Persistent Pulmonary Hypertension and Histologic Chorioamnionitis in Preterm Infants: Controlled Study.

Persistent pulmonary hypertension (PPHN) of the newborn is one of the most challenging acute disorders of postnatal transition with substantial morbidity and mortality. The aim of the study was to find if there is an association between persistent pulmonary hypertension and histologic chorioamnionitis in preterm infants. 27 preterm infants with echocardiographic evidence of PPHN within the first 3 days of life were eligible for the study. A matched control group of 27 patients was chosen according to gestational age, date of birth, and gender. Data collection included the need for respiratory support, use of nitric oxide oxygen supplementation, duration of rupture of membranes, blood culture, blood count, and C-reactive protein levels at birth and 12 h. Maternal clinical and laboratory data suggesting clinical chorioamnionitis Placentas of both groups were examined. Differences between groups were analyzed using two-tail t test, Kolmogorov-Smirnov test, Chi-square test. No statistically differences were found in all parameters compared between groups, except for a higher number of patients in the PPHN group who were treated by oxygen supplementation. An association was not found between the incidence of HCA and echocardiographic PPHN in preterm infants in the first 3 days of life.

Vacuum extraction and herpes simplex virus infection.

OBJECTIVE: To search for an association between delivery by vacuum extraction and an increased neonatal risk for herpes simplex virus (HSV) infection. METHODS: In a cross-sectional, descriptive, controlled study, the study (vacuum extraction) and control (spontaneous delivery) groups each included 50 consecutive women with no history of HSV infection. Cultures for HSV were obtained from the genital tracts of all parturient women and the scalps of their newborns. RESULTS: Following operative vaginal delivery, two newborns (4%) had scalp vesicles and cultures were positive for HSV for both mothers and newborns; two newborns (4%) had scalp vesicles and cultures were negative for HSV; and two newborns (4%) without scalp vesicles had cultures positive for HSV. Following spontaneous delivery, cultures were positive for HSV for four women and their newborns (8%). CONCLUSION: Herpes simplex virus isolated from the scalps of newborns may often result from colonization rather than infection.

Neonatologists are using much less dexamethasone.

Two historical cohorts (1993-1994 and 2001) of preterm infants ventilated for respiratory distress syndrome were compared. Dexamethasone administration fell from 22% to 6%. Chronic lung disease in survivors rose slightly from 13% to 17%, and mortality fell from 21% to 15% (other causes). The effect of restriction of dexamethasone use on chronic lung disease and mortality remains to be seen.

[Survival of a 300 gram infant].

Despite progress in neonatal medicine and the development of new methods of treatment such as surfactant administration and new modalities of ventilation, mortality remains significant among newborn infants weighing less than 500 gram. Neurodevelopmental outcome of infants born before 26 weeks gestation is perceived as very poor. As the result of recent reports, there have been calls for limitation of medical care for these infants. We report of only 4 infants weighing less than 400 grams, who have survived. Two of these infants developed respiratory failure and required aggressive conventional mechanical ventilation. We report on the survival of an infant delivered before the completion of 26 weeks gestation period and weighing 300 grams. The infant was ventilated by high frequency oscillatory ventilation for respiratory distress syndrome. She is the second smallest infant reported in the medical literature.

Variations in neutrophil count in preterm infants with respiratory distress syndrome who subsequently developed chronic lung disease.

Neutrophil counts were studied in 62 preterm infants receiving mechanical ventilation for neonatal respiratory distress syndrome (NRDS). Exploratory analysis indicated that the severity of NRDS, as demonstrated by fractional inspired oxygen (FiO2), mean airway pressure (MAP), arterial-alveolar PO2 ratio (a/APO2) and oxygenation index (OI), was correlated with percentage change of neutrophil counts during the first 5 days of life. Further analysis demonstrated that infants with NRDS who subsequently developed chronic lung disease (CLD) (n = 21) had statistically significant differences in variation of neutrophil counts when compared with the remainder (n = 41) without CLD (-35.0% +/- 4.3 vs. -16.9% +/- 5.8, p < 0.02). It is concluded that significant variations in neutrophil counts during the first 5 days of life may be found in infants with NRDS who subsequently develop CLD and that these changes may have predictive value regarding the development of CLD.

Factors affecting plasma bilirubin in preterm infants ventilated for respiratory distress syndrome.

OBJECTIVE: To evaluate the contribution of various factors to plasma bilirubin level in preterm infants with a birth weight of < 1500 gm in need of mechanical ventilation for respiratory distress syndrome (RDS) during their first week of life. METHODOLOGY: A total of 50 very low birth weight (< 1500 gm) preterm infants consecutively admitted to the neonatal intensive care unit were studied. Plasma bilirubin levels were determined every 8 hours for the first week of life. Data relating to daily body weight, daily fluid intake, age at onset of gavage feeds, daily caloric intake, and grade of intraventricular hemorrhage (IVH) were collected. Data relating to mechanical ventilation were collected every 4 hours as follows: fractional inspired O2, arterial PO2, arterial PCO2, and mean airway pressure. An arterial/alveolar PO2 ratio and a corrected oxygenation index were computed for the first 2 days of life. A bilirubin index (BI), defined as the ratio of peak plasma bilirubin level to birth weight1/3, was used to study the association between bilirubin and the above variables. A BI was also used as a criterion for starting and discontinuing phototherapy. Multiple linear regression analysis was used to model BI. RESULTS: IVH (p < 0.0001), age at onset of gavage feeds (p < 0.003), oxygenation index (p < 0.007), and gestational age (p < 0.05) made a significant contribution to variations in BI (37.16%, 43.71%, 48.99%, and 53.33%, respectively). CONCLUSION: Hyperbilirubinemia in ventilated preterm infants with RDS is most likely multifactorial; entities quite distinct from RDS (such as nutrition and IVH) may significantly contribute to its variation.

A prospective search for urinary tract abnormalities in infants with isolated preauricular tags.

OBJECTIVE: To determine whether isolated preauricular tags are associated with urinary tract abnormalities. METHODOLOGY: Seventy consecutive infants with isolated preauricular tags were examined by ultrasonography for urinary tract abnormalities on day 3 or 4 of life between January 1993 and August 1999, after parental consent and ethics approval. Karyotype analysis was conducted in all infants with urinary tract abnormalities. The study group was compared with a control group of 69 infants without preauricular tags hospitalized during the same period. The control group consisted of infants who underwent urinary tract ultrasonography as part of an investigation for persistent regurgitation and/or vomiting associated with cyanotic spells. RESULTS: Urinary tract abnormalities were detected in 6 infants with isolated preauricular tags (6/70; 8.6%). Types of anomalies were as follows: hydronephrosis in 5 cases and horseshoe kidney in 1 case. The causes of hydronephrosis were ureteropelvic junction obstruction in 3 cases and vescicoureteric reflux in 2 cases. None of the infants in the control group had such abnormalities. All infants with urinary tract abnormalities had normal chromosomes. No statistically significant differences existed between groups concerning birth weight, gestational age, intrauterine growth, and male-to-female ratio. CONCLUSIONS: This study suggests a significant prevalence of urinary tract abnormalities in infants with preauricular tags. We recommend, therefore, that urinary tract ultrasonography be conducted in the routine assessment of infants with isolated preauricular tags.

Intrauterine growth retardation and brainstem auditory-evoked response in preterm infants.

Intrauterine growth retardation is frequently associated with intrauterine undernutrition, and can deleteriously affect brain function. Twenty-eight premature small for gestational age infants were compared with 28 premature appropriate for gestational age infants to determine whether intrauterine growth retardation was associated with abnormalities in the auditory pathway in the early neonatal period. The auditory pathway was studied between 4-18 wk of life by analysis of brainstem auditory-evoked potentials elicited by a 10/s 75 decibel above normal adult hearing level (dB nHL) click stimulus presented at the infants' ears. Peak latencies of components I, III and V, and interpeak latencies I-III, III-V and I-V, yielded no statistically significant differences between groups. The present study indicates that intrauterine growth-retarded premature infants may not have abnormalities of brainstem auditory-evoked response in the early neonatal period.

Brainstem auditory evoked response in newborns and infants.

Brainstem auditory evoked response studies were carried out on 105 neonates, with gestational ages ranging from 26 to 43 weeks. The mean chronologic and postconception ages of the subjects were 6.5 weeks and 40.6 weeks, respectively. Statistically significant relationships between brainstem auditory evoked response and gestational age, postconception age (gestational age plus chronologic age), and the 5-minute Apgar score, were demonstrated. Shortening of brainstem auditory evoked response as related to postconception age was demonstrated and this trend was statistically significant. However, of these factors a statistically significant shortening (maturation) of evoked response was demonstrated only in relation to postconception age.

Failure of early postnatal dexamethasone to prevent chronic lung disease in infants with respiratory distress syndrome.

OBJECTIVE: To study the effect of early postnatal dexamethasone (days 1-3) on the incidence and severity of chronic lung disease in preterm infants with respiratory distress syndrome. METHODS: A multicentre, randomised, placebo controlled, blinded study was carried out in 18 neonatal intensive care units in Israel. The primary outcome measure was survival to discharge without requirement for supplemental oxygen therapy beyond 28 days of life. The secondary outcome measures were requirement for mechanical ventilation at 3 and 7 days, duration of ventilation or oxygen therapy, need for subsequent steroids for established chronic lung disease and incidence of major morbidities. RESULTS: The study consisted of 248 infants (dexamethasone n = 132; placebo n = 116). No differences were found in the outcome variables except for a reduction in requirement for mechanical ventilation at age 3 days in treated infants (dexamethasone 44%, placebo 67%; P = 0.001). Gastrointestinal haemorrhage, hypertension, and hyperglycaemia were more common in treated infants, but no life threatening complications, such as gastrointestinal perforation, were encountered. CONCLUSIONS: These data do no support the routine use of early postnatal steroids, but may justify further study in a selected, high risk group of infants.

Autologous umbilical cord blood transfusion.

The purpose of this study was to examine some aspects of umbilical cord blood collection for autologous transfusion in premature infants. All 120 microbacterial cultures (aerobic and anaerobic) of cord blood samples as well as 30 cultures of mycoplasma were treated. Cord prothrombin fragment (F 1 + 2) concentrations were quantified at one and 10 minutes after clamping of the cord. F 1 + 2 concentrations assessed on 25 newborn infants were similar and no linear association with time of clamping could be drawn. This means that cord blood thrombosis is not activated for at least 10 minutes following clamping of the cord. As far as is known, the first newborn infant to benefit from this method of transfusion is reported here. The premature infant received two portions of autologous blood (on days 5 and 7). No untoward effects were noted. Blood, collected from the umbilical cord, is a safe source for autotransfusion, provided that bacteriological testing has been carried out.

Predictive inability of cord zinc, magnesium and copper levels on the development of benign hyperbilirubinemia in the newborn.

Cord serum concentrations of zinc, magnesium and copper were determined in 90 healthy term infants. The infants were divided by peak bilirubin values into an icteric group (peak bilirubin > 136 mumol/l) (n = 21) and a control group (peak bilirubin < or = 136 mumol/) (n = 69). Mean cord serum zinc, magnesium and copper concentrations in the icteric group did not differ from those of the control group. Furthermore, no significant correlation was found between peak serum bilirubin concentrations and cord serum concentrations of these three elements. We conclude that cord serum concentrations of zinc, magnesium or copper are not useful in predicting which neonates will develop hyperbilirubinemia.

Transient neonatal hypothyroxinemia and the auditory brainstem evoked response.

Ten premature infants with low serum thyroxine levels (less than 84 nmol/L) were compared with 10 biochemically euthyroid infants to determine whether hypothyroxinemia in such infants can lead to alterations in the auditory pathway. The auditory pathway was studied between 6 and 11 wk of life by analyzing brainstem evoked potentials elicited by a 10/s, 75 dB above normal adult hearing level click stimulus presented at the infant's ears. Peak latencies of components I, III, and V and interpeak latencies I-III, III-V, and I-V did not yield statistically significant differences between groups. The present study indicates that untreated neonatal hypothyroxinemia does not lead to abnormalities of auditory brainstem evoked response.

Umbilical ascorbic acid levels in fetal distress.

Umbilical arterial and venous blood samples were obtained at birth immediately after clamping the cord in 38 infants. Simultaneously, maternal arterial samples were collected. Arterial blood samples were analyzed for acid-base blood gas content and venous blood samples were analyzed for plasma ascorbic acid levels. The umbilical plasma ascorbic acid level was significantly higher when compared with maternal plasma levels (172.9 +/- 39.2 vs. 57.8 +/- 21.0 mumol/liter, p < 0.0001). Correlations between maternal ascorbic acid levels and umbilical cord levels proved to be insignificant. Umbilical ascorbic acid levels in the 2 groups of infants characterized by the presence or absence of fetal distress showed significantly higher levels in the fetal distressed group (17 infants) when compared to the non-distressed group (21 infants)--191.9 +/- 36.0 vs. 157.4 +/- 34.6 mumol/liter, p < 0.005. The use of an umbilical cord ascorbic acid cut-off point of 95.8 mumol/liter gave a sensitivity of 76% and a specificity of 67% as predictors for the presence or absence of fetal distress (p < 0.025). The results of the present study demonstrate a substantial increase in ascorbic acid levels in infants exposed to intrapartum fetal distress, without any clinical sign of such insult at or after birth.

Onset of spontaneous labor and changes in E2 and progesterone levels--possible interrelation.

Unlike the findings in animal studies, in which a decline in progesterone levels is clearly associated with the onset of labor, investigation of progesterone levels among human parturients has resulted in controversy. This study was designed to address the issue and evaluate labor-onset related changes of estradiol-progesterone (E2-P) concentration in fetal scalp serum, umbilical vein serum and in the peripheral maternal serum. Seven women in spontaneous labor, were compared to 7 women in whom labor was induced. Our results reveal a significant decrease in the maternal serum P concentration when spontaneous labor is taking place (120.6 +/- 24.5 mg/ml verus 177.3 +/- 61.4 mg/ml, p < 0.05). Significant change in the ratio of the fetal scalp to the maternal serum E2/P ratio in women at spontaneous labor versus induced labor is also shown. We could not demonstrate any changes in the E2 levels in relation to labor. We conclude that the onset of labor in human pregnancy is most probably preceded by local changes in the levels of P and ratio of P to E2. These changes may play an important regulatory role in onset of labor.

Preincubation with intravenous lipid emulsion reduces chemotactic motility of neutrophils in cord blood.

Neutrophils from cord blood of healthy term infants were isolated and incubated for 30 min with varying concentrations of intravenous lipid emulsion (ILE) solution (4, 8, 20 mg/ml). In vitro assay of chemotaxis was performed after incubation for 120 min with endotoxin-activated serum (EAS). Neutrophil random motility was unchanged after ILE incubation yet chemotactic factor (EAS)-stimulated motility was significantly reduced in a dose-related pattern.