An infant formula toxicity and toxicokinetic feeding study on carrageenan in preweaning piglets with special attention to the immune system and gastrointestinal tract.

A toxicity/toxicokinetic swine-adapted infant formula feeding study was conducted in Domestic Yorkshire Crossbred Swine from lactation day 3 for 28 consecutive days during the preweaning period at carrageenan concentrations of 0, 300, 1000 and 2250 ppm under GLP guidelines. This study extends the observations in newborn baboons (McGill et al., 1977) to piglets and evaluates additional parameters: organ weights, clinical chemistry, special gastrointestinal tract stains (toluidine blue, Periodic Acid-Schiff), plasma levels of carrageenan; and evaluation of potential immune system effects. Using validated methods, immunophenotyping of blood cell types (lymphocytes, monocytes, B cells, helper T cells, cytotoxic T cells, mature T cells), sandwich immunoassays for blood cytokine evaluations (IL-6, IL-8, IL1ß, TNF-α), and immunohistochemical staining of the gut for IL-8 and TNF-α were conducted. No treatment-related adverse effects at any carrageenan concentration were found on any parameter. Glucosuria in a few animals was not considered treatment-related. The high dose in this study, equivalent to ~430 mg/kg/day, provides an adequate margin of exposure for human infants, as affirmed by JECFA and supports the safe use of carrageenan for infants ages 0-12 weeks and older and infants with special medical needs.

Estimation of neonatal outcome and perinatal therapy use.

OBJECTIVES: To learn whether US obstetricians and pediatricians accurately estimate rates of survival and freedom from handicap in preterm infants and to learn whether their knowledge and attitudes influence their choice of interventions that may enhance survival. METHODS: A cross-sectional survey of obstetricians and pediatricians practicing in the United States was performed using a pretested questionnaire designed to identify their knowledge regarding survival and handicap-free rates of infants born at 23 to 36 weeks of gestation. At each week of gestation, they were asked whether they would provide specific therapeutic interventions to either the expectant mother or infant. Survival and handicap-free rates were compared with published national rates. Obstetricians and pediatricians were divided into an optimists group and a pessimists group, based on their estimates of survival. The rates at which each group used therapeutic interventions were compared. RESULTS: Both obstetricians and pediatricians underestimated survival rates from 24 through 35 weeks of gestation and freedom from serious handicap from 23 through 36 weeks of gestation. On the average, optimists accurately predicted neonatal survival. Obstetricians who underestimated neonatal survival would less often administer antenatal corticosteroids, perform a cesarean section for fetal distress, and transfer a mother to a tertiary center. Pediatricians who underestimated neonatal survival would less often use mechanical ventilation, cardiopulmonary resuscitation, inotropes, intravenous fluids, thermal support, and oxygen supplementation. CONCLUSION: Physicians underestimate survival and freedom from handicap in preterm infants. Underestimation of outcome is associated with restriction in the use of appropriate interventions.

Growth of adolescents who were born at extremely low birth weight without major disability.

OBJECTIVE: To compare growth between adolescents who were born at extremely low birth weight (ELBW, /=2500 g). DESIGN/METHODS: Cross-sectional design. Fifty-three ELBW and 53 NBW adolescents without a major neurodevelopmental disability were matched by sex, race, age, and socioeconomic status. Anthropometrics (z scores), bone age, body composition (Lunar DPX-L densitometry), and sexual maturity were assessed. ELBW adolescents were classified as being born small for gestational age (SGA) or not (NSGA). RESULTS: Subjects were 58.5% female, 43.4% black, and 56.6% white. The mean birth weight for ELBW subjects was 849 g and 3355 g for NBW subjects. The mean age was 14.85 years. On average, ELBW adolescents were 4.8 cm shorter and 9.1 kg lighter than NBW adolescents. ELBW adolescents had lower mean z scores for height (P <.0001), weight (P <.0001), and head circumference (P <.0001) than NBW adolescents. ELBW/SGA subjects had lower mean z scores for height (P <.0001) and weight (P =.001) than NBW subjects. Head circumference z scores were lower for the ELBW/SGA group than the ELBW/NSGA group or the NBW group (P =. 003). Sexual maturity and relative body composition were similar between groups. Bone age, measured in SD units, was more advanced in the ELBW group (0.86 vs. 0.42, P =.039). CONCLUSIONS: ELBW adolescents who survive without a major neurodevelopmental disability attain lower growth measurements compared with NBW adolescents but have similar sexual maturation and relative body composition.

Cost of neonatal care according to gestational age at birth and survival status.

OBJECTIVE: This study was undertaken to determine the cost of initial hospital care for newborn infants according to gestational age at birth and survival status. STUDY DESIGN: This was a retrospective review of prospectively collected data on hospital and physician costs for all infants born in the study institutions at < or = 32 weeks' gestation for 1989 through 1992. A cohort of term and near-term infants was selected at random. Variables were examined by multiple logistic regression for their independent effects on cost. RESULTS: Length of stay and gestational age were related to cost among survivors born at < or = 32 weeks' gestation but not among nonsurvivors. Total cost of initial care for the US population of neonates is estimated at $10.2 billion annually, with 11.9% spent on infants born between 24 and 26 weeks' gestation and 42.7% spent on those born at > or = 37 weeks' gestation. CONCLUSIONS: Although costs for an individual surviving extremely premature baby may be high, the costs for extremely low gestational age infants is a small component of total neonatal care costs because so few infants are born at these gestational ages. The mathematic model developed from these data allows cost savings to be predicted for management strategies designed to alter gestational age at birth or survival.

Prediction of neurologic morbidity in extremely low birth weight infants.

OBJECTIVE: (1) Identify major determinants of adverse neurodevelopmental outcome in extremely low birth weight (ELBW) infants. (2) Compare neural networks and regression analysis in the prediction of major handicaps and Bayley scores (MDI and PDI) in individual ELBW neonates followed to 18 months. STUDY DESIGN: Retrospective cohort study of regional tertiary care NICU database. A database with 21 selected variables was divided into training (n = 144) and test sets (n = 74). The training set was used to train a neural network and develop regression equations to predict outcomes in the test set. RESULTS: Determinants (descending order of contribution to variance): Major handicap: intraventricular hemorrhage (IVH) grade, necrotizing enterocolitis > or = stage II, black race, and no chorioamnionitis; low MDI: IVH grade, plurality, bronchopulmonary dysplasia (BPD), lower maternal grade, and no chorioamnionitis; low PDI: IVH grade, BPD, periventricular leukomalacia, lower maternal grade, and no chorioamnionitis. Regression techniques and neural networks were comparable and had relatively low sensitivity and correlation with adverse outcomes. CONCLUSION: Much of the variance in ELBW neurologic outcome cannot be explained by either regression analysis or neural network approaches.

Results of operation in Mycobacterium avium-intracellulare lung disease.

BACKGROUND: Although operation remains part of the management of Mycobacterium avium-intracellulare lung disease, few series have assessed operation in the era of better therapeutic drugs (especially clarithromycin). METHODS: From January 1, 1989, through June 30, 1997, 28 patients with M avirum-intracellulare lung disease underwent pulmonary resection. All were receiving multidrug therapy (17 of 28 were receiving clarithromycin) before and after operation. Eight patients underwent pneumonectomy (6 right, 2 left); 20 patients underwent partial resections including 18 with upper lobe lobectomies (14 right, 4 left). The most common indications for operation were medical treatment failure (15) and as part of initial therapy (9). RESULTS: Mean postoperative follow-up was 39 months. Complications occurred in 9 of 28 patients (32%), and included persistent air leak requiring surgical correction (5), early postoperative death (2), and late bronchopleural fistulae (1 patient). Twenty-three of 26 patients were known to be acid fast bacilli culture negative within 1 month of operation. Only 1 of 26 patients who survived 2 years is known to have had a relapse. CONCLUSIONS: Operation continues to play an important role in treatment of M avium-intracellulare lung disease. More than 90% of patients become culture negative and remain so when they continue to receive drugs. Although morbidity is relatively high, it is manageable and the 12-month mortality in the current series was low (7%).

Estimation of outcome and restriction of interventions in neonates.

OBJECTIVE: To learn whether pediatricians accurately estimate rates of survival and freedom from handicap in preterm infants and to learn whether their knowledge and attitude influence their choice of interventions that may enhance survival of extremely preterm infants. METHODS: Pediatricians practicing in Alabama were surveyed using a pretested questionnaire designed to identify pediatricians' knowledge regarding survival and handicap-free rates of infants born at gestational ages between 21 and 36 weeks. For infants born at each week of gestation, they were asked if they would provide specific therapeutic interventions. Survival and handicap-free rates were compared with published national rates. Pediatricians were divided into an optimist group and a pessimist group based on how their estimates of survival compared with national published data. The rates at which each group used therapeutic interventions were compared. RESULTS: The 159 (57%) responding pediatricians underestimated survival rates from 23 through 34 weeks' gestation and freedom from serious handicap from 23 through 36 weeks. Responses of the optimists approximated actual data whereas the pessimists underestimated neonatal outcome. Those pediatricians who underestimated neonatal outcome would intervene less often with invasive therapies, including mechanical ventilation, cardiopulmonary resuscitation, inotropes, and intravenous fluids, compared with those who accurately predicted outcome from 23 through 27 weeks' gestation. CONCLUSION: Pediatricians often underestimate neonatal outcome of preterm infants. Appropriate neonatal practice may be affected by this underestimation of the survival potential of preterm infants.

Hearing loss associated with neonatal ECMO: a clinical investigation.

To answer the question as to the prevalence of sensori-neural hearing loss (SNHL) among neonates receiving ECMO, a retrospective chart review was conducted on 198 infants having surgery between November 1987 and January 1995. One hundred fifty-seven (79.7%) survived. One hundred thirty infants met our criteria of having a pre-discharge auditory brainstem evoked response (ABR) test and at least one follow-up behavioral audiologic examination. Strict criteria were set for normal hearing on both the ABR and follow-up examinations. Only follow-up results are reported. At the time of the most recent follow-up examination, two children could not be adequately studied, 106 exhibited normal hearing, 21 (16%) exhibited either unilateral or bilateral conductive hearing loss and three (2.3%) exhibited unilateral or bilateral SNHL. Only one child is using amplification. With the largest sample size to date, we found a lower prevalence of SNHL after ECMO than has been previously noted in the literature. Although the prevalence of hearing loss is low, the post-ECMO group of infants must be considered at risk for hearing loss. The prevalence of hearing loss cannot be based solely on a pre-discharge ABR, i.e. ongoing follow-up testing is necessary.

Home environment and cognitive abilities in infants born small-for-gestational-age.

BACKGROUND: In the present study we analyzed the relationship between home environment and cognitive abilities in small-for-gestational-age infants. METHOD: A group of 142 small-for-gestational-age infants and a control group of 172 appropriate-for-gestational-age infants were tested on the Fagan Test of Infant Intelligence at 7 months. The Home Screening Questionnaire was completed by the mothers when their infants were 13 months. RESULTS: The group of small-for-gestational age infants had significantly lower scores on both the Fagan test (p < 0.05) and on the Home Screening Questionnaire (p < 0.01). A significant relation between the Fagan test score and the home score was found for the small-for-gestational-age group (p < 0.05). When the home score was controlled for, the difference in mean Fagan score between the two groups of infants disappeared. CONCLUSIONS: It is suggested that small-for-gestational-age infants may be more vulnerable to adverse social conditions that infants born with a normal birthweight for gestational age. Results also suggest that cognitive impairments among small-for-gestational-age infants may be an effect of their social environments and their parents' general intelligence. Possible physical and neurological effects of intrauterine growth retardation may be less important for cognitive functioning.

Growth and development during the first year in a cohort of low income term-born American children.

BACKGROUND: Infants born small for gestational age (SGA) are at risk for poor postnatal growth and development. This study evaluates biologic and environmental determinants of outcome during the first year of life in a cohort of low income term-born American infants. METHODS: Seven hundred and seventeen of 949 (76%) singleton births to women followed from early pregnancy were studied over their first year of life and measures of growth, home environment, physical and cognitive development were obtained. Infants were categorized as SGA or non-SGA based on birthweight < 15th percentile for gestational age. SGA and non-SGA children's outcomes were analyzed by race, gender and symmetry. RESULTS: SGA infants were demographically similar to non-SGA infants but significantly lower in mean maternal height, weight and education. Birthweight, crownheel length and head circumference were all significantly smaller in SGA infants. By age 1 year, the SGA children were still shorter, lighter and had smaller head circumferences than the non-SGA children though their rate of growth during the first year was significantly greater for length and head circumference. Cognitive functioning as measured by the Bayley Scales of Infant Development and the Fagan Test of Infant Intelligence did not differ significantly except for a lower Bayley Psychomotor Development Index (PDI) in SGA infants. Since most of these children live in economically disadvantaged households, any negative consequences of poor intrauterine growth may be influenced by postnatal environment and longer term follow-up will be necessary to assess this relationship.

Pregnancy outcome and intelligence at age five years.

OBJECTIVE: Our purpose was to determine the influence of being small for gestational age at term and being preterm < 34 weeks on cognitive functioning at age 5 years. STUDY DESIGN: Five hundred forty-six children of black low-income mothers, nearly all at risk for being small for gestational age, followed up prenatally with early ultrasonographic gestational age dating, were classified as either term appropriate for gestational age, term small for gestational age, or preterm at < 34 weeks. At a mean of 5.5 +/- 0.5 years, a Wechsler Preschool and Primary Scale of Intelligence-Revised intelligence quotient test was administered. An intelligence quotient < 70 was used to define mental retardation. Univariate and multivariate analyses adjusted for maternal age, smoking, education and language skills, home environment, and child gender and preschool attendance were performed. RESULTS: Term small-for-gestational-age and preterm infants at < 34 weeks had 4 and 6 point intelligence quotient reductions compared with term appropriate-for-gestational-age infants. In the regression analyses these differences in intelligence quotient remained significant after confounders were adjusted. High maternal receptive language level (8 points), a positive home environment (5 points), and attendance at preschool (5 points) were each significantly associated with an increase in intelligence quotient. CONCLUSION: Both term small-for-gestational-age infants and those born at < 34 weeks had a significantly lower mean intelligence quotient, and small-for-gestational-age infants had an increased risk of mental retardation at age 5 years. Higher maternal language skills, a positive home environment, and attendance at preschool each were associated with an increase in the mean intelligence quotient of 5 to 7 points.

Physician opinions of preterm infant outcome and their effect on antenatal corticosteroid use.

Our purpose was to compare physician opinions about the appropriate use of corticosteroids with physician perceptions of preterm infant outcome. A total of 409 obstetricians and family physicians who provide maternity care in Alabama were surveyed to determine whether (and how) their perceptions of preterm infant outcome influenced their decision to use antenatal corticosteroids. Results were compared with those of a similar survey of Alabama physicians conducted in 1979. A total of 85% of physicians in 1992 versus 61% in 1979 reported that situations existed in which they would prescribe antenatal corticosteroids (p < 0.001). In 1992 physicians who underestimated preterm infant survival began corticosteroid use at later gestational ages than those physicians who did not underestimate survival (p < 0.02). In addition, 54% of physicians who underestimated preterm infant survival reported giving corticosteroids between 23 and 28 weeks' gestational age versus 73% of physicians with more accurate perceptions (p < 0.03). We conclude that in 1992, compared within 1979, more Alabama physicians reported antenatal corticosteroid use. Use of this treatment was influenced by each physician's perceptions of the probable outcome of the preterm infant.

24-hour mother-infant discharge with a follow-up home health visit: results in a selected medicaid population.

OBJECTIVE: To determine safety and cost-effectiveness of 24-hour discharge in selected mothers and newborns. METHODS: Women delivering at University Hospital (the University of Alabama at Birmingham) were screened to determine their eligibility for 24-hour discharge. Mothers were eligible if they had no medical problems and no history of substance abuse, had an uncomplicated vaginal delivery and postpartum course, were 12 or more hours after postpartum bilateral tubal ligation, and had reached 24 hours after delivery by 6:00 PM on the day of discharge. Newborns were eligible if they were term (37 weeks or greater), weighted 2500 g or greater, and had a normal examination at 24 hours of age. At 48 hours after delivery, each mother and infant pair was examined by a home health nurse. Telephone consultations with a staff physician were noted and outcomes were entered into a data base linked to hospital financial data. RESULTS: Of 5621 deliveries from October 1, 1993 to September 30, 1995, 972 mothers (17%) and 856 (15%) newborns were discharged at 24 hours. One mother was lost to follow-up after discharge. Nine-hundred fifty-six of 971 mothers (98.5%) had a normal examination at the home visit. Fifteen of 971 mothers (1.5%) had problems that required obstetrician telephone consultation. Seven mothers (0.7%) required a physician visit; two of these women were readmitted for treatment of an infection. Seven-hundred ninety-five of 856 (93%) newborns had a normal examination. Sixty-one newborns (7%) had problems that required pediatrician telephone consultation, primarily for jaundice, infant care questions, and a cardiac murmur. Twelve infants (1.4%) required a pediatric clinic visit. No infant was readmitted to the hospital. Net cost savings to our hospital for 24-hour discharge in these selected patients was $ 506,139 during a 2-year period. CONCLUSION: In a selected, low-risk, low-income population, mother-infant discharge 24 hours after delivery with a home follow-up visit is safe and cost-effective.

The feasibility of a randomized clinical perinatal trial: maternal magnesium sulfate for the prevention of cerebral palsy.

OBJECTIVE: Because recent epidemiologic data suggest an association between maternal magnesium sulfate use and a decreased risk of cerebral palsy in infants who survive preterm birth, we investigated the feasibility of a randomized trial of intrapartum maternally administered magnesium sulfate to prevent cerebral palsy in children who were born before term. STUDY DESIGN: On the basis of a literature review, we calculated cumulative rates of delivery, neonatal survival, and cerebral palsy for progressively longer gestational age intervals beginning at 24 weeks' gestation. Sample size estimates with two-tailed chi 2 tests without Yates' correction (alpha = 0.05, beta = 0.2, 50% effect size) for a clinical trial were calculated for these rates. RESULTS: In the 4-week interval from 24 weeks 0 days to 27 weeks 6 days the minimum number of neonates required to conduct a randomized trial would be 1189. Loss to follow-up of neonates, maternal ineligibility, and failure of enrollment would substantially increase the number of necessary gravid women delivered in the 4-week interval to complete such a trial, such that 1 million pregnancies would be required to generate the necessary number of eligible gravid women. Shorter gestational age intervals (e.g., 24 weeks 0 days to 25 weeks 6 days) required fewer neonates (n = 729) but more pregnancies (n = 1.5 million). Because of the decreasing prevalence of cerebral palsy at higher gestational ages, extending the gestational age interval (e.g., to 29 weeks 6 days) markedly increased the minimum number of neonates to 1982 but only slightly decreased the necessary number of pregnancies, to 900,000. CONCLUSIONS: A randomized trial of maternally administered intrapartum magnesium sulfate to reduce the rate of cerebral palsy in surviving preterm neonates would be a formidable undertaking, requiring a concerted multicentered effort.

MR hysterosalpingography in a rabbit model.

Our objective was to evaluate the efficacy of MR imaging as compared with conventional hysterosalpingography (HSG) for the detection of fallopian tube patency after uterine injection of contrast material. Rabbit uterine horns (n= 18) were catheterized transvaginally. Five fallopian tubes were ligated and 11 were left unaltered. T1-weighted gradient-echo MR images were obtained before, during, and after injection of 1.0-3.0 mL of a dilute gadolinium-containing contrast agent. Corresponding conventional studies were performed with an equivalent volume of iohexol. Images were evaluated by two blinded readers. Observers agreed in all cases on the presence (n = 11) or absence (n = 5) of peritoneal spill with conventional HSG. Interpretation of MR HSG concurred with conventional HSG in 14 of 16 cases for each observer (P > .05). Reasons for misdiagnosis included small amounts of spill (n = 2), artifact (n = 1), and subtle spill between bowel loops (n = 1). Sensitivity and specificity for MR HSG were 95.5% and 70%, respectively, for the diagnosis of tubal patency/occlusions. No statistical difference was found between MR HSG and conventional HSG for the diagnosis of fallopian tube patency/obstruction. Potential advantages of MR HSG include no ionizing radiation, potentially diminished local contrast toxicity, superior visualization of uterine fibroids and endometriosis, and visualization of ovaries. We conclude that this technique warrants further study, including the use of a primate model to better simulate human anatomy.

Influence of acid-base status at birth and Apgar scores on survival in 500-1000-g infants.

OBJECTIVE: To evaluate the influence of acid-base status at birth and Apgar scores on survival in very low birth weight infants. METHODS: We evaluated 1073 infants born alive and weighing 500-1000 g during 1979-1991; 658 had umbilical artery gas values examined. Apgar scores were assigned at 1 and 5 minutes after birth. Umbilical artery blood samples were collected at delivery for pH, carbon dioxide pressure (PCO2), and bicarbonate. Infants were grouped at 23-24, 25-26, 27-28, and 29 weeks or more. Using survival as the dependent variable, multiple logistic regression analyses were performed controlling for gestational age, birth weight, plurality, antenatal glucocorticoid use, mode of delivery, and year of birth, as well as for Apgar scores and cord blood gases. RESULTS: In every gestational age grouping, compared with infants with a pH lower than 7.05, survival was higher in infants with an umbilical artery pH of 7.05 or higher, significantly so at 27-28 weeks. There was no consistent relationship between umbilical artery PCO2 or bicarbonate and survival. However, with the exception of the 1-minute Apgar score at 23-24 weeks, the relationship of Apgar scores to survival was significant in all gestational age periods. Using multiple logistic regression analyses, the only significant relationships between any of the cord blood gases, Apgar scores, and mortality involved low 1-minute (odds ratio [OR] 2.7 [95% confidence interval (CI) 2.0-3.6]) and low 5-minute Apgar scores (OR 2.8 [95% CI 2.0-3.8]) and a bicarbonate less than 21 mEq/L (OR 1.6 [95% CI 1.1-2.4]). CONCLUSION: One- and 5-minute Apgar scores are better predictors of survival than umbilical artery blood gases in neonates weighing 500-1000 g at birth.

The origin and outcome of preterm twin pregnancies.

OBJECTIVE: To define the etiology of preterm twin births and determine the contribution of twin births to preterm birth and related morbidity and mortality. METHODS: The March of Dimes Multicenter Prematurity and Prevention Study included a total of 33,873 women who delivered between 1982-1986, 432 (1.3%) of which delivered twins. Women were classified by reason for preterm birth and ethnicity. Neonates were classified as to stillbirth, neonatal death, and various short-term morbidities. A second data set from one center consisted of infants who weighed 1000 g or less, were born between 1979-1991, and survived to 1 year of age (n = 386, 15% twins); this was used to determine if twins and singletons born at comparable gestational ages have a similar risk for major developmental handicaps. RESULTS: Of the deliveries in the data set, 54% of twins were preterm compared with 9.6% among singletons. Of those born preterm, twins were born at a significantly earlier gestational age than were singletons. Only 2.6% of all neonates born were twins, but they represented 12.2% of all preterm infants, 15.4% of all neonatal deaths, and 9.5% of all fetal deaths. Spontaneous labor accounted for 54% of twin births, premature rupture of membranes accounted for 22%, and indicated deliveries accounted for 23%. Of the indicated preterm births in twins, 44% were due to maternal hypertension, 33% to fetal distress or fetal growth restriction, 9% to placental abruption, and 7% to fetal death. Comparing infants of similar gestational age, twins weighed less, but had a mortality equivalent to that of singletons after 29 weeks. Between 26-28 weeks' gestation, the risk of mortality for twins versus singletons was 1.6 (95% confidence interval 1.1-2.5). Preterm twins did not have significantly more respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, or other short-term morbidity than did preterm singletons. Twins who weighed 500-1000 g and survived to 1 year had a 25% rate of major developmental handicaps. However, when gestational age was controlled, the rate of major handicaps was not higher in twins than in singletons. CONCLUSIONS: Twins accounted for a disproportional amount of preterm birth and associated morbidity and mortality. Also, when preterm twins were compared with preterm singletons and corrected for their gestational ages, the rates of morbidity were similar. Preterm twins weighing less than 1000 g did not have an increased prevalence of major handicaps at 1 year of age compared with preterm singletons.

The effect of cigarette smoking on neonatal anthropometric measurements.

OBJECTIVE: To estimate the effect of maternal cigarette smoking on birth weight, crown-heel length, and ten other neonatal anthropometric measurements. METHODS: Data are from a cohort study on risk factors for fetal growth retardation (FGR) in multiparous women conducted from December 1985 through October 1988. Information on smoking status was collected four times during pregnancy. Data analysis included 1205 singleton infants of women delivering at term. Neonatal anthropometric measurements were obtained within 48 hours of birth, including birth weight, crown-heel length, ponderal index, head and abdominal circumferences, arm length and circumference, femur length and thigh circumference, and triceps, thigh, and subscapular skinfold measurements. Analysis of covariance models were used to assess the independent effect of smoking on each neonatal measurement. RESULTS: Neonates born to women who reported smoking during the first trimester had a 0.6-1.9% reduction in most neonatal anthropometric measurements, resulting in an overall reduction of birth weight of 130 g (4%). Neonates born to women who continued to smoke throughout pregnancy had an average adjusted reduction in birth weight of 189 g (5.9%), compared with a 55 g (1.7%) reduction for neonates born to women who stopped smoking after the first trimester. For women who continued to smoke throughout pregnancy, an increased number of cigarettes smoked was associated with increased reductions in birth weight and neonatal chest and abdominal circumferences. For women who stopped smoking after the first trimester, stopping was a better predictor of neonatal anthropometric measurements than the number of cigarettes smoked early in pregnancy. CONCLUSIONS: Except for the ponderal index, all neonatal anthropometric measurements studied showed some negative effect of maternal cigarette smoking. Head circumference is the measurement least reduced. Smoking cessation is a better predictor of infant size than the number of cigarettes smoked in the first trimester.

Predicting low Apgar scores of infants weighing less than 1000 grams: the effect of corticosteroids.

OBJECTIVE: To evaluate maternal and neonatal factors that predict low Apgar scores in newborns weighing less than 1000 g. METHODS: From a data set of all live-born infants who were delivered between 1979-1991 and who weighed 1000 g or less, we reviewed the records of 837 neonates born at 24-28 weeks' gestation. Potential risk factors were evaluated for associations with a 1-minute Apgar score of 3 or less and a 5-minute Apgar score of 6 or less. Analyses used chi 2 test and multiple logistic regression. RESULTS: The prevalence of 1-minute Apgar scores of 3 or less decreased from 65.9% at 24 weeks to 38.2% at 28 weeks, and the prevalence of 5-minute Apgar scores of 6 or less decreased from 83.3% at 24 weeks to 51.2% at 28 weeks. As the birth weight increased from 500-599 g to 900-1000 g, 1-minute Apgar scores of 3 or less decreased from 77.0% to 39.6%, and 5-minute Apgar scores of 6 or less decreased from 89.2% to 56.4%. Aside from gestational age and birth weight, corticosteroid use was the strongest predictor of Apgar scores above 3 at 1 minute and above 6 at 5 minutes. Male and nonvertex-presenting infants had an increased likelihood of low Apgar scores, as did infants with cord blood pH less than 7.05 or bicarbonate value less than 17 mEq/L. CONCLUSION: Neonates at very low gestational ages and birth weights are more likely than larger or more mature infants to have low Apgar scores. Males, nonvertex-presenting infants, and those who are acidotic at birth also have an increased prevalence of low scores. Infants born to mothers treated with antenatal corticosteroids are less likely to have low Apgar scores. This finding indicates that antenatal corticosteroids may benefit the newborn at birth, before respiratory distress syndrome becomes apparent.