Incidence and geographical distribution of sudden infant death syndrome in relation to content of nitrate in drinking water and groundwater levels.

BACKGROUND: Previous studies indicate that the enteral bacterial urease is inhibited in victims of sudden infant death syndrome (SIDS). One possible inhibitor of this bacterial activity is nitrate. If ambient pollution by nitrate is involved in the etiology of SIDS only a fraction of the nitrate concentration not infrequently found in drinking water would be enough for this inhibition. METHODS: Occurrence of SIDS (n = 636) in Sweden during the period 1990 through 1996 were analysed regarding geographical and seasonal distribution in relation to the nitrate concentration in drinking water and changes in the groundwater level. RESULTS: Both the birth rate and the incidence of SIDS decreased during the study period. One quarter of the municipalities constituting 11% of the population had no cases, the maximum incidence being 6.5 per 1000 live births. Seasonality: The northernmost parts of the country had its highest incidence when the rest of the country had its lowest incidence, and the occurrence of individual deaths was associated with the recharge of groundwater which increases its nitrate content. The local incidence of SIDS was correlated (rs = 0.34-0.87) to maximally recorded concentrations of nitrate in drinking water. CONCLUSIONS: The seasonal distribution of SIDS was widely different from the south to the north of the country and seems to be associated with differences in the groundwater level changes subsequent to precipitation, frost penetration, and melting of snow. Use of drinking water with high peak concentrations or great variations in nitrate concentration was correlated to the incidence of SIDS.

The effect of smoking on glucose homeostasis and fetal growth in pregnant women.

OBJECTIVE: To examine the relationship between maternal blood glucose levels, cigarette smoking in pregnancy and fetal growth. DESIGN: A prospective study of healthy parous women from early pregnancy and their infants. SETTING: Three Scandinavian university hospitals covering all deliveries from well defined geographical areas. SUBJECTS: Study groups of non-smoking (150), light smoking (131) and heavily smoking mothers (218), para 1 and 2 and with > 37 weeks of gestational length. MAIN OUTCOME MEASURES: Oral glucose tolerance test performed in pregnancy week 37, glycated hemoglobin measured the 3rd day post partum and neonatal anthropometric parameters including skinfold measurements. RESULTS: Among heavily smoking mothers 12.4% displayed a 2-hour glucose value in the range of gestational diabetes (> 8.5 mmol/l) compared to 9.2% among light smokers and 6.0% among nonsmokers (p < 0.05). Heavily smoking mothers also had significantly (p < 0.05) higher glycated hemoglobin compared to nonsmokers, 5.01 v.s. 4.86. These changes in glucose parameters in smokers were not associated with higher birthweights. CONCLUSIONS: Smoking in pregnancy affects parameters of glucose homeostasis in the direction of gestational diabetes. The retarding effect of smoking on fetal growth abolished any expected growth stimulation from the higher blood glucose levels seen in the smokers.

Maternal smoking affects fetal growth more in the male fetus.

This study investigated the association between maternal cigarette smoking and fetal growth, evaluated by longitudinal ultrasound examinations and by neonatal anthropometric measurements. The investigation was carried out in a healthy population of affluent Scandinavian women, parity 1 and 2, who were selected consecutively and prospectively, and with term, normal pregnancies. Three hundred and six non-smoking, 242 light-smoking and 308 heavy-smoking mothers and their newborns were examined. Ultrasound measurements were performed in pregnancy weeks 17, 25, 33 and 37. Biparietal diameter (BPD), mean abdominal diameter (MAD) and femur length were recorded. The negative effect on fetal growth from maternal smoking was found to affect the male fetus proportionally more than the female. Boys born to heavy-smoking mothers had a weight reduction of 8.2% and a lower fat accretion (as measured by subscapular skinfold) of 12%, whereas girls had a weight and fat reduction of 4.8% and 2% respectively. In boys (but not girls) born to smokers, head circumference was significantly smaller, also reflected by significantly smaller mean BPD measurements recorded from pregnancy week 18 onwards. The MAD measurements became successively more negatively affected in the second half of pregnancy in both males and females. A greater intrauterine growth velocity and a different hormonal milieu are suggested as possible explanations of the greater male susceptibility.

Fetal growth impairment from smoking--is it influenced by maternal anthropometry?

BACKGROUND: It has been suggested that the effect of maternal smoking on fetal growth is partly mediated through nutritional factors. OBJECTIVE: To assess the effects of maternal smoking on birthweight in term pregnancies among mothers with different anthropometric stature. DESIGN: A prospective study from early pregnancy of healthy parous women and their infants. SETTING: Three Scandinavian university hospitals covering all deliveries from well defined geographic areas. SUBJECTS: Smoking (774) and non-smoking (325) mothers, para 1 and 2 and with > 36 weeks gestational length. MAIN OUTCOME MEASURE: Birthweight. RESULTS: Maternal age, smoking, pre-pregnancy weight, height, body mass index and pregnancy weight gain all independently influenced birthweight. Smoking mothers had significantly lower pre-pregnancy weight and lower body mass index compared to nonsmoking mothers. The negative influence of smoking on birthweight appeared to be uniformly distributed throughout all the different maternal height and weight groups. CONCLUSIONS: Birthweight was negatively related to amount cigarettes smoked per day, and no protective effect could be demonstrated from higher maternal weight, pregnancy weight gain or body mass index.

Hemoconcentration in smoking mothers is associated with impaired fetal growth.

OBJECTIVE: To examine the effect of maternal smoking on the relationship between maternal hemoglobin levels and pregnancy outcome. DESIGN: A prospective study of healthy parous women from early pregnancy and of their infants. SETTING: Three Scandinavian university hospitals covering all deliveries from well defined geographical areas. SUBJECTS: Smoking (669) and non-smoking (368) mothers, para 1 and 2 and with > or = 37 weeks of gestational length. MAIN OUTCOME MEASURES: Birth weight and placental weight. Ponderal Index and Placental Index as measures of possible discordant fetal and placental growth. RESULTS: In non-smoking mothers the hemoglobin levels in the three trimesters had no relation to birth weight. In smoking mothers a significantly lower birth weight was seen with a high hemoglobin level in the third trimester, but hemoglobin levels in early or mid-pregnancy had no association to birth weight. Smoking mothers also had a significantly greater fall in hemoglobin concentration from first to second and third trimester as compared to non-smokers although ferritin levels were similar in smokers and non-smokers, implying similar iron stores. The ratio of placental weight to the weight of the newborn was significantly higher in smokers, but no association was found to different hemoglobin levels. CONCLUSIONS: Fetal growth impairment associated with maternal smoking is even more pronounced in smoking mothers with high hemoglobin levels in late pregnancy. Smoking mothers were also found to have disproportional fetal/placental growth with relatively high placental weights. In non-smoking mothers hemoglobin levels had no relation to birthweight.

Maternal smoking and body composition of the newborn.

The influence on neonatal anthropometry of maternal cigarette smoking in pregnancy was investigated in 933 parous women. Anthropometric growth parameters including skinfold measurements were studied in the newborns. After adjustment for maternal age, pre-pregnancy weight, height and pregnancy weight gain, smoking had a clear dose-dependent negative effect on all anthropometric characteristics in the infant. In contrast to the results obtained in other investigations, the reduced birth weight of the infants of smoking mothers was not found to be primarily due to a reduction in lean body mass; nor was fat deposition found to be reduced. Fetal anthropometry was also negatively affected in infants born to mothers who stopped smoking during pregnancy.

Survival compared to the general population and changes in health status among intensive care patients.

In order to evaluate intensive care, all adult patients (980) admitted to a multidisciplinary intensive care unit (ICU) during 1 year were followed prospectively. The ICU mortality was 9.6%. One year after admission the survival was 73.6%. By that time the surviving patients had a further survival that was 96% of that of the general population. Of the 1-year survivors, 22.3% had deteriorated in health status compared to 3 months before the stay in ICU. In the admission groups with high mortality the survivors had a more pronounced deterioration in health status. Increased age and length of stay in the ICU were associated with higher mortality but not with changes in health status. We conclude that the outcome of intensive care can be evaluated by studying only the survival, since the survival rate is correlated to changes in health status among survivors in the different admission groups. One year after admission most of the surviving patients had regained their previous health status and their further survival was almost the same as that of the general population.

Survival of intensive care patients. I: Prognostic factors from the patient's medical history.

All adult patients (978) admitted in 1983 to a multidisciplinary intensive care unit (ICU) were studied prospectively. 9.6% died in the unit. The cumulative mortality was 26.5% 1 year after admission. Of the patients who were 65 years and older, 43.1% had died after 1 year compared to 10.6% in the youngest age group (15-44 years). Using multiple logistic regression analyses, prognostic factors for mortality were identified. All the factors were known at the time of admission. Risk factors for death in the ICU included age, admission for disorders in several organ systems, cardiopulmonary arrest and acute respiratory disorder. In addition to age and acute conditions at the time of admission, cumulative mortality after 1 year was also influenced by chronic conditions such as diabetes mellitus, chronic heart failure and cancer. These data document the importance of taking age and chronic illness into account when making a prognosis for intensive care patients.

Survival of intensive care patients. II: Outcome prediction 1 hour after admission.

978 patients from a multidisciplinary intensive care unit (ICU) were followed prospectively to evaluate outcome. At 1 year after admission the cumulative mortality was 26.5%. Age, medical history and different condition variables 1 h after admission were included in logistic regression models in order to identify risk factors for death in the ICU and afterwards. By combining these predictive factors, it was possible to describe clinically interesting patient groups with a low and a high risk, respectively, of dying. 330 patients younger than 65 years, without any history of cancer and without any condition risk factors 1 h after admission, had a cumulative mortality of 6% at 1 year as compared to another group of patients with a 1-year mortality of 63%. In a small group of patients who had all the identified risk factors, the mortality rate at 1 year was 100%. It was also possible to identify a low-risk group of 251 patients (26% of total) who had a risk of death in the ICU of less than 0.5% as compared to 9.6% for the average patient.

Postoperative complications after blood replacement with or without plasma. A trial in elective surgery.

A prospective, controlled and randomized study of 275 patients undergoing major surgery was performed to investigate if postoperative complications were influenced by restrictive use of plasma to replace operative blood loss. All patients were given 6% dextran (Macrodex) for thromboprophylaxis and haemodilution. The "Dextran Group" received equal amounts of 6% dextran and electrolyte solution as substitution for plasma loss. The need for red-cell transfusion (60% suspension in saline-adenine-glucose-mannitol storage medium) averaged 5.8 units in this group and 5.2 in the "Plasma Group". The respective mean totals of infused plasma and dextran were 400 ml and 1,383 ml in the Dextran Group, compared with 1,099 and 619 ml in the Plasma Group. The mean total electrolyte infusion in the first postoperative week was c. 7,500 ml in both groups. Serum albumin decreased considerably in both groups, but significantly more in the Dextran Group. The incidence and pattern of postoperative complications were similar in both groups. When blood loss is up to 50-60% of the total volume, Macrodex can be used in preference to plasma, unless administration of plasma protein is specifically indicated.

Quality of life among long-term survivors of intensive care.

Quality of life was examined in 717 individuals 1 yr after their admission to a multidisciplinary ICU. Of these, 87% were able to live at home 6 months after their admission. Of patients 65 yr and older, 90% had been living independently before admission compared to 80% 1 yr afterward. Of those younger than 65 yr, most of the 65% who had been working before admission could return to work. The length of hospitalization during the first year after admission varied greatly; 10% of the patients stayed more than 145 days. The patients who needed mechanical ventilation or who stayed 1 wk or more in the ICU tended to have worse outcomes than others. These data indicate that there is no great deterioration in quality of life among long-term survivors of intensive care.