The Effect of Heavy Metals and Trace Elements in the Meconium on Preterm Delivery of Unknown Etiology

Abstract

A AB BS ST TR RA AC CT T O Ob bj je ec ct ti iv ve e: : Prematurity is an important etiologic factor for perinatal mortality and morbidity. In our country, preterm births and complications of prematurity account for 26% of perinatal mortality. There are many maternal, fetal or placental, genetic and environmental etiologic factors that cause prematurity. There have been no studies to show an association between preterm delivery of unknown etiology and exposure to heavy metals and trace elements at toxic levels in meconium. The purpose of this study is to measure the levels of heavy metals (lead, cadmium) and trace elements (zinc, iron, copper) in meconium samples and to understand their associations with preterm delivery of unknown etiology. M Ma at te er ri ia al l a an nd d M Me et th ho od ds s: : The levels of heavy metals and trace elements in the meconiums of 810 term or preterm infants with known and unknown etiology for being preterm were measured with a flame atomic absorption spectrophotometer. R Re es su ul lt ts s: : Lead and cadmium were detected in all meconium samples. Heavy metal and trace element levels in meconium were significantly higher in preterms of unknown and known etiology for being preterm compared to term infants (for all p<0.0001). Lead levels in meconium were significantly higher in preterm of unknown etiology compared to preterm of known etiology in posthoc analysis with Bonferroni corrected Mann Whitney U test. C Co on nc cl lu us si io on n: : These results may suggest that lead levels in meconium samples are higher in preterm newborns especially with unknown etiology compared to term newborns. Therefore, we suggest that preterm delivery of unknown etiology may be decreased by decreasing air pollution. K Ke ey y W Wo or rd ds s: : Cadmium; lead; meconium Ö ÖZ ZE ET T A Am ma aç ç: : Prematürite perinatal mortalite ve morbidite için önemli bir risk faktörüdür. Ülkemizde erken doğumlar ve prematüritenin komplikasyonları perinatal mortalitenin %26'sından sorumludur. Prematüriteye neden olan çok sayıda maternal, fötal veya plasental, genetik ve çevresel etiyolojik faktör vardır. Etiyolojisi bilinmeyen erken doğumla mekonyumdaki toksik düzeylerde ağır metallere ve eser elemetlere maruziyet arasındaki iliskiyi gösteren hiçbir çalısma yoktur. Bu çalısmanın amacı mekonyum örneklerinde ağır metal (kursun, kadmiyum) ve eser element (çinko, demir, bakır) düzeylerini ölçmek ve etiyolojisi bilinmeyen erken doğumla ilişkilerini anlamaktır. G Ge er re eç ç v ve e Y Yö ön nt te em ml le er r: : Etiyolojisi bilinen ve bilinmeyen 810 term veya preterm bebeğin mekonyumlarındaki ağır metaller ve eser elementler alevli atomik absorbsiyon spektrofotometresi ile ölçüldü. B Bu ul lg gu ul la ar r: : Tüm mekonyum örneklerinde kursun ve kadmiyum saptandı. Mekonyumdaki ağır metal ve eser element düzeyleri etiyolojisi bilinen ve bilinmeyen pretermlerde term bebeklere göre belirgin olarak yüksekti (tümü için p<0,0001). Tukey testiyle post-hoc analizde sadece mekonyumdaki kursun düzeyleri etiyolojisi bilinmey...

Selected maternal, fetal and placental trace element and heavy metal and maternal vitamin levels in preterm deliveries with or without preterm premature rupture of membranes

“…The levels of lead in cord blood were suggested as a negative predictor of birthweight and length . Compared to term newborns, in preterm newborns, especially with unknown etiology, higher lead and cadmium levels were found and it was suggested that these metals may affect gestational age at the fetal stage . Although the available literature suggests that prenatal exposure to cadmium and lead may play a role in preterm birth, morbidity and mortality through the effect on pathogenesis of related oxidative stress, the results of our study show that preterm deliveries presenting with PPROM and those presenting with intact membranes do not differ from each other with respect to their roles in the etiology.…”

Prenatal Environmental Metal Exposure and Preterm Birth: A Scoping Review

“…Several studies presented Odds Ratios along with 95% confidence intervals while others presented the median or mean lead level in term birth vs. PTB. Regarding potential confounders, 13 papers [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] adjusted for one or more potential confounders, while seven papers [ 34 , 35 , 36 , 37 , 38 , 39 , 40 ] did not. Sixteen out of 20 studies were of high quality, while the remaining studies were of moderate quality ( Table 1 ).…”

“…We identified nine papers that assessed the relationship between exposure to environmental cadmium and PTB [ 24 , 29 , 31 , 38 , 40 , 45 , 46 , 47 , 48 ] ( Table 3 ). All but one of the studies had a reasonable sample size.…”

“…Two studies did not adjust for possible confounders [ 38 , 40 ]. Four studies were from the USA [ 46 ] or Europe [ 24 , 38 , 40 ], three were from China [ 45 , 47 , 48 ] and one was from each of Japan [ 29 ] and Myanmar [ 31 ]. The studies used varied specimen type including maternal blood, urine and meconium.…”

“…A study from Turkey by Ozsoy et al measured meconium Cd levels and found a significant association ( p < 0.001) between meconium Cd level and PTB [ 38 ]. A large study from Japan observed similar association between maternal blood Cd measured during 14–39 weeks of pregnancy and PTB [ 29 ].…”