Is fetal growth affected by cord entanglement?

Cord entanglement is a common occurrence during delivery. We examined the association of cord complications observed at delivery and birth weight. A retrospective survey of 12,241 births was performed, supplemented with a prospective study of an additional 456 deliveries. No adverse association was found in the retrospective data between cord coiled twice or more around the newborns' neck (8.3% of cases) and birth weight. Moreover, the incidence of cord around neck was significantly lower (p < 0.0006) in infants weighing less than 2000 gm at birth. A multiple regression analysis of the prospective data did not reveal any significant influence of cord complications on birth weight. We conclude that cord entanglement was not found to be a major cause of intrauterine disadvantage in pregnancies with a viable infant at term, as reflected by birth weight.

Quality assurance of immunodiagnostic tests in Australia: II. Five year review

A Royal College of Pathologists of Australasia (RCPA) sponsored quality assurance program in clinical immunopathology has, over a 5 year period, demonstrated: enrollment by the majority of immunodiagnostic laboratories in Australia and New Zealand; improved compliance with the program over time eg. increasing numbers returning their replies by the due date; different commercial techniques give different mean values for the same analyte. This appears to be due to the use of different reference materials in each technique; greater utilization of nephelometric techniques in quantitating immunoglobulins, C3, C4, CRP and rheumatoid factor resulting in better accuracy and precision; improvement in the frequency of detecting anticentromere antibody as most laboratories use proliferating cell lines as substrate for anti-nuclear antibody (ANA) detection; improved interlaboratory concordance of ANA titers by the provision of reference standards; improved detection of antibodies to extractable nuclear antigens (counter-immunoelectrophoresis being more sensitive than immunodiffusion); the Farr and radioimmunoassay technique for the demonstration of antibodies to native DNA have greater sensitivity than the Crithidia assay; improvement in accuracy and precision of cell phenotype analysis with the use of whole blood and cell flow cytometric techniques; development of techniques to rank each laboratories performance on a rating scale based on the average number of tests outliers (from the consensus mean) per mailing. However deficiencies in performance are still being observed. These relate to both technical factors causing systematic errors and in the provision of interpretive comments on the laboratory result. Continuing education and participation in quality assurance programs are emphasized to monitor and improve performance over time.

Are children born small for gestational age at increased risk of short stature?

OBJECTIVE

To assess the height outcome of newborns born small for gestational age.

DESIGN

A historical prospective study.

SETTING

A cohort of 1758 newborns born at a single university hospital maternity ward and subsequently examined at the military draft medical board at age 17 years.

PARTICIPANTS

Newborns whose weight at birth was below the third percentile were defined as small for gestational age. Their body measurements at age 17 years were compared with those of their peers who were appropriate for gestational age.

MEASUREMENTS/MAIN RESULTS

The adjusted mean +/- SEM height for boys born small for gestational age vs peers born appropriate for gestational age was 169.9 +/- 1.5 vs 175.4 +/- 0.8 cm (P < .0001); and for girls, 159.4 +/- 1.3 vs 163.1 +/- 0.8 cm (P < .0005). In addition, the risk for height attainment below the 10th percentile was significantly increased for newborns born small for gestational age. The adjusted odds ratio was 4.13 for boys (95% confidence interval, 1.66 to 10.25; P < .0006) and 3.32 for girls (95% confidence interval, 1.38 to 8.05; P < .0005).

CONCLUSION

Infants born small for gestational age may be at increased risk for short stature in late adolescence.

A 2-year prospective study of very low birthweight infants

A prospective 2-year follow-up study was carried out on 68 of the 69 surviving very low birthweight (VLBW) infants (< 1,501 g) born in Bikur Holim Hospital in the years 1985-87. The aims were a) to determine the incidence of major disability, and b) to compare the 2-year outcome of VLBW infants without major disability with that of a control group of full-term small-for-gestational-age infants, using the Mental Development Index (MDI) of the Bayley Scales. Mean birthweight of the VLBW infants was 1,234 +/- 216 g and mean gestational age was 30.7 +/- 2.4 weeks. Their neonatal mortality during the study period was 29.8%. Major disability was diagnosed in 11/68 infants (16%). At age 2 years there was no significant difference between the mean MDI of the VLBW infants without major disability (97.7 +/- 19.5) and that of the controls (99.7 +/- 17.0). These data, representing the outcome of VLBW infants from a community-based hospital with neonatal intensive care facilities, are comparable in incidence of major disability with data of large tertiary centers. Cognitive ability of VLBW infants without major disability at age 2 years was equivalent to that of their full-term peers.

Is cord blood erythropoietin a marker of intrapartum hypoxia?

A sensitive assay was used to compare the biological activity of cord serum erythropoietin in two groups of infants born with or without labor-induced hypoxia. The mean cord serum erythropoietin activity in 161 infants delivered after vaginal labor was 116 +/- 36 mU/mL, and was indistinguishable from that observed in 23 infants delivered by preplanned, elective cesarean section, 114 +/- 12 mU/mL (P = .75). The bioassay measured effective erythropoietin activity, including the contribution of potentiators in serum. These results indicate that duration and intensity of labor are insufficient to cause a significant increase in effective erythropoietin activity.

Survival of children with chronic myeloid leukemia

We analyzed survival in 203 children with Philadelphia-chromosome-positive chronic myeloid leukemia (CML). Median survival was 4.1 years; average annual risk of death was 20%. These survival data are similar to those reported in adults. Because there is no possibility of long-term disease-free survival in children with CML with conventional therapies, the findings of this study suggest that bone marrow transplantation should be considered in these patients.

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System functionality and physicochemical model of fentanyl transdermal system

Fentanyl is an opioid traditionally administered by infusion or injection and more recently in a rate-controlled transdermal dosage form. This system is a four-layer laminate on a protective liner. A backing layer seals and protects the drug reservoir, the source for continuous delivery of fentanyl. A membrane controls the release rate of fentanyl from the system. An adhesive layer attaches the system to skin and releases an initial loading dose of fentanyl. The rate of fentanyl delivery through skin is determined by the system and the skin at the application site. The release rate from the system is approximated by Fick's first law of diffusion and is controlled by the rate-controlling membrane. A complete simulation model that combines both in vitro release data and the pharmacokinetic model has been developed and used to show the influence of various physiologic and system variables on serum fentanyl concentrations.

Birth weight and intellectual performance in late adolescence

The impact of birth weight on cognitive performance in late adolescence was assessed in a study of 20,567 male infants born in Jerusalem between 1964-1970. The 17-year follow-up was performed by matching computerized data base records. Stepwise multiple regression analysis was used to estimate the effect of birth weight on intelligence test scores, adjusting for the influence of ethnic origin, maternal and paternal education, social class (determined by area of residence), maternal age, and birth order. These confounders explained 22% of the variance in intelligence test scores. The adjusted differences in intelligence test scores were significantly lower for groups with birth weight less than 2000 g (-6.5 points), 2000-2499 g (-3.6 points), and 2500-2999 g (-1.6 points) compared with the group weighing 3000-3499 g. Most low birth weight infants achieved intellectual performance within the normal range. However, despite this reassuring finding, low weight at birth in male subjects was found to have a statistically significant independent association with inferior intelligence test achievements in late adolescence.

The incubator as a chemical warfare protective device in neonatal intensive care units

During the Persian Gulf war chemical warfare (CW) protective devices were distributed to the entire population of Israel. Neonates were to be placed in a protective infant carrier (PIC) or an improved PIC ("active PIC") to which filtered air was actively introduced by a blower. The specific needs of low birthweight babies hospitalized in intensive care units and treated in incubators were not adequately addressed. Transfer to a PIC meant disconnecting the infants from life-supporting systems and monitoring devices and exposing them to changes in ambient temperature. To overcome this difficulty the original incubator was used as a CW protective device. Its ports were sealed and low-grade positive pressure was created. This avoided transfer of the neonates from their controlled environment, reduced physiological stress, and improved medical supervision.

The effects of high parity and socioeconomic status on obstetric and neonatal outcome

We studied the interaction of social status and high parity in 15,102 consecutive births in one inner-city hospital, of which 1874 (12.4%) occurred in mothers who had given birth to seven or more infants (Grand multiparae). Group 1 consisted of 1258 grand multiparae from a socioeconomically stable and homogeneous ultra-orthodox Jewish community in Jerusalem, and group 2, included all other grand multiparae of relatively greater age and lower socioeconomic status. A significantly higher rate of small for gestational age, low birth weight and preterm infants was found in group 2 compared with group 1. The results suggest that grand multiparity is not of itself a risk factor, but reflects the confounding effect of environmental conditions.

Pre-eclampsia and offspring's blood pressure, cognitive ability and physical development at 17-years-of-age

OBJECTIVE

To investigate the influence of maternal pre-eclampsia on the blood pressure, physique and intelligence of the offspring at the age of 17 years.

DESIGN

Data obtained at the age of 17 during assessment for drafting to the Israel Defence Forces and from the records of the mothers' pregnancies from the Jerusalem Perinatal Study.

SUBJECTS

Study subjects were 145 girls and 283 boys whose mothers had had pre-eclampsia and controls were 12,701 girls and 20,416 boys whose mothers did not have pre-eclampsia.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure, weight, height and intelligence scores at the age of 17 were related to birthweight and the occurrence of pre-eclampsia during their mothers' pregnancies.

RESULTS

Systolic blood pressure was greater than 140 mmHg in 6.9 and 11.0% of the study girls and boys, compared with 2.9 and 9.9% of the control girls and boys. The study boys but not the girls had a higher mean body mass index than the controls (P less than 0.001). There were no differences in the intelligence scores. Using multiple logistic regression to allow for the confounding effects of body mass index, weight and birthweight, the odds ratio for the risk of a systolic pressure greater than 140 mmHg was 2.30 (95% CI 1.80-4.46) for the study girls but was not significantly increased for the study boys.

CONCLUSION

Maternal pre-eclampsia does not impair growth and cognitive performance in the children who reach late adolescence but may be associated with hypertension.

Neonatal hyperbilirubinemia and physical and cognitive performance at 17 years of age

To estimate the effect of neonatal hyperbilirubinemia on long-term cognitive ability in full-term newborns with a negative Coombs test, we performed a 17-year historical prospective study of 1948 subjects. Intelligence tests and medical examinations performed at the military draft board were stratified according to serum bilirubin concentration. A logistic regression analysis was used to adjust for the confounding effects of gestational age, birth weight, Apgar score, ethnic origin, socioeconomic class, paternal education, birth order, and the administration of phototherapy and exchange transfusion. No direct linear association was shown between neonatal bilirubin levels and intelligence test scores or school achievement at 17 years of age. However, the risk for low intelligence test scores (IQ score less than 85) was found to be significantly higher (P = .014) among full-term male subjects with serum bilirubin levels above 342 mumol/L (20 mg/dL) (odds ratio, 2.96; 95% confidence interval, 1.29-6.79). This association was not observed among female subjects. We conclude that severe neonatal hyperbilirubinemia, among full-term male newborns with a negative Coombs test, could be associated with lower IQ scores at 17 years of age.

A longitudinal study of birth weight and being overweight in late adolescence

A total of 33,413 infants born in Jerusalem between 1964 and 1971 were followed up at 17 years of age by matching computerized database files. A logistic regression model was used to estimate the odds ratios for being overweight at 17 years of age for 500-g birth weight categories from less than 2500 g to 4500 g or greater. Information on the ethnic origin, paternal education, birth order, maternal age, and area of residence at birth was available, and these factors were used as possible confounders. The adjusted odds ratios for being overweight (greater than or equal to 90th percentile; body mass index greater than 24.6 kg/m2) and severely overweight (greater than or equal to 97th percentile; body mass index greater than 27.8 kg/m2) at 17 years of age was elevated for the three birth weight categories above the normal reference category of 3000 to 3499 g, with an estimate of 2.16 and 2.30 for male subjects with a birth weight greater than 4500 g and 2.95 and 4.39 for female subjects. The data suggest that higher birth weights correlate strongly with being overweight in late adolescence independently of other factors considered. However, the predictive power of this association is poor.

Long-term effects of vacuum and forceps deliveries

The long-term effects of vacuum and forceps deliveries are largely unknown. We determined the long-term outcome of instrumental deliveries in 52,282 infants born in Jerusalem between 1964 and 1972. For each individual, events at birth were related to results of an intelligence test and medical examination done at 17 years of age by the Israeli Defence Forces draft board. 1747 individuals were delivered by vacuum, 937 by forceps, 47,500 by spontaneous delivery, and 2098 by caesarean section. Crude data showed that mean intelligence scores at 17 were significantly higher (p less than 0.0001) in the vacuum and forceps deliveries groups than in the spontaneous-delivery group; however, after adjustment for confounding factors by stepwise multiple regression, these differences were no longer seen. Although the forceps-delivery group had functional impairment of feet, vision, and retina compared with the spontaneous-delivery group, and the vacuum-extraction group had impairment of the legs, differences were small. Our findings suggest that infants delivered by vacuum or forceps are not at risk of physical and cognitive impairment at 17 years of age.

Apgar scores and cognitive performance at 17 years of age

The association between low Apgar scores (7 or less) at 1 and 5 minutes and cognitive performance in late adolescence was assessed. A 17-year follow-up of 1942 subjects was performed. The intelligence test scores at 17 years of age were matched with 1- and 5-minutes Apgar scores. A multiple linear regression analysis was used to control for the possible confounding effect of perinatal factors (birth weight, gestational age, serum bilirubin levels, birth order) and demographic characteristics (ethnic origin, paternal education, social class). The sensitivity and positive predictive value of a low 1-minute Apgar score were 8 and 8% and of a low 5-minute Apgar score 1.5 and 5%, respectively. Low Apgar scores are poorly correlated with long-term intellectual outcome.

Birth weight, current body weight, and blood pressure in late adolescence

Objective--To study the effect of birth weight and body weight on blood pressure in late adolescence. Design--Analysis of data on weight, height, and blood pressure at age 17 of subjects from the Jerusalem perinatal study, according to their birth weight. Data for men and women were analysed separately. Setting--Jerusalem, Israel. Subjects--32,580 subjects (19,734 men and 12,846 women) born in the three major hospitals in Jerusalem during 1964-71 and subsequently drafted in to the army. MAIN OUTCOME MEASURES--Correlations between birth weight and blood pressure at age 17 and weight and height at age 17 and blood pressure. Results--Diastolic and systolic blood pressures were associated with birth weight in both young men and young women, but the correlation coefficients were low. A high body weight at age 17 (greater than 66 kg for women, greater than 75 kg for men) rather than a low birth weight (less than 2500 g) was linked with higher systolic and diastolic blood pressures in both men and women (p less than 0.01). Conclusions--Intrauterine environment, as reflected by birth weight, has little effect on blood pressure in young men and women. Modification of factors which lead to excess weight during adolescence may have a major role in preventing hypertension in adults.

Is low birth weight a risk factor for asthma during adolescence?

The effect of low birth weight on the incidence of asthma by 17 years of age was investigated by studying medical draft examination records of 20,312 male subjects born in Jerusalem between January 1967 and December 1971. Additional information on birth weight and other demographic factors was abstracted from the Jerusalem Perinatal Study computerised database. A stepwise multiple logistic regression was used to estimate the odds ratios for developing asthma by 17 years of age in 500 g birthweight categories from less than 2000 g to 4500 g. The odds ratios were adjusted for the confounding effects of ethnic origin, social class (determined by area of residence), paternal education, maternal age, and birth order. The group with low birth weights (less than 2500 g, n = 1004) had a significantly increased risk of developing asthma by 17 years of age, with an adjusted odds ratio of 1.44 (95% confidence interval (CI) 0.79 to 2.66) for birthweight group less than 2000 g and 1.49 (95% CI 1.05 to 2.12) for birthweight group 2000-2499 g compared with the reference group of 3000-3499 g. We conclude that infants with birth weights of less than 2500 g may have a higher risk of asthma during childhood and adolescence than infants who were heavier at birth.

Quality assurance of immunodiagnostic tests in Australasia

A Royal College of Pathologists of Australasia (RCPA) sponsored Quality Assurance Program (QAP) in Clinical Immunology, involving 128 laboratories over a 1 yr period, revealed the following: successful participation in the program by 16 overseas laboratories (distant from Australia); only 30% of laboratories succeeded in returning their results by the scheduled date on every occasion; quantitation of urinary total protein and Bence Jones protein was poor and varied over a log scale; immunofixation was more successful in characterizing urinary paraprotein than immunoelectrophoresis; densitometry of protein electrophoresis appeared the method of choice in quantitating serum paraproteins accurately; nephelometric techniques gave better concordance between laboratories than turbidometric, radial immunodiffusion or agglutination techniques; poor concordance between laboratories in detecting weakly positive antinuclear antibodies (ANA); some laboratories had difficulties in identifying ANA patterns (only 60% of laboratories correctly identified the anticentromere pattern); few laboratories could correctly identify antibodies to extractable nuclear antigens (ENA); flow cytometry gave a smaller dispersion of lymphocyte subpopulation percentages than microscopy. A method was established to rank laboratory performance of selected tests over the 1 yr period. Such a comparative ranking scheme may alert laboratories in identifying specific or generalized deficiencies in performance.