Nutrition and health

Objectives:
Leg cramps are one of the common symptoms during pregnancy. About 30%-50% of pregnant women experience leg cramps twice a week. Leg cramps may cause severe pain and sleep disturbance, hinder performance of daily activities and may lengthen the duration of pregnancy and the type of childbirth. Therefore, this review article has been conducted.

Does oral magnesium supplementation reduce leg cramps during pregnancy?

Study design:
This review article included 4 RCTs with a total of 332 pregnant women.

Results and conclusions:
The investigators found the frequency of leg cramps during pregnancy was not significantly decreased in the magnesium group compared to the control group (group without magnesium) [WMD = -0.47, 95% CI = -1.14 to 0.20, p = 0.167].

The investigators found oral magnesium supplementation did not significantly improved the recovery from leg cramps during pregnancy compared to the control group [OR = 0.47, 95% CI = 0.14 to 1.52, p = 0.207].

The investigators found oral magnesium supplementation had no significant side effects in the treatment group (group with magnesium) compared to the control group [OR = 1.82, 95% CI = 0.90 to 3.69, p = 0.094].

The investigators concluded that oral magnesium supplementation is not effective in the treatment of leg cramps during pregnancy.

Original title:
Effect of oral magnesium supplementation for relieving leg cramps during pregnancy: A meta-analysis of randomized controlled trials by Liu J, Song G, [...], Meng T.

Link:
https://pubmed.ncbi.nlm.nih.gov/34247796/

Additional information of El Mondo:
Find more information/studies on review article/meta-analysis/significantly, magnesium and pregnancy right here.

 

Objectives:
The effects of vitamin and mineral supplementation on women with gestational diabetes mellitus (GDM) have not been well established. Therefore, this review article has been conducted.

Does vitamin and mineral supplementation improve glycemic control (like, fasting plasma glucose, serum insulin, homeostasis model assessment-insulin resistance and homeostasis model of assessment for β cell function) and decrease risk of inflammation and oxidative stress in women with gestational diabetes mellitus?

Study design:
This review article included 12 RCTs with 698 patients.

Patients included were in the age range of 18-40 years and all reported gestational diabetes mellitus screening was conducted between 24 weeks and 28 weeks gestation.

All trials gave vitamin and mineral supplementation orally.

Types, doses, dose regimens and duration of vitamin and mineral supplementation were as follows: magnesium (100-250 mg), zinc (4-233 mg), selenium (200 μg), calcium (400-1000 mg) and vitamin E (400 IU) every day for 6 weeks, vitamin D (200-50000 IU) every day or every 2 or 3 weeks for 6 weeks. Magnesium, zinc, selenium, calcium, vitamin D or E was given separately or in different combinations: magnesium and vitamin E; zinc and vitamin E; calcium and vitamin D; magnesium, zinc, calcium and vitamin D.

All trials used placebo as control intervention.

Among the 12 trials, 8 were judged to be at low risk of bias and 4 as being at unclear risk of bias. Unclear risks were related to attrition bias and other bias.

No significant publication bias was found for the effect of vitamin and mineral supplementation on all 8 outcomes.

Results and conclusions:
The investigators found magnesium, zinc, selenium, calcium, vitamin D and E (alone or in combination) supplementation significantly improved glycemic control in women with gestational diabetes mellitus compared to those receiving placebos:
-fasting plasma glucose (FPG) [MD = - 9.02, 95% CI = -12.09 to -5.96, p   0.00001];
-serum insulin [MD = -4.33, 95% CI = -5.35 to -3.32, p  0.00001];
-homeostasis model assessment-insulin resistance (HOMA-IR) [MD = -1.34, 95% CI = -1.60 to -1.07, p  0.00001] and;
-homeostasis model of assessment for β cell function (HOMA-B) [MD = - 15.58, 95% CI = -23.70 to -7.46, p = 0.0002].
Significantly because the calculated p-value of 0.0002 was less than the p-value of 0.05.

The investigators found vitamin and mineral supplementation (magnesium, zinc, selenium, calcium, vitamin D and E (alone or in combination)) significantly decreased risk of inflammation and oxidative stress through decreasing high-sensitivity C-reactive protein (hs-CRP) [MD = -1.29, 95% CI = -1.82 to -0.76, p  0.00001], malondialdehyde (MDA) [MD = -0.71, 95% CI = -0.97 to -0.45, p  0.00001] and increasing total antioxidant capacity (TAC) [MD = 45.55, 95% CI = 22.02 to 69.08, p = 0.0001].

The investigators concluded that vitamin and mineral supplementation improves glycemic control and decreases risk of inflammation and oxidative stress in women with gestational diabetes mellitus.

Original title:
The effects of vitamin and mineral supplementation on women with gestational diabetes mellitus by Li D, Cai Z, [...], Zhang J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8145819/

Additional information of El Mondo:
Find more information/studies on review article/meta-analysis/significantly, vitamins, minerals and pregnancy right here.
 

Objectives:
Do high maternal or neonatal DHA and/or EPA levels increase offspring birth weight and weight in childhood?

Study design:
This review article included 27 RCTs with 6,408 infants and 14 observational studies.

Results and conclusions:
The investigators found in RCTs that >650 mg/day DHA and/or EPA supplementation significantly increased birth weight [MD = 87.5g, 95% CI = 52.3 to 122.6, n = 3,831 participants, moderate quality].

The investigators found in RCTs that >650 mg/day DHA and/or EPA supplementation significantly increased combined BMI and BMI z score at 5-10 years [SMD = 0.11, 95% CI = 0.04 to 0.18, n = 3,220 participant, moderate quality].

The investigators found results from the observational studies were generally inconsistent. High trans fatty acids levels during pregnancy seemed to be associated with lower birth weight.

The investigators concluded this review and meta-analysis support a relationship between high maternal or neonatal DHA and/or EPA levels and higher offspring birth weight and weight in childhood. More high-quality long-term studies are still needed.

Original title:
Systematic Literature Review and Meta-Analysis of the Relationship Between Polyunsaturated and Trans Fatty Acids During Pregnancy and Offspring Weight Development by Ren X, Vilhjálmsdóttir BL, […], Specht  IO.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027310/

Additional information of El Mondo:
Find more information/studies on review article/meta-analysis/significantly, DHA&EPA and pregnancy right here.

 

Objectives:
Does intake of folic acid during pregnancy reduce risk of offspring's autism spectrum disorders?

Study design:
This review article included 10 studies with 23 sub-studies (9,795 autism spectrum disorders cases).

Results and conclusions:
The investigators found folic acid supplementation during early pregnancy significantly reduced risk of offspring's autism spectrum disorders with 43% [OR = 0.57, 95% CI = 0.41 to 0.78].

The investigators found the consumption of a daily amount of at least 400 μg folic acid from dietary sources and supplements significantly reduced risk of offspring's autism spectrum disorders with 45% [OR = 0.55, 95% CI = 0.36 to 0.83].

The investigators concluded that the consumption of a daily amount of at least 400 μg (400 mcg) folic acid from dietary sources and supplements during pregnancy reduces risk of offspring's autism spectrum disorders.

Original title:
Prenatal Folic Acid Supplements and Offspring's Autism Spectrum Disorder: A Meta-analysis and Meta-regression by Liu X, Zou M, [...], Chen WX.

Link:
https://pubmed.ncbi.nlm.nih.gov/33743119/

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

 

Objectives:
Does vitamin A supplementation reduce risk of bronchopulmonary dysplasia (BPD) in premature infants?

Study design:
This review article included 9 RCTs with 709 infants received vitamin A treatment (intervention group) and 700 infants did not receive vitamin A treatment (control group).
The dose of vitamin A regimens varied from 1500 to 10,000 IU (450 to 3,003 micrograms) and the treatment durations generally lasted for 4 weeks.

The funnel plots for all synthesized outcomes remained symmetrical, indicating that there was no significant publication bias.

Results and conclusions:
The investigators found when compared to the control group, vitamin A supplementation significantly reduced the incidence of bronchopulmonary dysplasia in premature infants with 33% [OR  =  0.67, 95% CI = 0.52 to 0.88].
The sensitivity analyses were performed by excluding single RCT one by one. The results of sensitivity analysis of all outcomes had indicated no substantial result changes among the overall estimates.

The investigators concluded that vitamin A supplementation is beneficial to reduce bronchopulmonary dysplasia in premature infants.  

Original title:
Vitamin A supplementation prevents the bronchopulmonary dysplasia in premature infants: A systematic review and meta-analysis by Ding Y, Chen Z and Lu Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7837939/

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

Bronchopulmonary dysplasia is a form of chronic lung disease that develops in preterm neonates treated with oxygen and positive-pressure ventilation.
 

Objectives:
Does a high dietary cholesterol intake increase risk of gestational diabetes mellitus?

Study design:
This review article included 3 cohort studies, 4 cross-sectional studies and 2 case-control studies involving 30,123 participants and 3,237 women with gestational diabetes mellitus (diabetes mellitus in pregnancy).

Results and conclusions:
The investigators found comparing highest versus lowest category of dietary cholesterol intake, that the highest dietary cholesterol intake significantly increased risk of gestational diabetes mellitus with 49% [pooled RR = 1.49, 95% CI = 1.18 to 1.88].

The investigators found in dose-response analysis that the risk of gestational diabetes mellitus significantly increased by 32% [RR = 1.32, 95% CI = 1.20 to 1.45] for every increase of 100 mg per day in dietary cholesterol intake.

The investigators concluded a high dietary cholesterol intake (at least 100 mg per day) increases risk of gestational diabetes mellitus.

Original title:
Dietary Cholesterol Intake and Risk of Gestational Diabetes Mellitus: A Meta-Analysis of Observational Studies by Gao F and Cui CY.

Link:
https://pubmed.ncbi.nlm.nih.gov/33416437/

Additional information of El Mondo:
Find more information/studies on cholesterol, diabetes mellitus and pregnancy right here.
 

Objectives:
Does iron supplementation during pregnancy improve maternal haematological status and birth weight?

Study design:
This review article included 48 RCTs (17,793 women) and 44 cohort studies (1,851,682 women).

The dose of iron in RCTs ranged from 10 mg to 240 mg daily. Duration of supplementation varied from 7 to 8 weeks up to 30 weeks during pregnancy.

Significant heterogeneity existed for several outcomes that could not be explained substantially by pre-specified subgroups.

Results and conclusions:
The investigators found iron supplementation during pregnancy increased maternal mean haemoglobin concentration by 4.59 g/L [95% CI = 3.72 to 5.46] compared with controls.

The investigators found iron with folic acid was associated with a significant increase in mean haemoglobin concentration of 10.41 g/L [95% CI = 5.36 to 15.46, I2 = 0%, 9 trials] and reduction in risk of anaemia in the third trimester or at delivery of 56% [95% CI = 0.37 to 0.53, I2 = 44%, 5 trials]. Significant means there is an association with a 95% confidence.

The investigators found iron supplementation during pregnancy significantly reduced the risk of anaemia with 50% [95% CI = 0.42 to 0.59] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of iron deficiency (of the mother) with 41% [95% CI = 0.46 to 0.79] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of iron deficiency anaemia with 60% [95% CI = 0.26 to 0.60] compared with controls.

The investigators found iron supplementation during pregnancy significantly reduced the risk of low birth weight (2500 g) with 19% [95% CI = 0.71 to 0.93] compared with controls.

However, the investigators found iron supplementation during pregnancy non-significantly reduced the risk of preterm birth with 16% [95% CI = 0.68 to 1.03] compared with controls. Non-significant means there is no association with a 95% confidence.

The investigators found in cohort studies that anaemia in the first or second trimester was significantly associated with a higher risk for low birth weight of 29% [adjusted odds ratio 1.29, 95% CI = 1.09 to 1.53] and preterm birth with 21% [adjusted odds ratio = 1.21, 95% CI = 1.13 to 1.30].

The investigators found in exposure-response analysis that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was significantly 0.88 [95% CI = 0.84 to 0.92, p for linear trend 0.001].

The investigators found in exposure-response analysis that birth weight increased by 15.1 g [95% CI = 6.0 to 24.2, p for linear trend = 0.005] and risk of low birth weight significantly decreased by 3% [relative risk = 0.97, 95% CI = 0.95 to 0.98, p for linear trend 0.001] every 10 mg increase in dose/day.

Furthermore, the investigators found for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 g [95% CI = 6.8 to 21.8, p for linear trend = 0.002]. However, mean haemoglobin was not associated with the risk of low birth weight and preterm birth.

The investigators found no evidence of a significant effect on duration of gestation, small for gestational age births and birth length and duration of iron use was not significantly associated with the outcomes after adjustment for dose.

The investigators concluded daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight and a linear decrease in maternal anaemia with higher doses of iron, up to 66 mg/day.

Original title:
Anaemia, prenatal iron use, and risk of adverse pregnancy outcomes: systematic review and meta-analysis by Haider BA, Olofin I, […], Fawzi WW.

Link:
http://www.bmj.com/content/346/bmj.f3443

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

Iron deficiency anaemia occurs when there isn't enough iron in the body. Anaemia is a condition where the amount of haemoglobin in the blood is below the normal level.
Iron deficiency anaemia has been defined as haemoglobin 110 g/L and serum ferritin 12 µg/L.