–1.92), central nervous system (HR 1.74, 95% CI 1.46–2.07) and otologic disorders (HR 1.34, 95% CI 1.26–1.43). Subgroup analyses suggested that there was little difference in the association of PCOS with hospitalization among boys (HR 1.31, 95% CI 1.24–1.39) and girls (HR 1.34, 95% CI 1.26–1.43). LIMITATIONS, REASONS FOR CAUTION: We analyzed severe childhood morbidity requiring hospitalization, not mild diseases treated in ambulatory clinics. We lacked data on ethnicity, education and physical activity, and cannot rule out residual confounding. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that maternal PCOS is associated with an increased risk of childhood morbidity. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grant PJT-162300 from the Canadian Institutes of Health Research. N.A. acknowledges a career award from the Fonds de recherche du Québec-Santé (296785). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

The implications of maternal gestational weight gain (GWG) and vitamin D status to neonatal bone health are unclear. We tested whether maternal 25-hydroxyvitamin D (25(OH)D) and GWG relate to neonatal bone mineral content (BMC) and bone mineral density (BMD). Healthy term appropriate for gestational age breastfed neonates (n = 142) and their mothers were recruited 24–36 h after delivery and followed at 1.0 ± 0.5 month. At birth, obstetric data were collected and newborn serum 25(OH)D was measured. At 1 month, neonatal whole-body (WB) BMC, WB BMC relative to body weight (WB BMC/kg), lumbar spine BMC and BMD, maternal and neonatal 25(OH)D concentrations, and anthropometry were measured. Infant BMC and BMD between maternal 25(OH)D (<50, ≥50 nmol/L) and GWG (insufficient, adequate, and excessive) categories were compared. Maternal 25(OH)D was not related to infant whole-body BMC, BMC/kg, lumbar spine BMC, and BMD. Infants in the excessive maternal GWG category had greater (p = 0.0003) whole-body BMC and BMC/kg and lumbar spine BMC and BMD than inadequate GWG, and greater (p = 0.0063) whole-body BMC/kg and lumbar spine BMC and BMD than adequate GWG. These results suggest that maternal GWG, but not vitamin D status, modestly relates to bone mass in neonates.