Nutritional advice

Objectives:
Does dehydroepiandrosterone (DHEA) supplementation improve the outcomes of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in women with diminished ovarian reserve (DOR) and/or poor ovarian response (POR)?

Study design:
This review article included 9 RCTs, published between 2010 and 2017.
The sample sizes ranged from 24 to 208, with a total of 862 patients.
All of included patients had been diagnosed with diminished ovarian reserve (DOR) and/or poor ovarian response (POR).

The treatment intervention was 75 mg daily DHEA versus placebo.

The lack of significant asymmetry of funnel plot indicated the lack of potential publication bias in the included studies.

Results and conclusions:
The investigators found in a pooled analysis using the random effects model revealed a statistically significant increase in retrieved oocytes in the DHEA group, compared to the control group [MD = 0.91, 95% CI = 0.23 -1.59, p = 0.009, I2  = 53%, p = 0.06].

The investigators found in 8 studies (405 in the DHEA group and 415 in the control group) a statistically significant increase in the clinical pregnancy rate in the DHEA group compared to the control group [RR = 1.27, 95% CI = 1.01 -1.61, p = 0.04, I2 = 0%, p = 0.57].

The investigators found in 5 studies (189 in the DHEA group and 190 in the control group) a statistically significant increase in the live birth rate in the DHEA group, compared to the control group [RR = 1.76, 95% CI = 1.17 -2.63, p = 0.006, I2  = 0%, p = 0.43].

The investigators found in 3 studies (96 in the DHEA group and 99 in the control group) no significant difference in the miscarriage rates between the DHEA and control groups [RR = 0.37, 95% CI = 0.12-1.13, p = 0.08, I2 = 25%, p = 0.26].

The investigators concluded 75 mg daily DHEA supplementation increases the retrieved oocytes, clinical pregnancy rate and live birth rate in women with diminished ovarian reserve and/or poor ovarian response, who are undergoing in vitro fertilization or intracytoplasmic sperm injection.

Original title:
The Effect of Dehydroepiandrosterone (DHEA) Supplementation on IVF or ICSI: A Meta-Analysis of Randomized Controlled Trials by Xu L, Hu C, […], Li Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6620181/

Additional information of El Mondo:
Find more information/studies on pregnancy right here.

Your body naturally produces the hormone dehydroepiandrosterone (DHEA) in the adrenal gland. In turn, DHEA helps produce other hormones, like testosterone and estrogen. Natural dehydroepiandrosterone levels peak in early adulthood and then slowly fall as you age.

 

Objectives:
Free fatty acids, also known as nonesterified fatty acids, are proinflammatory molecules that induce insulin resistance in nonpregnant individuals. Nevertheless, the concentration of these molecules has not been systematically addressed in pregnant women. Therefore, this review article has been conducted.

Do higher plasma levels of free fatty acids increase risk of gestational diabetes mellitus?

Study design:
This review article included 12 case-control studies with a total of 2,426 women, from these, 21% (507/2,426) had a diagnosis of having gestational diabetes.

The mean gestational age at inclusion was 30.3 weeks of gestation.
The mean maternal age was 29 years.
No significant publication bias was found nor a trend towards greater results in small studies.

Results and conclusions:
The investigators found in random-effects model, when compared to controls, women with gestational diabetes had higher levels of free fatty acids [SMD = 0.86, 95% CI = 0.54-1.18, p 0.001, I2 = 91%].
Pooled results showed higher plasma levels of free fatty acid among women with gestational diabetes mellitus during the second trimester of pregnancy [SMD = 1.05 vs. 0.75].

The investigators found meta-regression analysis showed that the gestational age at inclusion was the only cofactor influencing the mean levels of free fatty acids, indicating a trend towards lower plasma levels of free fatty acids later in gestation [estimate = -0.074, 95% CI = -0.143 to -0.004, p = 0.036].

The investigators concluded that plasma levels of free fatty acids are higher in women diagnosed with gestational diabetes mellitus and that this difference is higher during the second trimester of pregnancy. However, more investigation is needed to assess the potential role of free fatty acids in the prediction of gestational diabetes earlier in pregnancy.

Original title:
Plasma Levels of Free Fatty Acids in Women with Gestational Diabetes and Its Intrinsic and Extrinsic Determinants: Systematic Review and Meta-Analysis by Villafan-Bernal JR, Acevedo-Alba M, […], Martinez-Portilla RJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6721400/

Additional information of El Mondo:
Find more information/studies on fatty acids and pregnancy right here.
 

Objectives:
Maternal folic acid supplementation is considered mandatory in almost every country in the world to prevent congenital malformations. However, little is known about the association of maternal folic acid intake with the occurrence of childhood cancer. Therefore, this review article has been conducted.

Does maternal folic acid supplementation during pregnancy reduce risk of childhood cancer?

Study design:
This review article included 17 case-control studies.

Results and conclusions:
The investigators found in random-effects model, maternal folic acid supplementation during pregnancy significantly reduced risk of childhood acute lymphoblastic leukaemia with 25% [OR = 0.75, 95% CI = 0.66 to 0.86].
Significantly because OR of 1 was not found in the 95% CI of 0.66 to 0.86. OR of 1 means no risk/association.

The investigators found in random-effects model, there was no significant association between maternal folic acid supplementation during pregnancy and acute myeloid leukaemia [OR = 0.70, 95% CI = 0.46 to 1.06] or childhood brain tumours [OR = 1.02, 95% CI = 0.88 to 1.19].
No significant because OR of 1 was found in the 95% CI of 0.88 to 1.19. OR of 1 means no risk/association.

The investigators concluded maternal folic acid supplementation during pregnancy reduces risk of childhood acute lymphoblastic leukaemia. Thus, healthcare professionals are recommended to provide regular health education and health promotion to the community on the benefits of folic acid supplementation during pregnancy.

Original title:
The Protective Effect of Maternal Folic Acid Supplementation on Childhood Cancer: A Systematic Review and Meta-analysis of Case-control Studies by Wan Ismail WR, Abdul Rahman R, […],Nawi AM.

Link:
https://www.jpmph.org/journal/view.php?doi=10.3961/jpmph.19.020

Additional information of El Mondo:
Find more information/studies on folic acid and pregnancy right here.
 

Objectives:
Does calcium supplement with or without other drugs reduce risk of preeclampsia and gestational hypertension?

Study design:
This review article included 27 RCTs, with 28,492 pregnant women.

Results and conclusions:
The investigators found calcium supplement significantly reduced risk of preeclampsia with 49% [RR = 0.51, 95% CI = 0.40 to 0.64].

The investigators found calcium supplement significantly reduced risk of gestational hypertension with 30% [RR = 0.70, 95% CI = 0.60 to 0.82].

The investigators found sub-analyses revealed high-dose (1.2-2 g/day), moderate-dose (0.6-1.2 g/day) and low-dose (0.6 g/day) of calcium supplement significantly reduced risk of preeclampsia.

The investigators found sub-analyses revealed high-dose (1.2-2 g/day) and moderate-dose (0.6-1.2 g/day) of calcium supplement significantly reduced risk of gestational hypertension.

The investigators concluded high-dose (1.2-2 g/day) and moderate-dose (0.6-1.2 g/day) of calcium supplement reduced both risk of preeclampsia and gestational hypertension. However, further studies with direct comparison of different dose of calcium supplementation are needed to explore the ideal dose of calcium supplementation to prevent preeclampsia and gestational hypertension.

Original title:
The association between calcium supplement and preeclampsia and gestational hypertension: a systematic review and meta-analysis of randomized trials by Sun X, Li H, [...], Zhang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30935246

Additional information of El Mondo:
Find more information/studies on calcium and pregnancy right here.

 

Objectives:
The role of chromium as a weight loss agent remains questionable and although previous meta-analyses findings have reported small reductions in body weight in individuals with overweight/obesity following chromium supplementation, there have been significant limitations with these findings. Therefore, this review article has been conducted.

Do individuals with overweight/obesity benefit from chromium supplementation?

Study design:
This review article included 21 RCTs with a total of 1,316 participants.

Results and conclusions:
The investigators found pooled analysis showed significant reductions in anthropometric indices associated with body composition for:
-weight loss [WMD = -0.75 kg, 95% CI = -1.04 to -0.45, p  0.001];
-body mass index (BMI) [WMD = -0.40, 95% CI = -0.66 to -0.13, p = 0.003] and;
-body fat percentage [WMD = -0.68%, 95% CI = -1.32 to -0.03, p = 0.04] in individuals with overweight/obesity following chromium supplementation. No changes were detected in controls.

The investigators found subgroup analysis showed significant improvements in weight loss and body fat percentage, particularly for study durations ≤12 weeks and doses ≤400 μg/d chromium.

The investigators concluded ≤400 μg/d chromium supplementation during ≤12 weeks is associated with some improvements in body composition in subjects with obesity/overweight. The effect size was medium and the clinical relevance of chromium as a weight loss aid remains uncertain. Therefore, further investigation from larger and well-designed randomized controlled studies, especially in patients with diabetes, is warranted.

Original title:
A meta-analysis of the effect of chromium supplementation on anthropometric indices of subjects with overweight or obesity by Tsang C, Taghizadeh M, […], Jafarnejad S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31115179

Additional information of El Mondo:
Find more information/studies on chromium and obesity/overweight right here.

Objectives:
The threshold for population-level optimal red blood cell (RBC) folate concentration among women of reproductive age for the prevention of neural tube defects has been estimated at 906 nmol/L. However, the dose-response relationship between folic acid intake and blood folate concentrations is uncharacterized. Therefore, this review article has been conducted.

Is there dose-response relationship between folic acid intake and blood folate concentrations?

Study design:
This review article included 23 articles for red blood cell folate and by 97 articles for serum/plasma folate.

Results and conclusions:
The investigators found in 17 studies red blood cell (RBC) folate concentration increased 1.78 fold [95% CI = 1.66 to 1.93] from baseline to steady-state at 375-570 µg folic acid/day and it took a median of 36 weeks of folic acid intake [95% CI = 27 to 52] to achieve steady-state red blood cell folate concentrations.

The investigators found for every 100 µg/day folic acid intake, serum/plasma folate concentrations increased 11.6% [95% CI = 8.4 to 14.9] from baseline to steady-state, over a median of 13 weeks [95% CI = 10 to 16].

The investigators concluded that there is a dose-response relationship between folic acid intake and changes in blood folate concentrations. At 375-570 µg folic acid/day, red blood cell folate concentrations increase 1.78 fold from baseline to steady-state, over a median of 36 weeks. For every 100 µg/day folic acid intake, serum/plasma folate concentrations increase 11.6% from baseline to steady-state, over a median of 13 weeks. These results can inform how much additional folic acid intake is needed among populations of women whose red blood cell folate concentrations are below the optimal threshold.

Original title:
Systematic Review and Bayesian Meta-analysis of the Dose-response Relationship between Folic Acid Intake and Changes in Blood Folate Concentrations by Crider KS, Devine O, […], Berry RJ.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356991/

Additional information of El Mondo:
Find here more information/studies about pregnancy and folaat (also called folic acid).
 

Objectives:
Diverse studies have investigated the impact of prenatal exposure to vitamin D levels on brain development. However, evidence in humans has never been systematically reviewed. Therefore, this meta-analysis (systematic review) has been conducted.

Has a high prenatal vitamin D level positive effect on brain development of the born child?

Study design:
This review article included 25 studies.

Results and conclusions:
The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels had no significant effects on cognition [pooled beta coefficients = 0.95, 95% CI = -0.03 to 1.93, p = 0.05].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels had no significant effects on psychomotor development [pooled beta coefficients = 0.88, 95% CI = -0.18 to 1.93, p = 0.10].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels significantly reduced risk of ADHD of the born child with 28% [pooled relative risk = 0.72, 95% CI = 0.59 to  0.89, p = 0.002].

The investigators found comparing with the lowest category of prenatal 25(OH)D levels (vitamin D level in blood), the highest prenatal 25(OH)D levels significantly reduced risk of autism-related traits of the born child with 58% [pooled odds ratio = 0.42, 95% CI = 0.25 to 0.71, p = 0.001].

The investigators found there was little evidence for protective effects of high prenatal 25(OH)D for language development and behaviour difficulties of the born child.

The investigators concluded this meta-analysis provides supporting evidence that increased prenatal exposure to 25(OH)D levels is associated with reduced risk of ADHD and autism-related traits of the born child later in life. Associations represent a potentially high public health burden given the current prevalence of vitamin D deficiency and insufficiency among childbearing aging and pregnant women.

Original title:
Neurodevelopmental effects of prenatal vitamin D in humans: systematic review and meta-analysis by García-Serna AM and Morales E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30696940

Additional information of El Mondo:
Find more information/studies on vitamin D and pregnancy right here.