Nursery survival for infants of birth weight 500-1500 grams during 1982-1995.

OBJECTIVE: To evaluate nursery survival of very low birth weight infants (VLBW) over time, born in the same large inner-city hospital with a predominantly Hispanic population. METHODS: All liveborn VLBW infants weighing 500-1500 g at birth were included in four time periods of 2 years' duration during 1982 to 1995. Demographics were collected for the obstetric population. Clinical data were collected including maternal and infant perinatal factors. All infants were assigned a cause of death and infants dying with lethal anomalies were then excluded from further evaluations. RESULTS: Overall survival improved progressively (p = 0.0001) with dramatic improvement in survival of infants 500-750 g birth weight (BW) in period 4 (1994-1995). The number of lethal anomalies did not increase but accounted for a larger portion of deaths in period 4. Decreases in other causes of death over time reflected changes in perinatal care. Although the mothers were high-risk, none of the maternal factors evaluated showed any consistent effect on infant survival. Improved labor and delivery care was associated with improvement in Apgar scores, a decrease in intracranial hemorrhage/intraventricular hemorrhage as a cause of death and an improvement in survival between the first two periods. In spite of the increase in Cesarean sections for infants of 500-750 g BW and their improved survival in period 4, no clear advantage for Cesarean section could be demonstrated. The marked improvement seen in period 4 was associated with three changes in care: increased use of maternal steroids, administration of surfactant, and the use of newer ventilatory methods including high-frequency oscillatory ventilation. Although female gender has been reported to confer a protective influence for survival, this was not found in the final period. Black mothers comprised only about 2.5% of the total obstetric population but delivered approximately 10% of the VLBW infants. Despite the increased incidence of small for gestational age (SGA) among black infants, there were no differences in survival between blacks and Hispanics. Mean birth weight and gestational age in both survivors and nonsurvivors decreased significantly over the four time periods. In period 4, 50% survival occurred at a birth weight of 600-700 g and a gestational age of 23 weeks. CONCLUSION: Nursery survival improved throughout the period of the study from 1982 to 1995 but especially during period 4 (1994-1995). Improved survival was associated with changes in both maternal and infant care. In infants of BW 500-750 g, gestational age rather than birth weight was more closely associated with survival.

Intrauterine growth curves of weight, length, and head circumference for a predominantly Hispanic infant population.

The purpose of this study was to develop intrauterine growth curves in a predominantly Hispanic population of low socioeconomic status near sea level and to compare them with published intrauterine growth curves. Infants born at Los Angeles County-University of Southern California Medical Center provided the study population. Gestational age was determined by maternal history and confirmed by Ballard clinical assessment in 6,100 infants. Growth curves were developed for weight, length, and head circumference from 24 through 44 weeks gestation. The intrauterine curves were similar to those developed from white non-Hispanic births in California and from white middle class infants born in Portland, OR. The Los Angeles curves differed from other curves developed in Denver, CO, where the infants were significantly smaller from the 34th week of gestation. The authors found no adverse effects on intrauterine growth by race or socioeconomic status. The curves presented in this paper are more appropriate than the Denver curves for white populations born near sea level regardless of socioeconomic status.

Prediction of neurodevelopmental outcome in infants with and without bronchopulmonary dysplasia.

In a group of 236 very low birth weight (VLBW) surviving infants, 60 had developed bronchopulmonary dysplasia (BPD) in the nursery. When compared with the 176 infants without BPD, infants with BPD were smaller, more immature, with lower one- and five-minute Apgar scores. Infants with BPD had a greater incidence of cardio-pulmonary and central nervous system (CNS) complications in the nursery. On follow-up, 25 (42%) of these infants were abnormal developmentally compared to 7% of infants without BPD (p less than .001). When comparisons were made within the group of infants with BPD, very few differences were found in maternal or infant risk factors between the normal and abnormal infants. The infants with BPD who had poor outcome more often had seizures and severe intraventricular hemorrhage (IVH). The infants with BPD who had good outcome were more often small for gestational age (SGA) and resuscitated with intubation at birth. They had apnea in the nursery more frequently than did abnormal infants with BPD. We conclude that VLBW infants with BPD are at greater risk for poor neurodevelopmental outcome than those without BPD. The risk for the infant with BPD relates to CNS complications rather than to chronic lung disease.

Maternal factors associated with delivery of infants with birthweight less than 2000 grams in a low socioeconomic population.

Women of low socioeconomic status (SES) are known to have a higher incidence of low birthweight (LBW) infants who are a major source of neonatal mortality and morbidity. SES, however, does not define a homogeneous population. If prenatal programs could be oriented specifically toward women of higher risk within the low SES population, they should be more effective. Within our uniformly low SES population, we compared mothers who had given birth to infants weighing less than 2000 g with mothers of infants weighing over 3000 g in order to identify factors associated with a LBW birth. We found medical factors, including hypertension and infection during pregnancy, demographic factors, including race, marital status, and lack of prenatal care, and lifestyle factors, including drug and alcohol abuse, to be more common among women giving birth to infants weighing less than 2000 g. These factors can be used to develop more effective intervention programs for low SES populations.

The premature small-for-gestational-age infant during the first year of life: comparison by birth weight and gestational age.

To determine the effect of intrauterine growth retardation on the outcome of the premature infant, we compared a group of 35 premature, small-for-gestational-age (SGA) infants with two groups of premature, appropriate-for-gestational-age (AGA) infants: one with similar birth weight (AGA-BW group) and the other with similar gestational age (AGA-GA group). Groups were matched by year of birth, race, gender, and socioeconomic status. Infants were free of major congenital anomalies and intrauterine infection. They were evaluated at term, at 20 and 40 weeks, and at 1 year corrected age. The SGA infants had a lower mean developmental quotient than the two groups of AGA infants. The SGA infants had significantly smaller body dimensions at birth, more nursery complications, and a higher incidence of major neurologic problems than their AGA-GA matches but were comparable to the AGA-BW matches. Poor growth constitutes an additional risk factor to prematurity. The results highlight the importance of comparing premature SGA infants with premature AGA infants of similar gestational age rather than similar birth weight.

Clinical manifestations of epidemic neonatal listeriosis.

We report the broad spectrum of clinical manifestations in 23 infants with positive cultures for Listeria monocytogenes who were treated in our hospital during a recent epidemic. The majority of infants (70%) were preterm and none was small for gestational age. Thirteen (56%) had respiratory distress at birth with evidence of congenital pneumonia. Four of the 5 deaths occurred among these infants. Four infants considered healthy after resuscitation developed fever and lethargy within 36 hours after birth. Only one of these infants had evidence of pneumonia. We conclude that congenital pneumonia with respiratory distress at birth is the major cause of mortality and morbidity from L. monocytogenes infection in the neonate.

Factors involved in the decline of the developmental quotient in the very low birth weight infant during the first two years.

The developmental status of 62 infants with birth weights less than 1,501 g was evaluated at nine or 12 months and at two years of age corrected for prematurity. The mean developmental scores were 99.8 at the first examination and 84.4 at the second, a significant drop (P less than 0.0001). Half of the infants (Group 1) dropped less than 16 points (mean score from 97.1 to 91.3) and half of the infants (Group 2) dropped less than 15 points (mean score from 102.8 to 76.9). The incidence of small for gestational age infants was overrepresented in Group 2. A multivariate analysis revealed that a group of factors including maternal hypertension and diabetes, gestational age, birth weight, and resuscitation at birth correctly classified 87 per cent of the infants into the two groups. The influence of this cluster of medical factors on developmental decline of the very low birth weight infant deserves further consideration.

Factors affecting nursery survival of very low birth weight infants.

398 infants with birthweight (BW) 500-1500 g born from January 2 1982 to December 1983 were studied to determine incidence and survival rate by BW and gestational age (GA) categories and to determine causes of death and factors influencing mortality. 58% of the group survived. Factors other than those in the perinatal and postnatal period did not significantly influence survival. Infants with BW below 1000 g delivered by elective C-section had better survival than those delivered vaginally. Survival increased progressively with increasing BW and GA categories with GA more than BW being the limiting factor. Eleven (6.6%) of the deaths in the very low birth weight infants occurred during the nursery period after 28 days of age. These deaths would not have been addressed in the neonatal mortality.

Epidemic perinatal listeriosis at autopsy.

Seven cases of listeriosis identified at perinatal autopsy are described. The cases occurred during the time of a 1985 Los Angeles, California, epidemic of listeriosis from suspected food contamination by Listeria monocytogenes. In only one of seven cases were gross pathologic lesions encountered. Microscopic lesions in six cases consisted of rare, localized microabscesses or granuloma-like lesions in multiple organs and contained histiocytes, monocytes, lymphocytes, and polymorphonuclear leukocytes with variable necrosis. One case had no gross or microscopic findings. Organomegaly was uncommon. The diagnosis was confirmed in three cases by postmortem blood culture. Complete perinatal autopsy is important for confirmation of listeriosis when microbiologic, gross, or microscopic findings alone may not yield characteristic features.

Attachment interaction behavior between young teenage mothers and their infants.

Behavioral interaction between teenage mothers and their infants was explored. Twenty-six (low income level) Hispanic teenage mothers (mean age 15 years) and their infants (mean age 13.5 months) were compared with an older control group of 30 mothers (mean age 26 years) and their infants (mean age 14.0 months). Infant attachment, exploration, and stress-adaptation behaviors and maternal ability to contact, encourage, and comfort the infant were evaluated. Twenty-six percent of the control infants showed limited ability to cope with stress compared to 47% of infants of teenage mothers. Control mothers differed significantly from teenage mothers in effective eye, verbal, physical contact, and smiling behaviors. These findings suggest that limited teenage maternal behaviors may potentially have a negative psychologic effect for both infants and their young mothers.

Infants with birth weight under 1500 g: physical, neurological, and developmental outcome.

One hundred and seventy-eight infants with birth weights less than or equal to 1500 g born in 1973-1975 were followed for a period of 1-3 years, and the physical, neurological, and developmental outcome evaluated. Although there was a high incidence of maternal problems, these did not correlate with outcome. Asphyxia at birth followed by neonatal complications leading to ventilatory assistance was significantly correlated with poor outcome. Over 50% of infants less than 100 g birth weight required assisted ventilation, but the outcome in small ventilated infants was comparable to that of ventilated infants of 1001-1500 g birth weight. Infants with neurological abnormality showed a high incidence of associated abnormalities in growth, vision, hearing, and development. Spastic quadriplegia emerged as the most common neurological diagnosis. Despite the many perinatal problems, 82% of the group were normal neurologically and 66% developmentally. The overall outcome was generally favorable in these infants even for those requiring ventilation.

Effect of phototherapy on growth of low-birth-weight infants--two-year follow-up.

The effect of phototherapy on subsequent growth of low-birth-weight infants has been evaluated at two-year follow-up of infants from two separate controlled neonatal studies. Growth of weight, length, and head circumference in the treated infants of Group I was slower than that of control subjects. Growth was comparable in treated infants and control subjects in Group II, and the two control groups, although not concurrent were also similar. Infants whose heads were growing at a normal rate, even though below 2 SD from the norms, were developing normally. Only infants who had deceleration in rate of head growth were abnormal. It is unlikely that phototherapy was responsible for the slow growth patterns seen in Group I, since these patterns were not reproducible in Group II.

Effect of phototherapy in preterm infants on growth in the neonatal period.

A total of 120 preterm infants were randomly divided at 24 hr of age into three groups: Group I, controls; Group II, continuous phototherapy for 5 days; and Group III, intermittent phototherapy (12 hr on and 12 hr off) for 5 days. At the end of week 1 80% of the control group regained and surpassed their birth weight as opposed to 44 and 57.6% in the continuous and intermittent phototherapy groups, respectively. In weeks 2 and 3 both phototherapy groups had greater weight gain than the control group. Similar but less marked differences were observed in body lenth and head circumference in the three groups. Data suggest decreased growth during phototherapy with subsequent catch-up in growth during weeks 2 and 3. Differences were less marked between infants on intermittent (rather than continuous) phototherapy and controls. Increased metabolic demands and decreased intestinal absorption during phototherapy may be two of the factors responsible for the observed differences in growth in the three groups.