Relation of birth spacing with birth weight,morbidity and mortality of the Newborn

Conclusion The present study showed that two-thirds of the babies were born at birth spacing interval of less than 2 1/2 years. The mean birth weight of the infants showed a rise till a birth interval of 3 1/2 years. There was a lower incidence of low birth weight infants as birth spacing increased up to 3 1/2 years. The morbidity and mortality were considerably lower when birth spacing was two- and-a-half to three-and-a-half years.     

Changing two-year outcome of infants weighing 500 to 999 grams at birth: a hospital study.

Survival and neurodevelopmental outcome to 2 years were determined for two cohorts of infants weighing 500 to 999 gm at birth, born in a tertiary maternity hospital. Live births increased over time from an annual average of 48.7 in the first era (January 1977 to March 1982) to 64.6 in the second era (January 1985 to December 1987), largely from referrals of additional mothers with pregnancy complications. In the first era, 33.6% (86/256) of infants survived to 2 years; the survival rate improved significantly to 45.9% (89/194) in era 2. After adjustment for birth weight, the odds ratio for survival in era 2 versus era 1 was 1.39 (95% confidence interval = 1.12, 1.73; p less than 0.01). One known survivor in each era was not seen at 2 years of age. In the first era, 59.3% (51/86) of 2-year-old children were free of disability compared with 68.5% (61/89) in era 2 (NS), but the Mental Development Index of the Bayley Scales improved significantly, from 90.0 in era 1 to 98.0 in era 2. For infants weighing less than 800 gm at birth, not only did the 2-year survival rate improve, adjusted for birth weight (odds ratio = 1.53; 95% confidence interval = 1.06, 2.20; p less than 0.05), but there was also a significant reduction in neurologic disabilities in survivors (p = 0.03). For infants weighing 800 to 999 gm at birth, there was a significant improvement in the survival rate, adjusted for birth weight (odds ratio = 1.37; 95% confidence interval = 1.04, 1.79; p less than 0.05), but the rate of neurologic disabilities was unchanged. Increased survival in our tertiary maternity center was achieved without increasing the annual number of severely disabled 2-year-old survivors.     

Outcome of low birth weight infants in a West African village

Low birthweight (LBW) infants are at risk of increased mortality, impaired growth, and increased morbidity. We studied the progress of all LBW infants (less than 2.5 kg) born in a West African village where there is a resident pediatrician and midwife. There were 426 live births during the 8 years studied of which 42 (10 per cent) were of LBW. There were 17 infant deaths (IMR = 40/1000). Mean birthweight and gestation of infants dying in the first year were significantly lower than those of all live birth (2.33 kg v. 2.99 kg, P less than 0.001; 36.9 w v. 38.9 w, P less than 0.05). The mean weights of the 32 surviving LBW infants (15 preterm, 17 full term, small for gestational age) were compared with those of 32 full term, appropriate for gestational age matched controls over the first year. Growth velocities of paired groups were identical. The significant differences in weight at 1 year (P less than 0.005) reflected those at birth (P less than 0.001). There were no significant differences in clinic attendance rate or incidence of diarrhoea and respiratory disease between the four groups. We conclude that LBW is a strong risk factor for infant mortality, but not for diarrhoeal and respiratory morbidity in a community with ready access to obstetric and pediatric care.     

Outcome in infants 501 to 1000 gm birth weight delivered to residents of the McMaster Health Region

The mortality and morbidity for all 255 live births of infants with birth weight 501 to 1000 gm and delivered to residents of a geographically defined region between 1977 and 1980 are reported. In all, 117 (46%) infants were discharged alive; there were four postdischarge deaths, and three infants were lost to follow-up. The mean birth weight and gestational age of the survivors was 850 +/- 118 gm and 27.1 +/- 2 weeks, respectively. Neurosensory handicaps were detected in 26 (24%) of 110 survivors followed for a minimum of 2 years corrected age. In addition, 29 (26%) infants had nonneurologic problems and 55 (50%) were considered apparently normal. Within 100 gm birth weight groups, survival improved significantly with increasing birth weight, but the handicap rate among survivors remained relatively constant. These figures are proposed for use in describing the current prognosis at birth for liveborn tiny infants from comparable unselected populations.     

Influence of birth weight on mortality from infectious diseases: a case-control study

The association between birth weight and infant mortality from infectious diseases was investigated in a population-based case-control study in two urban areas in southern Brazil. All deaths of children, seven to 364 days of age, occurring in a year were studied and the parents of the 357 infants dying of an infectious cause were interviewed, as were the parents of two neighborhood control infants for each case. Low birth weight infants (less than 2,500 g) were found, after allowing for confounding factors, to be 2.3 (90% confidence interval = 1.6 to 3.4) times more likely to die of an infection than those of higher birth weight. The odds ratios were 2.0 (1.1 to 3.6) for deaths due to diarrhea, 1.9 (1.0 to 3.6) for respiratory infections, and 5.0 (1.3 to 18.6) for other infections. These estimates of the risks associated with low birth weight are considerably lower than those from studies in developed countries.     

Decreased disability rate among 3-year-old survivors weighing 501 to 1000 grams at birth and born to residents of a geographically defined region from 1981 to 1984 compared with 1977 to 1980

In this article we report the survival and morbidity rates for all live-born infants weighing 501 to 1000 gram at birth and born to residents of a defined geographic region from 1977 to 1980 (n = 255) compared with 1981 to 1984 (n = 266). During these periods, there were no changes in the proportion of infants delivered at the tertiary care center or community hospitals (171/84 vs 194/72); use of the tertiary care center increased only slightly, from 84% to 91%; and changes in neonatal management were mainly in improvements in diagnostic and monitoring techniques. When infants were grouped according to birth weights in 100 gm increments, survival improved significantly only for infants weighing between 501 and 600 gm at birth (2% vs 20% p less than 0.001). There were no differences in the overall survival rates to hospital discharge (46% vs 48%). The prevalence of neurosensory impairments was 24% in period 1 and 17% in period 2. There was a significant improvement in the proportion of infants considered to have disabilities by a functional classification assigned at 3 years corrected age (50% vs 27%, p less than 0.001), but only for infants weighing more than 800 gm at birth (49% vs 22%, p less than 0.001). Infants delivered at the community hospitals had a higher prevalence of neurosensory impairments compared with infants delivered at the tertiary care center (period 1, 35% vs 21%, not significant; period 2, 37% vs 14%, p less than 0.05). These data are encouraging; further efforts should be directed toward assessing which, if any, components of perinatal care are contributing to the improvement in morbidity rates.     

Outcome studies of low birth weight infants published in the last decade: a metaanalysis

We conducted a metaanalysis and methods review of 80 studies, published in the last decade, that explored the outcome of low birth weight infants; 27% involved infants whose birth weights were less than or equal to 2500 gm (low birth weight), 44% less than or equal to 1500 gm (very low birth weight), and 29% less than or equal to 1000 gm (extremely low birth weight). Problems found in these studies were grouped into three categories: subject and methods issues, environmental factors, and outcome measurement. The combined average intelligence quotient/developmental quotient (IQ/DQ) of all low birth weight groups was 97.77 (SD 6.19); for control subjects the mean IQ/DQ was 103.78 (SD 8.16). This difference was statistically significant but perhaps not clinically significant. No differences in mean IQ/DQ scores were found among the low birth weight, very low birth weight, and extremely low birth weight subgroups. Statistically significant differences among all groups and control subjects were found when categoric data were analyzed, as were differences among the three subgroups; however, the variety of outcome criteria makes interpretation of the categoric analyses difficult.     

Infants weighing 1,000 grams or less at birth: developmental outcome for ventilated and nonventilated infants

The neurodevelopmental outcome at a mean age of 40 months was investigated in 23/25 surviving infants of birth weights less than or equal to 1,000 gm. Eight infants required intubation and assisted ventilation and 17 were not ventilated. One ventilated infant was lost to follow-up and one nonventilated infant was a victim of sudden infant death syndrome at age 6 months. Fifteen (65%) had a good outcome but the differences between ventilated and nonventilated infants were striking. Thirteen (81%) of the nonventilated group were normal, but only two ventilated survivors (28%) were normal (P less than 0.05). Cicatricial retrolental fibroplasia occurred in three (43%) of the ventilated survivors and in none of the nonventilated infants (P less than .02). The requirement for assisted ventilation in these very low-birth-weight infants is associated with significant morbidity. Improvement in outcome may depend as much upon better understanding and management of prenatal events as upon improvements in neonatal care.     

Mortality and morbidity rates among lower birth weight infants (2000 to 2500 grams) treated with extracorporeal membrane oxygenation.

To assess the validity of the currently accepted lower weight limit of 2 kg for treatment of neonates with extracorporeal membrane oxygenation (ECMO), we reviewed the outcome of lower birth weight (2.0 to 2.5 kg, n = 29) and higher birth weight (n = 235) for infants treated with venoarterial ECMO at our institution from 1984 through 1990. Newborn infants with congenital diaphragmatic hernia were not included. The mortality rate was significantly greater after venoarterial ECMO in lower than in higher birth weight infants (relative risk 3.45; confidence interval = (1.68, 5.79)). For infants with the diagnosis of respiratory distress syndrome, the mortality rate was 56% (5/9) for lower and 8% (2/25) for higher birth weight infants (p less than 0.01). The most frequent cause of death in lower birth weight infants was intracranial hemorrhage (7/10 deaths). The overall incidence of any neuroimaging abnormality was significantly greater for lower birth weight infants (p = 0.044), primarily because of the higher incidence of major intracranial hemorrhage. Finally, the risk of developmental delay (development quotient less than 70 at 1 to 2 years of age) among survivors available for follow-up was significantly higher among the lower than the higher birth weight infants. These outcome data suggest that further reduction of the current lower weight limit for ECMO should not become standard without prospective research or technologic advances.     

Cerebrospinal fluid values in the very low birth weight infant

The cerebrospinal fluid values obtained in the first 12 weeks of life from 43 infants with birth weights of 1500 gm or less were analyzed to determine the ranges for leukocyte count and chemistry values. All these neonates had birth weights appropriate for gestational age, negative cerebrospinal fluid culture for bacteria, and no evidence of intracranial bleeding by head ultrasound examination. The mean birth weight was 1002 gm (range 550 to 1500 gm), and mean gestational age was 27 weeks (range 24 to 33 weeks). The mean cerebrospinal fluid leukocyte count was 5 cells/mm3 (range 0 to 44 cells/mm3); leukocyte differential was 7% polymorphonuclear leukocytes (range up to 66%) and 85% mononuclear leukocytes (range 13% to 100%). Additional values included protein concentration, 142 mg/dl (range 45 to 370 mg/dl); and glucose, 60 mg/dl (range 29 to 217 mg/dl). Knowledge of these measurements should help in the interpretation of the cerebrospinal fluid values of the very low birth weight infant undergoing examination of a central nervous system disorder.     

Introduction of intravenous lipid administration on the first day of life in the very low birth weight neonate

OBJECTIVE: To investigate lipid tolerance in sick, ventilator-dependent, very low birth weight infants from the first day of life and the effects of early introduction of intravenously administered lipid (IVL) on glucose homeostasis. METHOD: Twenty-nine infants in the neonatal intensive care unit with birth weight less than 1500 gm received isocaloric, isonitrogenous parenteral feedings from day 1 with either IVL, 1 gm/kg from day 1 to 3 gm/kg from day 4 (group I; n = 16), or IVL added only from day 8 (group II; n = 13). Possible adverse clinical effects were monitored. Blood metabolites, nonesterified fatty acids, serum triglycerides, and insulin levels were determined daily. Arterial blood gases were measured and changes in partial pressures of oxygen and of carbon dioxide in arterial blood were compared between the two groups. RESULTS: Early lipid infusion did not appear to have deleterious effects on blood gas tensions or to increase respiratory morbidity. The incidence of other adverse clinical effects that may be associated with IVL was not increased by earlier introduction of lipid. Serum lipid values were comparable to those of preterm infants receiving IVL at a later postnatal age. Blood glucose concentrations were higher in group II (mean, 7.50 (SEM 0.43) mmol/L) than in group I (mean, 6.01 (SEM 0.28) mmol/L; p less than 0.05). There was no evidence of increased gluconeogenesis in infants in group I and no correlation between blood glucose concentrations and serum nonesterified fatty acid concentrations. CONCLUSION: When given infusion rates not exceeding 0.15 gm/kg/hr, sick, very low birth weight infants can tolerate IVL with stepwise dose increases from the first day of life without an increased incidence of possible adverse effects.     

Medical care and preterm infants of normal birth weight

Preterm infants of normal birth weight (born before 37 completed weeks of gestation and weighing more than 2,250 g) experience a neonatal mortality risk almost four times higher than do term infants in the same weight range. In an analysis of the effect of hospital level of birth on neonatal mortality, such preterm normal weight infants were found to experience higher mortality if born outside of a Level 3 (tertiary care) center. For all singleton infants in this weight-gestation category born in New York City maternity services during a 3-year period (N = 23,257), the relative mortality risk for Level 1 births (compared with Level 3) was 1.72 (P less than .01) and for Level 2 births 1.47 (P less than .05). The excess mortality at Level 1 and Level 2 units was almost entirely due to a more than twofold higher death rate in black infants born in these units. Several potentially confounding socioeconomic, demographic, and biologic variables entered into a logistic regression model could not account for the higher mortality rates for black infants born in Level 1 and Level 2 units. Among black infants born at Level 1 units, deaths in preterm normal birth weight infants were less likely to occur in a receiving tertiary care center than were either deaths in low birth weight infants or deaths in term normal weight infants, suggesting that the need for special care of preterm normal birth weight infants is underestimated in some hospitals without newborn intensive care units.     

Association between low birth weight and infant mortality in children born to human immunodeficiency virus 1-infected mothers in Tanzania

BACKGROUND: The relationship between low birth weight and infant mortality among children born to human immunodeficiency virus (HIV)-infected mothers has not been thoroughly investigated. METHODS: A total of 1078 HIV-infected pregnant women in Tanzania were followed up until delivery and with their infants thereafter. The babies' HIV status was assessed at birth, 6 weeks and every 3 months thereafter. Using Cox proportional hazards models, we estimated the associations of low birth weight with neonatal, post-neonatal and infant mortality and further examined whether the association between low birth weight and mortality was modified by pediatric HIV infection. RESULTS: Among 823 singletons, low birth weight was strongly related to neonatal mortality (relative risk, 5.14; 95% confidence interval, 2.32-11.39). The association with postneonatal mortality was modified by child's HIV status. Among infants who were either negative or indeterminate at 6 weeks of age, low birth weight was associated with a 3-fold increased risk of mortality (relative risk, 3.16; 95% confidence interval, 1.36-7.37). In the positive infants, however, the association was no longer significant. CONCLUSIONS: Although the importance of preventing HIV transmission cannot be overemphasized, efforts to reduce the incidence of low birth weight would enhance the benefit of preventing HIV transmission. Even in populations with no access to antiretroviral treatments, interventions to reduce the incidence of low birth weight would result in a significant reduction in infant mortality.     

Neonatal mortality and morbidity of low birth weight premature infants (less than or equal to 1500 g)]

Neonatal mortality and morbidity were reported over a 4-yr period from 1986-1989 in premature infants weighing less than 1,500 g, 278 of whom were born in the same obstetrico-neonatal unit. Total mortality was 15%, and was higher in premature infants weighing less than 1,000 g (38%) and lower if the gestational age was greater than 27 wk. Mortality was lower in small for gestational age (SGA) infants than in appropriate for gestational age (AGA) infants (5% vs 19%, P less than 0.001), and lower in inborn babies than in outborn (12% vs 19%, P less than 0.02) but only in neonates weighing less than 1,000 g. Neonatal morbidity was mainly due to hyaline membrane disease and cerebral haemorrhage. The incidence of broncho-pulmonary dysplasia was low (4%). These results indicate that gestational age, birth weight and place of delivery play a role in mortality and morbidity in very low birth weight premature infants.     

Effects of varying protein and energy intakes on growth and metabolic response in low birth weight infants

Growth (weight, length, head circumference, and skinfold thickness), retention of major nutrients (nitrogen, sodium, potassium, chloride, calcium, and phosphorus), and chemical indices of protein adequacy (plasma albumin and transthyretin concentrations) and excess (blood urea nitrogen concentration and acid-base status; plasma amino acid concentrations) were determined serially from the time desired intake was tolerated until discharge weight (2200 gm) was reached in low birth weight infants (birth weight 900 to 1750 gm) fed one of three formulas, which provided protein and energy intakes, respectively, of 2.24 gm/kg/day and 115 kcal/kg/day (group 1), 3.6 gm/kg/day and 115 kcal/kg/day (group 2), and 3.5 gm/kg/day and 149 kcal/kg/day (group 3). Weight gain and rate of increase in length and head circumference were less in group 1 than in groups 2 and 3. Retention of most major nutrients also was less in group 1, as was blood urea nitrogen concentration, plasma albumin and transthyretin concentrations, and plasma concentrations of several amino acids. The rate of weight gain was not significantly greater in group 3 than in group 2, but the rate of increase in skinfold thickness was greater in this group. Neither nutrient retention nor metabolic indices differed between groups 2 and 3. These results suggest that a protein intake of 2.24 gm/kg/day is inadequate for the type of LBW infants studied, that the higher protein intakes are well tolerated, and that an energy intake of 149 vs 115 kcal/kg/day does not enhance utilization of the higher protein intakes studied.     

Predictive value of Apgar score in infants with very low birth weight

BACKGROUND: Accurate prediction of the prognosis of infants with very low birth weight is beneficial both for their parents and for healthcare professionals. METHODS: This was a population-based study of all low-birth-weight infants admitted to neonatal units in one region in Japan. The Apgar score at 1 and 5 min and neonatal mortality were retrospectively analyzed to obtain the predictive values of the scores. The results were stratified into two categories by birth weight and three time periods (1980-1986, 1987-1993 and 1994-2000). RESULTS: The predictive values improved in the later years, and therefore only the data obtained in the period 1994-2000 were used. A score of less than 5 at 5 min appears to be a good predictor of neonatal mortality in infants with a birth weight between 1500 g and 2499 g (positive likelihood ratio, 17.59 [95% confidence interval (CI) 12.68-24.40]); however, there is no evidence that the score is a good predictor of neonatal mortality in infants with very low birth weight. CONCLUSION: In infants with a low birth weight between 1500 g and 2499 g, an Apgar score at 5 min of less than 5 is a good predictor of neonatal mortality. The score is not useful in predicting the short-term prognosis of very low-birth-weight infants.     

A controlled trial of human surfactant replacement therapy for severe respiratory distress syndrome in very low birth weight infants

In a randomized, controlled study, human surfactant derived from amniotic fluid was administered within 12 hours of birth to infants with severe respiratory distress syndrome who were born at 24 to 32 weeks of gestation weighing less than or equal to 1500 gm. A second dose of surfactant was given to patients in the treatment group if they met ventilator requirements indicating relapse or lack of response to the initial dose. No significant improvement was observed in mortality rate (9/28 vs 15/31) or incidence of bronchopulmonary dysplasia (5/28 vs 3/31) when surfactant-treated infants were compared with control subjects, although there was a significant reduction in initial respirator and inspired oxygen requirements and the arterial/alveolar oxygen ratio improved. In addition, there was a significant reduction in pulmonary air leak in treated infants (10/28 vs 20/31; p less than 0.05). Retreatment was associated with an attenuated ventilatory response and with a higher mortality rate (7/14) than that of infants who did not require a second dose (2/14; p = 0.05), indicating a more severe form of disease. Multiple discriminant analysis, including eight independent variables, revealed that increasing birth weight, earlier age at surfactant treatment, and female gender were significantly associated with survival. These data suggest that early surfactant treatment may reduce mortality rates in very low birth weight infants with severe respiratory distress syndrome, as well as reduce ventilator requirements and the incidence of pulmonary air leaks.     

Vitamin E and neonatal bilirubinemia.

A study was designed to determine the effect of vitamin E on bilirubinemia in the preterm infant. Twenty infants with birth weight between 1,000 and 1,500 gm and 20 infants with birth weights between 1,501 and 2,000 gm were studied. Half the infants in each birth weight group received vitamin E administered intramuscularly in a total dose of 50 mg/kg during days 1 to 3 of life; the remaining infants served as controls. The administration of vitamin E produced significantly increased plasma tocopherol concentrations and normal hydrogen peroxide hemolysis tests by the end of the first week of life. Infants with birthweights less than or equal to 1500 gm who received vitamin E demonstrated a significant decrease in serum bilirubin on day 3 of life (6.5 +/- 2.2 vs 8.8 +/- 2.2 mg/dl) as well as a significant decrease in peak serum bilirubin during the first week of life (8.3 +/- 2.2 vs 10.6 +/- 2.6 mg/dl). The duration of phototherapy also was significantly less in the vitamin E-supplemented group (48 +/- 18 vs 107 +/- 31 hours). These differences were less pronounced in infants with birth weights more than 1,500 gm.     

Insulin infusion with parenteral nutrition in extremely low birth weight infants with hyperglycemia

From Nov. 7, 1983, to Nov. 6, 1986, all infants with birth weight less than or equal to 1000 gm admitted to Oregon Health Sciences University who had persistent hyperglycemia and glycosuria were treated with graded insulin infusion while energy intake was increased to at least 100 kcal/kg/day (419 kilojoules/kg/day). The records of these infants were reviewed to define the clinical characteristics of infants likely to develop hyperglycemia and to see whether insulin administration would allow goals for energy intake to be met. There were 76 surviving infants; 34 received insulin and 42 did not. Treated infants were smaller (767 +/- 161 vs 872 +/- 98 gm; p = 0.0004), were more immature (26.8 +/- 1.4 vs 27.7 +/- 2.0 weeks; p = 0.0115), and required mechanical ventilation longer (28 +/- 19 vs 17 +/- 15 days; p = 0.0196). There were no significant differences between the groups at 3, 7, 10, or 14 days for intravenously administered glucose or for total nonprotein energy intake at 3, 7, 10, 14, 28, or 56 days. Treated infants achieved an intake of 100 kcal/kg/day (419 kilojoules/kg/day) at 15 +/- 8 vs 17 +/- 11 days and regained birth weight at 12 +/- 6 vs 13 +/- 6 days (NS). There was no difference in percent change from birth weight at 7, 14, 28, or 56 days. Treated infants had a glucose concentration of 195 +/- 60 mg/dl (10.8 +/- 3.3 mmol/L) while receiving 7.9 +/- 3.0 mg/kg/min (43 +/- 17 mumol/kg/min) of glucose at the start of insulin infusion on days 1 to 14. Insulin was given for 1 to 58 days. The initial dose was 40 to 100 mU/gm of dextrose infused (57 to 142 nmol/mol) and then gradually decreased. Less than 0.5% of blood glucose values were 25 to 40 mg/dl (1.4 to 2.2 mmol/L). We conclude that insulin infusion improves glucose tolerance in extremely low birth weight infants and allows hyperglycemic infants to achieve adequate energy intake similar to that of infants who do not become hyperglycemic.