Maternal Serum Zinc Research Articles

Serum copper and zinc concentrations in intrahepatic cholestasis of pregnancy: a controlled study

A prospective, controlled study was undertaken in parturients with normal pregnancy and in parturients with intrahepatic cholestasis of pregnancy (IHC) to assess changes in maternal serum copper and zinc concentrations. Cord serum levels of these trace metals were measured, as well. Copper and zinc were measured by particle-induced X-ray emission (PIXE) analysis on two occasions during pregnancy; and immediately, 5 days and 5 weeks after delivery. Maternal serum copper was significantly higher in the IHC group as compared to the control group at 36–40 weeks of pregnancy and immediately and 5 days after delivery. There were no statistically significant differences between the control and study groups for maternal and cord serum zinc and cord copper concentrations. A positive correlation between maternal serum copper and serum aspartate aminotransferase was observed.

Cellular necrosis in zinc-deficient rat embryos.

Abnormal cellular necrosis was studied in 9.5-11.5-day embryos obtained from zinc-deficient rats. At periods of low maternal zinc status induced by a high intake of a zinc-deficient diet, cell death was observed in those regions of the embryo that were most sensitive to teratogenic insult at that time. As the maternal serum zinc level increased during the fasting phase of the feeding cycle, the degree of necrosis decreased, leaving the tissue histologically more normal even though the embryos were grossly malformed. The mitotic index of cells in the neural epithelium and limb buds of zinc-deficient, non-necrotic embryos was found to be elevated, but there was no evidence of blockage at any particular stage of mitosis. It can be hypothesised that during the early stages of organogenesis, periods of low maternal zinc status initiate unscheduled cell death by some as yet undefined mechanism that in turn, gives rise to the morphological anomalies observed later.

Maternal zinc status: a determination of central nervous system malformation.

Maternal serum zinc concentrations were estimated during 244 normal pregnancies and 15 abnormal pregnancies. The serum zinc concentrations were lower in the anencephalic pregnancies than in the normal control subjects. The serum zinc levels in women whose pregnancies terminated in a spontaneous abortion were normal. There was no variation of serum zinc level with gestational age between 15 to 18 weeks in normal pregnancies.

Trace metals in postdate pregnancy.

Maternal and cord serum calcium, copper, iron and zinc concentrations were analyzed in 20 women with a postdate pregnancy. The control group consisted of 20 parturients with delivery at term and their newborns. Serum free estriol (E3) was also determined. Maternal serum copper, zinc and E3 were statistically significantly lower, while cord serum copper and fetomaternal ratio of zinc were significantly higher in the study group than in the control group. Further, a positive correlation between E3 and maternal serum copper level (r = 0.63) was found.

The Role of Calcium, Copper, Iron and Zinc in Preterm Delivery and Premature Rupture of Fetal Membranes

Maternal and cord blood samples were collected in 60 cases with or without rupture of membranes before and at term. Serum concentrations of calcium, copper, iron and zinc were determined by proton-induced X-ray emission. Maternal and cord serum ceruloplasmin and maternal hemoglobin were also determined. Mothers with preterm delivery showed significantly lower hemoglobin values than those with delivery at term. Concentrations of calcium, iron and zinc were higher in cord than in maternal serum whereas maternal copper levels were higher than respective cord levels in all groups. The cord copper and ceruloplasmin and also their fetal/maternal ratios were significantly lower in the group with preterm premature rupture of fetal membranes (PROM) than in other groups. Maternal serum zinc and calcium were lower in preterm groups than in term groups. The study suggests a possible role of copper in preterm PROM and of zinc in the initiation of preterm labor, whereas calcium and iron do not seem to be involved in the etiology of prematurity or PROM.

Maternal Serum Copper and Zinc Concentrations in Normal and Small-for-Date Pregnancies

Serum concentrations of copper (Cu) and zinc (Zn) were determined in 20 non-pregnant healthy menstruating women and in 20 pregnant women during the 1st, 2nd and 3rd trimesters and 5 weeks postpartum as a longitudinal study. Also a cross-sectional population of 106 women was studied. Further, Cu and Zn concentrations were measured in 13 pregnant women who gave birth to small-for-date (SFD) infants; this was done during the 3rd trimester of pregnancy. The serum Cu concentration in nonpregnant women was 0.91 +/- 0.19 mg/l. During pregnancy it was significantly higher (1.48 +/- 0.31, 1.91 +/- 0.25 and 2.20 +/- 0.36 mg/l during the 1st, 2nd and 3rd trimesters, respectively) and 5 weeks postpartum it was still higher (1.09 +/- 0.17 mg/l) than in the nonpregnant women. In the cross-sectional population, serum Cu and Zn values were of the same magnitude as in the longitudinal study. When longitudinal and cross-sectional values of serum Cu during the 3rd trimester were combined, the mean level (2.23 +/- 0.40 mg/l) was significantly higher than that in the SFD group (2.06 +/- 0.25 mg/l). Serum Zn in the SFD group (0.48 +/- 0.12 mg/l) did not differ significantly from the normal pregnant values.

A prospective study of serial maternal serum zinc levels and pregnancy outcome.

A prospective study of 878 pregnant women in Adelaide, South Australia, examined the relationship of maternal serum zinc concentration to pregnancy outcome. Blood samples were obtained at weeks 18 and 32 of pregnancy, and from the umbilical cord. Additional detailed data were obtained, via standardised antenatal interview and review of clinical records, on antenatal care, personal, behavioural, and sociodemographic characteristics, and, subsequently, on delivery and neonatal assessment. Maternal mid-pregnancy zinc status was negatively correlated, although very weakly, with duration of gestation and with birthweight (including, in particular, the 18 recorded cases of intrauterine growth retardation). This finding accords with recent suggestions that, in non-experimental human studies in populations in which frank zinc deficiency is absent, maternal serum zinc level may be an outcome, rather than a determinant, of fetal growth later in pregnancy. Low mid-pregnancy zinc levels were associated with increased risk of intrapartum haemorrhage. In general, the greatest risk of having some complication or abnormality of delivery or neonatal functional status occurred in pregnant women who had both an initially below-average, and subsequently decreasing, serum zinc concentration. This corroborates other recent research. While it might be inferred that above-average fetal growth, by depressing maternal zinc status, could itself impair delivery and neonatal functioning, our data indicate that these effects operated independently.

Fetal and maternal serum copper and zinc levels in human pregnancy

Copper and zinc levels were measured in maternal mid-pregnancy (18-week and 32-week) and umbilical cord sera samples taken from approximately 1,000 women in South Australia. The data were related to pregnancy outcome, and to the ethnic background and certain characteristics of the mothers. Copper levels rose in the maternal serum during gestation while zinc levels were lower in pregnant than in non-pregnant women. Cord serum copper was lower than in the maternal samples but cord zinc was higher. Neither maternal weight, age nor parity appeared to exert a major effect on thelevels of either element, but clinically-assessed maternal obesity was associated with elevated serum copper levels. Maternal serum copper and zinc levels were unrelated to the length of gestation or to fetal birthweight, although superficially there appeared to be a negative correlation. This observation is discussed in the light of recent, similar findings by other workers concerning maternal zinc status and infant birthweight.

Acrodermatitis in Breast-Fed Premature Infants: Evidence for a Defect of Mammary Zinc Secretion

Two 9-week-old, breast-fed premature infants developed acrodermatitis and hypozincemia because of low zinc content in their mothers' breast milk. All symptoms of zinc deficiency disappeared within seven days after the infants were treated orally with zinc and did not recur when zinc was discontinued after 11 months (infant 1) and three weeks (infant 3). After a subsequent term pregnancy, one of the mothers had lower breast milk zinc content (P less than .025) and greater exponential decline (P less than .025) of zinc content through 40 weeks of lactation compared with 34 control subjects. Her second infant (infant 2) had hypozincemia at 7 months of age but did not develop clinical zinc deficiency. When the mothers of the affected infants took oral zinc supplements, there was no increase in their breast milk zinc content. Zinc secretion into breast milk appears to be a controlled process that is independent of maternal zinc intake or serum zinc level. Breast milk may be low in zinc because of defective mammary secretion and this may lead to severe symptomatic zinc deficiency in premature infants.

Prevention possibility for brain dysfunction in rat with the fetal alcohol syndrome — Low-zinc-status and hypoglycemia —

As a treatable cause of CNS dysfunctions in the fetal alcohol syndrome (FAS), low-zinc-status in addition to hypoglycemia has been investigated in experimental rat models. During the premating period female rats of an ethanol group and a control group received 30% ethanol (E) and water (W), respectively. During pregnancy, some of both groups received zinc or nicotinamide-adenine dinucleotide (NAD) or nicotinamide throughout pregnancy and glucose for gestational day (gd) 15 to 19 with E or W. Independent of maternal blood glucose levels, maternal insulin levels were lower on gd 15 and 18 in the ethanol group than in the control one. A decrease in the activity of carbonic anhydrase in the hippocampal area on postnatal day (pd) 1 was observed in the ethanol group. Administration of zinc with E resulted in a better effect on fetal total body weight and on preventing resorption, mean fetal body weight and protein content in the cerebrum than administration of E alone. Administration of glucose only in the late gestational period resulted in a better effect on fetal cerebral weight than administration of E alone, with a decrease in the litter size. Administration of zinc with E during pregnancy resulted in higher maternal serum zinc levels, without an increase in fetal cerebral zinc content, than administration without zinc with E. There was a positive correlation between fetal body ethanol levels and maternal blood ethanol levels, and a negative correlation between fetal body ethanol levels and fetal total body weight. The beneficial effect of supplementary zinc on fetal growth may possibly help preventing the CNS dysfunctions of FAS, but it is important that the effect was not good compared to the control without E.

Beneficial Effect of Zinc Supplementation on Reproduction in Rats Fed Rapeseed Protein Concentrate

Three groups of 33 90-day-old female Sprague-Dawley rats were fed, ad libitum, the following diets for 2 weeks before breeding. Diet 1 (D1) contained 20% protein from casein, diet 2 (D2) had the same level of protein from Tower rapeseed (Brassica napus) protein concontrate (RPC) and diet 3 (D3) was the same as D2 with a zinc supplement (70 mg/l) in the drinking water. From each group 6 animals were killed before breeding and 5-9 animals were killed at 1 and 2 weeks of gestation and post-partum. From each rat, blood, thyroids, liver and femur were collected for the determination of zinc, copper, iron, manganese, calcium and magnesium. As a measure of the reproductive performance, body weight, number of pups in the uterus or delivered live or dead, and gestations days before parturition were recorded. The pups were examined for obvious deformities and also analysed for the above mineral elements by atomic absorption spectroscopy. In group D2, levels of zinc in maternal serum, liver, femur and in the pups were significantly lower than the comparable levels in the other two groups. The zinc supplemented RPC-fed group did not show the anorexia experienced by the unsupplemented group and there was neither a significant difference between reproductive performances of groups D1 and D3 nor was there any significant difference between the zinc levels determined. It was concluded that the toxic symptoms caused by RPC feeding was attributable to zinc deficiency probably caused by the high phytate level in the RPC.

Concentrations of Zinc, Cobalt, Bromine, Rubidium and Gold in Maternal and Cord Blood Serum

Concentrations of zinc, cobalt, bromine, rubidium and gold have been determined by neutron activation analysis in 18 maternal and umbilical cord blood sera as well as in 7 healthy non-pregnant women who served as controls. The concentrations of essential trace elements (zinc and cobalt) were significantly lower while levels of non-essential trace elements were similar (bromine and rubidium) or increased (gold) in sera of pregnant as compared to sera of non-pregnant women. The mean value of zinc in the umbilical cord was 1.9 times higher than that of mothers. However, no correlation exists between the values of zinc in maternal and umbilical cord blood sera. These data support the hypothesis that zinc is actively transported from mother to fetus through the placenta.

Preterm Delivery: Role of Zinc

Background: Preterm delivery is a very challenging obstetric complication in Bangladesh. Reducedserum zinc (Zn) concentration of the pregnant mother may have some role in causing preterm delivery.Objectives: To measure serum zinc level in preterm delivery mother and their respective neonates toobserve their status. Methods: This cross sectional study was carried out in the Department ofPhysiology, Sir Salimullah Medical College, Mitford Hospital, Dhaka, during the period of 1st Januaryto 31st December 2009. A total 136 subjects were included in this study, of whom 27 were full termdelivery mother with their respective neonates (group B), treated as control group and another 27were preterm delivery mothers with their respective neonates (group C), treated as study group. Ageranged of preterm and full term mother were from 20-40 years. Again, 28 non pregnant women with agerange from 20-30 years were taken as reference value (groupa A). Statistical analysis was done byusing appropriate method as applicable. Results: Mean serum zinc level was significantly (p<0.001)lower in preterm mother in comparison to that of full term mother and also in preterm neonates thanthat of full term neonates. Serum total protein and albumin were significantly (p<0.001) lower inpreterm mother than those of full term mother and also in preterm neonates than those of theirrespective mothers and full term neonates. Again, maternal serum zinc level showed positive correlationwith birth weight of neonates and also with zinc concentration of neonatal blood. Conclusions: Thepresent study revealed a lower level of serum zinc in pre-term delivery mother and their neonates.These hypozincemia may be responsible for low birth weight of the fetus.Key Words: Zinc; pretermDOI: 10.3329/jbsp.v5i1.5415J Bangladesh Soc Physiol. 2010 June; 5(1): 27-33