Impact of cesarean section on metabolic syndrome components in offspring rats.

INTRODUCTION: Epidemiological evidence suggests an association between CS and offspring metabolic syndrome (MetS), but whether a causal relationship exists is unknown. METHODS: In this study, timed-mated Wistar rat dams were randomly assigned to cesarean section (CS), vaginal delivery (VD), and surrogate groups. The offspring from both CS and VD groups were reared by surrogate dams until weaning, and weaned male offspring from both groups were randomly assigned to receive normal diet (ND) or high-fat/high-fructose diet (HFF) ad libitum for 39 weeks. RESULTS: By the end of study, CS-ND offspring gained 17.8% more weight than VD-ND offspring, while CS-HFF offspring gained 36.4% more weight than VD-HFF offspring. Compared with VD-ND offspring, CS-ND offspring tended to have increased triglycerides (0.27 mmol/l, 95% CI, 0.05 to 0.50), total cholesterol (0.30 mmol/l, -0.08 to 0.68), and fasting plasma glucose (FPG) (0.30 mmol/l, -0.01 to 0.60); more pronounced differences were observed between CS-HFF and VD-HFF offspring in these indicators (triglyceride, 0.66 mmol/l, 0.35 to 0.97; total cholesterol, 0.46 mmol/l, 0.13 to 0.79; and FPG, 0.55 mmol/l, 0.13 to 0.98). CONCLUSIONS: CS offspring were more prone to adverse metabolic profile and HFF might exacerbate this condition, indicating the association between CS and MetS is likely to be causal. IMPACT: Whether the observed associations between CS and MetS in non-randomized human studies are causally relevant remains undetermined. Compared with vaginally born offspring rats, CS born offspring gained more body weight and tended to have compromised lipid profiles and abnormal insulin sensitivity, suggesting a causal relationship between CS and MetS that may be further amplified by a high-fat/high-fructose diet. Due to the high prevalence of CS births globally, greater clinical consideration must be given to the potential adverse effects of CS, and whether these risks should be made known to patients in clinical practice merits evaluation.

Association of caesarean delivery with offspring health outcomes in full-cohort versus sibling-comparison studies: a comparative meta-analysis and simulation study.

BACKGROUND: Full-cohort and sibling-comparison designs have yielded inconsistent results about the impacts of caesarean delivery on offspring health outcomes, with the effect estimates from the latter being more likely directed towards the null value. We hypothesized that the seemingly conservative results obtained from the sibling-comparison design might be attributed to inadequate adjustment for non-shared confounders between siblings, particularly maternal age at delivery. METHODS: A systematic review and meta-analysis was first conducted. PubMed, Embase, and the Web of Science were searched from database inception to April 6, 2022. Included studies (1) examined the association of caesarean delivery, whether elective or emergency, with offspring health outcomes; (2) simultaneously conducted full-cohort and sibling-comparison analyses; and (3) reported adjusted effect estimates with 95% confidence intervals (95% CIs). No language restrictions were applied. Data were extracted by 2 reviewers independently. Three-level meta-analytic models were used to calculate the pooled odds ratios (ORs) and 95% CIs for caesarean versus vaginal delivery on multiple offspring health outcomes separately for full-cohort and sibling-comparison designs. Subgroup analyses were performed based on the method of adjustment for maternal age at delivery. A simulation study was then conducted. The simulated datasets were generated with some key parameters derived from the meta-analysis. RESULTS: Eighteen studies involving 21,854,828 individuals were included. The outcomes assessed included mental and behavioral disorders; endocrine, nutritional and metabolic diseases; asthma; cardiorespiratory fitness; and multiple sclerosis. The overall pooled OR for estimates from the full-cohort design was 1.14 (95% CI: 1.11 to 1.17), higher than that for estimates from the sibling-comparison design (OR = 1.08; 95% CI: 1.02 to 1.14). Stratified analyses showed that estimates from the sibling-comparison design varied considerably across studies using different methods to adjust for maternal age at delivery in multivariate analyses, while those from the full-cohort design were rather stable: in studies that did not adjust maternal age at delivery, the pooled OR of full-cohort vs. sibling-comparison design was 1.10 (95% CI: 0.99 to 1.22) vs. 1.06 (95% CI: 0.85 to 1.31), in studies adjusting it as a categorical variable, 1.15 (95% CI: 1.11 to 1.19) vs. 1.07 (95% CI: 1.00 to 1.15), and in studies adjusting it as a continuous variable, 1.12 (95% CI: 1.05 to 1.19) vs. 1.12 (95% CI: 0.98 to 1.29). The severe underestimation bias related to the inadequate adjustment of maternal age at delivery in sibling-comparison analyses was fully replicated in the simulation study. CONCLUSIONS: Sibling-comparison analyses may underestimate the association of caesarean delivery with multiple offspring health outcomes due to inadequate adjustment of non-shared confounders, such as maternal age at delivery. Thus, we should be cautious when interpreting the seemingly conservative results of sibling-comparison analyses in delivery-related studies.

Effects of vaginal seeding on gut microbiota, body mass index, and allergy risks in infants born through cesarean delivery: a randomized clinical trial.

BACKGROUND: Vaginal seeding-exposure of neonates to maternal vaginal fluids-has been proposed to improve the microbiota of infants born through cesarean delivery, but its impacts on the infants' subsequent health outcomes remain unclear. OBJECTIVE: This study aimed to examine the impacts of vaginal seeding on gut microbiota, growth, and allergy risks in infants born through cesarean delivery. STUDY DESIGN: This randomized controlled trial was conducted at Liuyang Maternal and Child Health Care Hospital in Hunan, China. We estimated that a minimum sample size of 106 was needed by assuming a standardized effect size of 0.6 for the primary outcomes, with a statistical power of 80%, a 2-sided type I error of 0.05, and an expected loss to follow-up rate of 15%. Finally, 120 singleton term pregnant women scheduled for cesarean delivery were enrolled from November 2018 to September 2019. Infant follow-up was completed in September 2021. The participants were randomized in a 1:1 ratio to the vaginal seeding group (n=60; infants were swabbed immediately after birth using gauze preincubated in maternal vagina) or the control group (n=60; routine standard care). The first set of primary outcomes was infant body mass index and body mass index z-scores at 6, 12, 18, and 24 months of age. The other primary outcome was the total allergy risk score at 18 months for 20 common allergens (each scored from 0-6 points). Characteristics of gut microbiota, overweight/obesity, and allergic diseases and symptoms were included as secondary outcomes. The main analyses were performed according to the modified intention-to-treat principle. RESULTS: Of 120 infants, 117 were included in the analyses. Infant body mass index and body mass index z-scores did not significantly differ between the 2 groups at any of the 4 time points, with the largest difference in point estimates occurring at 6 months: the mean (standard deviation) body mass index was 17.5 (1.4) kg/m2 and 17.8 (1.8) kg/m2 in the vaginal seeding and control groups, respectively (mean difference, -0.31 kg/m2 [95% confidence interval, -0.91 to 0.28]; P=.30), and body mass index z-score was 0.2 (1.0) and 0.4 (1.1), respectively (mean difference, -0.20 [95% confidence interval, -0.58 to 0.18]; P=.31). The median total allergy risk score was 1.5 (interquartile range, 0.0-4.0) in the vaginal seeding group and 2.0 (interquartile range, 1.0-3.0) in the control group (median difference, 0.00 [95% confidence interval, -1.00 to 1.00]; P=.48). For infants from the vaginal seeding group, the relative abundance of genera Lactobacillus and Bacteroides in the gut microbiota was slightly yet nonsignificantly elevated at birth and 6 months, and the risk of overweight/obesity was lower at 6 months (0/57 vs 6/59; relative risk, 0.03 [95% confidence interval, 0.00-0.57]; P=.03) though not at subsequent time points. Other secondary outcomes did not differ between groups. No adverse events related to the intervention were reported. CONCLUSION: For infants born through cesarean delivery, vaginal seeding has no significant impacts on the gut microbiota, growth, or allergy risks during the first 2 years of life.

Gestational Diabetes Mellitus as an Effect Modifier of the Association of Gestational Weight Gain with Perinatal Outcomes: A Prospective Cohort Study in China.

The association of gestational weight gain (GWG) with perinatal outcomes seems to differ between women with and without gestational diabetes mellitus (GDM). Whether GDM is an effect-modifier of the association has not been verified. This study aimed to assess the modifying effect of GDM on the association of GWG with perinatal outcomes. Data on 12,128 pregnant women (3013 with GDM and 9115 without GDM) were extracted from a prospective, multicenter, cohort study in China. The associations of total and trimester-specific GWG rates (GWGR) with perinatal outcomes, including small size for gestational age, large size for gestational age (LGA), preterm birth, cesarean delivery, and gestational hypertension disorders, were assessed. The modifying effect of GDM on the association was assessed on both multiplicative and additive scales, as estimated by mixed-effects logistic regression. As a result, total GWGR was associated with all of the perinatal outcomes. GDM modified the association of total GWGR with LGA and cesarean delivery on both scales (all p < 0.05) but did not modify the association with other outcomes. The modifying effect was observed in the third trimester but not in the first or the second trimester. Therefore, maternal GWG is associated with perinatal outcomes, and GDM modifies the association with LGA and cesarean delivery in the third trimester.

Cesarean delivery on maternal request and common child health outcomes: A prospective cohort study in China.

Background: Cesarean delivery vs vaginal delivery was reported to increase the risks of childhood obesity, pneumonia, anemia, and neurobehavioral disorders, but few studies were able to deal with the confounding biases associated with medical conditions indicating cesareans. This prospective cohort study aims to investigate the associations of non-medically indicated cesarean delivery on maternal request (CDMR) with these child health outcomes. Methods: Among 17 748 liveborn infants whose mothers (primiparas) participated in a randomized controlled trial on micronutrient supplementation and pregnancy outcomes during 2006-2009 in 5 rural counties in Hebei Province, China, 6972 singletons born by full-term spontaneous vaginal delivery (SVD) and 3626 by CDMR were extracted for the assessments of obesity (weight-for-height z-score >3) and pneumonia (self-reported) at 1.5-5 years in 2011. Some children were further randomly selected from these two groups for the assessments of anemia (hemoglobin <110 g/L, 2341 SVD and 2417 CDMR) and neurobehavioral disorders (raw score of Child Behavior Checklist larger than the 90th percentile of the normative sample, 1257 SVD and 1060 CDMR). Results: Compared with SVD, CDMR was associated with increased risks of obesity (adjusted odds ratio (aOR) = 1.41, 95% confidence interval (CI) = 1.14-1.75, P = 0.002) and anemia (aOR = 1.65, 95% CI = 1.28-2.12, P < 0.001), but not with the risk of pneumonia (aOR = 1.16, 95% CI = 0.94-1.45, P = 0.17) or neurobehavioral disorders (aORs varied from 0.82 to 0.91, P > 0.05) in childhood. Conclusions: Cesarean delivery, independent of cesarean indications, is likely associated with childhood obesity and anemia, indicating a need to keep pregnant women informed, especially those seeking CDMR, a need to explore possible improvement on obstetric service, and even a need for main stakeholders to reach a compromise in making a cesarean decision. Trial registration: ClinicalTrials.gov: NCT00133744 and NCT01404416.

Geographic variations and determinants of EPA plus DHA and EPA alone in pregnant and lactating women from China.

EPA and DHA are essential for maternal and fetal health, but epidemiological data are sparse in China. We examined the trends of EPA alone and a combination of EPA plus DHA in pregnant and lactating women in three distinct geographic regions in China and explored their potential influencing factors. A total of 1015 healthy women during mid-pregnancy, late pregnancy or lactation were recruited from Weihai (coastland), Yueyang (lakeland) and Baotou (inland) cities of China between May and July of 2014. Maternal EPA and DHA concentrations (percentage of total fatty acids) in plasma and erythrocytes were measured by capillary GC. Adjusted EPA plus DHA concentrations in both plasma and erythrocytes significantly declined from mid-pregnancy (2·92 %, 6·95 %) to late pregnancy (2·20 %, 6·42 %) and lactation (2·40 %, 6·29 %) (Ptrend < 0·001); and both concentrations were highest in coastland, followed by lakeland, and lowest in inland (P < 0·001). Regarding EPA alone, the concentrations were higher in women during lactation or late pregnancy and in women in coastland and inland areas. Moreover, concentrations of EPA or EPA plus DHA were higher in women with older age, higher education, higher annual family income per capita and higher dietary intake of marine aquatic product and mutton. In lactating women, erythrocyte EPA concentration was higher in those having breast-feeding partially v. exclusively. In conclusion, maternal plasma and erythrocyte concentrations of EPA plus DHA or EPA alone differed with geographic regions, physiological periods and maternal characteristics, indicating a need of population-specific health strategies to improve fatty acids status in pregnant and lactating women.

Effects of prenatal micronutrients supplementation timing on pregnancy-induced hypertension: Secondary analysis of a double-blind randomized controlled trial.

In this secondary analysis of data from a double-blind randomized controlled trial (clinicaltrials.gov identifier: NCT00133744) of micronutrient supplementation (multiple micronutrients [MMN], iron-folic acid [IFA] and folic acid [FA] alone), we examined the potential modifying effect of gestational age at enrolment on the association of antenatal supplementation and pregnancy-induced hypertension (PIH). We included 18,775 nulliparous pregnant women with mild or no anaemia who were enrolled at 20 weeks of gestation or earlier from five counties of northern China. Women were randomly assigned to receive daily FA, IFA or MMN from enrolment until delivery. We used logistic regression to evaluate the association between PIH and timing of micronutrient supplementation. The incidence of PIH was statistically significantly lower among women who began MMN supplementation before 12 gestational weeks compared with women who began MMN supplementation at 12 weeks or later (RR = 0.74, 95% CI: 0.60-0.91). A similar protective effect was observed for both early-onset (<28 weeks, RR 0.45, 0.21-0.96) and late-onset of PIH (≥28 weeks, RR 0.77, 0.63-0.96). No statistically significant association was observed between PIH occurrence and timing of supplementation for FA or IFA. Maternal MMN supplementation and antenatal enrolment during the first trimester of pregnancy appeared to be of importance in preventing both early- and late-onset of PIH.

Trends and influencing factors of plasma folate levels in Chinese women at mid-pregnancy, late pregnancy and lactation periods.

Folate status for women during early pregnancy has been investigated, but data for women during mid-pregnancy, late pregnancy or lactation are sparse or lacking. Between May and July 2014, we conducted a cross-sectional study in 1211 pregnant and lactating women from three representative regions in China. Approximately 135 women were enrolled in each stratum by physiological periods (mid-pregnancy, late pregnancy or lactation) and regions (south, central or north). Plasma folate concentrations were measured by microbiological assay. The adjusted medians of folate concentration decreased from 28·8 (interquartile range (IQR) 19·9, 38·2) nmol/l in mid-pregnancy to 18·6 (IQR 13·2, 26·4) nmol/l in late pregnancy, and to 17·0 (IQR 12·3, 22·5) nmol/l in lactation (Pfor trend < 0·001). Overall, lower folate concentrations were more likely to be observed in women residing in the northern region, with younger age, higher pre-pregnancy BMI, lower education or multiparity, and in lactating women who had undergone a Caesarean delivery or who were breastfeeding exclusively. In total, 380 (31·4 %) women had a suboptimal folate status (folate concentration <13·5 nmol/l). Women in late pregnancy and lactating, residing in the northern region, having multiparity and low education level had a higher risk of suboptimal folate status, while those with older age had a lower risk. In conclusion, maternal plasma folate concentrations decreased as pregnancy progressed, and were influenced by geographic region and maternal socio-demographic characteristics. Future studies are warranted to assess the necessity of folic acid supplementation during later pregnancy and lactation especially for women at a higher risk of folate depletion.

Erratum: Patients' Attitudes to Unproven Therapies in Treating COVID-19 Merit Evaluation.

[This corrects the article DOI: 10.1016/j.xinn.2020.100028.].

Screening-based and Risk-based Strategy for the Prevention of Early-onset Group B Streptococcus/Non-group B Streptococcus Sepsis in the Neonate: A Systematic Review and Meta-analysis.

BACKGROUND: Screening-based and risk-based strategies are the 2 strategies for preventing group B streptococcus (GBS) diseases in neonates. We aimed to compare the effects of these 2 strategies in reducing the incidence of early-onset GBS sepsis (GBS-EOS) and their effects on the incidence of non-GBS sepsis. METHODS: PubMed, Embase, Web of Science and The Cochrane Central Register of Controlled Trials were searched for the period from January 1, 1996, to December 31, 2018. Randomized controlled trials and cohort studies that compared the effects of risk-based and screening-based strategies were eligible for the meta-analysis. The I statistic was used for assessing the statistical heterogeneity across studies. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated using the random effects model. RESULTS: There were 18 cohort studies comparing the incidence of GBS-EOS between the 2 strategies, involving a total of 604,869 newborns and 791 GBS-EOS cases. The heterogeneity across studies was moderate (I = 45%), and the pooled analysis yielded a 55% decreased risk of GBS-EOS for screening-based versus risk-based strategy (RR = 0.45; 95% CI: 0.34-0.59). For total early onset non-GBS sepsis (non-GBS-EOS), 7 studies with low heterogeneity (I = 18%) had a pooled RR of 0.91 (95% CI: 0.74-1.11), whereas for ampicillin resistant Escherichia coli-EOS, a subgroup of non-GBS-EOS, 3 studies with very low heterogeneity (I = 0%) had a pooled RR of 1.28 (95% CI: 0.74-2.21) for screening-based strategy compared with risk-based strategy. CONCLUSIONS: Compared with risk-based strategy, screening-based prophylaxis was associated with a reduced risk of GBS-EOS.

Patients' Attitudes to Unproven Therapies in Treating COVID-19 Merit Evaluation.

Since the outbreak of COVID-19, many randomized controlled trials have been launched to test the efficacy of promising treatments. These trials will offer great promise for future treatment. However, a public health emergency calls for a balance between gathering sound evidence and granting therapeutic access to promising trial drugs as widely as possible. In an electronic survey, we found that 3.9% of the participants preferred to receive an unproven trial drug directly in the hypothetical scenario of mild COVID-19 infection. This percentage increased drastically to 31.1% and 54.2% in the hypothetical scenario of severe and extremely severe infection, respectively. Our survey indicates a likelihood of substantial receptivity of trial drugs among actual patients in severe conditions. From the perspective of deontological ethics, a trial can only be approved when potential benefits of the investigational treatment are presumed to outweigh risks, so compassionate or off-label use of investigational therapies merits evaluation.

Impact of gestational hypertension and preeclampsia on fetal gender: A large prospective cohort study in China.

BACKGROUND: Recent studies suggested an association between fetal sex preponderance and hypertensive disorders during pregnancy, but the conclusions were inconsistent. Our objective was to investigate whether the occurrence of gestational hypertensive disorders would affect the possibility of delivering boys. METHODS: Data were obtained from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included participants who were registered in 2 southern Chinese provinces, and whose information of blood pressure and sex delivery were recorded in detailed. Blood pressure was measured during pregnancy by trained health care workers and other health-related information was recorded prospectively. We used log-binomial regression to evaluate the association between gestational hypertension or preeclampsia and the chance of male delivery. RESULTS: Among 205,605 singleton pregnancy women, the overall incidences of gestational hypertension and preeclampsia were 9.5% and 2.4%, respectively. The prevalence of male delivery was 51.1% and 50.2% in the groups of gestational hypertension and preeclampsia, while in the normotension group was 52.0%. After adjustment for the effects of the main potential confounders, women with gestational hypertension and preeclampsia both showed significantly decreased probability of giving birth to a boy. The adjusted risk ratios (RRs) were 0.98 (95% confidence interval (CI): 0.97-0.99) and 0.96 (95% CI: 0.94-0.99), respectively. CONCLUSIONS: Our results support a slight but significant association between gestational hypertension or preeclampsia and decreased likelihood of male delivery.

Association of China's universal two child policy with changes in births and birth related health factors: national, descriptive comparative study.

OBJECTIVE: To measure the association of China's universal two child policy, announced in October 2015, with changes in births and health related birth characteristics. DESIGN: National, descriptive before-and-after comparative study. SETTING: Every county in 28 of 31 provinces of mainland China. PARTICIPANTS: Births included in two national databases: 67 786 749 births from county level monthly aggregated data between January 2014 and December 2017; and 31 786 279 deliveries from individual level delivery information records between January 2015 and December 2017. MAIN OUTCOME MEASURES: Monthly mean number of births and mean proportion of multiparous mothers and mothers aged 35 and over, preterm deliveries, and caesarean deliveries. RESULTS: The study had two phases: the baseline period (up to and including June 2016, nine months after the policy announcement) and the effective period (from July 2016 to December 2017). The estimated number of additional births attributable to the new policy between July 2016 and December 2017 was 5.40 million (95% confidence interval 4.34 to 6.46). The monthly mean percentage of multiparous mothers and mothers aged 35 and over increased by 9.1 percentage points (95% confidence interval 6.4 to 11.7) and 5.8 percentage points (5.2 to 6.4), respectively. This increase in older mothers, however, was not associated with a concurrent increase in the overall rate of preterm birth. The monthly mean caesarean delivery rate among multiparous mothers increased by 1.2 percentage points (0.8 to 1.6) from 39.7% to 40.9%, and decreased by 3.0 percentage points (-3.5 to -2.5) among nulliparous mothers from 39.6% to 36.6%. CONCLUSIONS: Since its announcement in October 2015, the universal two child policy has been associated with a rise in births in China and with changes in health related birth characteristics: women giving birth have been more likely to be multiparous, and more likely to be aged 35 and over. No evidence of concurrent worsening outcomes (that is, premature births) was seen.

Maternal haemoglobin concentrations before and during pregnancy as determinants of the concentrations of children at 3-5 years of age: A large follow-up study.

OBJECTIVE: To examine the association between haemoglobin (Hb) concentrations in mothers before and during pregnancy and those in children at 3-5 years of age. METHODS: The study included 78,923 women who conceived during 1993-1996 and delivered a singleton live infant. Maternal Hb concentrations were measured at pre-pregnancy health check-up and first prenatal visit, and during the second and third trimester. Hb concentrations of children born to these women were measured at 3-5 years of age. Associations between Hb levels in mothers and children were examined. Unconditional logistic regression was used to explore the association between maternal Hb levels and risk for anaemia in children. RESULTS: Maternal Hb levels before and during pregnancy were positively associated with children's Hb levels. Using maternal Hb ≥ 130 g/L as the referent, the risk for anaemia in children at 3-5 years of age was higher when maternal second trimester Hb concentrations were 70-99 g/L (odds ratio [OR] = 1.76, 95% confidence interval [CI] = 1.56-1.99), 100-109 g/L (OR = 1.45, 95% CI = 1.29-1.64), and 110-119 g/L (OR = 1.18, 95% CI = 1.04-1.33). Children were 1.52 and 1.23-times more likely to suffer from anaemia when maternal third trimester Hb concentrations were 70-99 and 100-109 g/L, respectively. A pre-pregnancy Hb concentration of 80-109 g/L and first prenatal visit Hb concentrations of 80-109 and 100-119 g/L were also associated with increased risks for childhood anaemia. CONCLUSION: Low maternal Hb concentrations before or during pregnancy increase the risk for anaemia in children at 3-5 years of age.

Prenatal iron containing supplements provided to Chinese women with no or mild anemia had no effect on hemoglobin concentration in post-partum women or their infants at 6 and 12 months of age.

BACKGROUND: Although prenatal iron-containing supplements have been associated with lower anemia prevalence in later pregnancy, few trials have examined the effect of supplements on the anemia status of post-partum women and their infants. OBJECTIVE: We compared the effects of folic acid alone (FA), iron-folic acid (IFA) and multiple micronutrients (MMN) when provided to pregnant women with no or mild anemia on the hemoglobin levels of post-partum women and their infants at 6 and 12 months of age. We also examined the potential modifying effect of maternal hemoglobin concentration at enrollment. METHODS: A double-blind randomized controlled trial was conducted in China; 18,775 nulliparous women with a hemoglobin concentration > 100 g/L were randomly assigned to receive daily FA (400 µg); IFA (FA, Fe 30 mg), or MMN (FA, Fe and 13 micronutrients) from before 20 gestational weeks until delivery. RESULTS: Compared with daily prenatal FA, supplementation with IFA or MMN did not affect the prevalence of anemia at 4-6 weeks post-partum (27.2%, 26.8%, and 26.3%, respectively). At 6 months of age, the anemia prevalence in infants was 6.9%, 6.7%, and 6.7%, respectively. Findings were similar at 12 months of age. Among both post-partum women and infants, findings were similar across all levels of hemoglobin at enrollment. CONCLUSIONS: Compared to FA alone, prenatal IFA and MMN provided to women with no or mild anemia did not affect anemia in women post-partum or their infants regardless of baseline maternal hemoglobin concentration at enrollment.

A Correlation Study of DHA Intake Estimated by a FFQ and Concentrations in Plasma and Erythrocytes in Mid- and Late Pregnancy.

Adequate docosahexaenoic acid (DHA) is essential for the optimal growth and development of the fetus. Maternal DHA content fluctuates during pregnancy. The correlation of DHA content with dietary intake might be varied over the course of pregnancy. We aimed to compare the dietary DHA intake, estimated by a DHA-specific semiquantitative food frequency questionnaire (FFQ) against its blood content, among mid- and late-term pregnant women. A total of 804 Chinese pregnant women completed the tailored FFQ and provided fasting venous blood samples. Dietary DHA intake (mg/day) in the previous month was calculated from the FFQ using Chinese Food Composition Table. DHA concentrations (weight percent of total fatty acids) in plasma and erythrocytes were measured by capillary gas chromatography. Spearman correlation coefficients (rs) between DHA intake and its relative concentrations were calculated. After adjustment for maternal age, pre-pregnancy body mass index, stage of pregnancy, parity, education level, ethnicity, and annual family income per capita, the correlation coefficients of DHA intake with its concentrations in plasma and erythrocytes were 0.35 and 0.33, respectively (p < 0.001). The correlations were relatively stronger among women in late pregnancy (rs = 0.44 in plasma and 0.39 in erythrocytes) than those in mid-pregnancy (rs = 0.25 and 0.26). The significant correlations were consistently observed in subgroups stratified by regions, except for erythrocytes in women living in a coastland area. Multiple regression analyses also indicated significant positive linear correlations between DHA intake and its plasma or erythrocytes concentrations (p < 0.001). In conclusion, dietary DHA intake, estimated by the FFQ, was positively correlated with its concentrations in plasma and erythrocytes in Chinese pregnant women, especially for women in late pregnancy, with the exception of the erythrocytes of those living in a coastland area.

Effects of Prenatal Micronutrient Supplementation on Spontaneous Preterm Birth: A Double-Blind Randomized Controlled Trial in China.

In this secondary analysis of data from a double-blind randomized controlled trial carried out in northern China, we aimed to assess the effect of prenatal supplementation with multiple micronutrients (MMN) or iron + folic acid (IFA), versus folic acid (FA) alone, on risk of spontaneous preterm birth (SPB) and the impact of supplementation timing on SPB. A total of 18,775 nulliparous pregnant women enrolled between 2006 and 2009 were randomly assigned to receive daily FA, IFA, or MMN from the period before 20 weeks' gestation to delivery. The incidences of SPB for women consuming FA, IFA, and MMN were 5.7%, 5.6% and 5.1%, respectively. Compared with women given FA, the relative risks of SPB for those using MMN and IFA were 0.99 (95% confidence interval: 0.85, 1.16) and 0.89 (95% confidence interval: 0.79, 1.05), respectively. SPB incidence in women who started consuming FA, IFA, and MMN before the 12th week of gestation (4.6%, 4.2%, and 3.9%, respectively) was significantly reduced compared with starting supplement use on or after the 12th gestational week (6.9%, 7.2%, and 6.4%, respectively). Starting use of FA, IFA, or MMN supplements before the 12th week of gestation produced a 41%-45% reduction in risk of SPB. Early prenatal enrollment and micronutrient use during the first trimester of pregnancy appeared to be of particular importance for prevention of SPB, regardless of supplement group.