Zinc deficiency is not a cause for abortion, congenital abnormality and small-for-gestational age infant in Chinese women

Summary. Zinc concentration in serum and hair was measured in a cross-sectional study of 437 Chinese women of whom 310 were normal controls studied at various stages of pregnancy and up to 12 months after delivery. The rest had spontaneous abortions, fetuses with a birthweight below the 10th centile for gestation or congenital abnormalities. Zinc concentration fell throughout normal pregnancy, the fall being greater in serum than in hair. There was no correlation between serum and hair levels. The infant birthweight had a positive correlation with serum level but a negative correlation with hair level. Abortion, low birthweight and congenital abnormality were not associated with low concentrations of zinc in plasma or hair.     

Zinc concentrations in maternal blood during pregnancy and post partum, in cord blood and amniotic fluid

Zinc deficiency was reported to lead to congenital malformations and abnormal fetal development, and zinc concentration in amniotic fluid has been found to be correlated with fetal birth weight. In the present study, zinc concentrations were estimated in 8 pregnant women at 15 gestational weeks and 68 pregnant women at term. Maternal serum zinc concentration in early and term pregnancy was significantly lower than that of the non-pregnant controls (mean values +/- SEM being 9.8 +/- 0.6, 9.3 +/- 0.2, and 11.5 +/- 0.3 mumol/l, respectively). Maternal serum zinc concentrations reached the non-pregnant level by one week post partum. The mean serum zinc concentration in cord blood was 14.4 (+/- 0.4) mumol/l. The zinc concentration in the amniotic fluid was very low both in early pregnancy and at term 1.1 and 0.8 mumol/l, respectively, and no correlation was found to the birth weight. Low serum zinc content in pregnant women occurs as a normal feature and congenital malformation as a consequence of disturbed zinc metabolism is probably only to be seen in instances of extreme zinc deficiency in conjunction with malnutrition.     

Cigarette consumption and serum cotinine in relation to birthweight

The concentration of serum cotinine (the major metabolite of nicotine) was measured in sera from 4211 women at between 15 and 21 weeks gestation to determine whether a serum cotinine level was a better predictor of low birthweight than the self-reported number of cigarettes smoked per day. Both cotinine levels and smoking history were significantly associated with reduced birthweight, but cotinine correlated significantly better. Smokers of greater than or equal to 25 cigarettes per day, representing the 2.7% of women with the greatest cigarette consumption, had infants 289 g lighter than the 68% of women who were nonsmokers. Women with serum cotinine levels in the top 2.7% (greater than or equal to 284 ng/ml) had infants 441 g lighter than the 68% of women with the lowest cotinine levels (less than or equal to 24 ng/ml). Our results strengthen the evidence linking smoking with low birthweight and also demonstrate that cotinine can be satisfactorily used to assess and monitor cigarette smoking in pregnancy.     

Zinc and copper in Asian pregnancies--is there evidence for a nutritional deficiency?

In 92 Hindu Asians, 59% of them vegetarian, and 51 Europeans longitudinal measurements were made during pregnancy of the zinc and copper concentrations in plasma and hair together with urinary zinc excretion, as indices of their zinc and copper status. Maternal diets were assessed once at booking. Zinc intakes ranged from 3.1 to 16.9 mg/day, with average intakes least in vegetarian Hindus and most in Europeans. Average copper intakes ranged between 1.48 and 1.80 mg/day and were similar in the three patient groups. Both ethnic groups showed the pregnancy-associated fall in the plasma concentration of zinc and rise in that of copper but throughout the study Hindus had statistically significant lower levels of zinc and higher levels of copper than Europeans. Urinary zinc excretion was not only significantly lower throughout the study in Hindus than in Europeans but the increase in excretion which occurred after 20 weeks gestation was smaller. There were no ethnic differences in the zinc content of hair. Urinary zinc excretion correlated with both plasma zinc levels and dietary zinc. Mean birthweight in the Hindus was 2912 g and 34% of infants were below the 10th centile, using the Aberdeen standards, compared with 6% of the European babies (mean birthweight 3349 g). No association was found between crude or adjusted birthweight and any of the measures of zinc or copper status in either ethnic group. The Hindus had an apparently lower average zinc status than the Europeans, but there was no evidence that this had acted as a nutritional constraint and was the cause of their slower rate of intrauterine growth.     

Zinc and copper in Asian pregnancies–is there evidence for a nutritional deficiency?

Summary. In 92 Hindu Asians, 59% of them vegetarian, and 51 Europeans longitudinal measurements were made during pregnancy of the zinc and copper concentrations in plasma and hair together with urinary zinc excretion, as indices of their zinc and copper status. Maternal diets were assessed once at booking. Zinc intakes ranged from 3·1 to 16·9 mg/day, with average intakes least in vegetarian Hindus and most in Europeans. Average copper intakes ranged between 1·48 and 1·80 mg/day and were similar in the three patient groups. Both ethnic groups showed the pregnancy-associated fall in the plasma concentration of zinc and rise in that of copper but throughout the study Hindus had statistically significant lower levels of zinc and higher levels of copper than Europeans. Urinary zinc excretion was not only significantly lower throughout the study in Hindus than in Europeans but the increase in excretion which occurred after 20 weeks gestation was smaller. There were no ethnic differences in the zinc content of hair. Urinary zinc excretion correlated with both plasma zinc levels and dietary zinc. Mean birth-weight in the Hindus was 2912 g and 34% of infants were below the 10th centile, using the Aberdeen standards, compared with 6% of the European babies (mean birthweight 3349 g). No association was found between crude or adjusted birthweight and any of the measures of zinc or copper status in either ethnic group. The Hindus had an apparently lower average zinc status than the Europeans, but there was no evidence that this had acted as a nutritional constraint and was the cause of their slower rate of intrauterine growth.     

Antenatal screening for congenital nephrosis in Finland by maternal serum alpha-fetoprotein

In the Kuopio and North-Karelia districts of Finland 10724 pregnancies were screened for congenital nephrosis by maternal serum alpha-fetoprotein (AFP) measurement. Outcome was known for 10504 (98%) pregnancies, of which 509 (4 X 8%) had a serum AFP level greater than or equal to 2 X 5 multiples of the normal median (MoM) at 15-18 weeks gestation. After exclusion of those women who had a normal serum AFP level (less than 2 X 5 MoM) in a second sample, 'wrong dates' or multiple pregnancy, 267 (2 X 5%) remained with a high serum AFP level. Amniocentesis was carried out in 225 (2 X 1%) and 16 women had an amniotic fluid AFP level greater than 10 SD above the normal mean. In this group there were six fetuses with congenital nephrosis (four confirmed and two suspected), six other serious malformations (including an intrauterine death) and four without obvious abnormality. In the 98% pregnancies followed up there were no infants with congenital nephrosis that had been missed. Babies with congenital nephrosis require permanent hospitalization and have a mean survival of 8 months. In Finland, within certain areas, the birth prevalence is as high as 1 in 2600 per year. In such areas maternal serum AFP measurement appears to be a useful method of screening for congenital nephrosis. The service was also well accepted since 94% of the women with raised serum AFP levels wished to be screened again in a future pregnancy.     

Previous miscarriage and stillbirth as risk factors for other unfavourable outcomes in the next pregnancy.

OBJECTIVE: To look for associations between previous fetal loss and fetal malformation or low birthweight in a subsequent pregnancy. DESIGN: A case-control study with place of birth, time and sex matched controls. SETTING: 72 South American maternity hospitals. SUBJECTS: 18,534 malformed, 1150 non-malformed babies of low birthweight and 16,394 controls. All babies were from mothers with at least one previous pregnancy. MAIN OUTCOME MEASURES: Frequency of stillbirths and miscarriages in the previous pregnancy and outcome of the index pregnancy. RESULTS: Multiple malformation, Down's syndrome, anencephaly, spina bifida, pes equinovarus, congenital dislocation of the hip and low birthweight are associated with previous fetal loss. CONCLUSION: A miscarriage or a stillbirth in a previous pregnancy should be taken into account when the risk of malformations or low birthweight in a subsequent pregnancy is assessed.     

Antenatal screening for congenital nephrosis in Finland by maternal serum α-fetoprotein

Summary. In the Kuopio and North-Karelia districts of Finland 10 724 pregnancies were screened for congenital nephrosis by maternal serum AL-fetoprotein (AFP) measurement. Outcome was known for 10 504 (98%) pregnancies, of which 509 (4.8%) had a serum AFP level ≤ 2.5 multiples of the normal median (MoM) at 15–18 weeks gestation. After exclusion of those women who had a normal serum AFP level (< 2.5 MoM) in a second sample,'wrong dates'or multiple pregnancy, 267 (2.5%) remained with a high serum AFP level. Amniocentesis was carried out in 225 (2.1%) and 16 women had an amniotic fluid AFP level > 10 SD above the normal mean. In this group there were six fetuses with congenital nephrosis (four confirmed and two suspected), six other serious malformations (including an intrauterine death) and four without obvious abnormality. In the 98% pregnancies followed up there were no infants with congenital nephrosis that had been missed. Babies with congenital nephrosis require permanent hospitalization and have a mean survival of 8 months. In Finland, within certain areas, the birth prevalence is as high as 1 in 2600 per year. In such areas maternal serum AFP measurement appears to be a useful method of screening for congenital nephrosis. The service was also well accepted since 94% of the women with raised serum AFP levels wished to be screened again in a future pregnancy.     

Association between first trimester maternal serum pregnancy associated plasma protein-A and adverse pregnancy outcome

AIMS: To investigate whether low pregnancy associated plasma protein-A (PAPP-A) levels in the first trimester of pregnancy are associated with subsequent intrauterine fetal growth restriction, stillbirth and preterm delivery. METHODS: A retrospective review of pregnancy outcomes was undertaken in women who had PAPP-A carried out in the first trimester of pregnancy at the time of nuchal translucency scan. Pregnancy outcomes were assessed by the review of medical records, and postal questionnaires. Delivery details were collected, including livebirth, neonatal birthweight and gestational age at delivery. The chi2 test was used to investigate the association between low first trimester serum PAPP-A levels and adverse fetal outcomes. Unpaired t-test was used for continuous variables. Sensitivities and specificities were then calculated. RESULTS: A total of 894 women who had blood collected for PAPP-A were identified, and data was obtained for 827 deliveries. Each had a normal karyotype. There were six intrauterine deaths, 13 babies with birthweights below the 3rd centile, 55 babies weighing below the 10th centile, and 96 women who delivered prematurely. Four of six intrauterine deaths had low PAPP-A levels (<0.5 multiples of the median), with a relative risk of 13.75. Low PAPP-A levels were associated with fetal weight below the 10th centile (P = 0.01) but not the 3rd centile. There was no statistically significant association between low maternal serum PAPP-A levels and preterm delivery. CONCLUSION: At 11-13 weeks' gestation, low maternal serum PAPP-A levels are associated with fetal death in utero and birthweight below the 10th centile. First trimester PAPP-A may be a useful tool for identifying pregnancies at risk of adverse fetal outcomes.     

Vitamin A concentration in amniotic fluid and maternal serum related to neural-tube defects

The vitamin A concentration of amniotic fluid and maternal serum was measured during the second trimester of pregnancy in 106 women, 12 of whom had a baby with a neural-tube defect. In these 12 pregnancies the amniotic fluid vitamin A concentration was significantly higher than in 94 normal pregnancies. There was a highly significant correlation between amniotic fluid vitamin A and both zinc and alpha-fetoprotein (AFP) levels. The maternal serum vitamin A levels were also significantly related to serum zinc levels. Women with a raised serum AFP level, but a normal baby, had significantly higher amniotic fluid vitamin A levels and significantly lower serum vitamin A levels compared with those in women with normal serum AFP levels.     

Influence of maternal nutrition on infant birthweight

OBJECTIVES: The aim of the study was to examine relation between maternal prepregnancy BMI, pregnancy weight gain and infant birthweight. MATERIALS AND METHODS: In 1998 the questionnaire was sent to 227 women who were pregnant in 1993. RESULTS: 56.4% of the women under study responded the questionnaire. We excluded 33 answers because of miscarriage, stillbirths, twin pregnancies and also missing data. In the remaining 95 women 37.9% had low prepregnancy BMI (< 19.8 kg/m2). 83 women gave birth to a child at term. There was a statistically significant difference in mean birthweight of infants born by women of various prepregnancy BMI (BMI < 19.8 kg/m2, 19.8-26 kg/m2, > 26 kg/m2) and also of various pregnancy weight gain (according to IOM recommendations). Underweight women gave birth to infants of lower mean birthweight than women of normal or excessive weight (p<0.05). 10.7% of underweight women gave birth to infants of low birthweight (< 2500 g). None of the women who were not underweight before pregnancy gave birth to a child of low birthweight. Women of low pregnancy weight gain gave birth to infants of lower mean birthweight than women of normal or excessive weight pregnancy weight gain. It seems that lower birth weight of infants could result from lower maternal energy, protein, calcium and iron consumption. CONCLUSIONS: 1) Large proportion (37.8%) of women under study were underweight before pregnancy. 2) Birthweight was related to maternal prepregnancy BMI and pregnancy weight gain. Women who were underweight before pregnancy and those whose weight gain was too low gave birth to smaller infants than women who were not underweight before pregnancy and those who gained more weight during pregnancy.     

Vitamin A concentration in amniotic fluid and maternal serum related to neural-tube defects

Summary. The vitamin A concentration of amniotic fluid and maternal serum was measured during the second trimester of pregnancy in 106 women, 12 of whom had a baby with a neural-tube defect. In these 12 pregnancies the amniotic fluid vitamin A concentration was significantly higher than in 94 normal pregnancies. There was a highly significant correlation between amniotic fluid vitamin A and both zinc and α-fetoprotein (AFP) levels. The maternal serum vitamin A levels were also significantly related to serum zinc levels. Women with a raised serum AFP level, but a normal baby, had significantly higher amniotic fluid vitamin A levels and significantly lower serum vitamin A levels compared with those in women with normal serum AFP levels.     

The blood pressure response to infusions of angiotensin II during normal pregnancy: relation to plasma angiotensin II concentration, serum progesterone level, and mean platelet volume.

OBJECTIVE: This study is a survey of the determinants of refractoriness to the pressor effects of angiotensin II during normal pregnancy. STUDY DESIGN: In 25 normal pregnant women, the effective angiotensin II pressor dose was determined 88 times from the twenty-fifth to the thirty-second week of gestation. Immediately before the angiotensin II infusion, blood samples were collected and measured for plasma angiotensin II concentration, serum progesterone level, platelet count, and mean platelet volume. RESULTS: The effective pressor dose had a significantly positive correlation with plasma angiotensin II concentration and serum progesterone level and a negative correlation with mean platelet volume. CONCLUSION: The pregnancy-associated refractoriness to angiotensin II is physiologically determined, at least in part, by the elevated circulating levels of endogenously produced angiotensin II and by the progesterone produced by the placenta, whereas platelet activation attenuates the relative refractoriness during normal pregnancy.     

Factors affecting fetal weight distribution in women with type I diabetes

Objective To identify factors independently affecting fetal weight in women with type I diabetes.
Design Prospectively recorded data in consecutive women with type I diabetes, between 1975–1992.
Setting Simpson Memorial Maternity Hospital, Edinburgh.
Population Three hundred and two pregnancies with type I diabetes identified before pregnancy, with antenatal care and delivery in the Simpson Memorial Maternity Hospital, a singleton pregnancy, and the same diabetic physician.
Methods Normal ranges for birthweight were established for the total hospital population. All cases and the total population had pregnancy dating by ultrasound. The relation between standardised birth-weight and explanatory variables was investigated using correlation analysis, t tests and χ² tests as appropriate, and subsequently using multiple linear regression.
Results Standardised birthweight in cases, compared with the reference population, showed a unimodal, approximately normal distribution, markedly shifted to the right (mean + 1.26 SD). The most predictive variable was glycated haemoglobin concentration at 27–33 weeks, which explained 6.3% of the birthweight variance, while smoking explained 2.7% and maternal weight 2.0%. There was a trend towards a negative relationship with glycated haemoglobin concentration at 6–12 weeks. Smoking and glycated haemoglobin concentration were strongly intercorrelated.
Conclusions Most of the variance in standardised birthweight remains unexplained, but glycated haemoglobin concentration at 27–33 weeks is the most powerful explanatory variable. Possible reasons why there is not a stronger relationship between markers of maternal glycaemia and birthweight are discussed.     

Maternal and neonatal hair mercury concentrations: the effect of dental amalgam

Objective To evaluate maternal and fetal hair mercury levels in relation to the placement of dental amalgam tooth restorations.
Design Cross sectional study involving women who never had dental amalgam restorations placed, women who had amalgam restorations placed before pregnancy and women who had restorations placed during the index pregnancy.
Setting North of England Maternity Hospital.
Sample Fifty-three healthy women who delivered healthy babies at term.
Methods Maternal and fetal hair was collected in a standardised manner in the first few days following delivery.
Main outcome measures Maternal and neonatal hair mercury concentrations.
Results When compared with women without restorations, there was a significant increase in the maternal hair mercury concentration in women who had dental amalgam placed outside of the index pregnancy and also in women who had dental amalgam placed during the index pregnancy. The fetal hair mercury concentration was significantly higher in babies when mothers had been exposed to dental amalgam either before pregnancy or during pregnancy compared with unexposed babies. There was no difference in the maternal or fetal hair mercury levels in the groups of patients who had dental amalgam placed before or during pregnancy.
Conclusion Maternal and fetal hair mercury levels were significantly higher in women who previously had dental amalgam restorations placed. There was no evidence that placement of dental amalgam restorations in pregnant women who had already similar restorations increased the maternal or fetal hair mercury level.     

Selenium concentrations in serum, hair and tumor tissue from patients with ovarian tumors

Selenium (Se) concentration was determined in 150 samples of serum, 135 samples of hair and 96 samples of ovarian tissue from patients with malignant or benign ovarian tumors and normal subjects. The serum Se level in patients with malignant ovarian tumors was significantly lower than that in patients with benign ovarian tumors and normal subjects. No difference of Se concentrations of hair among different groups was observed. Se level in malignant ovarian tumor tissue was significantly higher than that in benign ovarian tumor tissue and normal ovarian tissue. The low serum Se level in patients with malignant ovarian tumors was probably the result of protective migration of Se from blood to the cancer tissue.     

Glucose, insulin, HGH and IGF-I levels in maternal serum, amniotic fluid and umbilical venous serum: a comparison between late normal pregnancy and pregnancies complicated with diabetes and fetal growth retardation.

Fetal growth and development is dependent upon various growth factors such as glucose, insulin, HGH and IGF-I. These growth factors were measured in maternal serum (MS), amniotic fluid (AF) and umbilical venous serum (UV) in late gestation in normal, insulin dependent diabetic pregnancies (IDDM) and in pregnancies complicated with intrauterine growth retardation (IUGR). The UV glucose values of 1.9 +/- 0.9 mmol/L and UV insulin values of 8.0 +/- 1.8 mU/L were the lowest in IUGR pregnancies, and the highest were in UV serum from IDDM pregnancies, and the difference was statistically significant for this two groups. IGF-I values in UV indicated that there was significant difference in IGF-I concentrations when both, IUGR and IDDM groups were compared to the controls. There was a parallel shift in AF and MS glucose and insulin concentration as birthweight increased. The highest IGF-I values of 7.2 +/- 9.6 mumol/L in AF and MS were found in pregnancies with infants whose birthweight was 3500 grams and greater. Infants from pregnancies complicated with IUGR and IGF-I low values of 0.6 +/- 1.2 mumol/L in AF. HGH concentrations of 15.6 +/- 9.4 micrograms/L in UV were observed in IDDM pregnancies and significantly lower than the values in IUGR and normal pregnancies. HGH umbilical venous values decreased with duration of pregnancy and with increase in fetal size. The high HGH concentrations in the fetus and its dramatic fall after parturition, and the obtained negative correlation between HGH and IGF-I in umbilical vein may exhibit the maturation of the hypothalamic-growth hormone-IGF-I axis. It seems likely that changes in maternal serum, umbilical venous and amniotic fluid insulin-like growth factor I influence birthweight in normal and IUGR infants and in those of diabetic mothers.     

Cocaine use in pregnant women in a large public hospital

Cocaine has been reported to be associated with several pregnancy complications such as abruptio placentae, an increase in the incidence of low birthweight infants, and congenital malformations in the newborn. With the increasing frequency of cocaine abuse of women of childbearing age in the United States, clinicians can reasonably be expected to encounter increasing numbers of pregnant women who use cocaine. The exact prevalence of cocaine use during pregnancy is not known. In the present series of 102 pregnant women, the prevalence of cocaine use was 9.8%, with a 95% confidence interval of 3.9 to 15.7%. There was one mother who had an abruptio placentae and there was one infant who had a congenital malformation among the ten women with a history of cocaine use during pregnancy. The mean birthweight was 3180 +/- 380 gm for infants born to mothers who used cocaine compared with 3250 +/- 422 gm (p = NS) for the infants born to mothers who did not use cocaine. A significant number of pregnant women in our population use cocaine during pregnancy.     

Hair zinc and dietary zinc intake during pregnancy and puerperium.

A longitudinal study of hair zinc concentration was carried out in 36 pregnant women at 12 and 36 weeks of gestation and 40 days postpartum. A progressive decrease in hair zinc concentration was noted through pregnancy; the decline between 12 and 36 weeks of gestation was statistically significant (P < 0.005) remaining without significant changes in the postpartum. Nutrient intakes were calculated from 3-day weighed food records at the same periods and at 20 weeks of gestation. Zinc, energy and protein intakes decreased during pregnancy. Mean zinc intake at 20 and 36 weeks of gestation was about 66% of the recommended dietary allowance (RDA) (9.8 and 10 mg, respectively) and about 52% of the RDA in the postpartum (9.8 mg). Although hair zinc levels do decline in pregnancy and zinc intake was lower than RDA, the study revealed that zinc nutriture was adequate for normal growth and development of fetus.     

正常新生儿黄疸与围产因素的调查

目的 探讨围产期各种非病理因素对正常新生儿血清胆红素水平的影响。方法 对801例正常新生儿生后24h内开始监测血清胆红素水平,并记录围产期可能与新生儿黄疸有关的各种因素。被检测的新生儿按血清胆红素水平分为高胆红素组和随机对照组,比较两组间各种围产因素对生后5d内血清胆红素的影响。结果 母乳喂养、妊娠高血压综合征（简称妊高征）、出生体重下降和生后红细胞压积增高对正常新生儿早期血清胆红素水平有显著影响（P＜0．001）。母亲年龄、分娩方式、第二产时间、催产素使用时间、出生体重等两组比较差异无显著性。结论 母乳喂养,母亲妊高征、出生体重下降和生后红细胞压积增高,是正常新生儿出生后胆红素水平上升时期影响血清胆红素水平的重要潜在因素。