Iodine supplementation for women during the preconception, pregnancy and postpartum period

Abstract

There were insufficient data to reach any meaningful conclusions on the benefits and harms of routine iodine supplementation in women before, during or after pregnancy. The available evidence suggested that iodine supplementation decreases the likelihood of postpartum hyperthyroidism and increases the likelihood of the adverse effect of digestive intolerance in pregnancy - both considered potential adverse effects. We considered evidence for these outcomes low or very low quality, however, because of study design limitations and wide confidence intervals. In addition, due to the small number of trials and included women in our meta-analyses, these findings must be interpreted with caution. There were no clear effects on other important maternal or child outcomes though these findings must also be interpreted cautiously due to limited data and low-quality trials. Additionally, almost all of the evidence came from settings with mild or moderate iodine deficiency and therefore may not be applicable to settings with severe deficiency.More high-quality randomised controlled trials are needed on iodine supplementation before, during and after pregnancy on maternal and infant/child outcomes. However, it may be unethical to compare iodine to placebo or no treatment in severe deficiency settings. Trials may also be unfeasible in settings where pregnant and lactating women commonly take prenatal supplements with iodine. Information is needed on optimal timing of initiation as well as supplementation regimen and dose. Future trials should consider the outcomes in this review and follow children beyond the neonatal period. Future trials should employ adequate sample sizes, assess potential adverse effects (including the nature and extent of digestive intolerance), and be reported in a way that allows assessment of risk of bias, full data extraction and analysis by the subgroups specified in this review.

Effects of nutrition interventions during pregnancy on low birth weight: an overview of systematic reviews

“…31 There was no evidence of an effect of any supplement containing BMJ Global Health iodine versus the same supplement without iodine or no intervention/placebo for the reported outcomes LBW, PTB and SGA.…”

“…30 The number of included participants in the reviews ranged from 603 participants 41 to over 310 000 participants. 24 Supplementation with vitamins was reported in five reviews, 24-26 45 46 supplementation with minerals in eight reviews [27][28][29][30][31][32][33][34] and MMN supplementation was assessed in three reviews. [35][36][37] There was one review on protein supplementation and nutritional education 38 and two reviews reported on marine oil and fatty acid supplementation.…”

Effect of Thyroid Hormones on Neurons and Neurodevelopment

“…A recent metanalysis concluded that there is a 3-fold increased risk of child cognitive impairment when hypothyroxinemia is detected in mothers during gestation, although the big heterogeneity among the definitions of cognitive delay, the tests performed, and the assessment periods limits these findings [59]. In terms of iodine supplementation, another metanalysis concluded that, at present, the literature data are undermined by low evidence and several limitations, and no clear benefits or risks of iodine supplementation on children’s outcomes can be summarized [60]. …”

Evidence-Based Practices During Pregnancy and Midwifery Approach

“…(2017) tarafından toplam 2.7.00 kadının dahil edildiği 11 çalışmanın meta analizinde, kadınların gebelik öncesinde, gebelikte veya sonrasında rutin iyot kullanmalarının etkileri araştırılmış ancak faydaları ve zararları üze-rine anlamlı sonuçlar elde etmek için yeterli veri bulunamamıştır. 58 Çalışmanın sonucunda zayıf kalitede kanıt düzeyinde iyot takviyesinin postpartum hipertiroidizm olasılığını azalttığı, ancak gebelikte sindirim intoleransını arttırdığı ileri sü-rülmektedir. Hipotroidi olan gebelerde iyot takviyesinin faydalarını gösterecek yeterli kanıt buluna mamıştır.…”

“…Hipotroidi olan gebelerde iyot takviyesinin faydalarını gösterecek yeterli kanıt buluna mamıştır. 58 …”