Interhospital Transfers of Maternal Patients: Cohort Analysis of Nationwide Inpatient Sample, 2011

OBJECTIVE

The objective of this study was to estimate the annual rate of interhospital transfers of pregnant and postpartum women in the United States and analyze associated patient and health system characteristics as measures of regionalized perinatal care performance.

METHODS

Separate weighted univariate analyses of the 2011 Nationwide Inpatient Sample (NIS) were performed for all maternal discharges, in-hospital deaths, and transfers. Multivariable logistic regression analyses for transfer dispositions adjusted for health system characteristics, maternal demographics, and diagnoses were performed. Additional perinatal service characteristics were analyzed using NIS merged with the 2011 American Hospital Association Annual Survey database.

RESULTS

An estimated 18,082 patients, 0.43% of maternal hospitalizations, were transferred to an acute care hospital; 81% occurred without childbirth delivery before transfer. Transfers were toward larger, urban teaching hospitals and hospitals with higher levels of obstetrical and neonatal care and were more likely in states with ≥4.0 maternal-fetal medicine specialists/10,000 live births. Blacks and Native Americans were more likely and Hispanics and Asians were less likely than white patients to be transferred. Privately insured women were less likely to be transferred than were others. Transfers were associated with life-threatening maternal diagnoses and fetal indications.

CONCLUSION

Transfers reflected a risk-based regionalized system of perinatal care, with racial and payer differences.

Neonatal Enterovirus Infection: Case Series of Clinical Sepsis and Positive Cerebrospinal Fluid Polymerase Chain Reaction Test with Myocarditis and Cerebral White Matter Injury Complications

Objective We describe five neonates with enteroviral (EV) infection to demonstrate central nervous system (CNS) and cardiac complications and report successful treatment of myocarditis with immunoglobulin intravenous (IVIG) in two. Study Design Case series identified during three enteroviral seasons in one neonatal intensive care unit (NICU) by cerebral spinal fluid (CSF) reverse transcriptase polymerase chain reaction (PCR) testing for EV in neonates suspected to have sepsis, but with sterile bacterial cultures. Results Cases were identified in each of three sequential years in a NICU with 800 to 900 admissions/year. Two cases were likely acquired perinatally; all were symptomatic with lethargy and poor feeding by age 5 to 10 days. All had signs of sepsis and/or meningitis; one progressed to periventricular leukomalacia and encephalomalacia. Two recovered from myocarditis after treatment that included IVIG 3 to 5 g/kg. Conclusion Neonates who appear septic without bacterial etiology may have EV CNS infections that can be diagnosed rapidly by CSF PCR testing. Cases may be underdiagnosed in the early neonatal period if specific testing is not performed. Neonates with EV infection should be investigated for evidence of periventricular leukomalacia, screened for myocarditis, and considered for IVIG treatment.

Surgery and neurodevelopmental outcome of very low-birth-weight infants

IMPORTANCE

Reduced death and neurodevelopmental impairment among infants is a goal of perinatal medicine.

OBJECTIVE

To assess the association between surgery during the initial hospitalization and death or neurodevelopmental impairment of very low-birth-weight infants.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort analysis was conducted of patients enrolled in the National Institute of Child Health and Human Development Neonatal Research Network Generic Database from 1998 through 2009 and evaluated at 18 to 22 months' corrected age. Twenty-two academic neonatal intensive care units participated. Inclusion criteria were birth weight 401 to 1500 g, survival to 12 hours, and availability for follow-up. A total of 12 111 infants were included in analyses.

EXPOSURES

Surgical procedures; surgery also was classified by expected anesthesia type as major (general anesthesia) or minor (nongeneral anesthesia).

MAIN OUTCOMES AND MEASURES

Multivariable logistic regression analyses planned a priori were performed for the primary outcome of death or neurodevelopmental impairment and for the secondary outcome of neurodevelopmental impairment among survivors. Multivariable linear regression analyses were performed as planned for the adjusted mean scores of the Mental Developmental Index and Psychomotor Developmental Index of the Bayley Scales of Infant Development, Second Edition, for patients born before 2006.

RESULTS

A total of 2186 infants underwent major surgery, 784 had minor surgery, and 9141 infants did not undergo surgery. The risk-adjusted odds ratio of death or neurodevelopmental impairment for all surgery patients compared with those who had no surgery was 1.29 (95% CI, 1.08-1.55). For patients who had major surgery compared with those who had no surgery, the risk-adjusted odds ratio of death or neurodevelopmental impairment was 1.52 (95% CI, 1.24-1.87). Patients classified as having minor surgery had no increased adjusted risk. Among survivors who had major surgery compared with those who had no surgery, the adjusted risk of neurodevelopmental impairment was greater and the adjusted mean Bayley scores were lower.

CONCLUSIONS AND RELEVANCE

Major surgery in very low-birth-weight infants is independently associated with a greater than 50% increased risk of death or neurodevelopmental impairment and of neurodevelopmental impairment at 18 to 22 months' corrected age. The role of general anesthesia is implicated but remains unproven.

Increased risk of death among uninsured neonates

OBJECTIVE

To estimate the contribution of health insurance status to the risk of death among hospitalized neonates.

DATA SOURCES

Kids' Inpatient Databases (KID) for 2003, 2006, and 2009.

STUDY DESIGN

KID 2006 subpopulation of neonatal discharges was analyzed by weighted frequency distribution and multivariable logistic regression analyses for the outcome of death, adjusted for insurance status and other variables. Multivariable linear regression analyses were conducted for the outcomes mean adjusted length of stay and hospital charges. The death analysis was repeated with KID 2003 and 2009.

PRINCIPAL FINDINGS

Of 4,318,121 estimated discharges in 2006, 5.4 percent were uninsured. There were 17,892 deaths; 9.5 percent were uninsured. The largest risks of death were five clinical conditions with adjusted odds ratios (AOR) of 13.7-3.1. Lack of insurance had an AOR of 2.6 (95 percent CI: 2.4, 2.8), greater than many clinical conditions; AOR estimates in alternate models were 2.1-2.7. Compared with insureds, uninsureds were less likely to have been admitted in transfer, more likely to have died in rural hospitals and to have received fewer resources. Similar death outcome results were observed for 2003 and 2009.

CONCLUSIONS

Uninsured neonates had decreased care and increased risk of dying.

Prediction of survival in infants with congenital diaphragmatic hernia based on stomach position, surgical timing, and oxygenation index

OBJECTIVE

To identify characteristics predictive of survival of patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Retrospective analysis of clinical characteristics including severity of lung disease measured by oxygenation index (OI) associated with single-center survival in CDH patients (n = 81) from 1992 to 2008. Data were analyzed using univariate and multivariable logistic regression, effect plots, and receiver operating characteristic (ROC) plots.

RESULTS

No patient died if the stomach was located in the abdomen. A left thoracic stomach position predicted decreased survival with ROC area under the curve (AUC) = 0.70. OI of ≤ 26 averaged over the first 12 hours of life predicted ≥ 50% survival for all patients, with AUC = 0.86. OI effect plots allow prediction of survival over a continuous OI range. No patient survived if mean OI was >51 in the first 12 hours of life. Delaying surgery for a median of 6 days improved survival probability for all patients with presurgery OI values ≤ 51.

CONCLUSION

Position of the stomach in the abdomen, delayed surgery, and less severe cardiopulmonary disease during the first 12 hours of life, as measured by mean OI, predicted improved survival probability among patients with CDH. Our CDH model, using mean OI, permits specific individual prediction of survival probability over a range of OI values.

Cytochrome P450 (CYP2D6) genotype is associated with elevated systolic blood pressure in preterm infants after discharge from the neonatal intensive care unit

OBJECTIVE

To determine genetic and clinical risk factors associated with elevated systolic blood pressure (ESBP) in preterm infants after discharge from the neonatal intensive care unit (NICU).

STUDY DESIGN

A convenience cohort of infants born at <32 weeks gestational age was followed after NICU discharge. We retrospectively identified a subgroup of subjects with ESBP (systolic blood pressure [SBP] >90th percentile for term infants). Genetic testing identified alleles associated with ESBP. Multivariate logistic regression analysis was performed for the outcome ESBP, with clinical characteristics and genotype as independent variables.

RESULTS

Predictors of ESBP were cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6) (rs28360521) CC genotype (OR, 2.92; 95% CI, 1.48-5.79), adjusted for outpatient oxygen therapy (OR, 4.53; 95% CI, 2.23-8.81) and history of urinary tract infection (OR, 4.68; 95% CI, 1.47-14.86). Maximum SBP was modeled by multivariate linear regression analysis: maximum SBP=84.8 mm Hg + 6.8 mm Hg if cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6) CC genotype + 6.8 mm Hg if discharged on supplemental oxygen + 4.4 mm Hg if received inpatient glucocorticoids (P=.0002).

CONCLUSIONS

ESBP is common in preterm infants with residual lung disease after discharge from the NICU. This study defines clinical factors associated with ESBP, identifies a candidate gene for further testing, and supports the recommendation to monitor blood pressure before age 3 years, as is suggested for term infants.

Risk of adverse drug events in neonates treated with opioids and the effect of a bar-code-assisted medication administration system

PURPOSE

The risk of adverse drug events (ADEs) in neonates treated with opioids and the effect of a bar-code-assisted medication administration (BCMA) system were studied.

METHODS

A prospective cohort study of neonates in a neonatal intensive care unit (NICU) was conducted. A BCMA system was operative for 50% of the study period. Structured medical record audits were conducted to identify medication errors and preventable ADEs. Stratified frequency distribution and Cox proportional hazards analyses were used.

RESULTS

Of 618 patients, 78 (12.6%) received postoperative care, 280 (45.3%) required assisted ventilation, and 72 (11.7%) were treated with opioids during their hospitalization. A total of 32 first preventable ADEs occurred. Univariate analyses demonstrated that postoperative status, assisted ventilation, and opioid administration were each significantly associated with ADEs. However, stratified frequency distribution analyses indicated that opioid administration during hospitalization was associated with preventable ADEs, controlling for postoperative status (p = 0.0019) or assisted ventilation (p = 0.0007). The odds ratio for any preventable ADE occurrence in a patient treated with an opioid was 4.74 compared with an infant not treated with an opioid. Patients who were treated with an opioid in the absence of a BCMA system had a 10% probability of an ADE after hospitalization for six days.

CONCLUSION

Infants in a NICU who were treated with opioids were at greater risk of a preventable ADE than other patients, adjusted for two medical conditions, assisted ventilation and postoperative status. A BCMA system reduced the risk of harm from an opioid medication error.

Impact of timing of birth and resident duty-hour restrictions on outcomes for small preterm infants

OBJECTIVE

The goal was to examine the impact of birth at night, on the weekend, and during July or August (the first months of the academic year) and the impact of resident duty-hour restrictions on mortality and morbidity rates for very low birth weight infants.

METHODS

Outcomes were analyzed for 11,137 infants with birth weights of 501 to 1250 g who were enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network registry in 2001-2005. Approximately one-half were born before the introduction of resident duty-hour restrictions in 2003. Follow-up assessments at 18 to 22 months were completed for 4508 infants. Mortality rate, short-term morbidities, and neurodevelopmental outcome were examined with respect to the timing of birth.

RESULTS

There was no effect of the timing of birth on mortality rate and no impact on the risks of short-term morbidities except that the risk of retinopathy of prematurity (stage > or =2) was higher after the introduction of duty-hour restrictions and the risk of retinopathy of prematurity requiring operative treatment was lower for infants born during the late night than during the day. There was no impact of the timing of birth on neurodevelopmental outcome except that the risk of hearing impairment or death was slightly lower among infants born in July or August.

CONCLUSION

In this network, the timing of birth had little effect on the risks of death and morbidity for very low birth weight infants, which suggests that staffing patterns were adequate to provide consistent care.

"Nurses Don't Hate Change" -- survey of nurses in a neonatal intensive care unit regarding the implementation, use and effectiveness of a bar code medication administration system

A bar code medication administration (BCMA) system reduced preventable adverse drug events (ADEs) by 47% in our neonatal intensive care unit (NICU). However, it is often expected that providers will not welcome technological change. Two years after BCMA system implementation, we studied the perceptions of nurses in our NICU to better understand their opinions about patient safety, use, acceptance and occupational effects of the new technology. Forty-six nurses (median age < 30 years) completed a 30-item questionnaire. Most nurses reported comfort using the system within two weeks. The majority believed that the system had prevented a medication error or ADE, although they were aware that medication errors persisted and workarounds occurred. Most reported that medication administration required more time with the BCMA system, but they believed that the alerts, which most reported occurred with < or =25% scheduled administrations, were not excessive. Over half of the nurses felt that the new system improved job satisfaction and increased professionalism. Although overall stress levels were moderate, nurses reported greater stress resulting from computer breakdowns than from other situations. Nurses reported strong support from supervisors, physicians and hospital administrators. These nurses were adaptive to the new technology when they believed it increases patient safety, nursing professionalism and job satisfaction and when they were supported by colleagues.

Effectiveness of a barcode medication administration system in reducing preventable adverse drug events in a neonatal intensive care unit: a prospective cohort study

OBJECTIVE

Patients are at risk of harm from medication errors. Barcode medication administration (BCMA) systems are recommended to mitigate preventable adverse drug events (ADEs). Our hypothesis was that a BCMA system would reduce preventable ADEs by 45% in a neonatal intensive care unit.

STUDY DESIGN

We conducted a prospective, observational, cohort study of a BCMA system intervention in a neonatal intensive care unit. Participants were admitted neonates during 50 weeks. Medication errors and potential or preventable ADEs were detected by a daily structured audit of each subject's medical record, with assignment of an event as a preventable ADE made by blinded assessors. The generalized estimating equation method was used in modeling the targeted, preventable ADE rate with covariates.

RESULTS

A total of 92,398 medication doses were administered to 958 subjects. The generalized estimating equation method yielded a relative risk of preventable ADE when the system was implemented of 0.53 (95% confidence limits 0.29 to 0.91, P = .04), adjusted for log(10)doses of medication/subject/day, a significant predictive covariate (P < .001), as well as for birth weight, sex, Caucasian race, birth cohort number, and nursing hours/subject/day.

CONCLUSION

The BCMA system reduced the risk of targeted, preventable ADEs by 47%, controlling for the number of medication doses/subject/day, an important risk exposure.

Abortion and the risk of subsequent preterm birth: a systematic review with meta-analyses

OBJECTIVE

To conduct a systematic review and meta-analyses of studies that test the association between induced or spontaneous abortion and subsequent preterm birth.

STUDY DESIGN

International databases were reviewed (1995-2007) using the terms preterm, premature, birth, labor, delivery, abortion, induced abortion, miscarriage and spontaneous abortion. Only studies that met prespecified objective criteria for methodologic design and reporting were included in the meta-analyses.

RESULTS

Twelve induced and 9 spontaneous abortion studies met inclusion criteria. Common adjusted odds ratios (ORs) for preterm birth following 1 and > or = 2 induced abortions were 1.25 (95% confidence interval [95% CI] 1.03-1.48) and 1.51 (95% CI 1.21-1.75), respectively. Four studies provided a common adjusted OR for < or = 32 weeks' births of 1.64 (95% CI 1.38-1.91). Meta-regression analysis revealed a previously unrecognized inverse relationship between the In OR and the control population preterm birth rate, explaining in part the observed heterogeneity among studies. Analysis of spontaneous abortion and subsequent preterm birth revealed a similar common adjusted OR and inverse meta-regression on the control preterm birth rates.

CONCLUSION

Induced and spontaneous abortion are associated with similarly increased ORs for preterm birth in subsequent pregnancies, and they vary inversely with the baseline preterm birth rate, explaining some of the variability among studies.

Evidence for a role of volatile amines in the development of neonatal hypergastrinemia

We investigated the presence of volatile aliphatic amines by fluorescamine and gas chromatographic-head space analysis in human breast milk and amniotic fluid to assess their role in neonatal hypergastrinemia. These volatile nitrogenous amino acid metabolites have been previously demonstrated to stimulate gastrin release in in vivo and in vitro laboratory preparations. In the present study we demonstrated that these gastrin-stimulatory volatile amines were present in significant concentrations in breast milk during the first several weeks after parturition and in amniotic fluid. The individual amines that were identified in both human milk and amniotic fluid samples were methylamine, dimethylamine, ethylamine, trimethylamine, propylamine, isobutylamine, and butylamine. This study provides indirect evidence to support the possibility that the hypergastrinemia measured in the fetus/neonate during the period immediately before and after birth may be attributable, in part, to the ingestion of fluid containing high concentrations of gastrin-stimulating amines.

Ontogenic development of gastrointestinal motility: IV. Duodenal contractions in preterm infants

Duodenal motility was studied by intraluminal manometry in 27 healthy infants of 26 to 42 weeks, gestational age. The frequency of contractions, the number of contractions per burst, and the intraluminal peak pressure during contractions all increased during a narrow postconceptual period, 29 to 32 weeks, regardless of length of gestation before birth. Antenatal beta-methasone administration to the mothers of 11 additional infants of 26 to 32 weeks gestational age was associated with increased duodenal contraction rate, number of contractions per burst, and intraluminal peak pressure compared with infants of similar gestational age whose mothers did not receive beta-methasone. The maturational effect of beta-methasone on duodenal motility was most pronounced in infants whose gestational age at birth was 26 to 29 weeks. Seven infants of 31 weeks' or longer gestational duration who had a CNS abnormality or insult had fasting duodenal contraction rates that were less than one half of the rate for normal infants of similar gestational age. These observations suggest that neonatal duodenal motility undergoes marked maturational changes between 29 and 32 weeks after conception and that these changes may be inducible before 29 weeks by corticosteroid administration. An intact CNS appears to be required for full expression of the maturational changes.

Relationship of human milk pH during course of lactation to concentrations of citrate and fatty acids

Human milk pH was measured in 309 samples obtained from 52 women who had delivered at term and lactated for as long as 10 months thereafter. The mean pH decreased from 7.45 for colostrum to a nadir of 7.04 during the second week of lactation. Thereafter, the pH of milk remained between 7.0 and 7.1 until 3 months postpartum and then increased gradually to 7.4 by 10 months. The change in hydrogen ion concentration in milk was associated with corresponding changes throughout lactation in the concentration of citrate but not with the concentration of lactose. Lactose concentration increased gradually for 3 weeks; the concentration of saturated medium-chain fatty acids increased more rapidly. One interpretation of these findings is that the hydrogen ions and citrate generated by mammary secretory cell metabolism are used after the second week of lactation for de novo synthesis of fatty acids more rapidly than they are synthesized. Milk samples from ruminants were found to have concentrations of hydrogen ions and citrate that are greater than and pH that is less than the respective measurements in human milk. The significance for the recipient infant of the predictable changes in human milk pH during lactation and of the higher pH of human milk throughout lactation relative to bovine milk is unknown. However, drug excretion into milk, milk enzyme activity, milk leukocyte function, and neonatal gastrointestinal function are affected by ambient pH and may be influenced by the pH of milk.

Ontogeny of ovine fetal liver and kidney plasma membrane insulin receptors and fetal growth

This investigation was performed to define certain characteristics of insulin-receptor interaction during the last 2 months of gestation in fetal sheep liver and kidney. Twenty-one sheep carrying a total of 46 fetuses were sacrificed at various gestational ages from 94 days to term; fetal and maternal livers and kidneys were analyzed by a radioreceptor assay for insulin binding characteristics. Specific binding of insulin to partially purified ovine fetal liver and kidney plasma membranes increased as gestation approached term, at which time specific binding was two- to fourfold greater to fetal than to maternal tissues. Associated with increased specific binding were late gestational increases in affinity of insulin for receptors in both fetal liver and kidney and an earlier increase in insulin receptor concentration in fetal kidney. These observations in fetal sheep liver and kidney are similar to reported observations in other species. However, the increase in specific binding of insulin to male fetal liver membranes was exponential; in contrast, there was no apparent increase in specific binding to female fetal liver membranes during the gestational interval surveyed. Both the weights and the vertebral column lengths of these fetuses were shown by multivariate analysis to be significantly affected by the interaction between specific binding of insulin and fetal sex. However, in 30 additional sheep fetuses we observed no difference between male and female fetuses in the increase with time in liver glycogen content. The lack of sex difference in this postreceptor event is consonant with the demonstrated dissociation between liver insulin receptors and glycogen synthesis in the late fetal rat. Our observations suggest that late gestational differences between male and female sheep fetuses in insulin specific binding to liver and, possibly, to other tissues such as cartilage, muscle, and/or fat, that are coupled to postreceptor events may account for differences in fetal growth between the sexes.

Fetal cartilage xylosyltransferase activity and skeletal growth in sheep

The activity of UDP-D-xylose:proteoglycan core protein beta-D-xylosyltransferase (EC 2.4.2.26), the enzyme that catalyzes the initiation of the polysaccharide chain linkage to the core protein of proteoglycans, was measured in costal cartilage from 20 fetal sheep of 65-138 days gestation. Activity of the enzyme was estimated from the transfer of [14C]xylose from UDP-[14C]xylose to silk as the acceptor protein. The specific activity decreased approximately 10-fold and was found to be highly correlated with the decremental rate of growth in length of the fetal vertebral column. These observations, together with the known gestational decrease in the in vitro rate of uptake of radiolabeled sulfate by ovine fetal cartilage, a subsequent step in proteoglycan synthesis, support the hypothesis that normal fetal skeletal growth is dependent during the last one-half of gestation on the activity of xylosyltransferase in cartilage.

Effects of ovine maternal hyperglycemia on fetal regional blood flows and metabolism

Fetal combined ventricular output (CVO) and regional distribution of blood flow were measured in 12 ewes in late gestation by the radiolabeled microsphere method. Three sets of determinations were made in sequence beginning with a control study and repeating the measurements after the ewe had received intravenous glucose at 0.35 g X min-1 for 90 min and again after the ewe had received glucose at 0.85 g X min-1 for a second 90-min period. Maternal whole blood glucose concentrations were 2.98 +/- 0.18 (means +/- SE), 10.43 +/- 0.45, and 21.59 +/- 0.90 mM during the respective study periods. Fetal CVO did not change during maternal hyperglycemia; however, it was redistributed, with a decrease in umbilical blood flow to the placenta from 43.5% of CVO to 31.9 and 30.8%, respectively. The fetal carcass, heart, intestines, kidneys, liver, and adrenals each received increased percent CVO; these increases equaled the decrease in placental blood flow. Fetuses became hypoxemic and developed a mixed acidemia during induced maternal hyperglycemia, but oxygen delivery to the heart, brain, and kidneys was unchanged. These observations indicate that maternal hyperglycemia results in previously unsuspected fetal cardiovascular responses.

Decreases in ovine fetal cartilage sulfate uptake and serum sulfate during gestation

In vitro assays for [35S]sulfate uptake by ovine fetal costal cartilage were used to assess gestational changes in cartilage metabolism. Addition of 20% normal human serum to the incubation medium increased fetal cartilage [35S]sulfate incorporation into glycosaminoglycans. Both basal and human serum-stimulated uptakes of [35S]sulfate by fetal sheep cartilage decreased from midgestation to full term. The incremental response in [35S]sulfate uptake that was stimulated by human serum decreased as gestation proceeded to full-term. Fetal serum sulfate concentration decreased logarithmically during gestation, raising the possibility that cartilage sulfate uptake might become substrate limited as full term is approached. Perfusion of seven late gestation sheep fetuses for 7 days with Na2SO4 to achieve serum sulfate concentrations similar to those observed earlier in gestation resulted in a 33% increase in mean cartilage [35S]sulfate uptake compared with that of control twin fetuses, but uptake was not increased to values that occurred spontaneously earlier in gestation. These results suggest that the decreasing rate of [35S]sulfate uptake by fetal cartilage during the last half of gestation is associated only minimally with decreasing serum sulfate levels and is most consistent with intrinsic change in resting chondrocyte metabolism during gestation.

Contraplacental hypogastrinemic effect of gastrin infusion in sheep

Infusion of gastrin, G-17I, at 0.4 microgram/min into either the maternal or fetal venous circulation of six late gestation sheep was associated with increases in serum gastrin concentration in the infused circulation and reciprocal decreases in the serum gastrin concentration in the other circulation (contraplacental) that perfused the placenta. Pentagastrin infusion at 0.4 microgram/min was associated with an increase in C-terminal specific gastrin immunoreactivity in both the infused and the contraplacental circulations. These observations suggest that biologically active fragments of gastrin, but not the intact molecule, may cross the ovine placenta. An alternative explanation for our results is that gastrin infusion into either the maternal or fetal circulation which perfuses the placenta may result in the release of an inhibitor (i.e., somatostatin) into the other circulation. Of broad importance, these observations indicate that although intact polypeptide hormones may not traverse the placenta, their concentrations in maternal and fetal sera may not be as independent as previously believed. Serum gastrin half-life values in late gestation sheep fetuses, lambs, and ewes were determined to be 13.7 +/- 1.9, 16.7 +/- 2.6, and 15.2 +/- 2.8 min, respectively. These similar values indicate that the relatively high serum gastrin concentrations observed in near-term sheep fetuses are not the result of prolonged half-life in the fetus.

Umbilical glucose and lactate extractions during maternal hyperglycemia in sheep

Umbilical glucose and lactate extractions were determined in previously instrumented pregnant ewes into some of which D-glucose was infused to produce graded levels of maternal hyperglycemia as great as 20 mM. While fetal arterial glucose concentration continued to increase linearly as a function of maternal arterial glucose concentration during maternal hyperglycemia, the umbilical venoarterial difference in blood glucose concentration did not, and umbilical glucose extraction approached a plateau at approximately 0.063 mmol X min-1 X kg fetus-1 at maternal glucose concentrations greater than approximately 8 mM. The observed plateau in glucose extraction is consistent with saturation at high maternal glucose concentrations of the carrier mechanism for transport of glucose from the maternal to the fetal aspects of the trophoblast. The observed value of the plateau in umbilical extraction of glucose is slightly less than the maximum extraction predicted from previously published equations for this species, but the maternal blood glucose concentration at which the observed maximum occurred agrees closely with the value predicted by those equations. Umbilical lactate extraction, 0.031 +/- 0.021 mmol X min-1 X kg fetus-1, was independent of maternal arterial blood glucose and lactate concentrations and was independent of umbilical glucose extraction.

Comparison of the gastrointestinal growth- promoting effects of rat colostrum and mature milk in newborn rats in vivo

The purpose of this study was to compare the effects of rat colostrum and mature milk on newborn rat gastrointestinal growth under conditions that controlled the possible confounding effects of energy intake and mode of feeding. Newborn Sprague-Dawley rat pups were tubefed equicaloric amounts of rat colostrum or mature rat milk for 40 h before they were killed. Compared to littermates that were killed immediately after birth, both groups of fed rats demonstrated increases in the weights of stomach and intestine, but there was no organ weight difference detected between colostrum-fed and mature milk-fed rat pups. However, both the concentration of DNA and the rate of synthesis of DNA in the intestines were greater in rats fed colostrum than in those at birth or those mature milk. Although the pancreas exhibited no detectable increase in weight by 41 h, the DNA concentration and total DNA content increased and RNA/DNA ratio decreased in both fed groups, also without apparent difference between rats fed colostrum and those fed mature milk. The rate of 3H-thymidine incorporation into DNA in pancreas, however, was greater in colostrum-fed pups than in mature milk-fed pups. These differences at 40 h age in intestinal and pancreatic cell replication activity, but not organ weights, can be ascribed to feeding colostrum.

Ontogenic studies of gastrointestinal function. II. Lower esophageal sphincter maturation in neonatal beagle puppies

The purpose of the present study was to investigate the postnatal development of lower esophageal sphincter (LES) competence in the beagle and to determine the role of gastrin in LES functional ontogeny. Eleven beagle puppies taken from two litters were studied. All puppies were allowed to suckle during the first 3 postnatal wk. In the 4th wk, all puppies were weaned, and by the 5th wk only solid chow was offered. Intraluminal manometric pressure determinations were obtained in unanesthetized, unsedated puppies using twin-lumen, 1.7 mm OD, 1 mm ID polyvinyl catheters. A 12-15 min baseline period of intraluminal pressure was monitored, after which the puppies received successive doses of 0.03, 0.1, 1.0, and 8.0 micrograms/kg pentagastrin (PG) SC spaced at 45-min intervals. Progressive increases in LES pressure both during basal periods and during gastric contractions and in gastric fundus (GF) pressures during gastric contractions occurred during the 1st 5 weeks of life. An increase in pressure gradient between the LES and GF during gastric contraction occurred from birth through 5 wk of age. There was no response to 0.1-8.0 micrograms/kg PG until postnatal days 5-6 when the LES pressure gradient in the basal state increased in response to each of these doses. There was also no significant response by the LES to PG during gastric contraction until days 11-12 when all doses of PG evoked enhancement of LES pressure. These studies suggest that an increase in LES-GF intraluminal pressure gradient develops during the initial 2 postnatal wk in this species and that this development does not involve the hormone gastrin. Later, however, the pressure gradient may depend upon both age and gastrin since a two-way analysis of variance indicated that not only is LES pressure affected by postnatal age and by PG dose, but that there is an interaction between postnatal age and PG dose which is significant. By the fifth wk, there was an apparent dose-response effect in which the lower two doses produced increased LES pressure and the larger two doses produced decreased LES pressures.

Effect of maternal serum insulin on umbilical extraction of glucose and lactate in fed and fasted sheep

In 18 chronically instrumented pregnant ewes in late gestation, umbilical extractions of glucose and lactate were determined before and during the continuous infusion of ovine insulin, 0.25 mU/kg . min, into one uterine artery. Studies were conducted in both well-nourished and fasting ewes. Exogenous insulin increased the umbilical extraction of glucose without altering the umbilical extraction of lactate over the range of concentrations of maternal blood glucose encountered in the fed and fasted states. Moreover, the efflux of lactate into the uterine venous circulation in two additional ewes was not altered by the administration of insulin. These studies support the hypothesis that maternal circulating insulin binds to insulin receptors on the microvillous brush border of the placenta to effect an increase in the carrier-mediated transfer of glucose rather than cause an intraplacental decrease in the catabolism of glucose to lactate. The results suggest that, as maternal levels of blood glucose and serum insulin spontaneously rise in concert over the physiologic range, both factors may contribute to the increasing umbilical extraction of glucose. Furthermore, these observations raise the possibility that decreased binding of insulin by placental insulin receptors, which is reported to occur in placentas from diabetic women, may be accompanied by a relatively decreased umbilical uptake of glucose for a given maternal concentration of glucose, but not of lactate.

Ontogeny of tissue and serum gastrin concentrations in fetal and neonatal sheep

We investigated the perinatal ontogenic changes in ovine serum and tissue gastrin concentration. Fetal and maternal serum gastrin levels in serums obtained from indwelling catheters in the fetal and maternal circulations and tissue gastrin levels were assessed by radioimmunoassay and immunohistochemistry. Fetal serum gastrin concentration was undetectable until the 107th day of gestation and significantly increased to levels surpassing maternal values. Neonatal serum hormone concentration continued to rise, reaching a peak during the 4th postnatal wk and decreasing after the 4th wk coincident with weaning. Maternal serum gastrin concentration did not vary during pregnancy and did not correlate with fetal serum gastrin levels. Fetal abomasal and duodenal gastrin concentrations and abomasal G-cell number increased in parallel with the developmental alterations in fetal serum hormone levels during gestation. The developmental increase in abomasal gastrin concentration was not associated with a shift in the molecular form of the hormone. These findings support the hypothesis that circulating gastrin in the fetus is of fetal origin.

Hydrolysis of dipeptides by human and ovine placentas

Human and ovine placental tissue homogenates were assayed for dipeptidase activity in vitro. Glycyl-L-leucine, L-leucyl glycine, glycyl-L-lysine, and L-lysyl glycine were hydrolyzed by placental homogenates. The pH optimum for the reaction was 8.0. The relationship between enzyme activity and concentration was linear for placental homogenate concentrations between 0.01 and 0.10 mg protein/ml of reaction mixture. Enzyme activities were 1.92 +/- 0.12 (S.E.) micromoles/min/mg protein for hydrolysis of glycyl-L-leucine, 0.34 +/- 0.06 (S.E.) micromoles/min/mg protein for hydrolysis of glycyl-L-lysine by human placenta, and 2.79 +/- 0.80 micromoles/min/mg protein and 0.41 +/- 0.25 micromoles/min/mg protein, respectively, by ovine placenta. The infusion of glycyl-L-leucine into the uterine artery of unstressed catheterized pregnant ewes yielded increased concentrations of both component amino acids in uterine venous blood and of leucine in umbilical venous blood.

Effects of fasting on uterine blood flow and substrate uptake in sheep

Twelve chronically instrumented late-gestation ewes fasted for 5 days were found to have a 25% decrease in total uterine blood flow and a 20% decrease in placental blood flow. Cardiac output was unchanged but was redistributed, as measured by radiolabeled microspheres, in a pattern similar to that produced by catecholamines. Fasting also was associated with hypoglycemia and altered whole blood amino acid concentrations. Uterine uptakes of glucose, oxygen, essential amino acids and glutamine, an important uterine and fetal nutrient, were decreased significantly during fasting. The increased hepatic blood flow and decreased arterial concentrations of glucogenic amino acids observed during fasting are consistent with a redistribution of maternal cardiac output to support maternal hepatic gluconeogenesis at the expense of nutrient supply to the gravid uterus.

CSF neurotransmitter studies. An infant with ascorbic acid-responsive tyrosinemia

A female newborn infant with Marfan-like habitus experienced lethargy and hypothermia associated with tyrosinemia that was not corrected by the administration of ascorbic acid at 50 mg/day but that subsequently responded to ascorbic acid at 500 mg/day. Cerebrospinal fluid analysis for neurotransmitter metabolites showed elevated concentrations of homovanillic acid and 5-hydroxyindoleacetic acid when the child was symptomatic and normal concentrations after successful ascrobic acid therapy. These observations suggest that a high level of tyrosine in serum can affect the metabolism in the brain of dopamine and serotonin.

Intraventricular hemorrhage in the neonate born at term

Four term infants were found by computerized cerebral tomography (CT) to have intraventricular hemorrhage. All were male infants who had experienced substantial intrapartum complications. One infant had subtle clinical signs at 2 days of age; the others had major neurologic findings including seizures and ophthalmoplegia that occurred at 1, 4, and 6 weeks of age, respectively. Three infants in whom the hemorrhages were indistinguishable by CT from those described in preterm infants now have arrested hydrocephalus and normal development. The fourth infant was found to have a large glioblastoma at the site of origin of his initial hemorrhage. These cases emphasize the need to consider this diagnosis in neonates born at term who have abnormal neurologic signs.

Neonatal gastric motility in dogs: maturation and response to pentagastrin

Postnatal changes in the pH of gastric secretions, gastric motility, serum gastrin concentration, and response of the stomach to pentagastrin administration were studied in 15 beagle puppies from birth to 5 wk of age. Motility was monitored manometrically via twin-lumen catheters 3--6 h postprandially. Mean gastric pH was stable at 5.85 until the 7th postnatal day when pH decreased to 3.45; pH then increased to a mean value of 4.95 through the 18th day. Antral contractions increased from 0.2 contractions per min on the day of birth to a maximum 2.3 contractions per min on the 11th day and then gradually declined. Pentagastrin (8.0 microgram/kg sc) had no effect on gastric pH or motility until the 2nd postnatal wk. Pentagastrin inhibited the rate and peak pressure of antral contractions from the 2nd through the 5th wk. Mean serum gastrin concentrations in six puppies were greater than values for adult dogs, attaining a preweaning maximum on the 9th day.

Human colostral cytotoxicity: I. Antibody-dependent cellular cytotoxicity against Herpes simplex viral-infected cells mediated by colostral cells

Human colostral cells in combination with antibody were able to destroy Herpes simplex virus-infected cells (Antibody-dependent cellular cytotoxicity--ADCC) while demonstrating very low spontaneous (non-antibody mediated) cytotoxicity (SCT). The colostral cells involved in ADCC required a high effector to target ratio, were mononuclear, adherent and totally inhibited by latex particles. These results demonstrate that a subpopulation of human colostral macrophages can mediate ADCC against virus-infected target cells. The biologic implications of intact colostral cell ADCC and low SCT in regard to protecting the neonate from infection and maternal cell mediated gastrointestinal damage are discussed.

Effect of uterine artery insulin infusions on umbilical glucose uptake in sheep

Although glucose is an important fuel for fetal oxidative metabolism, regulation of its availability to the mammalian fetus is poorly understood. This study was performed to determine the effect of infusions of insulin into the uterine arterial circulation on umbilical uptake of glucose in chronically instrumented, unstressed sheep. Twenty-eight determinations of umbilical glucose uptake and diffusion clearance of glucose by the placenta were made in four ewes. Immediately following a control study during which saline was infused into the uterine artery, porcine regular insulin diluted in saline was infused at 0.05 to 8.1 mU/min . kg uterine weight for 20--30 min and the determinations were repeated. Subsequent studies were performed at the conclusion of additional infusions of insulin to a maximum of 21.6 mU/min . kg. There was a significant increase in umbilical glucose uptake during initial insulin infusions (4.47 +/- 0.6 mg/min . kg fetus) compared to the control studies (3.08 +/- 0.6 mg/min . kg) associated with an increase in diffusion clearance (13.8 +/- 1.9 ml/min . kg fetus vs. 8.99 +/- 1.8 ml/min . kg). When the total cumulative dose of exogenous insulin, It, was 162 mU/kg uterine weight or less, the umbilical uptake of glucose, Q, may be expressed as a function of maternal arterial blood glucose concentration in milligrams per dl, [A], and of It.

Determination of newborn special care bed requirements by application of queuing theory to 1975-1976 morbidity experience

The movement of newborn infants from the delivery room of a level III perinatal center to nursing units that provided different levels of care was prospectively documented for 1975 and 1976. These data were employed in a computer modeling experiment based on sequential queuing theory to determine the relationships between numbers of available intermediate and maximum care nursery beds, the probability that a given newborn arrival could not be accommodated, and the occupancy rates for each level of care. The nursery bed requirements for the level III center were used to estimate the number of special care beds needed by the regional Health Service Area.

Congenital torsion of the penis in father-son pairs

Congenital torsion of the penis was observed in 5 newborns, 3 of whom had fathers with torsion of the penis. We believe that this common benign condition may be transmitted as an autosomal dominant trait.

Syndrome of inappropriate antidiuretic hormone secretion in neonates with pneumothorax or atelectasis

Nine episodes of the syndrome of inappropriate antidiuretic hormone secretion occurred in five newborn infants following atelectasis or pneumothorax. All infants had pre-existing lung disease and were being treated with positive pressure ventilation. The mean interval between acute atelectasis or pneumothorax and the development of diagnostic hyponatremia, hypo-osmolal serum, hyperosmolal urine, and oliguria was 13.4 hours. Fluid restriction and removal of the triggering event resulted in resolution of the abnormalities within 1.5 to 4 days. Infants who develop atelectasis or pneumothorax should be evaluated for the subsequent occurrence of SIADH; the administration of a water load to them may result in dilutional hyponatremia, for which fluid restriction, not sodium infusion, is the proper therapy.

Rapid karyotypic diagnosis of a case of trisomy 18 in the neonatal intensive care unit

Recent modifications in the technic of bone marrow preparation for karyotypic analysis permit confirmation of chromosomal aneuploidy such as trisomy 13, 18, or 21 within two to four hours. The patient reported illustrates how the technic of bone marrow karyotyping may assist the pediatrician in treating an acutely ill newborn, in accurately counseling parents, and in selecting with them an appropriate course of management.

Osmolalities of infant formulas

The osmolalities of breast milk and of 36 products that may be fed to infants were determined by the freezing-point depression method. A wide range of osmolality was observed among formulas that provide 67 kcal/100 ml, and many have osmolalities greater than 400 mOsm/kg of water. Reconstituted powdered formulas have osmolalities that are widely varied from batch to batch, are greater when prepared by scoop measures when the osmolalities of corresponding ready-to-feed formulas, and are greater than the osmolalities of the formulas prepared by weighed measures from the manufacturer's formulation. The osmolality of products for oral consumption should be considered in the selection of formulas for preterm infants.

Development of gluconeogenic enzymes in fetal sheep liver and kidney

In the sheep, the system of enzymes necessary for conversion of nonhexose substrates to glucose becomes active during late fetal life. Glucose-6-phosphatase and fructose-1,6-diphosphatase, two of the four key gluconeogenic enzymes, appear in significant amounts between 100 and 120 days gestation. Phosphoenolpyruvate carboxykinase activity is comparable to mature animals as early as 45 days gestation. Two aminotransferases, necessary to allow amino acid access to the gluconeogenic pathway, likewise have substantial activity as early as 45 days gestation. Hence, the surge of glucose-6-phosphatase and fructose-1,6-diphosphatase at 100-120 days gestation makes possible the endogenous production of new glucose by fetal sheep at a time when the amount of glucose transferred from the maternal circulation is less than the total aerobic substrate utilized by the fetus. Both renal cortex and liver have similar developmental patterns for the gluconeogenic enzymes, although renal cortex generally shows greater activity than liver. This observation holds true for tissue from both fetal and mature animals.

Effect of estradiol-17beta on blood flow to reproductive and nonreproductive tissues in pregnant ewes

The effect of estradiol-17beta (1 mug per kilogram) on regional blood flow and cardiac output was studied by means of radionuclide-labeled microspheres in 6 nonpregnant and 13 pregnant ewes five to seven days after operation. Estradiol caused vasodilation in myometrium, endometrium, and placental cotyledons throughout pregnancy, but these responses were significantly less than the fifteenfold increase seen in the nonpregnant uterine tissues. Significant vasodilation also occurred in the ovaries, cervix, vagina, uterine tubes, mammary gland, skin, and adrenal glands of pregnant ewes. Cardiac output increased by 14%. No significant change in uterine oxygen consumption was associated with the increase in blood flow to the pregnant uterus.