{'fraction_non_alphanumeric': 0.04685942173479561, 'fraction_numerical': 0.020438683948155532, 'mean_word_length': 5.667774086378738, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Associations of prepregnancy body mass index, gestational weight gain, and intelligence in offspring: A systematic review and meta-analysis

Objective: Increasing evidences have shown that prepregnancy maternal weight and gestational weight gain (GWG) may associate with offspring's neurodevelopment. However, the effects of prepregnancy maternal overweight, obesity, and excessive GWG on offspring's intelligence remain controversial. This meta-analysis aimed to re-assess the association between prepregnancy body mass index (BMI), GWG, and children's intelligence. Methods: We systematically searched multiple databases, including PubMed, EMBASE, Cochrane Library, and Ovid Medline, from their inception through February 2021. Studies assessing the association between prepregnancy BMI or GWG and children's intelligence were further screened manually before final inclusion. Cohorts that analyzed the association between prepregnancy BMI or GWG and intelligence of offspring were included, and we used the Mantel–Haenszel fixed-effects method to compute the weighted mean difference (WMD) and 95% confidence interval (CI) of each study. Results:A total of 12 articles were included in this systematic review, while six of them in the meta-analysis. There was a significant full-scale IQ reduction in children born from overweight and obese mothers, with WMDs of −3.08 (95% CI: −4.02, −2.14) and −4.91 (95% CI: −6.40, −3.42), respectively. Compared with control group, the WMDs for performance and verbal intelligence quotient (IQ) were decreased in overweight and obesity groups. However, we observed no association between children's full-scale IQ and excessive GWG with WMD of −0.14 (95% CI: −0.92, 0.65). Conclusions: Women's prepregnancy overweight and obesity adversely associate with children's intelligence but no association with excessive GWG. Our study suggests that further researches focusing on the effect of prepregnancy maternal health on offspring's intelligence development are needed.