Maternal glucocorticoid therapy and reduced risk of bronchopulmonary dysplasia

Because of substantial clinical and laboratory evidence of the efficacy of glucocorticoids in the treatment of acute pulmonary surfactant deficiency in preterm newborns, we explored the hypothesis that maternal antenatal glucocorticoid receipt is followed by reduced risk of bronchopulmonary dysplasia (BPD). A sample of 223 intubated infants weighing less than 1751 g birth weight provided 76 infants with BPD (defined by both oxygen requirement and compatible chest radiograph) and 147 who had neither BPD characteristic by day 28 of life. When compared to babies who received a complete and timely course of antenatal glucocorticoids, those whose mothers received no glucocorticoids were at prominently increased risk of BPD (odds ratio = 3.0; 95% confidence interval = 1.1, 8.2). Babies whose mothers received a partial course of glucocorticoids were not at increased risk of BPD (odds ratio = 1.3; 95% confidence interval = 0.4, 4.3). Stratification by gender and birth weight at 1 kg showed a benefit of therapy in all strata except that of extremely low birth weight male infants. These data support the hypothesis that maternal antenatal glucocorticoid therapy offers very low birth weight infants protection against BPD.     

Antenatal glucocorticoids increase early total thyroxine levels in premature infants

BACKGROUND: Hypothyroxinemia is associated with adverse neonatal outcomes including white matter damage, cerebral palsy, poor neurodevelopment and death. It has become increasingly important to understand the natural history and modifiers of thyroid function in the premature infant. It is standard obstetrical practice to offer antenatal glucocorticoids to pregnant women with threatened preterm delivery. Few studies have investigated the effect of antenatal glucocorticoids on neonatal thyroid function. OBJECTIVE: To examine the association between antenatal exposure to glucocorticoids and early total thyroxine (T4) levels among extremely premature infants. METHODS: We studied 521 infants born at 4 medical centers. Entry criteria included a gestational age of 23-28 weeks and a serum thyroxine level obtained in the first postnatal week. Receipt of antenatal glucocorticoids was recorded as none, partial, or complete. A complete course consisted of two doses of betamethasone or four doses of dexamethasone within a 48-hour period between 2 and 7 days of delivery. Early total T4 levels were obtained from state-mandated newborn screening programs. RESULTS: Controlling for potential maternal, perinatal and neonatal confounding variables, infants exposed to a complete course of antenatal glucocorticoids had total T4 levels 0.8 microg/dl higher than their peers who were not exposed to a complete course of antenatal glucocorticoids (p = 0.03). CONCLUSIONS: Extremely premature infants who received a complete course of antenatal glucocorticoids had significantly higher total thyroxine levels in the first postnatal week. Maternal, perinatal, and early neonatal variables did not completely explain this association. We speculate that antenatal glucocorticoids influence early neonatal thyroid function.     

The effect of antenatal betamethasone on cord blood concentrations of retinol-binding protein, transthyretin, transferrin, retinol, and vitamin E

We assessed the effect of short-term (less than or equal to 1 week) and prolonged (greater than 1 week) exposure to antenatal betamethasone on umbilical cord serum concentrations of retinol-binding protein (serum t 1/2 = 12 h), transthyretin (t 1/2 = 2 days), transferrin (t 1/2 = 8 days), retinol (vitamin A), and vitamin E in appropriate-for-gestational-age preterm newborn infants of less than 36 weeks' gestation. A group of 30 infants whose mothers received a single course of betamethasone less than or equal to 1 week prior to delivery had significantly elevated mean retinol-binding protein and transthyretin but not transferrin concentrations when compared with a group of 30 gestational age- and birth weight-matched infants with no exposure to antenatal betamethasone. A group of eight infants whose mothers received multiple (more than two) weekly courses of betamethasone prior to delivery had significantly elevated mean serum concentrations of all three proteins when compared with eight gestational age- and weight-matched control infants with no betamethasone exposure. Serum retinol and vitamin E concentrations were measured in a group of 21 infants exposed to short-term prenatal betamethasone and were significantly greater than in a group of 21 control infants without steroid exposure. We conclude that antenatal steroids increase the umbilical cord serum concentrations of retinol-binding protein, transthyretin, transferrin, retinol, and vitamin E. The effect on the various serum proteins is dependent on the duration of exposure to steroids.     

Multiple courses of antenatal steroids

The benefits and risks of multiple courses of antenatal steroids (ANS) are still unresolved issues. This was a prospective cohort study in a level III neonatal unit. Preterm babies ≤35 wk gestation were included. Malformations, chronic maternal steroid intake, exchange transfusions prior to cortisol sampling and incomplete ANS courses were exclusion criteria. Subjects were classified into: No course (Group 0), 1 course (group 1), 2 courses (Group 2), >2 courses (Group 3) of antenatal dexamethasone. The key outcome was adrenal function assessed by basal and post-ACTH cortisol on day 3. Other outcomes were neonatal morbidity, mortality, growth parameters at birth, long term growth and neuro-development. Of 210 eligible babies, 124 were enrolled. 38, 51, 10 and 25 babies belonged to groups 0, 1, 2 and 3 respectively. Basal and post-ACTH serum cortisol did not show any significant difference between groups (p=0.5 and p=0.9 respectively). Incidence of severe HMD requiring ventilation was significantly lower (p=0.02) in multiple course group (combined groups 2 and 3) compared to single course group. There were no differences in other neonatal morbidity, birth OFC and weight between single and multiple ANS groups. Follow up data at a mean age of 22 mth was available in 59 subjects (69%) belonging to groups 1–3. No differences were noted in the proportion of patients with abnormal neurological examination (p=0.1), abnormal PDI (p=0.9), abnormal MDI (p=0.9) and physical growth between multiple and single course groups. Multiple courses of antenatal dexamethasone resulted in a significant decrease in severe forms of RDS and they did not cause adrenal suppression, decreased growth or impaired neurodevelopment.     

The effects of repeated antenatal glucocorticoid therapy on the developing brain

Antenatal glucocorticoid (GC) therapy improves infant outcome following preterm birth. As approximately 50% of women given a first course of antenatal GCs remain undelivered 7-14 d later, many clinicians administer further courses. GCs are known to be neurotoxic and there is concern that exposure during early development may have adverse effects on the immature brain. The aim of this investigation was to compare magnetic resonance (MR) indices of brain maturation in infants exposed to repeated antenatal GC therapy and born at or close to term, with non-GC exposed control infants. MR images were obtained during quiet sleep without sedation. T1 weighted volume images were obtained in the sagittal plane and T1, T2 weighted spin echo and inversion recovery images in the transverse plane. Brain volume and surface area were calculated from segmented image slices, and a measure of the complexity of cortical folding, the whole cortex convolution index (WCCI), from computerized analysis of a vector coded contour following algorithm. Analysis of covariance was used to compare the two groups after allowing for the effect of postmenstrual age. There were 10 infants in the GC group (range of antenatal GC exposure, 3-11 courses) and 6 controls. Each GC course comprised two 12-mg IM doses of betamethasone 24 h apart. GC exposed infants had a significantly lower WCCI (p = 0.001) and smaller surface area (p = 0.02), after allowing for postmenstrual age. There was no significant difference in brain volume (p = 0.5). Repeated antenatal GC exposure results in measurable differences in brain maturation when compared with gestational age matched non-GC exposed controls. The clinical relevance of these observations is not known.     

Blood pressure support in extremely premature infants is affected by different courses of antenatal steroids

Objective:  To examine the effects of partial, single and multiple courses of antenatal corticosteroids (ANS) on the need for blood pressure support in extremely premature infants.
Methods:  Extremely premature infants with gestational age of 24 to 28 weeks were included in this study during a 5-year period. The main outcome measure of the study was the amount of blood pressure support during the first 3 days of life.
Results:  The study infants (n = 163) were divided into: infants not exposed (ANS; n = 27) and exposed to ANS (ANS; n = 136). Blood pressure support was significantly lower in ANS compared with No ANS (65% vs 96%; p = 0.003) and in single course (SANS; n = 73) and ≥2 courses (MANS; n = 34) compared with partial course of ANS (PANS; n = 29) (62%, 56% vs 86%; p = 0.03). The number of infants who received volume support and the amount of volume support were significantly lower in ANS compared with that in No ANS (p < 0.001) and in SANS and MANS compared with that in PANS (p < 0.02).
Conclusion:  Exposure to multiple courses of ANS was as beneficial as single course of ANS in decreasing the need for blood pressure support in extremely premature infants.     

Antenatal corticosteroids for preterm birth: dose-dependent reduction in birthweight, length and head circumference

Aim: This study was undertaken to evaluate the effects of repeated courses of antenatal corticosteroids (ACS) on foetal growth. Methods: We studied 94 infants exposed to 2–9 courses of ACS. Mean gestational age (GA) at first exposure was 29 and at birth 34 weeks. Exposure data were retrieved from case record files. Information on potential confounders was collected from the Swedish Medical Birth Registry. Standard deviation scores (SDS) for birthweight (BW), birthlength (BL) and head circumference (HC) were calculated and considered as outcomes. Results: GA at start of ACS did not affect outcome. BW‐SDS, BL‐SDS and HC‐SDS were ?0.21, ?0.19 and +0.25 in infants exposed to two courses, compared to ?1.01, ?1.04 and ?0.23 in infants exposed to ≥4 courses of ACS (p = 0.04–0.07). In multiple regression analyses, ≥4 courses were associated with lower BW‐SDS, BL‐SDS and HC‐SDS (p = 0.007–0.04) compared to SDS after 2–3 courses. The effects from ≥4 courses on BW and BL were comparable to reduction in birth size seen in twins and on HC to that observed after maternal smoking. Conclusions: Multiple courses of ACS are associated with a dose‐dependent decline in foetal growth, which may affect later development and health.     

Single course of antenatal steroids did not alter cortisol in preterm infants up to 18 months

Aims: To determine whether a single course of antenatal dexamethasone alters resting cortisol at 3, 8 and 18 months corrected age in preterm infants. Methods: Preterm infants born ≤32 weeks gestational age were recruited during 2001–2004 from a single neonatal intensive care unit. Resting salivary cortisol was collected at least once at 3, 8 and 18 months corrected age in a longitudinal cohort. A mixed‐effects repeated measures analysis was used to accommodate cases with less than complete follow‐up. Results: One hundred and thirty three infants were included in the present study, contributing 266 cortisol samples. Of these, 107 infants had been exposed to a single course of antenatal dexamethasone and 26 not exposed to antenatal steroids. There was no significant main effect of antenatal steroids on resting cortisol at any age. This result was not altered after adjusting for gestational age at birth, neonatal cumulative pain, morphine exposure, mechanical ventilation days and post‐natal steroid exposure. Conclusions: No effect of a single course of dexamethasone on resting salivary cortisol, an indicator of hypothalamic‐pituitary‐adrenal axis function, was found in infancy up to 18 months corrected age in infants born very preterm.     

Association between maternal serum ionized magnesium levels at delivery and neonatal intraventricular hemorrhage

OBJECTIVES: To determine whether magnesium sulfate (MgSO(4)) exposure is associated with a reduced risk for neonatal intraventricular hemorrhage (IVH). STUDY DESIGN: In a randomized, controlled trial, women in preterm labor were randomly assigned to receive MgSO(4), "other" tocolytic, or saline control. At delivery, we collected maternal antecubital and umbilical cord blood for determination of serum ionized magnesium levels. Neonatal IVH was diagnosed by cranial ultrasonogram. RESULTS: Among 144 infants, 24 were diagnosed with IVH. Using crude intention-to-treat analysis, we found that 18% (13/74) of survivors exposed after birth to MgSO(4) had IVH compared with 16% (11/70) of babies who were not exposed. Infants who had IVH were more likely to have been delivered by mothers with higher serum ionized magnesium (Mg) levels (0.75 vs 0.56 mmol/L) (P =.01). Using multivariable logistic regression, we confirmed that higher Mg levels are a significant predictor of neonatal IVH (adjusted odds ratio, 15.8; 95% CI, 1.4-175.0) even when adjusted for birth weight, gestational age, antenatal hemorrhage, and neonatal glucocorticoid exposure. CONCLUSIONS: In mothers with preterm labor, our data indicate that antenatal MgSO(4) exposure may be associated with an increased risk for IVH among their newborns.     

Antenatal steroids are associated with a reduction in the incidence of cerebral white matter lesions in very low birthweight infants

AIMS: To investigate whether antenatal steroids reduce the incidence of cerebral white matter lesions in very low birthweight infants. METHODS: A total of 224 newborn infants of < 31 weeks gestational age and weighing < 1500 g was studied between January 1998 and June 2000. Obstetric and neonatal information was obtained from the case notes. The study population was subdivided into two groups according to antenatal steroid exposure. A complete course of treatment consisted of two doses of 12 mg each of betamethasone given at an interval of 12-24 hours. Infants in group 1 were born to mothers who had not received betamethasone, or were delivered within 24 hours of receiving the first dose of steroid. Infants in group 2 were born to mothers who had received one or more complete courses of betamethasone and were delivered > 24 hours after receiving the first dose of steroid. RESULTS: The two groups contained statistically similar proportions of boys and girls, and the infants had similar birth weights and survival rates. Those in group 2, compared with those in group 1, had a lower gestational age (p = 0.02) and a lower incidence of white matter lesions on cranial ultrasound scans (p = 0.03). Stepwise logistic regression analysis showed that gestational age (p = 0.0002) and a complete course of antenatal steroids (p = 0.02) had independent effects on cerebral white matter lesions. CONCLUSIONS: These observations suggest that a complete course of antenatal steroids may have a protective effect against cerebral white matter lesions in very low birthweight infants.     

Perinatal glucocorticoid therapy and neurodevelopmental outcome: an epidemiologic perspective

A relatively brief course of antenatal glucocorticoids (ACS), given to reduce the severity of respiratory distress syndrome in preterm infants, improves survival and appears to protect against brain damage. In clinical trials as well as observational studies, ACS have been associated with a decreased risk of intraventricular haemorrhage and cerebral palsy. In observational studies a decreased risk of white-matter damage, identified with cranial ultrasound, has been observed. There is some evidence, from observational studies, that repeated courses of ACS (typically given at weekly intervals) can reduce the rate of fetal head growth, and experiments in animals provide further support for this possibility. In contrast to the effects of a brief course of ACS, postnatal glucocorticoids (PCS), given to preterm infants to reduce the severity of chronic lung disease have been associated with an increased risk of neurologic impairment. Available evidence suggests that PCS does not improve survival. Further study is needed of the neurodevelopmental consequences of both multiple courses of ACS, as well as PCS.     

A new mixed micellar preparation for oral vitamin K prophylaxis: randomised controlled comparison with an intramuscular formulation in breast fed infants

OBJECTIVE: To compare a new oral preparation of vitamin K1 (Konakion MM) containing lecithin and glycocholic acid with a standard intramuscular (IM) preparation during the first 8 weeks of life in exclusively breast fed infants. METHODS: Infants were randomised at birth to the IM group (1 mg vitamin K) or the oral group (2 mg given at birth and repeated at 7 and 30 days of life). Prothrombin time (INR), plasma vitamin K1, and PIVKA II (undercarboxylated prothrombin) were monitored at 14, 30, and 56 days of age. RESULTS: Seventy nine infants were randomised to the oral group and 77 to the IM group. Sixty seven infants in each group completed eight weeks of the study. Prothrombin times did not differ between the two groups. Mean (SD) plasma vitamin K1 values (in ng/ml) decreased in both groups over time, but were higher in the oral group at 14 and 56 days: 2.0 (1.6) v 1.3 (1.1) at 14 days; 0.5 (0.3) v 0.5 (0.7) at 30 days; and 0.5 (0.8) v 0.2 (0.2) at 56 days of life. PIVKA II was raised (> or = 0.1 AU/ml) in cord blood in 47% of the infants. By 14 days, only one infant in each group had a raised PIVKA II value and both of these initially had high concentrations of PIVKA II in cord blood. At 30 days, there were no raised PIVKA II values. At 56 days, there were no raised PIVKA II values in the oral group, although three infants in the IM group had raised values. CONCLUSIONS: Plasma vitamin K concentrations were at least equal or significantly higher in babies given oral vitamin K supplements compared with IM treated babies at the time points measured. Through the first 8 weeks of life, multiple doses of the new oral preparation maintain haemostasis and vitamin K status in breast fed infants at least equal to that of the intramuscular preparation.     

Follow up of a randomised trial of two different courses of dexamethasone for preterm babies at risk of chronic lung disease

OBJECTIVES: To report 18 month outcome of a randomised trial of two courses of dexamethasone to prevent chronic lung disease of prematurity. STUDY DESIGN: Babies of birth weight 1250 g or less ventilated at 7 days of age were randomised to a 42 day reducing course (long) or a 3 day pulsed (pulse) course of dexamethasone. Growth, cardiovascular status, and respiratory and neurodevelopmental outcomes were assessed at 18 months. RESULTS: Seventy six babies were enrolled. Nine died and three were lost to follow up. Babies receiving the long course were weaned off oxygen more quickly than those receiving the pulse course (47% v 69% on oxygen at 28 days; p = 0.01), but there were no differences in 18 month outcomes. However, children averaged -1 SD for growth parameters, half had moderate or severe disability, and 35% and 19% respectively required oxygen at 36 weeks and discharge. CONCLUSIONS: The dexamethasone course used did not influence long term outcome. However, entry criteria for this study selected a group of babies at high risk of poor long term outcome.     

Comparison of single and repeated antenatal corticosteroid therapy to prevent neonatal death and morbidity in the preterm infant

INTRODUCTION: In the case of threatened preterm delivery, repeat administration of antenatal corticosteroids is a common practice in women who have not delivered 7-14 days after the first course of corticosteroids. However, the benefits of this policy as compared to single-course administration have not been proven. AIM: Our purpose was to compare neonatal death and morbidity after repeat antenatal courses of corticosteroids with neonatal death and morbidity after a single course. METHODS: We performed a cohort study with matched controls. Neonates treated with repeat antenatal courses of corticosteroids were matched with neonates treated with a single course. Matching criteria were sex, single or multiple gestation, route of delivery, gestational age at delivery and year of birth. Intrauterine growth-restricted infants were matched separately. We excluded neonates with congenital malformation and neonates with an unknown number of antenatal corticosteriod courses. Outcome measures were the incidences of neonatal death, respiratory distress syndrome, intraventricular haemorrhage and necrotizing enterocolitis. RESULTS: From the neonates treated with two or three courses of antenatal corticosteroids, 56 appropriate grown neonates and 24 intrauterine growth-restricted neonates could be matched. The incidences of neonatal death, respiratory distress syndrome, intraventricular haemorrhage and necrotizing enterocolitis did not show statistically significant differences after single and repeat courses of corticosteroids. Appropriate grown and intrauterine growth-restricted neonates showed the same results. CONCLUSION: From our study, it can be concluded that in preterm neonates, repetition of antenatal corticosteroids seems not to improve neonatal outcome.     

Effect of antenatal corticosteroids on postmortem brain weight of preterm babies

OBJECTIVES: To investigate the effects of single and repeated courses of antenatal corticosteroids on brain growth in very preterm babies. DESIGN: Retrospective study of 110 very preterm babies delivered at a single University Teaching Hospital between 1992 and 1999 who had a full necropsy including detailed examination of the brain. RESULTS: Mean brain weight did not differ significantly between babies who received corticosteroids and those who did not 160 vs. 157 g, (p=0.82), nor was there a difference between mean brain weight of stillborn or liveborn babies in relation to steroid use 164 vs. 159 g, (p=0.84) and 156 vs. 152g (p=0.81). There was no apparent dose-response relationship between the total number of doses of corticosteroids or timing since the first dose of corticosteroids and brain weight, p=0.95 and p=0.87. CONCLUSIONS: Single and multiple courses of antenatal corticosteroids had no significant effect on brain growth in babies delivered preterm who died but long-term follow-up studies are required to evaluate the functional neurological outcome of surviving children.     

Foetal and congenital talipes: interventions and outcome

Aim: Talipes is a congenital anomaly that can be corrected conservatively or surgically. Despite advances in management, a proportion of pregnancies still result in termination. We therefore aimed to establish the birth prevalence, interventions and outcome of talipes in our population.
Methods: Cases with foetal talipes were identified from the ultrasound register at the James Cook University Hospital between 1990 and 2006. Infants with congenital talipes between 1998 and 2006 were identified from the physiotherapy database. Management details were obtained from case records.
Results: A total of 46 cases with foetal talipes were identified among 75 933 pregnancies. Of the 34 live-born infants, 24 (70.5%) required surgery to correct the talipes. Congenital talipes was found in 69 infants, giving a birth prevalence of 2 per 1000 live births. Sixteen (72.7%) infants with an antenatal diagnosis required surgical correction. Infants with an antenatal diagnosis were at an increased risk of requiring surgery (relative risk [RR]= 1.6).
Conclusion: Surgical management was required in more than two-thirds of babies with foetal talipes. Conservative management was successful in the majority of the babies without an antenatal diagnosis. Infants with an antenatal diagnosis are 1.6 times as likely to need surgical correction as infants without an antenatal diagnosis.     

Control of breathing in babies of narcotic- and cocaine-abusing mothers.

To learn if chemoreceptor control of breathing is abnormal in babies whose mothers took narcotics, cocaine, or both drugs during pregnancy, we performed hypoxia and hypercapnia challenges on 28 babies (greater than or equal to 36 weeks gestation). Six babies were exposed to narcotics, six to cocaine, nine to both drugs, and seven babies were controls. Studies were done at 3 and 8 weeks and 3 and 5 months of age. Gestational ages were similar, but birth weight was lower in the cocaine group. Respiratory rate was higher in both groups of cocaine-exposed babies at 3 weeks. End-tidal partial pressure of CO2 (PCO2) was decreased and partial pressure of O2 (PO2) increased at 3 and 8 weeks in babies exposed to narcotics plus cocaine. At 3 weeks, babies exposed to narcotics plus cocaine had a shift to the left in CO2 response with a normal slope; at 8 weeks, both intercept and slope were decreased. Responses to hypoxia were similar among the four groups. Babies exposed to narcotics plus cocaine before birth have abnormalities in control of breathing in the first months after birth.     

The Maternal Lifestyle Study (MLS): effects of prenatal cocaine and/or opiate exposure on auditory brain response at one month

OBJECTIVE: To study absolute and interpeak latencies of the auditory brain response in infants exposed to cocaine and/or opiates in utero.Study design The sample included 477 exposed and 554 comparison infants matched for race, sex, and gestational age. Mothers were recruited at 4 urban university-based centers; most were black, receiving public assistance, and had received adequate prenatal care. Exposure was determined by meconium assay and self-report with alcohol, marijuana, and tobacco present in both groups. At 1 month, infants were tested by masked examiners with the auditory brain response. RESULTS: Analyses were conducted for exposed and comparison groups and for level of prenatal cocaine exposure with adjustment for covariates (alcohol, marijuana, tobacco, gestational age at birth, social class, and site). Heavy prenatal cocaine exposure (>/=3 days per week, first trimester) led to an increase in the I-III, I-V, and III-V interpeak latencies and to a shorter latency to peak I. Infants with prenatal opiate exposure showed a longer latency to peak V and a longer III-V interpeak latency. CONCLUSIONS: Prenatal cocaine and/or opiate exposure affects neural transmission. Detection of these effects requires a large sample with control for gestational age, other drugs, and level of cocaine use.     

Effect of single and multiple courses of prenatal corticosteroids on 17-hydroxyprogesterone levels: implication for neonatal screening of congenital adrenal hyperplasia

Measurement of 17-hydroxyprogesterone (17-OHP) from filter-paper blood is widely used to screen for congenital adrenal hyperplasia (CAH). However, in pregnancies with an expected preterm delivery, prenatal treatment with steroids to induce pulmonary maturation could suppress the fetal adrenals and interfere with this screening. In 160 infants who were born between 25 and 35 wk of gestation, we measured 17-OHP in filter-paper blood at 72-96 h and compared the values between those who had not received antenatal steroids (n=50) and those who had (n=110). A single course of steroids was two 12-mg injections of betamethasone given within a 24-h interval: 30 infants received a half single course, 45 received a full single course, and 35 received multiple courses. Results are expressed as medians (25th percentile; 75th percentile). Blood 17-OHP differed significantly among groups: 23.7 (14.2; 30.7) nmol/L, 26.1 (15.0; 50.1) nmol/L, 20.1 (13.8; 29.1) nmol/L, and 14.9 (9.5; 26.2) nmol/L (for, respectively, no steroid, half a single course, a full single course, and multiple courses; p <0.05, multiple comparisons with the Kruskal-Wallis test). However, only infants who were treated with multiple antenatal courses of steroids had lower blood 17-OHP than those who were untreated (p <0.05 with the Mann-Whitney U test). In multiple regression analysis, steroid treatment and intrauterine growth retardation were significant negative predictors of blood 17-OHP, whereas respiratory distress syndrome was a significant positive predictor (multiple R=0.50, p <0.001). Multiple courses of steroids in preterm infants decrease 17-OHP values by approximately 30% in filter-paper blood, thus raising the risk of false-negative results in screening programs for CAH.     

极早产儿产房复苏插管影响因素分析

目的 探讨极早产儿产房复苏插管影响因素以降低插管风险.方法 回顾性分析2017年1月至2019年12月入住新生儿重症监护病房的极早产儿455例,依据复苏时是否插管分为插管组(79例)和非插管组(376例),分析复苏插管的影响因素.结果 极早产儿中复苏时插管发生率为17.4％(79/455).非插管组胎龄、出生体重及剖宫...