Maternal lifestyle and nutritional status in relation to pregnancy and infant health outcomes in Western China: protocol for a prospective cohort study

Maximising the potential of Chinese birth cohort studies: a systematic review of mother-baby cohorts in mainland China

OBJECTIVES

There is now a growing interest in early-life influences on adult diseases in China. A number of birth cohorts have been established. This systematic review provided a better understanding of the development of mother-baby cohorts in China.

STUDY DESIGN

Systematic review.

METHODS

We conducted a systematic review for research or profile papers in English/Chinese that reported data from mother-baby cohorts in mainland China, with ≥1y follow-up after birth. We identified 315 papers, corresponding to 31 cohorts from 19 provinces/megacities.

RESULTS

All cohorts started in 1999-2017 (21 after 2010) and were set up with broad objectives or specific scientific focus. The baseline sample size varied, from <500 to >300,000 mothers. A majority of cohorts were initiated during pregnancy and followed children to <10y, only six to adolescence and none into adulthood. These cohorts mostly collected samples from mothers and babies, in addition to using interviews/questionnaires to collect information about pregnancy, birth and child health. Most cohorts were recruited from a single province/city. The large western region was understudied.

CONCLUSIONS

Mother-baby cohorts have developed rapidly in China, but usually with a short follow-up duration. Extending the follow-up of children and developing cross-cohort collaboration will increase the diversity, size and coverage of the sample, allow studying early influences on life-course health and identify targets for early intervention in the Chinese population.

Emmetropization and nonmyopic eye growth

Most eyes start with a hypermetropic refractive error at birth, but the growth rates of the ocular components, guided by visual cues, will slow in such a way that this refractive error decreases during the first 2 years of life. Once reaching its target, the eye enters a period of stable refractive error as it continues to grow by balancing the loss in corneal and lens power with the axial elongation. Although these basic ideas were first proposed over a century ago by Straub, the exact details on the controlling mechanism and the growth process remained elusive. Thanks to the observations collected in the last 40 years in both animals and humans, we are now beginning to get an understanding how environmental and behavioral factors stabilize or disrupt ocular growth. We survey these efforts to present what is currently known regarding the regulation of ocular growth rates.

Investigating New Sensory Methods Related to Taste Sensitivity, Preferences and Diet of Mother-Infant Pairs and its Relationship to Body Composition and Biomarkers: Protocol for an Explorative Study (Preprint)

Background

Early experiences with different flavors play an important role in infant development, including food and taste acceptance. Flavors are already perceived in utero with the development of the taste and olfactory system and are passed on to the child through breast and bottle feeding. Therefore, the first 1000 days of life are considered a critical window for infant developmental programming.

Objective

The objective of our study is to investigate, both in the prenatal and postnatal period, taste sensitivity, preferences, and dietary diversity of mother-infant pairs. The explorative study design will also report on the impact of these variables on body composition (BC) and biomarkers. In contrast to conventional methods, this study involves long-term follow-up data collection from mother-infant pairs; moreover, the integration of audiovisual tools for recording infants' expressions pertaining to taste stimuli is a novelty of this study. Considering these new methodological approaches, the study aims to assess taste-related data in conjunction with BC parameters like fat-free mass or fat mass, biomarkers, and nutritional intake in infants and children.

Methods

Healthy pregnant women aged between 18 and 50 years (BMI≥18.5 kg/m² to ≤30 kg/m²; <28 weeks of gestation) were recruited from January 2014 to October 2014. The explorative design implies 2 center visits during pregnancy (24-28 weeks of gestation and 32-34 weeks of gestation) and 2 center visits after delivery (6-8 weeks postpartum and 14-16 weeks postpartum) as well as follow-up visits at 1, 3-3.5, and 6 years after delivery. Data collection encompasses anthropometric and biochemical measurements as well as BC analyses with air displacement plethysmography, taste perception assessments, and multicomponent questionnaires on demographics, feeding practices, and nutritional and lifestyle behaviors. Audiovisual data from infants’ reactions to sensory stimuli are collected and coded by trained staff using Baby Facial Action Coding and the Body Action Posture System. Birth outcomes and weight development are obtained from medical records, and additional qualitative data are gathered from 24 semistructured interviews.

Results

Our cohort represents a homogenous group of healthy women with stringent exclusion criteria. A total of 54 women met the eligibility criteria, whereas 47 mother-child pairs completed data collection at 4 center visits during and after pregnancy. Follow-up phases, data analyses, and dissemination of the findings are scheduled for the end of 2023. The study was approved by the ethics committee of the Medical University of Graz (EC No 26–066 ex 13/14), and all participants provided informed consent.

Conclusions

The results of this study could be useful for elucidating the connections between maternal and infant statuses regarding diet, taste, biomarkers, and prenatal and postnatal weight development. This study may also be relevant to the establishment of further diagnostic and interventional strategies targeting childhood obesity and early body fat development.

International Registered Report Identifier (IRRID)

DERR1-10.2196/37279

Day-3-embryo fragmentation is associated with singleton birth weight following fresh single blastocyst transfer: A retrospective study

BACKGROUND

Previous studies have arguably associated poor embryo morphology with low birth weight in singletons following single embryo transfer. However, the association between birth weight and specific morphological features in the cleavage stage remains less known. The purpose of the study was to investigate whether morphological features of embryos at the cleavage stage affect birth weight following blastocyst transfer.

METHODS

The single-center retrospective cohort study included 4,226 singletons derived from fresh single cleavage-stage embryo transfer (ET; n = 1,185), fresh single blastocyst transfer (BT; n = 787), or frozen-thawed single blastocyst transfer (FBT; n = 2,254) between 2016 and 2019. Morphological parameters including early cleavage, day-3 fragmentation, symmetry, blastomere number, and blastocyst morphology were associated with neonatal birth weight and birth weight z-score in multivariate regression models. The models were adjusted for maternal age, body mass index (BMI), parity, peak estradiol level, endometrial thickness, insemination protocol, female etiologies, order of transfer, mode of delivery, and year of treatment.

RESULTS

Adjusted for confounders, day-3 fragmentation was the only morphological feature associated with birth weight and birth weight z-score, while early cleavage, symmetry, blastomere number, and blastocyst morphology were not. Day-3 fragmentation increased the birth weight in both the ET (115.4 g, 95% CI: 26.6-204.2) and BT groups (168.8 g, 95% CI: 48.8-288.8) but not in the FBT group (7.47 g, 95% CI: -46.4 to 61.3). The associations between birth weight and these morphological parameters were confirmed through birth weight z-score analyses. The adjusted odds of large for gestational age (LGA) and high birth weight were also significantly greater in singletons following the transfer of fragmented embryos in the BT group [odds ratio (OR) 3, 95% CI: 1.2-7.51 and OR 3.65, 95% CI: 1.33-10, respectively]. The presence of fragmentation at the cleavage stage also affected the association between the blastocyst morphology and birth weight. Inner cell mass grades were negatively associated with birth weight in blastocysts with day-3 fragmentation but not in blastocysts without.

CONCLUSIONS

The birth weight following blastocyst transfer was found to be positively associated with fragmentation at the cleavage stage. The data did not support the argument that transferring a poor-looking embryo may increase the risks of low birth weight. However, concerns for LGA infants remain.

Risk Factors Associated with Low Birth Weight Among Infants: A Nested Case-Control Study in Southeastern Iran

BACKGROUND

Mortality rate in low-birth-weight infants is almost 30 times more than that in those with normal weight, so the birth of low-birth-weight infants is one of the most serious health problems in the world. Therefore, this nested case-control study was conducted to investigate the risk factors associated with low birth weight among infants in the rural population of Kerman province.

METHODS

This nested case-control study was performed in rural areas of Kerman province, southeastern Iran. Case (n = 155) and control (n = 310) groups were selected using risk set sampling. Data were analyzed through Point and distance estimation (OR, CI) using conditional logistic regression method by Stata-12 software.

RESULTS

The results of multivariate analysis showed that maternal BMI [OR = 0.3, CI 95% (0.1, 0.9)], gestational age [OR = 3.8, CI 95% (0.9, 6.1)], history of stillbirth [OR = 4.8, CI 95% (1.3, 11)], history of pregnancy bleeding [OR = 3.7, CI 95% (0.7, 9)], pregnancy craving [OR = 3, CI 95% (1.1, 3.8)], and the level of health workers' care [OR = 0.4, CI 95% (0.1, 0.9)] are the risk factors affecting LBW in infants (P < 0.05).

CONCLUSIONS

Low birth weight is a multifactorial phenomenon. Therefore, raising public awareness, providing nutritional counseling to pregnant mothers, regular referral to health homes to receive health care, and identifying risk factors and referral to higher level specialists and health centers can be effective in reducing the risk of birth of LBW infants.

WeChat-based intervention to support breastfeeding for Chinese mothers: protocol of a randomised controlled trial

Background

Exclusive breastfeeding for the first 6 months of life is the optimal way to feed infants. However, recent studies suggest that exclusive breastfeeding rates in China remain low and are well below the recommended target. There has been evidence that a lack of awareness of, or exposure to, breastfeeding information is associated with poor breastfeeding practices. WeChat, the most widely used social networking platform in China, has shown some potential to promote health behaviours. We thus hypothesised that a breastfeeding intervention program delivered via WeChat would achieve at least a 10% increase in exclusive breastfeeding prevalence at 6 months compared to the control group.

Methods

A two-arm, parallel, multicentre randomised controlled trial of 1000 pregnant women will be conducted at four maternity hospitals of Chengdu, China. Eligible women who consent to participate in the trial will be recruited at 28–30 weeks of gestation, and randomly allocated to either the intervention group (participants receive breastfeeding-related information from WeChat) or the control group (participants receive non-breastfeeding information from WeChat) using a central randomisation system on a 1:1 ratio at each participating site. The primary outcomes are exclusive breastfeeding rate and full breastfeeding rate at 6 months postpartum. All randomised participants will be included in the outcome analyses with missing data being imputed based on the best-case and worst-case scenarios. Multilevel mixed regression models will be used in the primary analyses to assess the effectiveness of intervention program on the breastfeeding rates.

Discussion

This trial uses the most widely used social media program as a means of delivering messages to mothers to increase exclusive breastfeeding in China. Increasing exclusive breastfeeding will contribute to meeting the health and environmental goals of the Sustainable Development Guidelines.

Trial registration ClinicalTrials.gov, NCT04499404. Registered 5 August 2020—Retrospectively registered, https://clinicaltrials.gov/show/NCT04499404

Role of Maternal Nutrition in the Health Outcomes of Mothers and Their Children: A Retrospective Analysis

BACKGROUND Low nutrition status of mothers plays an important role in increasing the prevalence of poor pregnancy outcomes. Poor pregnancy outcomes are the most common in the Guangzhou region of China. The objective of the study was to evaluate the role of maternal nutrition in the improvement of health outcomes for mothers and their children in the Guangzhou region of China. MATERIAL AND METHODS In this study, pregnancy medical records of women were analyzed. Data related to questionnaires which had been provided during hospital stays for nutritional consumption were gathered. Demographic characteristics and health outcomes of mothers and their children were recorded. Correlations of health outcomes with maternal nutrition were tested with respect to Z-scores at 95% confidence level. RESULTS Based on the health outcomes of mothers and their children, the study divided participants into 2 groups. The first group was mothers and their children with good health outcomes (live births with weighing ≥2.5 kg; the GHO group, n=130) and the second group was mothers and their children with poor health outcomes (miscarriage or premature birth with weighing less than 2.5 kg; the PHO group, n=70). These results showed positive correlation between financial status of the mother (salaried, P<0.001), maternal body mass index (P=0.001), maternal nutrition (P<0.001), maternal education (in years, P<0.001), and maternal age (P=0.004)) with health outcomes of mothers and their children. CONCLUSIONS The financial status of the mother, maternal nutrition, maternal age, and maternal education were the key determinants for predicting health outcomes of mothers and their children.

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

Early infant growth and development has attracted worldwide attention. Although numerous studies have demonstrated that maternal syphilis increases the risk of adverse pregnancy outcomes and congenital syphilis, the subsequent growth pattern and morbidity of syphilis-exposed uninfected infants are less understood. We conducted a longitudinal study to compare the growth pattern and disease distribution of syphilis-exposed and syphilis-unexposed uninfected children, and World Health Organization (WHO) reference standards from birth to 18 months of age. We obtained data from a prospective cohort study in three representative regions of Zhejiang Province in China. A total of 333 syphilis-uninfected children born to women with syphilis were recruited at birth and matched with 333 syphilis-uninfected children born to women without syphilis during pregnancy. Children were followed-up by medical staff every 3 months until 18 months of age. The mixed-effects model was used to compare changes in growth patterns and influencing factors between the two groups. Mean weight, length, and head circumference of children, as well as disease prevalence, were similar between the groups. Multilevel analysis indicated that, after controlling confounders, growth velocities were comparable in both weight and length measures from birth to 18 months old between the two groups; however, low birth weight had a negative impact on weight gain in both groups. There was no significant negative association between syphilis exposure and early growth and health in children, under 18 months in a setting with universal coverage of therapeutic interventions for maternal syphilis. These findings may contribute to improving prevention efforts for mother-to-child transmission of syphilis, such as early screening for syphilis in pregnant women, universal coverage of treatment, and interventions for exposed children. Children with low birth weight should be given priority as this is a risk factor for weight gain.

Gestational diabetes incidence and delivery outcomes in Western China: A prospective cohort study

BACKGROUND

Few studies have examined the age-standardized incidence of gestational diabetes mellitus (GDM) for comparison between populations. Information on delivery outcomes is also lacking for Chinese women with GDM. Therefore, the present study aimed to determine age-standardized GDM incidence and assess its association with maternal and neonatal outcomes.

METHODS

A total of 1901 pregnant women were recruited in Chengdu, Sichuan Province. GDM was diagnosed between 24 and 28 weeks' gestation using oral glucose tolerance tests. Age-standardized incidence rates of GDM were calculated using the direct method. Delivery outcomes were extracted from medical records and compared between the GDM and non-GDM groups.

RESULTS

The age-standardized GDM incidence was 18.3% (95% CI 15.6-21.1) and increased with maternal age and prepregnancy body mass index (BMI). Women with GDM experienced longer length of stay in hospital, shorter gestation at delivery, and a higher risk of cesarean delivery. Their newborns were more likely to be macrosomic or small for gestational age, and to require neonatal intensive care.

CONCLUSIONS

The incidence of GDM was high in Western China, especially among older and overweight women. Moreover, women with GDM had higher rates of adverse delivery outcomes. The findings lend further support for the screening, prevention, and management of GDM in Chinese women.

Dietary patterns during pregnancy and risk of gestational diabetes: a prospective cohort study in Western China

BACKGROUND

Previous research has demonstrated the association between maternal dietary patterns and gestational diabetes (GDM), but evidence in Asian populations remains limited and inconsistent. This study investigated the association between dietary patterns during early pregnancy and the risk of GDM among pregnant women in Western China.

METHODS

A prospective cohort study was conducted among 1337 pregnant women in Western China. Dietary intakes were assessed at 15-20 weeks of gestation using a validated food frequency questionnaire. GDM was diagnosed by oral glucose tolerance tests at 24-28 weeks of gestation. Exploratory factor analysis was performed to derive dietary patterns, and logistic regression models were used to examine the association between dietary patterns and GDM.

RESULTS

A total of 199 women (14.9%) developed GDM. Three dietary patterns were identified, namely, a plant-based pattern, a meat-based pattern and a high protein-low starch pattern. Notwithstanding a lack of association between dietary patterns and GDM risk in the whole cohort, there was a significant reduction in GDM risk among overweight women (BMI ≥24 kg/m²); the odds ratio being 0.29 (95% confidence interval 0.09 to 0.94) when comparing the highest versus the lowest score of the high protein-low starch pattern.

CONCLUSIONS

There was no significant association between early pregnancy dietary patterns and GDM risk later in pregnancy for women in Western China, but high protein-low starch diet was associated with lower risk for GDM among women who were overweight at pre-pregnancy.