Antenatal steroids and fluid balance in very low birthweight infants

Association of different doses of antenatal corticosteroids exposure with early major outcomes and early weight loss percentage in extremely preterm infants or extremely low birthweight infants: a multicentre cohort study

OBJECTIVES

To determine the dose-dependent associations between antenatal corticosteroids (ANS) exposure and the rates of major morbidities, and the early weight loss percentage (EWLP) in hospital among extremely preterm infants (EPI) or extremely low birthweight infants (ELBWI).

METHODS

A multicentre, retrospective cohort study of EPI or ELBWI born between 2017 and 2018 was conducted. Infants were classified into no ANS, partial ANS and complete ANS exposure group; three subgroups were generated by gestational age and birth weight. Multiple logistic regression and multiple linear regression were performed.

RESULTS

There were 725 infants included from 32 centres. Among no ANS, partial ANS and complete ANS exposure, there were significant differences in the proportions of bronchopulmonary dysplasia (BPD) (24.5%, 25.4% and 16.1%), necrotising enterocolitis (NEC) (6.7%, 2.0% and 2.0%) and death (29.6%, 18.5% and 13.5%), and insignificant differences in the proportions of intraventricular haemorrhage (IVH) (12.5%, 13.2% and 12.2%), and extrauterine growth restriction (EUGR) (50.0%, 56.6% and 59.5%). In the logistic regression, compared with no ANS exposure, complete ANS reduced the risk of BPD (OR 0.58, 95% CI 0.37 to 0.91), NEC (OR 0.21, 95% CI 0.08 to 0.57) and death (OR 0.36, 95% CI 0.23 to 0.56), and partial ANS reduced the risk of NEC (OR 0.23, 95% CI 0.07 to 0.72) and death (OR 0.54, 95% CI 0.34 to 0.87). Compared with partial ANS exposure, complete ANS decreased the risk of BPD (OR 0.58, 95% CI 0.37 to 0.91). There were insignificant associations between ANS exposure and IVH, EUGR. In the multiple linear regression, partial and complete ANS exposure increased EWLP only in the ≥28 weeks (w) and <1000 g subgroup (p<0.05).

CONCLUSIONS

Different doses of ANS (dexamethasone) exposure were protectively associated with BPD, NEC, death in hospital, but not EUGR at discharge among EPI or ELBWI. Beneficial dose-dependent associations between ANS (dexamethasone) exposure and BPD existed. ANS exposure increased EWLP only in the ≥28 w and<1000 g subgroup. ANS administration, especially complete ANS, is encouraged before preterm birth.

TRIAL REGISTRATION NUMBER

NCT06082414.

The effect of antenatal corticosteroid use on offspring cardiovascular function: A systematic review

BACKGROUND

Antenatal corticosteroids (ACS) are recommended in threatened preterm labour to improve short-term neonatal outcome. Preclinical animal studies suggest detrimental effects of ACS exposure on offspring cardiac development; their effects in humans are unknown.

OBJECTIVES

To systematically review the human clinical literature to determine the effects of ACS on offspring cardiovascular function.

SEARCH STRATEGY

A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines in MEDLINE, EMBASE and Cochrane databases.

SELECTION CRITERIA

Offspring who had been exposed to ACS during fetal life, in comparison with those not receiving steroids, those receiving a placebo or population data, were included. Studies not performed in humans or that did not assess cardiovascular function were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the studies, extracted the data and assessed the quality of the studies. Results were combined descriptively and analysed using a standardised Excel form.

MAIN RESULTS

Twenty-six studies including 1921 patients were included, most of which were cohort studies of mixed quality. The type of ACS exposure, gestational age at exposure, dose and number of administrations varied widely. Offspring cardiovascular outcomes were assessed from 1 day to 36 years postnatally. The most commonly assessed parameter was arterial blood pressure (18 studies), followed by echocardiography (eight studies), heart rate (five studies), electrocardiogram (ECG, three studies) and cardiac magnetic resonance imaging (MRI, one study). There were no clinically significant effects of ACS exposure on offspring blood pressure. However, there were insufficient studies assessing cardiac structure and function using echocardiography or cardiac MRI to be able to determine an effect.

CONCLUSIONS

The administration of ACS is not associated with long-term effects on blood pressure in exposed human offspring. The effects on cardiac structure and other measures of cardiac function were unclear because of the small number, heterogeneity and mixed quality of the studies. Given the preclinical and human evidence of potential harm following ACS exposure, there is a need for further research to assess central cardiac function in human offspring exposed to ACS.

Antenatal corticosteroids is associated with better postnatal growth outcomes of very preterm infants: A national multicenter cohort study in China

INTRODUCTION

Antenatal corticosteroids (ACS) administration is a standardized prenatal care for accelerating fetal maturation before anticipated preterm delivery, however, its effect on nutrition and growth is yet uncertain. This study aimed to examine if ACS application is associated with improvement in postnatal growth and nutrition in very preterm infants (VPIs).

METHODS

This was a secondary analysis of a multicenter prospective survey included infants born before 32 weeks gestation and admitted to 28 tertiary neonatal intensive care units throughout China from September 2019 to December 2020. Infants were divided into no ACS, partial ACS and complete ACS groups according to the steroids exposure. For infants exposed to antenatal corticosteroids, complete ACS was defined as receiving all doses of steroids 24 h-7 days before delivery, otherwise it was referred to partial ACS. The primary outcomes of postnatal growth were compared among the 3 groups. The multivariable regression analyses were applied to evaluate the association of different steroids coverage with postnatal growth and nutritional outcomes while adjusting for potential confounders. For each outcome, no ACS coverage was defined as the reference group. Data were presented as unstandardized coefficients or adjusted odds ratios with 95% confidence intervals, P < 0.05 (2-sided) indicated statistical significance.

RESULTS

Among 2,514 infants included, complete ACS, partial ACS and no ACS group accounted for 48.7% (1,224/2,514), 29.2% (735/2,514) and 22.1% (555/2,514), respectively. The median weight growth velocity was 14.6 g/kg/d, 14.1 g/kg/d and 13.5 g/kg/d in complete, partial and no ACS group respectively with significant difference (P < 0.001). In multivariable analyses, both complete and partial ACS coverage were associated with shorter cumulative fasting time, faster weight growth velocity, less dramatic decline in Z-score of weight, and lower incidence of extrauterine growth restriction [aOR (95%CI): 0.603 (0.460, 0.789) and 0.636 (0.476,0.851), respectively] when compared with no ACS. Moreover, the faster length growth velocity and earlier enteral feeding start time were observed only in infants with complete ACS coverage.

CONCLUSIONS

Both complete and partial ACS are associated with better postnatal growth outcomes in very preterm infants. This efficacy appeared to be more obvious in infants exposed to complete ACS.

Total body water in full-term and preterm newborns: systematic review and meta-analysis

BACKGROUND

Total body water (TBW) is one component of fat-free mass and changes in TBW are influenced by fluid shifts (especially during transition to postnatal life), electrolyte balance and nutritional status. Normal values for term-born neonates and preterm infants at birth have not been defined in large cohorts, limiting investigation into its monitoring and use in clinical practice.

OBJECTIVE

To systematically review the evidence base for percentage of TBW in term-born infants, quantify the effect of prematurity on TBW at birth, and describe normal progression of TBW over time in preterm infants.

METHODS

Systematic review of Medline, Web of Science Core Collection and EBSCO-CINAHL (January 1946 to January 2020). Included articles used dilutional methods to assess TBW.

RESULTS

Searches identified 2349 articles of which 22 included data suitable for analysis. Mean TBW in term-born newborns was 73.8% (95% CI 72.47% to 75.06%, 15 studies, 433 infants). Meta-regression showed that TBW was higher in preterm infants (up to 90% at 26 weeks gestation, dropping to 75% at 36 weeks corrected gestation) and was negatively correlated with gestation at birth, falling 1.44% per week (95% CI 0.63% to 2.24%, 9 studies, 179 infants). Analysis of TBW over time during the ex utero growth of preterm infants was not possible due to paucity of data.

CONCLUSION

This review defines the normal TBW percentage in term-born infants and confirms and quantifies previous findings that preterm infants have a higher TBW percentage.

Blood urea in preterm infants on routine parenteral nutrition: A multiple linear regression analysis

BACKGROUND

Blood urea is considered a marker of amino acid utilization in preterm infants on routine parenteral nutrition. However, the association between blood urea and intravenous amino acid intake remains debated.

AIMS

To evaluate the association between blood urea and both nutrition and clinical data, in a large cohort of preterm infants.

METHODS

Consecutively admitted preterm infants with a gestational age of less than 32 weeks and a birth weight lower than 1250 g on routine parenteral nutrition from the first hour of life were studied. Clinical and nutrition data collected hourly during the hospitalization were used in multiple linear regression analysis.

RESULTS

We studied 674 patients and 1863 blood urea determinations. Blood urea concentration was positively associated with blood creatinine concentration, intravenous amino acid intake, patent ductus arteriosus and respiratory distress syndrome, and negatively associated with intravenous non-protein energy intakes, daily weight change, gestational age, being small for gestational age, antenatal steroids therapy and reverse flow in the umbilical artery (p < 0.001; R = 0.7).

CONCLUSIONS

From a nutrition perspective, in our large cohort of small preterm infants blood urea was positively correlated with intravenous amino acid intake and negatively correlated with intravenous non-protein energy intake. This is in line with current knowledge in human physiology and suggest that a reduction of intravenous amino acid intake based on blood urea concentrations was justified.

[Risk factors for the development of early hyponatraemia in the premature infant. A review of the practice of giving sodium in the first days of life]

INTRODUCTION

A retrospective study was conducted in the Neonatal Intensive Care Unit of a tertiary hospital to determine the incidence of early hyponatraemia (first 48hours of life) in preterm infants. Risk and protection factors in this condition were also examined as a starting point for a change in the medical action when prescribing intravenous fluids.

MATERIAL AND METHODS

The study included a sample of 256 premature babies (gestational age: 23⁵-36⁶) admitted to the Neonatal Intensive Care Unit of a tertiary hospital between January 2016 and June 2018. The number of patients receiving intravenous sodium in different intervals during the first 48hours of life was determined, as well as the number of those with hyponatraemia of any type (<135mmol / l), and moderate-severe (<130mmol / l). An analysis was made of the relationship between early hyponatraemia and weight / gestational age, antenatal steroids exposure, respiratory pathology, early sepsis, and perinatal asphyxia.

RESULTS

Hyponatraemia occurred in 81 patients, 31.64% of the total (up to 50% in<30 weeks of gestational age), and was moderate-severe (<130mmol / l) in 17.3% of the cases. The period of time with the most cases of hyponatraemia was in the first 12hours of life (22.64%). Weight (P=.034), gestational age (P<.001) and respiratory disease (P<.001) were found to be risk factors and, in a multivariate analysis, the latter was independently related to early hyponatremia (P<.01, OR=5.24, 95% CI: 2.79-9.84). Antenatal betamethasone exposure did not show to be a protection factor.

CONCLUSION

According to the results of this study, it is considered an advantage to provide sodium in the intravenous fluids prescribed during the first days of life, particularly in preterm infants of lower gestational age and with respiratory disease involvement.

Use of Glucocorticoids for the Fetus and Preterm Infant

The soon-to-be-delivered fetus and preterm infant have been treated with glucocorticoids to prepare for postnatal life, historically for more than 40 years. The use of glucocorticoids is as much for replacement of cortisol in the setting of a poorly functioning hypothalamic-pituitary-adrenal axis in the preterm infant, as it is for prevention of long-term lung dysfunction. Potential negative effects of glucocorticoid treatment on brain development and function have been observed more often with dexamethasone therapy than with use of other glucocorticoids. Overall, glucocorticoid treatment has improved the outcome of the preterm infant.

The effects of antenatal glucocorticoid exposure on fetal and neonatal skin maturation

AIMS

The use of antenatal glucocorticoids in women with preterm labor has dramatically improved outcomes for premature infants. The most commonly used antenatal glucocorticoids are betamethasone and dexamethasone. Glucocorticoids accelerate fetal lung growth by several mechanisms, including the maturation of type II pneumocytes enabling surfactant production. Furthermore, the lipids in the lung share similarity with those in the skin. Therefore, antenatal administration of glucocorticoids may have effects on the structure and function of the developing epidermal barrier in fetuses and neonates.

METHODS

We performed a systematic review to characterize these effects, identifying 11 studies (six animal and five human studies).

RESULTS

Five out of the six animal studies used a rodent model for investigating the effects of antenatally administered glucocorticoids, while the other used an ovine model. Antenatally administered glucocorticoids accelerated skin maturation in animal studies, but studies of human fetuses found conflicting results. None of the reviewed studies compared the effects of different types of glucocorticoids.

CONCLUSIONS

More human studies are needed to fully understand the effects of antenatal steroids. However, as the antenatal use of glucocorticoids in preterm pregnancies has become part of standard clinical practice, it would be unethical to carry out a large randomized controlled trial. We may have to rely on animal models to improve our understanding of the effects of antenatal glucocorticoid exposure on the fetal and neonatal skin maturation.

Water balance in the fetus and neonate

Fetal water balance is dependent prenatally on the placental transfer of water from maternal to fetal circulation. Adequate amniotic fluid volume is one indicator of stable fetal status and development. Excessive or less than expected amniotic fluid volume may be a precursor to postnatal morbidity and mortality. Postnatal transition is marked by predictable changes in body water including contraction of extracellular volume and insensible fluid loss, primarily across the skin barrier. The degree to which these occur is determined by gestational and postnatal age. Neonatal complications and clinical conditions associated with either retention or excessive loss of body water can occur. Fluid therapy in the neonatal intensive care unit may be guided using three clinical indicators: change in body weight, serum sodium concentration, and urine output.

Significance of antenatal glucocorticoid exposure for pressure injury prevalence in neonates

AIMS

Studies have highlighted that antenatal steroids could have an effect on neonatal skin maturation. This study examined if there was a relationship between the administration of antenatal glucocorticoids for mothers and the skin injuries in their neonates. Data from skin injury audit were extracted from the neonatal database and analyzed to determine differences in the prevalence of neonates with pressure injuries [cases] whose mothers had received antenatal steroids, compared to those without pressure injuries [control].

RESULTS

Of 247 neonates audited, 77 [31%], had documented pressure injuries, 170 [69%] had no documented injury. The median birth weight and gestation were 1400 g [IQR 893-2268 g] and 30.3 weeks [IQR 26.3-40.0 weeks] respectively. Of the neonates born less than 34 weeks, 80% were exposed to antenatal steroids and were equally distributed across patient genders. Within the 77 cases, 53 [66%] were exposed to antenatal steroids compared to controls in which 88 [53%] had not. The effect between cases and controls was not statistically significant [χ2 = 2.81, P = 0.09]. However a difference was noted between genders, as female neonates benefited from the exposure to steroids [OR = 0.317, 95% [CI 0.105-0.956], p value -0.041].

CONCLUSION

Antenatal glucocorticoids appear to be beneficial in reducing pressure injury prevalence in female neonates.

Renal impairment associated with indomethacin treatment for patent ductus arteriosus in extremely preterm neonates—is postnatal age at start of treatment important?

OBJECTIVE

To study serum creatinine (SCr) levels following indomethacin for patent ductus arteriosus (PDA) closure in extremely preterm neonates in relation to postnatal age at the start of treatment.

METHODS

This was a retrospective (January 2000-December 2002) analysis of data on preterm neonates (gestation <29 weeks) who received indomethacin for PDA. Pre-existing renal malformation and/or impairment and high serum levels of nephrotoxic drugs were criteria for exclusion.

RESULTS

Indomethacin was commenced at postnatal age <7 days and >or=7 days in 60 (group 1) and 30 (group 2) neonates, respectively. The median (Q1, Q3) gestational age and birth weight for group 1 and group 2 neonates were 25 (23, 27) vs. 25 (24, 26) weeks and 740 (620, 909) vs. 780 (663, 966) grams, respectively. Postnatal age <7 days at start of indomethacin was associated with higher baseline (0.083 (0.074, 0.090) vs. 0.073 (0.054, 0.083) mmol/L, p=0.001) and peak SCr levels (0.099 (0.089,0.109) vs. 0.090 (0.064, 0.104) mmol/L, p=0.015). Logistic regression analysis controlling for gestational age and baseline SCr level indicated that postnatal age >or=7 days was a risk factor for elevated SCr after indomethacin (OR=13.4, 95% CI: 3.8-46.6, p < 0.001).

CONCLUSION

Postnatal age >or=7 days at the start of indomethacin is a predictor of a significant rise in SCr in extremely preterm neonates.

Fluid and electrolyte management in the premature infant

Caring for the premature infant in the NICU requires knowledge and understanding of the physiologic adaptation to extrauterine life and how prematurity affects that transition. Nurses play an integral role in managing fluid and electrolyte balance in these infants. This article addresses postnatal adaptation and all aspects of fluid and electrolyte management of the preterm infant.