Comparison of skin-to-skin contact with standard contact in low-birth-weight infants who are breast-fed

OBJECTIVE

To evaluate the effects of maternal-infant skin-to-skin contact (SSC) vs standard contact (SC) on low-birth-weight infants' physiological profile, maternal milk production, and duration of breast-feeding.

DESIGN

Prospective, randomized, interventional study with cohort followed up for 6 months after discharge from the hospital.

SETTING

Special care nursery with follow-up telephone calls after discharge from the hospital.

PATIENTS

Fifty infants, with birth weights less than 1500 g and whose mothers planned to breast-feed, randomized to 2 groups: SSC (experimental) and SC (control).

INTERVENTION

In the SSC group, infants were clothed in diaper and held upright between mothers' breasts; both mother and infant were covered with a blanket. In the SC group, infants were clothed, wrapped in blankets, and held cradled in mother's arms.

MAIN OUTCOME MEASURES

Infant physiological data, ie, oxygen saturation, heart rate, respiratory rate, and axillary temperature; maternal milk production; and duration of breast-feeding.

RESULTS

Oxygen saturation was higher during SSC than during SC (P < .001); 11% of the oxygen saturation recordings during SSC vs 24% during SC indicated the values less than 90% (P < .001). A more stable milk production was noted in the SSC group. No differences were noted in infant temperature, heart rate, or respiratory rate. Ninety percent of mothers in the SSC group vs 61% in the SC group continued breast-feeding for the duration of the infants' hospitalization (P < .05), and 50% in the SSC group vs 11% in the SC continued breast-feeding through 1 month after discharge (P < .01).

CONCLUSIONS

During SSC with their mothers, low-birth-weight infants maintain a higher oxygen saturation and are less likely to have desaturation to less than 90% oxygen than are infants exposed to SC. Mothers in the SSC group are more likely to continue breast-feeding until 1 month after discharge.

Attitudes about sibling visitation in the neonatal intensive care unit

OBJECTIVE

To survey the attitudes and recommendations of staff members before and after the implementation of sibling visitation in a neonatal intensive care unit.

DESIGN

Staff survey conducted before (1992) and after (1993) the implementation of sibling visitation.

SETTING

A perinatal tertiary care center.

PARTICIPANTS

Staff members including physicians, nurses, respiratory therapists, social workers, and unit clerks (n = 139 in 1992; n = 120 in 1993).

MEASUREMENTS AND MAIN RESULTS

A 7-point Likert scale survey (1 = strongly disagree: 7 = strongly agree) was designed for the study. In both 1992 and 1993, the staff most strongly agreed that visitation requires special supervision, should have designated times, increases sibling knowledge, enhances sibling attachment to the baby, and increases family satisfaction. Wilcoxon rank sum tests comparing the staff across the 2 years indicated substantial attitudinal changes in favor of sibling visitation, including less perceived interference with nursing care and nursery routines (P < .01) and less concern about the infants' risk of respiratory infection and exposure to chickenpox (P < .05). There was greater attitudinal agreement between disciplines in 1993 than in 1992, suggesting better staff consensus about sibling visitation following its implementation. The recommended minimum age for visitation was 4.67 years and 4.05 years in 1992 and 1993, respectively. Brief visits of 10 to 15 minutes' duration were consistently recommended. Staff rated the sibling visitation program as successful (median = 6) on a scale ranging from 1 (very poor) to 7 (very successful).

CONCLUSIONS

Staff members have concerns about sibling visitation that include increased risk of infection, organization, and supervision. A sibling visitation program that addresses these concerns can be successfully implemented and supported by staff, thereby fostering family-centered care in the neonatal intensive care unit.

Neurodevelopmental outcome at 36 months' corrected age of preterm infants in the Multicenter Indomethacin Intraventricular Hemorrhage Prevention Trial

OBJECTIVES

Low-dose indomethacin has been shown to prevent intraventricular hemorrhage (IVH) in very low birth weight neonates, and long-term neurodevelopmental follow-up data are needed to validate this intervention. We hypothesized that the early administration of low-dose indomethacin would not be associated with adverse cognitive outcome at 36 months' corrected age (CA).

METHODS

We enrolled 431 neonates of 600 to 1250 g birth weight with no IVH at 6 to 12 hours in a randomized, prospective trial to determine whether low-dose indomethacin would prevent IVH. A priori, neurodevelopmental follow-up examinations, including the Stanford-Binet Intelligence Scale and Peabody Picture Vocabulary Test-Revised, and standard neurologic examinations were planned at 36 months' CA.

RESULTS

Three hundred eighty-four of the 431 infants survived (192 [92%] of 209 infants receiving indomethacin versus 192 [86%] of 222 infants receiving saline), and 343 (89%) children were examined at 36 months' CA. Thirteen (8%) of the 166 infants who received indomethacin and 14 (8%) of 167 infants receiving the placebo were found to have cerebral palsy. There were no differences in the incidence of deafness or blindness between the two groups. For the 248 English-monolingual children for whom IQ data follow, the mean gestational age was significantly younger for the infants who received indomethacin than for those who received the placebo. None of the 115 infants who received indomethacin was found to have ventriculomegaly on cranial ultrasound at term, compared with 5 of 110 infants who received the placebo. The mean +/- SD Stanford-Binet IQ score for the 126 English-monolingual children who had received indomethacin was 89.6 +/- 18.92, compared with 85.0 +/- 20.79 for the 122 English-monolingual children who had received the placebo. Although maternal education was strongly correlated with Stanford-Binet IQ at 36 months' CA, there was no difference in educational levels between mothers of the infants receiving indomethacin and the placebo.

CONCLUSIONS

Indomethacin administered at 6 to 12 hours as prophylaxis against IVH in very low birth weight infants does not result in adverse cognitive or motor outcomes at 36 months' CA.

Behavioral intervention and post-natal growth in full-term intrauterine growth retarded (IUGR) infants

The purpose of this study was twofold: (1) to describe the patterns of post-natal growth in full-term infants as a function of IUGR and (2) to assess the impact of an individualized behavioral feeding intervention with the mothers on these patterns of infant growth. Eighty-eight (88) full-term infants, including 54 with IUGR, half of whom received behavioral intervention were included. Weight, length, skinfold thickness, head circumference and Ponderal Index were measured at birth and at 1, 4, 8, 12, and 18 months. Results show positive intervention effects between birth and 1 month in weight, length, skinfold thickness, and Ponderal Index. However, there were no intervention effects at subsequent ages. No evidence was found for catch-up growth in full-term IUGR infants in weight, length, and head circumference. We conclude that an individualized behavioral feeding intervention can accelerate early growth in IUGR infants, but the positive effects on growth are only seen while the intervention lasts (between birth and 1 month). On most parameters of physical growth, there is no lasting catch-up growth over the first 18 months in IUGR full-term infants.

Early-onset sepsis in very low birth weight neonates: a report from the National Institute of Child Health and Human Development Neonatal Research Network

OBJECTIVE

Early-onset sepsis (occurring within 72 hours of birth) is included in the differential diagnosis of most very low birth weight (VLBW) neonates. To determine the current incidence of early-onset sepsis, risk factors for disease, and the impact of early-onset sepsis on subsequent hospital course, we studied a cohort of 7861 VLBW neonates (401 to 1500 gm) admitted to the 12 National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centers during a 32-month period (1991-1993).

METHODS

The NICHD Neonatal Research Network maintains a prospectively collected registry on all VLBW neonates born or cared for at participating centers. Data from this registry were analyzed retrospectively.

RESULTS

Blood culture-proven early-onset sepsis was uncommon, occurring in only 1.9% of VLBW neonates. Group B streptococcus was the most frequent pathogen associated with early-onset sepsis (31%), followed by Escherichia coli (16%) and Haemophilus influenzae (12%). Decreasing gestational age was associated with increased rates of infection. Antibiotic therapy for suspected sepsis is frequently initiated at birth in VLBW neonates. Almost half of the infants in this cohort were considered to have clinical sepsis and continued to receive antibiotics for 5 or more days, despite a negative blood culture result in 98% of cases. These findings underscore the difficulty of ruling out sepsis in the symptomatic immature neonate and the special concern for culture-negative clinical sepsis in the face of maternal antibiotic use. Neonates with early-onset sepsis were significantly more likely to have subsequent comorbidities, including severe intraventricular hemorrhage, patent ductus arteriosus, and prolonged assisted ventilation. Although 26% of VLBW neonates with early-onset sepsis died, only 4% of the 950 deaths that occurred in the first 72 hours of life were attributed to infection. For those infants discharged alive, early-onset sepsis was associated with a significantly prolonged hospital stay (86 vs 69 days; p <0.02).

CONCLUSIONS

Early-onset sepsis remains an important but uncommon problem among VLBW preterm infants. Improved diagnostic strategies are needed to enable the clinician to distinguish between the infected and the uninfected VLBW neonate with symptoms and to target continued antibiotic therapy to those who are truly infected.

Effects of maternal hypertension in very-low-birth-weight infants

OBJECTIVE

To determine the effects of mild vs severe maternal hypertension on the neonatal morbidity of very-low-birth-weight infants.

DESIGN

Cohort case-control study.

SETTING

Tertiary care center neonatal intensive care unit.

PATIENTS

Thirty-nine infants born to mothers with maternal hypertension (blood pressure > or = 140/90 mm Hg on 2 occasions during pregnancy) among 267 very-low-birth-weight infants (< or = 1250 g) admitted to the special care nursery between January 1, 1991, and December 31, 1992. Each infant was matched for gestational age and survival to 2 control infants born to normotensive mothers. The cohort included 11 infants of mothers with mild hypertension, 28 with severe hypertension, and 78 controls.

MAIN OUTCOME MEASURES

Late and variable decelerations, incidence of small size for gestational age, respiratory distress syndrome, intraventricular hemorrhage, patent ductus arteriosus, apnea, ventilator therapy, oxygen requirement, and bronchopulmonary dysplasia.

RESULTS

The mild and severe maternal hypertension groups had significantly lower birth weights and more infants small for gestational age than did controls. The incidence of respiratory distress syndrome, however, was significantly lower in infants of mothers with mild hypertension than in those with mothers with severe hypertension. Those in the mild group had fever days of ventilatory therapy and lower oxygen requirements than both the infants in the severe group and control infants. The incidence of apnea in the mild hypertension group was significantly lower than that in the severe hypertension group.

CONCLUSIONS

Although mothers with both mild and severe hypertension have an increased incidence of infants small for gestational age, the infants born to mothers with mild hypertension had less respiratory distress syndrome, apnea, ventilator therapy, oxygen requirements, and bronchopulmonary dysplasia when compared with very-low-birth-weight infants born to mothers with severe hypertension.

Effects of in utero substance exposure on infant neurobehavior

OBJECTIVE

This study had two objectives: (1) to assess infant behavior by using the NICU Network Neurobehavioral Scale (NNNS), an assessment designed specifically for prenatally drug-exposed infants; and (2) to control for the effects of polydrug use involving alcohol, marijuana, and cigarettes on the neurobehavioral status of the newborn infant.

METHODS

The subjects and controls in this study were full-term infants of appropriate gestational age with no medical problems. At 1 to 2 days of age, 20 infants exposed to cocaine, alcohol, marijuana, and cigarettes; 17 infants exposed to alcohol and/or marijuana and cigarettes; and 20 drug-free infants were evaluated by using the Neonatal Intensive Care Unit Network Neurobehavioral Scale. The data were reduced to reflect clinically defined categories of neurobehavioral function and were analyzed by using analysis of variance and chi 2 statistics.

RESULTS

Cocaine-exposed infants showed increased tone and motor activity, more jerky movements, startles, tremors, back arching, and signs of central nervous system and visual stress than unexposed infants. They also showed poorer visual and auditory following. There were no differences in how the examination was administered to cocaine-exposed and nonexposed infants. Reduced birth weight and length were also observed in cocaine-exposed infants.

CONCLUSION

Differences attributable to cocaine-exposed infants were related to muscle tone and motor performance, following during orientation, and signs of stress. However, cocaine-exposed infants were not more difficult to test, nor did they require an alteration in the examination. Both neurobehavioral patterns of excitability and lethargy were observed. Findings may have been due to the synergistic effects of cocaine with alcohol and marijuana.

Late-onset sepsis in very low birth weight neonates: a report from the National Institute of Child Health and Human Development Neonatal Research Network

OBJECTIVE

Late-onset sepsis (occurring after 3 days of age) is an important problem in very low birth weight (VLBW) infants. To determine the current incidence of late-onset sepsis, risk factors for disease, and the impact of late-onset sepsis on subsequent hospital course, we evaluated a cohort of 7861 VLBW (401 to 1500 gm) neonates admitted to the 12 National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centers during a 32-month period (1991 to 1993).

METHODS

The NICHD Neonatal Research Network maintains a prospectively collected registry of all VLBW neonates cared for at participating centers. Data from this registry were analyzed retrospectively.

RESULTS

Of 6911 infants who survived beyond 3 days, 1696 (25%) had one or more episodes of blood culture-proven sepsis. The vast majority of infection (73%) were caused by gram-positive organisms, with coagulase-negative staphylococci accounting for 55% of all infections. Rate of infection was inversely related to birth weight and gestational age. Complications of prematurity associated with an increased rate of infection included intubation, respiratory distress syndrome, prolonged ventilation, bronchopulmonary dysplasia, patent ductus arteriosus, severe intraventricular hemorrhage, and necrotizing enterocolitis. Among infants with bronchopulmonary dysplasia, those with late-onset sepsis had a significantly longer duration of mechanical ventilation (45 vs 33 days; p <0.01). Late-onset sepsis prolonged hospital stay: the mean number of days in the hospital for VLBW neonates with and without late-onset sepsis was 86 and 61 days, respectively (p <0.001). Even after adjustment for other complications of prematurity, including intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia, infants with late-onset sepsis had a significantly longer hospitalization (p <0.001). Moreover, neonates in whom late-onset sepsis developed were significantly more likely to die than those who were uninfected (17% vs 7%; p <0.000 1), especially if they were infected with gram-negative organisms (40%) or fungi (28%). Deaths attributed to infection increased with increasing chronologic age. Whereas only 4% of deaths in the first 3 days of life were attributed to infection, 45% of deaths after 2 weeks were related to infection.

CONCLUSIONS

Late-onset sepsis is a frequent and important problem among VLBW preterm infants. Successful strategies to decrease late-onset sepsis should decrease VLBW mortality rates, shorten hospital stay, and reduce costs.

Interlaboratory variability of bilirubin measurements

During an 8-month study, 14 laboratories used automated analytical systems to measure total bilirubin concentrations in lyophilized bovine specimens containing 38, 169, and 253 micromol/L bilirubin (2.2, 9.9, and 14.8 mg/dL, respectively). The measured mean +/- SD (n, range) were: 39 +/- 7 micromol/L (n = 90, 31-53) [2.3 +/- 0.4 mg/dL (1.8-3.1)]; 176 +/- 29 micromol/L (n = 89, 146-222) [10.3 +/- 1.7 mg/dL (8.5-13.0)]; and 260 +/- 43 micromol/L (n = 103, 208-316) [15.2 +/- 2.5 mg/dL (12.1-18.5)]. In comparison with target values, measurements were consistently lower at 4, higher at 6, and within +/- 4% at 4 laboratories for each of the three concentrations. The measured values for each concentration remained fairly constant during the study at each laboratory. We conclude that bilirubin measurements differed significantly from the established target values at most of the participating laboratories.

Interlaboratory variability of bilirubin measurements

During an 8-month study, 14 laboratories used automated analytical systems to measure total bilirubin concentrations in lyophilized bovine specimens containing 38, 169, and 253 micromol/L bilirubin (2.2, 9.9, and 14.8 mg/dL, respectively). The measured mean +/- SD (n, range) were: 39 +/- 7 micromol/L (n = 90, 31-53) [2.3 +/- 0.4 mg/dL (1.8-3.1)]; 176 +/- 29 micromol/L (n = 89, 146-222) [10.3 +/- 1.7 mg/dL (8.5-13.0)]; and 260 +/- 43 micromol/L (n = 103, 208-316) [15.2 +/- 2.5 mg/dL (12.1-18.5)]. In comparison with target values, measurements were consistently lower at 4, higher at 6, and within +/- 4% at 4 laboratories for each of the three concentrations. The measured values for each concentration remained fairly constant during the study at each laboratory. We conclude that bilirubin measurements differed significantly from the established target values at most of the participating laboratories.

Psychological distress in mothers of preterm infants

The purpose of this study was to identify infant and maternal characteristics that predict psychological distress among mothers of preterm infants admitted to the neonatal intensive care unit (NICU). Infant characteristics included birth weight, gestational age, and ventilatory support, and maternal characteristics included age, parity, and socioeconomic status. Mothers (n = 142) completed questionnaires including a demographic form, the Parental Stressor Scale, and the Symptom Checklist 90-R. In hierarchical regression analyses, maternal NICU-specific distress was more strongly predicted by infant characteristics [F(3,135) = 6.80, p < .05] with maternal variables covaried. Maternal general psychological distress was more strongly predicted by maternal characteristics [F(3,135) = 6.05, p < .05]) with infant variables covaried. Twenty-eight percent of mothers reported clinically significant psychological distress compared with 10% in a normative population. Psychological distress among mothers of preterm infants appears to be common and deserves clinical consideration. The use of standardized questionnaires as part of the assessment process may improve case identification and psychosocial service delivery in the NICU.

Maternal and neonatal morbidity associated with in vitro fertilization

OBJECTIVE

The purpose of this case-control study was to examine the maternal and neonatal morbidities associated with in vitro fertilization (IVF) in a single large teaching hospital. It was hypothesized that IVF mothers would have more perinatal complications and IVF infants would have higher mortality and morbidity rates than non-IVF control subjects.

METHODS

One hundred forty-three gestations resulting from 101 IVF pregnancies, which included singletons (n = 62), twins (n = 72), and triplets (n = 9), were compared with equal numbers of non-IVF control subjects. Each pregnancy was matched by maternal age, race, insurance type, neonatal gender, order of gestation, order in delivery, and date of delivery (+/- 6 months). Among the 143 matched gestations, six IVF and seven control infants died, leaving 137 IVF and 136 control neonates for comparison.

RESULTS

The IVF mothers had more pregnancy-induced hypertension (21% vs 4%), premature labor (44% vs 22%), labor induction (25% vs 1%), and preterm delivery (37% vs 21%). The IVF infant survivors had a lower mean (+/- SD) birth weight (2623 +/- 857 gm vs 3006 +/- 797 gm), more frequent occurrence of low birth weight (42% vs 27%), and shorter gestations (37 +/- 4 vs 38 +/- 3 weeks). The IVF infants had longer hospitalizations, more days of oxygen therapy, more days of continuous positive airway pressure, and increased prevalence of respiratory distress syndrome, patent ductus arteriosus, and sepsis.

CONCLUSIONS

Couples who undergo IVF appear to be at increased risk of having low birth weight and preterm infants, and multiple gestations account for most of the neonatal morbidities. Both the mothers who conceive multiple gestations by means of IVF and their neonates are at an increased risk of having multiple morbidities.

Effects of indomethacin on brain blood flow, cerebral metabolism, and sagittal sinus prostanoids after hypoxia

We tested the hypotheses that during recovery from hypoxia, newborn piglets exhibit a posthypoxic cerebral hyperemia, indomethacin-pretreated piglets exhibit a posthypoxic cerebral hypoperfusion, and that the changes caused by indomethacin are dose dependent and related to the loss of prostanoids. We studied piglets exposed to 40 min of hypoxia after pretreatment with high (5 mg/kg, n = 9) or low (0.3 mg/kg, n = 8) doses of indomethacin or placebo (n = 9) and allowed to recover for 120 min. In the placebo and low-dose pretreatment groups, total and regional brain blood flow increased during hypoxia but returned to baseline 10 min after hypoxia. High-dose indomethacin pretreatment was associated with a posthypoxic hypoperfusion to certain brain regions at 10 min of recovery to values similar to those after indomethacin treatment before the onset of hypoxia. During and after hypoxia, the cerebral metabolic rate of oxygen was preserved in both the placebo and low-dose groups and decreased significantly during hypoxia in the high-dose group. Sagittal sinus prostacyclin was reduced significantly in both indomethacin-treated groups throughout the study. We conclude that a posthypoxic hyperemia is not observed in newborn piglets. This finding was not altered by pretreatment with a therapeutic dose of indomethacin, whereas a pharmacological dose was associated with selective hypoperfusion to certain brain regions both before hypoxia and during recovery from hypoxia.

Postnatal maturation of the blood-brain barrier for unbound bilirubin in newborn piglets

The postnatal maturation of the blood-brain barrier (BBB) for unbound bilirubin was studied in 2-day- and 2-week-old piglets. Hyperbilirubinemia was induced by bolus infusion of bilirubin at 25 mg/kg followed by continuous infusion of 20 mg/kg/h for 3 h. During the study period, arterial blood pH and blood gas tensions, serum osmolarity, and mean arterial blood pressures were within the physiologic range. Brain bilirubin content and the brain/blood distribution ratio for bilirubin were higher in the 2-day-old than in the 2-week-old piglets. In both age groups, regional brain bilirubin concentration and brain/blood ratios were higher in subcortical regions (cerebellum and brainstem) than in the cerebral cortex. We conclude that in newborn piglets the blood-brain barrier for unbound bilirubin matures with increasing postnatal age and that irrespective of maturity the relative permeability of the BBB for bilirubin appears higher in subcortical than in cortical regions.

Effects of maternal preeclampsia on brain-stem auditory evoked response in very low birth weight infants

OBJECTIVE

Because stress in utero may enhance neuromotor maturation, we hypothesized that infants born to mothers with preeclampsia would have a shorter absolute latency V and interpeak latency I-V period (brain-stem conduction time) of brain-stem auditory evoked response (BAER) than infants born to normotensive mothers.

STUDY DESIGN

A retrospective cohort study was performed to assess the effects of maternal preeclampsia on BAER of very low birth weight infants. The cohort consisted of 24 infants with a birth weight less than 1251 gm born to mothers with preeclampsia, and 48 infants born to normotensive mothers, matched for birth date within 2 months, gestational age, and chronologic age at the time of the BAER test. The BAER test was completed before discharge, with the infant in a quiet state and the use of a 30 dB stimulus.

RESULTS

The mean latencies of wave V were shortened bilaterally (left 8.60 +/- 0.6 msec vs 9.02 +/- 0.6 msec, p < 0.008; right 8.61 +/- 0.6 msec vs 8.96 +/- 0.6 msec, p < 0.033, and the interpeak latency of I-V was significantly shortened compared with the control subjects on the left (left 4.91 +/- 0.5 msec vs 5.38 +/- 0.6 msec, p < 0.003; right 5.17 +/- 0.5 msec vs 5.37 +/- 0.6 msec, not significant).

CONCLUSION

These results suggest that the intrauterine stress of maternal preeclampsia accelerates the maturation of the auditory nerve and brain-stem auditory pathway in very low birth weight infants.

Developmental outcome as a function of the goodness of fit between the infant's cry characteristics and the mother's perception of her infant's cry

OBJECTIVE

To determine whether the "goodness of fit" between infant cry characteristics and the mother's perception of the cry is related to developmental outcome at 18 months of age.

DESIGN

This was a prospective, longitudinal study from birth to 18 months performed in a blinded manner.

SETTING

The study was conducted in a maternity hospital, including normal and special care nurseries and a laboratory for developmental follow-up.

PATIENTS

The 121 term and preterm infants and their mothers were selected to meet medical criteria.

MEASUREMENT

Acoustic analysis of 1-month infant cry and the mother's perception of the same cry was used to divide subjects into four groups representing matches and mismatches between infant cry characteristics and maternal cry perception. Primary outcome measures of cognitive, language, motor, and neurologic outcome were administered at 18 months. Caretaking environment measures were also recorded.

RESULTS

Statistically significant (P < .05) findings showed that matched groups scored higher on measures of language and cognitive performance than infants in the mismatch groups, with a particular advantage for infants in the matched group in which mothers accurately perceived the higher-pitched cries of their infants. There were no differences between the groups in biologic or sociodemographic factors. Group differences were observed in social support and maternal self-esteem.

CONCLUSIONS

Matches and mismatches between infant cry characteristics at 1 month and the mother's perception of the cry are related to cognitive and language outcome at 18 months in term and preterm infants. This relation is probably due to transactional processes in which developmental outcome is affected by the clarity of the infants' signals and by the ability of the mother to accurately perceive her infant's signals. The mother's ability to read her infant's cues may be affected by factors such as social support and self-esteem.

Antenatal steroids, delivery mode, and intraventricular hemorrhage in preterm infants

OBJECTIVE

The relationship between antenatal steroids, delivery mode, and early-onset intraventricular hemorrhage was examined in very-low-birth-weight infants.

STUDY DESIGN

A total of 505 preterm infants (birth weight 600 to 1250 gm) were enrolled in a multicenter, prospectively randomized, controlled trial evaluating the efficacy of postnatal indomethacin to prevent intraventricular hemorrhage. All infants had echoencephalography between 5 and 11 hours of life.

RESULTS

Seventy-three infants had intraventricular hemorrhage within the first 5 to 11 hours (mean age at echoencephalography 7.5 hours). Four hundred thirty-two infants did not have early intraventricular hemorrhage. There was less antenatal steroid treatment (19% vs 32%, p = 0.03) and more vaginal deliveries (71% vs 45%, p < 0.0001) in the group with early intraventricular hemorrhage. Of 152 infants who received antenatal steroids, those delivered by cesarean section had significantly less early-onset intraventricular hemorrhage than did those delivered vaginally (4% vs 17%, p = 0.02). Of the 353 not exposed to antenatal steroids, 10% of infants delivered by cesarean section and 22% delivered vaginally had early intraventricular hemorrhage (p = 0.003).

CONCLUSION

These data are the first to suggest that both antenatal steroids and cesarean section delivery have an important and independent role in lowering the risk of early-onset intraventricular hemorrhage.

Lack of production and growth-modulating effects of 1a,25-dihydroxyvitamin D3 in cultured fetal rat hepatocytes

1a,25-Dihydroxyvitamin D3 [1,25(OH)2D3], the hormonal form of vitamin D3, has been shown to play a role in the regulation of growth of the regenerating adult rat liver following partial hepatectomy. In addition, a recent study implicated the neonatal liver as a possible extrarenal site of 1,25(OH)2D3 synthesis. Therefore, in our present study we used rapidly growing fetal hepatocytes in culture as a model cell line for regenerating hepatocytes and tested the hypothesis that fetal hepatocytes locally produce 1,25(OH)2D3 which in turn regulates their growth. Hepatocytes isolated from 19-day rat fetuses were grown in culture for 24 h in minimal essential medium without added serum or mitogens. To identify 1,25(OH)2D3 production, we incubated fetal hepatocytes in culture with 3H-25-hydroxyvitamin D3 (3H-25-OH D3) for 2, 6 and 24 h. High-pressure liquid chromatographic analysis of the lipid extract of the medium and cells revealed no evidence of conversion of 3H-25-OH D3 into 3H-1,25(OH)2D3. Additionally, to investigate the effect of 1,25(OH)2D3 on DNA synthesis in fetal liver, we measured 3H-thymidine incorporation by the cultured fetal hepatocytes following 24 h of exposure to various concentrations of 1,25(OH)2D3. The results of DNA synthesis revealed no effect of 1,25(OH)2D3 on fetal hepatocyte growth. As alterations in growth regulation by 1,25(OH)2D3 in other cells are thought to be mediated by intracellular vitamin D receptors (VDR), the expression of the VDR message in the fetal and maternal tissues of a pregnant rat was studied. RNA was first isolated from fetal liver, fetal kidney, maternal liver and maternal kidney, and the corresponding cDNA was then generated by reverse transcription.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of single dose calcium gluconate infusion in hypocalcemic preterm infants

We conducted a prospective, double-blind study of 43 preterm infants to examine the effect of a single calcium gluconate infusion as therapy for neonatal hypocalcemia on serum calcium concentrations and hypocalcemic signs in preterm infants with low total serum calcium concentrations. Total and ionized serum calcium was measured and signs of irritability, jitteriness, and twitching were scored (scale 0-9) by blinded observers before and after receiving one dose of either calcium gluconate (100 mg/kg) or placebo (normal saline). Total and ionized serum calcium increased 3 to 6 hours following the calcium, but not the placebo, infusion. Of the infants with hypocalcemic signs, the average score of hypocalcemic signs decreased in the 11 calcium-treated infants; the 12 infants with hypocalcemic signs showed no change of hypocalcemic signs following treatment with placebo. We conclude from this study that a single dose of calcium gluconate (100 mg/kg) in hypocalcemic preterm infants raise total and ionized serum calcium and decrease clinical signs of hypocalcemia.

Outcome of extremely low-birth-weight infants: 1980-1990

Neonatal and follow-up data of infants from the special care nursery whose birth weights were < 750 g, born between 1980 and 1990, were reviewed. There was a 20% relative improvement in the odds of surviving the neonatal period, a 16% improvement in the odds of being discharged and a 19% improvement in the odds of surviving until 2 years of age with each consecutive year. Home oxygen use increased significantly over the study period. The neurodevelopmental outcomes of infants were similar over the 11-year period, with 53% being classified as neurologically normal, with a mean developmental index of 83 at 1 to 2 years of age. We conclude that there has been an improved survival of infants with birth weights < 750 g in our institution, and that the overall incidence of serious neurodevelopmental deficits among survivors has remained stable.

Bilirubin production in healthy term infants as measured by carbon monoxide in breath

To describe total bilirubin production in healthy term infants, we measured the end-tidal breath CO, corrected for ambient CO (ETCOc), with an automated sampler and electrochemical (EC) CO instrument. For infants of mothers with a negative Coombs' test, the ETCOc was 1.3 +/- 0.7 microL/L (n = 397) and the serum bilirubin on day 3 postpartum was 73 +/- 35 mg/L (n = 381). In contrast, the ETCOc for infants with ABO or Rh incompatibility, a positive direct Coombs' test, and bilirubin &gt; 130 mg/L (n = 9) was significantly higher, 1.8 +/- 0.8 microL/L, than for those who had a positive Coombs' test result but whose bilirubin was &lt; or = 130 mg/L (n = 12), 1.0 +/- 0.5 microL/L (P &lt; 0.05). At 2 to 8 h postpartum seven term babies from mothers with insulin-dependent diabetes had ETCOc of 1.8 +/- 0.7 microL/L, significantly higher than that in the other term infants [1.3 +/- 0.7 microL/L (n = 390), P &lt; 0.04]. Their bilirubin concentration at 72 +/- 12 h was also higher: 121 +/- 45 mg/L (n = 7) vs 73 +/- 34 mg/L (n = 374; P = 0.03). We conclude that ETCOc measurements may be helpful in understanding the mechanisms of jaundice in healthy term infants in a variety of conditions.

Semiportable electrochemical instrument for determining carbon monoxide in breath

Measurements of carbon monoxide (CO) in breath can be used for the diagnosis of hemolytic disease. A small, semiportable, easy-to-operate CO instrument was developed at Stanford University and tested at 12 Neonatal Research Network Centers of the National Institute of Child Health and Human Development. A syringe pump delivers 7.7 mL of sample per minute through an activate carbon filter to an electrochemical (EC) sensor having a sensitivity of 0.10 +/- 0.01 V per 1 microL/L CO in air. The electronically processed sensor signal is displayed on a digital multimeter. For a typical end-tidal CO measurement, corrected for inhaled CO, three 10- to 12-mL breath and room air samples are manually or mechanically collected and analyzed. CO determination in breath samples from 108 healthy, 1-day-old infants of nonsmoking mothers compared favorably with determinations by gas chromatography (GC), 1.3 +/- 0.8 vs 1.2 +/- 0.8 (mean +/- SD), respectively, with a regression equation of EC = 0.95 GC+0.13 (r2 = 0.98). The results demonstrate that the EC-CO instrument yields results that are comparable with those obtained by the more difficult to perform GC assay.

Bilirubin production in healthy term infants as measured by carbon monoxide in breath

To describe total bilirubin production in healthy term infants, we measured the end-tidal breath CO, corrected for ambient CO (ETCOc), with an automated sampler and electrochemical (EC) CO instrument. For infants of mothers with a negative Coombs' test, the ETCOc was 1.3 +/- 0.7 microL/L (n = 397) and the serum bilirubin on day 3 postpartum was 73 +/- 35 mg/L (n = 381). In contrast, the ETCOc for infants with ABO or Rh incompatibility, a positive direct Coombs' test, and bilirubin > 130 mg/L (n = 9) was significantly higher, 1.8 +/- 0.8 microL/L, than for those who had a positive Coombs' test result but whose bilirubin was < or = 130 mg/L (n = 12), 1.0 +/- 0.5 microL/L (P < 0.05). At 2 to 8 h postpartum seven term babies from mothers with insulin-dependent diabetes had ETCOc of 1.8 +/- 0.7 microL/L, significantly higher than that in the other term infants [1.3 +/- 0.7 microL/L (n = 390), P < 0.04]. Their bilirubin concentration at 72 +/- 12 h was also higher: 121 +/- 45 mg/L (n = 7) vs 73 +/- 34 mg/L (n = 374; P = 0.03). We conclude that ETCOc measurements may be helpful in understanding the mechanisms of jaundice in healthy term infants in a variety of conditions.