Human milk oligosaccharide composition following supplementation with folic acid vs (6S)-5-methyltetrahydrofolic acid during pregnancy and mediation by human milk folate forms.

Supplementation with folic acid versus (6S)-5-methyltetrahydrofolic acid (5-MTHF) results in different folate forms in human milk, with folic acid increasing unmetabolized folic acid (UMFA) at the expense of reduced folate forms. It is unknown whether folate forms present in human milk have further effects on human milk composition, such as human milk oligosaccharide (HMO) concentrations. We randomized 60 pregnant women in Canada to 0.6 mg/day folic acid or (6S)-5-MTHF. Human milk folate forms (LC-MS/MS) and nineteen HMOs (HPLC) were quantified at 1 week postpartum. Linear regression and causal mediation analysis were used to evaluate the effect of folate supplementation on HMO concentrations, and possible mediation by concentrations of UMFA and reduced folate forms in human milk (controlling for secretor status and parity). HMO concentrations were not different between groups, with no evidence of mediation by reduced folate forms; however, increased UMFA was associated with reduced concentrations of total HMOs and 3'-sialyllactose.

Optimizing vitamin D status in polycystic ovary syndrome: a systematic review and dose-response meta-analysis.

CONTEXT: Polycystic ovary syndrome (PCOS) is a common and complex endocrine disorder in women of reproductive age. Vitamin D supplementation is a promising complementary therapy for PCOS, yet there is no consensus on an optimal dose, leading to a lack of evidence-based supplementation guidelines. OBJECTIVE: The objective of this study was to conduct a vitamin D dose-response meta-analysis among women with PCOS. DATA SOURCES: MEDLINE, CINAHL, and EMBASE databases from inception to November 2022 were searched for relevant articles. DATA EXTRACTION: Study screening and bias assessment were conducted by 2 independent reviewers. Eight relevant studies were identified; data for serum 25(OH)D (nmol/L) at baseline and at 12 weeks in each intervention group (mean ± SD) and vitamin D dose were extracted. DATA ANALYSIS: Estimates across studies were used to create a pooled curve, using restricted cubic splines with knots at the 10th, 50th, and 90th percentiles of the distribution of doses, to estimate the mean difference in effect for serum 25(OH)D at each dose compared with 0 IU/day. Sensitivity analyses were conducted fixing knots at 4000 IU/day and 7000 IU/day, which were a priori identified as potentially important thresholds, and to assess model fit and estimate heterogeneity. The pooled analysis demonstrated strong evidence of a dose-response relationship (P < .001), suggesting an increasing effect with increasing dose. An initial increase in serum 25(OH)D was evident until doses of approximately 3000 IU/day; this was followed by a plateau in effect between approximately 3000 IU/day and 5000 IU/day. The effect of supplementation with >5000 IU/day was unclear, given the minimal data at higher doses. The curve produced robust results for moderate doses (3000 IU/day to 4000 IU/day), which were not sensitive to model specification. CONCLUSION: Women with PCOS are responsive to vitamin D supplementation, but the benefit of providing doses of >3000 IU/day appears minimal. Further data is required to determine dose-response at doses of >5000 IU/day, and whether higher intakes provide a clinically meaningful advantage in this population. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021259396.

The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials.

CONTEXT: Iron deficiency and anemia have serious consequences, especially for children and pregnant women. Iron salts are commonly provided as oral supplements to prevent and treat iron deficiency, despite poor bioavailability and frequently reported adverse side effects. Ferrous bisglycinate is a novel amino acid iron chelate that is thought to be more bioavailable and associated with fewer gastrointestinal (GI) adverse events as compared with iron salts. OBJECTIVE: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the effects of ferrous bisglycinate supplementation compared with other iron supplements on hemoglobin and ferritin concentrations and GI adverse events. DATA SOURCES: A systematic search of electronic databases and grey literature was performed up to July 17, 2020, yielding 17 RCTs that reported hemoglobin or ferritin concentrations following at least 4 weeks' supplementation of ferrous bisglycinate compared with other iron supplements in any dose or frequency. DATA EXTRACTION: Random-effects meta-analyses were conducted among trials of pregnant women (n = 9) and children (n = 4); pooled estimates were expressed as standardized mean differences (SMDs). Incidence rate ratios (IRRs) were estimated for GI adverse events, using Poisson generalized linear mixed-effects models. The remaining trials in other populations (n = 4; men and nonpregnant women) were qualitatively evaluated. DATA ANALYSIS: Compared with other iron supplements, supplementation with ferrous bisglycinate for 4-20 weeks resulted in higher hemoglobin concentrations in pregnant women (SMD, 0.54 g/dL; 95% confidence interval [CI], 0.15-0.94; P < 0.01) and fewer reported GI adverse events (IRR, 0.36; 95%CI, 0.17-0.76; P < 0.01). We observed a non-significant trend for higher ferritin concentrations in pregnant women supplemented with ferrous bisglycinate. No significant differences in hemoglobin or ferritin concentrations were detected among children. CONCLUSION: Ferrous bisglycinate shows some benefit over other iron supplements in increasing hemoglobin concentration and reducing GI adverse events among pregnant women. More trials are needed to assess the efficacy of ferrous bisglycinate against other iron supplements in other populations. PROSPERO REGISTRATION NO: CRD42020196984.

An evidence review and nutritional conceptual framework for pre-eclampsia prevention.

Pre-eclampsia is a serious complication of pregnancy, and maternal nutritional factors may play protective roles or exacerbate risk. The tendency to focus on single nutrients as a risk factor obscures the complexity of possible interactions, which may be important given the complex nature of pre-eclampsia. An evidence review was conducted to compile definite, probable, possible and indirect nutritional determinants of pre-eclampsia to map a nutritional conceptual framework for pre-eclampsia prevention. Determinants of pre-eclampsia were first compiled through an initial consultation with experts. Second, an expanded literature review was conducted to confirm associations, elicit additional indicators and evaluate evidence. The strength of association was evaluated as definite relative risk (RR) < 0·40 or ≥3·00, probable RR 0·40-0·69 or 1·50-2·99, possible RR 0·70-0·89 or 1·10-1·49 or not discernible RR 0·90-1·09. The quality of evidence was evaluated using Grading of Recommendations, Assessment, Development and Evaluation. Twenty-five nutritional factors were reported in two umbrella reviews and twenty-two meta-analyses. Of these, fourteen were significantly associated with pre-eclampsia incidence. Higher serum Fe emerged as a definite nutritional risk factors for pre-eclampsia incidence across populations, while low serum Zn was a risk factor in Asia and Africa. Maternal vitamin D deficiency was a probable risk factor and Ca and/or vitamin D supplementation were probable protective nutritional factors. Healthy maternal dietary patterns were possibly associated with lower risk of developing pre-eclampsia. Potential indirect pathways of maternal nutritional factors and pre-eclampsia may exist through obesity, maternal anaemia and gestational diabetes mellitus. Research gaps remain on the influence of household capacities and socio-cultural, economic and political contexts, as well as interactions with medical conditions.

Calcium for pre-eclampsia prevention: A systematic review and network meta-analysis to guide personalised antenatal care.

BACKGROUND: Calcium supplementation reduces the risk of pre-eclampsia, but questions remain about the dosage to prescribe and who would benefit most. OBJECTIVES: To evaluate the effectiveness of high (≥1 g/day) and low (<1 g/day) calcium dosing for pre-eclampsia prevention, according to baseline dietary calcium, pre-eclampsia risk and co-interventions, and intervention timing. SEARCH STRATEGY: CENTRAL, PubMed, Global Index Medicus and CINAHL, from inception to 2 February 2021, clinical trial registries, reference lists and expert input (CRD42018111239). SELECTION CRITERIA: Randomised controlled trials of calcium supplementation for pre-eclampsia prevention, for women before or during pregnancy. Network meta-analysis (NMA) also included trials of different calcium doses. DATA COLLECTION AND ANALYSIS: Two independent reviewers extracted published data. The meta-analysis employed random-effects models and the NMA, a Bayesian random-effects model, to obtain direct and indirect effect estimates. MAIN RESULTS: The meta-analysis included 30 trials (N = 20 445 women), and the NMA to evaluate calcium dosage included 25 trials (N = 15 038). Calcium supplementation prevented pre-eclampsia similarly with a high dose (RR 0.49, 95% CI 0.36-0.66) or a low dose (RR 0.49, 95% CI 0.36-0.65). By NMA, high-dose (vs low-dose) calcium did not differ in effect (RR 0.79, 95% CI 0.43-1.40). Calcium was similarly effective regardless of baseline pre-eclampsia risk, vitamin D co-administration or timing of calcium initiation, but calcium was ineffective among women with adequate average baseline calcium intake. CONCLUSIONS: Low- and high-dose calcium supplementation are effective for pre-eclampsia prevention in women with low calcium intake. This has implications for population-level implementation where dietary calcium is low, and targeted implementation where average intake is adequate. TWEETABLE ABSTRACT: A network meta-analysis of 25 trials found that low-dose calcium supplementation (<1 g/day) is as effective as high-dose calcium supplementation (≥1 g/day) in halving the risk of pre-eclampsia when baseline calcium intake is low.

Anemia and adverse outcomes in pregnancy: subgroup analysis of the CLIP cluster-randomized trial in India.

BACKGROUND: Iron-deficiency anemia is a known risk factor for several adverse perinatal outcomes, but data on its impact on specific maternal morbidities is less robust. Further, information on associations between anemia in early pregnancy and subsequent outcomes are understudied. METHODS: The study population was derived from the Community Level Interventions for Pre-eclampsia (CLIP) trial in Karnataka State, India (NCT01911494). Included were women who were enrolled in either trial arm, delivered by trial end date, and had a baseline measure of hemoglobin (Hb). Anemia was classified by WHO standards into four groups: none (Hb ≥ 11 g/dL), mild (10.0 g/dL ≤ Hb < 11.0 g/dL), moderate (7.0 g/dL ≤ Hb < 10.0 g/dL) and severe (Hb < 7.0 g/dL). Targeted maximum likelihood estimation was used to estimate confounder-adjusted associations between anemia and a composite (and its components) of adverse maternal outcomes, including pregnancy hypertension. E-values were calculated to assess robustness to unmeasured confounding. RESULTS: Of 11,370 women included, 10,066 (88.5%) had anemia, that was mild (3690, 32.5%), moderate (6023, 53.0%), or severe (68, 0.6%). Almost all women (> 99%) reported taking iron supplements during pregnancy. Blood transfusions was more often administered to those with anemia that was mild (risk ratio [RR] 2.16, 95% confidence interval [CI] 1.31-3.56), moderate (RR 2.37, 95% CI 1.56-3.59), and severe (RR 5.70, 95% CI 3.00-10.85). No significant association was evident between anemia severity and haemorrhage (antepartum or postpartum) or sepsis, but there was a U-shaped association between anemia severity and pregnancy hypertension and pre-eclampsia specifically, with the lowest risk seen among those with mild or moderate anemia. CONCLUSION: In Karnataka State, India, current management strategies for mild-moderate anemia in early pregnancy are associated with similar rates of adverse maternal or perinatal outcomes, and a lower risk of pregnancy hypertension and preeclampsia, compared with no anemia in early pregnancy. Future research should focus on risk mitigation for women with severe anemia, and the potential effect of iron supplementation for women with normal Hb in early pregnancy.