Growth in syphilis-exposed and -unexposed uninfected children from birth to 18 months of age in China: a longitudinal study

Effects of feeding patterns during the first 6 months on weight development of infants ages 0-12 months: a longitudinal study

The purpose of this study was to investigate the effect of feeding patterns during the first 6 months on weight development of infants ages 0-12 months. Using monitoring data from the Maternal and Child Health Project conducted by the National Center for Women and Children's Health of the Chinese Center for Disease Control and Prevention from September 2015 to June 2019, we categorized feeding patterns during the first 6 months as exclusive breastfeeding, formula feeding, or mixed feeding. We calculated weight-for-age Z scores (WAZ) according to the World Health Organization's (WHO) 2006 Child Growth Standard using WHO Anthro version 3.2.2. A multilevel model was used to analyze the effect of feeding patterns during the first 6 months on the WAZ of infants ages 0-12 months in monitoring regions. Length of follow-up (age of infants) was assigned to level 1, and infants was assigned to level 2. Characteristics of infants, mothers, and families and region of the country were adjusted for in the model. The average weight of infants ages 0-12 months in our study (except the birth weights of boys who were formula fed or mixed fed) was greater than the WHO growth standard. After we adjusted for confounding factors, the multilevel model showed that the WAZ of exclusively breastfed and mixed-fed infants were statistically significantly higher than those of formula-fed infants (coefficients = 0.329 and 0.159, respectively; P < 0.05), and there was a negative interaction between feeding patterns and age (both coefficients = - 0.020; P < 0.05). Infants who were exclusively breastfed were heavier than formula-fed infants from birth until 12 months of age. Mixed-fed infants were heavier than formula-fed infants before 8 months, after which the latter overtook the former. Infants' weight development may be influenced by feeding patterns during the first 6 months. Exclusive breastfeeding during the first 6 months may be beneficial for weight development of infants in infancy.

Growth and development of syphilis-exposed and -unexposed uninfected children during their first 18 months of life in Suzhou, China: a nested case-control study with propensity score matching

Background

With the successful implementation of Prevention of Mother-to-Child Transmission (PMTCT) policies, the proportion of infants with exposure to both syphilis and antibiotic medication in utero has increased in China, but there is limited evidence about the early growth and development of such infants.

Methods

We conducted a retrospective nested case-control study based on data from the China PMTCT program conducted in Suzhou from 2016 to 2021. Propensity score matching (PSM) was employed to extract 826 syphilis-exposed but uninfected (SEU) infants and 1,652 syphilis-unexposed uninfected (SUU) infants from a total of 712,653 infants. Maternal characteristics were collected through questionnaires, such as parity, age, education level, smoking and drinking habits during pregnancy. Infantile characteristics were retrieved from medical records or via questionnaires, such as gestational age, gender, mode of delivery, Apgar scores, birth weight and length, outdoor time, vitamin D intake, and feed pattern. Mixed effects models, adjusting for potential influencing factors, were used to investigate the early infantile growth pattern of SEU and SUU infants. All statistical analysis were conducted using R (version 4.2.0).

Results

Length and weight were slightly higher in SEU infants than in the SUU infants at some time points (months 0 and 18 for length, p-values <0.05; months 0, 6, and 18 for weight, p < 0.05). In the mixed effects model, SEU group was found to be associated with higher weight [exponentiated beta exp.(β) = 1.15, 95% Confidence Interval (CI) = 1.06, 1.25], length [exp(β) = 1.42, 95% CI = 1.14, 1.77], and BMI z-score [exp(β) = 1.09, 95% CI = 1.00, 1.19].

Conclusion

With the effective prevention of congenital syphilis under the PMTCT program, SEU infants have non-inferior growth patterns during their first 18 months of life compared with SUU controls in Suzhou, China.