Antenatal corticosteroid administration for foetal lung maturation

Addressing the long-term risks of administering antenatal steroids

INTRODUCTION

A single course of antenatal steroid (ANS) therapy is standard of care for women at risk of preterm birth, reducing the risk of neonatal respiratory distress syndrome, neonatal morbidity, and mortality. An unresolved challenge relates to the potential risk of adverse long-term effects, and how these risks might be balanced with therapeutic benefit.

AREAS COVERED

We outline key concepts in glucocorticoid signaling, pharmacokinetics/pharmacodynamics, and clinical use before presenting data on the potential long-term harms of ANS therapy.

EXPERT OPINION

Our assessment is that: i) Currently used, high dose ANS regimens can induce multi-system changes in the fetus that alter growth and development, potentially increasing long-term disease risk; and ii) relative risks likely increase proportionally to the magnitude and duration of steroid exposure, in late preterm and term ANS use, and in off-target treatments. A single course of ANS therapy to at risk women between 24- and 34-weeks' gestation is well justified. Efforts should be made to improve dosing and patient selection. At periviable gestations, the high immediate risk of serious disease or death justifies modest long-term risks. At late preterm and term gestations, where steroids do not provide notable survival or health benefits, supporting routine ANS use is more difficult.

Meta-analysis and Mendelian randomization study on the association between exposure to chlorinated disinfection byproducts and preterm birth risk

OBJECTIVE

This study aims to investigate the correlation between exposure to disinfection byproducts of chlorination and preterm birth (PTB) through evidence-based medicine Meta-analysis and Mendelian randomization (MR) analysis.

STUDY DESIGN

Meta-analysis was conducted on 17 studies involving 1,251,426 neonates, revealing a higher risk of PTB with exposure to total trihalomethanes (TTHMs) and chloroform. Mendelian randomization (MR) analysis confirmed a causal relationship between chlorides and PTB.

RESULTS

TTHMs and chloroform were associated with increased PTB risk, while haloacetic acids showed no significant association. TTHMs were linked to small gestational age. Ethnicity and study design influenced heterogeneity.

CONCLUSIONS

Exposure to chlorination byproducts, particularly TTHMs and chloroform, poses a significant risk for PTB. MR analysis supports a causal relationship between chlorides and PTB, highlighting the importance of water disinfection byproduct control in preventing PTB.

Off-label use of drugs in pregnancy: A critical review of guidelines, current practices, and a clinical perspective

OBJECTIVE

The objective of this narrative review was twofold: to delineate the usage patterns of the main off-label drugs during pregnancy (i.e., misoprostol, nifedipine, and corticosteroids) and to offer a medical examiner's perspective on the use of these medications.

METHODS

An extensive review of the literature was performed to assess the off-label use of corticosteroids, nifedipine, and misoprostol in pregnancy.

RESULTS

Overall, 503 records about the use of off-label medicines during pregnancy were identified. After the exclusion of papers published in languages other than English and experimental studies in animals, 340 studies were considered eligible. Studies with medicines other than corticosteroids, misoprostol, and nifedipine were removed, leaving a total of 240 articles. From the remaining records, 24 reports were not retrieved. The research strategy allowed the final identification of 76 references.

CONCLUSION

Off-label drug use in obstetrics has transitioned from being an exception to a routine, scientifically validated practice. While its application is justified by clinical outcomes and international protocols, healthcare providers must navigate a strict framework of ethical and legal responsibility.

Timing of antenatal corticosteroid exposure and its association with childhood mental disorders in early- and full-term births: A population-based cohort study

Although the administration of antenatal corticosteroids (ACS) is generally recognized as cost-effective and beneficial, recent studies have indicated potential long-term adverse effects on neurodevelopment, particularly for term-born infants. However, limited research has explored the association between the timing of ACS exposure, gestational age (GA) at birth, and their potential implications for mental and behavioral outcomes in offspring compared to non-exposed infants. This study aimed to examine the association between the timing of antenatal corticosteroid (ACS) exposure for threatened preterm labor and childhood mental disorders among early-term and full-term births. All eligible term infants born between 2010 to 2014 were included in this nationwide study and followed until the end of 2021. The primary outcome was any childhood mentaldisorders, with secondary outcomes being attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and developmental delay (DD). Compared to unexposed infants, ACS exposure before 34 weeks of GA increased the risk of developing mental behavior disorders. Exposure to ACS before 34 weeks was significantly associated with an increased risk of ADHD and DD; however, this association was observed only in early-term births but not in those born at full-term.

CONCLUSION

Our finding suggests a need for further investigation into the influence of GA at birth on these disorders and supports that the risk of childhood mental disorders in term infants varied among different ACS exposure timing.

WHAT IS KNOWN

• While administration of antenatal corticosteroids (ACS) for preterm birth threats is widely acknowledged as both cost-effective and beneficial, recent studies have raised concerns about potential long-term adverse effects on neurodevelopment, particularly in term-born infants. • Previous studies have found that early-term birth is associated with lower intelligence, ADHD, and poorer school performance compared to full-term birth.

WHAT IS NEW

• There is an interaction between the timing of ACS treatment and gestational age at birth with respect to the likelihood of neurodevelopmental outcomes in term-born infants. • Exposure to ACS before 34 weeks is associated with an increased risk of any childhood mental disorders, specifically ADHD and DD, among early-term births, whereas this association was not observed in infants who reached full-term gestation.

A short-course of low-dose insulin detemir effectively decreases blood glucose levels in gestational diabetic women undergoing dexamethasone treatment to promote newborn lung maturity

Pregnant women with gestational diabetes mellitus undergoing glucocorticoid treatment to prevent neonatal respiratory distress syndrome could have increased glucose level. We performed a retrospective study and reviewed gestational diabetic women who received an intramuscular dexamethasone injection (6 mg, every 12 hours, 4 times) in our hospital between December 2018 and June 2020. Eligible pregnant women were assigned to the study group (with simultaneous subcutaneous insulin detemir injection, 2-4 units per day) or the control group (without insulin detemir injection). The fasting and 2-hour postprandial blood glucose levels were measured before and on days 1, 2, and 3 after the insulin detemir injection. The changes in their blood glucose levels were compared before and after the drug administrations as well as between the 2 groups. A total of 104 pregnant women were analyzed, including 48 women in the study group and 56 women in the control group. The blood glucose levels increased, with the peak levels occurring on the next day, after the dexamethasone administration in both groups. Compared with the control group, the study group had lower 2-hour postprandial blood glucose levels on days 2 and 3 after the insulin detemir injection (P < .05). There were no statistically significant differences in the fasting blood glucose levels between the 2 groups. Dexamethasone administration increased the blood glucose levels in the pregnant women with gestational diabetes mellitus. A short-course of low-dose insulin detemir administration effectively lowered the blood glucose levels in these women.

Diagnosis and Treatment of Eclampsia

Hypertensive disorders of pregnancy affect approximately 5% to 10% of pregnant women. Eclampsia is a serious hypertensive disorder that is primarily characterized by the onset of grand mal seizure activity in the absence of other causative conditions. While eclampsia is diagnosed clinically, laboratory tests are recommended to assess for complications. Treatment strategies for eclampsia focus on controlling seizures and managing hypertension. Acute care during a seizure is critical because of the need for immediate medical interventions, including the management of the airway, breathing, and circulation, as well as ensuring the safety of the patient during convulsions. Magnesium sulfate is the preferred anticonvulsant drug. Care must be taken during administration to prevent magnesium toxicity. Antihypertensive drugs used in eclampsia include labetalol, hydralazine and nifedipine. The definitive treatment of eclampsia is delivery. Close monitoring of both mother and fetus is important to identify any indications for delivery. The timing and mode of delivery depend on obstetric indications, the severity of eclampsia, the gestational age of the fetus, and the overall clinical status of the patient. Neuraxial anesthesia is the anesthesia of choice for conscious, seizure-free, and with stable vital signs women undergoing cesarean section.

Systematic Quantitative Analysis of Fetal Dexamethasone Exposure and Fetal Lung Maturation in Pregnant Animals: Model Informed Dexamethasone Precision Dose Study

Dexamethasone (DEX) was applied in neonatal respiratory distress syndrome treatment of pregnant women. We established a pharmacokinetics (PK)/pharmacodynamics(PD)/end point model of pregnant animals based on published data and then extrapolated to simulate fetal exposure and lung maturation in pregnant women. We first established the PK/PD/end point model for DEX in pregnant sheep. We considered the competitive effect of cortisol (Cort) and DEX binding with glucocorticoid receptor and then used the indirect response model to describe disaturated-phosphatidylcholine (DSPC) dynamics. Based on that, we established a regression relationship between DSPC and fetal lung volume (V40). We then extrapolated the PD/end point model of pregnant sheep to pregnant monkeys by corrected stages of morphologic lung maturation in two species. Finally, we utilized the interspecies extrapolation strategy to simulate fetal exposure (AUC0-48h) and V40 relationship in pregnant women. The current model could well describe the maternal-fetal PK of DEX in pregnant animals. Simulated DEX AUC0-24h values of the umbilical venous to maternal plasma ratio in pregnant sheep and monkeys were 0.31 and 0.27, respectively. The simulated Cort curve and V40 in pregnant sheep closely matched the observed data within a 2-fold range. For pregnant monkeys, model-simulated V40 were well fitted with external verification data, which showed good interspecies extrapolation performance. Finally, we simulated fetal exposure-response relationship in pregnant women, which indicated that the fetal AUC0-48h of DEX should not be less than 300 and 100 ng/mL·hr at GW28 and GW34 to ensure fetal lung maturity. The current model preliminarily provided support for clinical DEX dose optimization.

Maternal and Perinatal Outcomes in Placenta Previa: A Comprehensive Review of Evidence

Placenta previa poses significant risks to maternal and perinatal health, yet its management remains challenging. This comprehensive review synthesizes current evidence on maternal and perinatal outcomes in placenta previa, addressing its epidemiology, pathophysiology, diagnosis, and management strategies. Placenta previa complicates pregnancies, with increasing incidence linked to factors such as advanced maternal age and rising cesarean rates. Maternal complications, including hemorrhage and placenta accreta spectrum disorders, pose substantial risks. At the same time, perinatal outcomes are marked by increased rates of preterm birth, intrauterine growth restriction, and neonatal morbidity and mortality. Timely diagnosis and appropriate management, including antenatal corticosteroids and multidisciplinary care, are critical for optimizing outcomes. Future research should focus on improving diagnostic methods, evaluating novel interventions, and assessing long-term neurodevelopmental outcomes. This review underscores the importance of informed clinical practice and ongoing research efforts to enhance outcomes for women and infants affected by placenta previa.

Factors associated with maternal hyperglycaemia and neonatal hypoglycaemia after antenatal betamethasone administration in women with diabetes in pregnancy

AIMS

Bespoke glycaemic control strategies following antenatal corticosteroids for women with diabetes in pregnancy (DIP) may mitigate hyperglycaemia. This study aims to identify predictive factors for the glycaemic response to betamethasone in a large cohort of women with DIP.

METHODS

Evaluation of a prospective cohort study of 347 consecutive DIP pregnancies receiving two doses of 11.4 mg betamethasone 24 h apart between 2017 and 2021 and treated with the Pregnancy-IVI intravenous insulin protocol. Regression modelling identified factors associated with maternal glycaemic time-in-range (TIR) and maternal insulin requirements following betamethasone. Factors associated with neonatal hypoglycaemia (glucose <2.6 mmol/L) in infants born within 48 h of betamethasone administration (n = 144) were investigated.

RESULTS

The mean maternal age was 31.9 ± 5.8 years, with gestational age at betamethasone of 33.5 ± 3.4 weeks. Gestational diabetes was present in 81% (12% type 1; 7% type 2). Pre-admission subcutaneous insulin was prescribed for 63%. On-infusion maternal glucose TIR (4.0-7.8 mmol/L) was 83% [IQR 77%-90%] and mean on-IVI glucose was 6.6 ± 0.5 mmol/L. Maternal hypoglycaemia (<3.8 mmol/L) was uncommon (0.47 h/100 on-IVI woman hours). Maternal glucose TIR was negatively associated with indicators of insulin resistance (type 2 diabetes, polycystic ovary syndrome), late-pregnancy complications (pre-eclampsia, chorioamnionitis) and the 1-h OGTT result. Intravenous insulin requirements were associated with type of diabetes, pre-eclampsia and intrauterine infection, the 1-h OGTT result and the timing of betamethasone administration. Neonatal hypoglycaemia was associated with pre-existing diabetes but not with measures of glycaemic control.

CONCLUSION

An intravenous infusion protocol effectively controls maternal glucose after betamethasone. A risk-factor-based approach may allow individualisation of therapy.

Gestational Diabetes Mellitus and Antenatal Corticosteroid Therapy-A Narrative Review of Fetal and Neonatal Outcomes

BACKGROUND

There, we review the pathogenesis of gestational diabetes mellitus (GDM), its influence on fetal physiology, and neonatal outcomes, as well as the usage of antenatal corticosteroid therapy (ACST) in pregnancies complicated by GDM.

METHODS

MEDLINE and PubMed search was performed for the years 1990-2022, using a combination of keywords on such topics. According to the aim of the investigation, appropriate articles were identified and included in this narrative review.

RESULTS

GDM is a multifactorial disease related to unwanted pregnancy course and outcomes. Although GDM has an influence on the fetal cardiovascular and nervous system, especially in preterm neonates, the usage of ACST in pregnancy must be considered taking into account maternal and fetal characteristics.

CONCLUSIONS

GDM has no influence on neonatal outcomes after ACST introduction. The ACST usage must be personalized and considered according to its gestational age-specific effects on the developing fetus.

Trends and characteristics of multiple births in Baoan Shenzhen: A retrospective study over a decade

Background

Shenzhen has the largest and youngest foreign population among all cities in China. The reproductive health of pregnant women from different backgrounds is a social issue that deserves attention. In the past decade, China has liberalized its population policies to stimulate population growth, and the proportion of multiple births has continued to increase.

Method

This retrospective cohort included 526,654 newborns born in Baoan, Shenzhen, from January 1, 2009, to December 31, 2019, including 515,016 singletons and 11,638 twins or triplets. Univariate regression models were used to analyze the effects of maternal sociodemographic characteristics, physiological characteristics, medical history, antenatal care and other factors associated with single vs. multiple births and to elucidate the changing trends of different factors affecting multiple births in the past 11 years. Additionally, fetal development in multiple births was analyzed by generalized linear mixed models.

Results

The rates of pregnancy complications, preterm birth, and advanced-age pregnancy were significantly higher in the multiple birth mothers than in single birth mothers, and more multiple pregnancies were achieved through assisted reproductive technologies. The rates of adverse outcomes such as stillbirth, malformation, hypoxia, and ultralow body weight in multiple fetuses were significantly higher than that in singleton fetuses. The trend analysis from 2009 to 2019 showed that the socioeconomic status and health level of mothers with multiple births improved over time, and the risk during pregnancy generally decreased. Simultaneously, the development indicators of multiple fetuses have improved year by year, and the proportion of adverse outcomes has also decreased significantly. A low pre-natal care utilization rate was shown to be detrimental to the development of multiple fetuses. Independent risk factors for hypoxia and very low birth weight were also identified. The differences in secular trends between two birth groups were further revealed by time series models.

Conclusion

This study presented a comprehensive survey of multiple pregnancies in the area with the largest population inflow in China. This study identified the factors that affect the health of multiple birth mothers and their fetuses, particularly suggesting that preterm birth rates and the use of assisted reproduction remain high. The findings provide a basis for the formulation of individualized pre-natal care, assisted reproductive guidance and healthcare policies for multiple births.

Impact of quality improvement outreach education on the incidence of acute brain injury in transported neonates born premature

OBJECTIVE

To evaluate impact of a quality improvement (QI) outreach education on incidence of acute brain injury in transported premature neonates.

STUDY DESIGN

Neonates born at &lt;33 weeks gestation outside the tertiary center were included. The QI intervention was a combination of neuroprotection care bundle, in-person visits, and communication system improvement. Descriptive and regression (adjusting for Gestational Age, Birth Weight, Gender, and antenatal steroids, Mode of delivery, Apgars at 5 minutes, Prophylactic indomethacin, PDA, and Inotropes use) analyses were performed. The primary outcome was a composite of death and/or severe brain injury on cranial ultrasound using a validated classification.

RESULTS

181 neonates studied (93 before and 88 after). The rate and adjusted odds of death and/or severe brain injury reduced significantly post intervention (30% vs 15%) and (AOR 0.36, 95%CI, 0.15-0.85, P = 0.02) respectively.

CONCLUSION

Implementation of outreach education targeting neuroprotection can reduce acute brain injury in transported premature neonates.

Comparison of respiratory distress syndrome amongst preterm twins (28-34 Weeks) born within and after two weeks of completion of single antenatal corticosteroid course: A bidirectional cohort study

BACKGROUND

The literature on neonatal outcomes in preterm twins delivered before 34 weeks but within and after 14 days of a single initial steroid course is limited.

MATERIAL AND METHODS

This bidirectional (226 prospective and 42 retrospectives) cohort study was performed at a tertiary care teaching hospital in South India. We compared the respiratory distress syndrome and neonatal death amongst preterm twins from 28 to 34 weeks born < 14 days (Group A, n=268) and after 14 days (Group B, n=268) of completion of a single course of antenatal steroids. We used multivariable regression analysis (log-binomial model) to adjust for confounding variables. We generated a propensity-matched score with probit regression to analyse outcomes (respiratory distress and neonatal deaths).

RESULTS

The two groups had significant differences in the distribution of birthweight, gestation period and mode of delivery. On adjusted analysis, the period of gestation below 33 weeks and weight below 1.5 kg had the maximum influence on respiratory and other morbidities, and weight less than 1 kg on neonatal death. [adjusted relative risk (ARR) 26.06, (95%CI=2.37-285.5), p=0.008]. On propensity scoring after matching all these variables, we found an [ARR of 2.0 (95% CI: 1.03-3.88), P=0.017] for neonatal death after 14 days of steroid injection. The ARR for respiratory distress syndrome was 1.13 in those born after 14 days of steroids, though it did not reach statistical significance.

CONCLUSION

On propensity scoring, the steroid-delivery interval more than 14 days was associated with a significantly increased risk (ARR of 2) of neonatal death.

Prenatal glucocorticoid administration accelerates the maturation of fetal rat hepatocytes

BACKGROUND

Prenatal glucocorticoid (GC) is clinically administered to pregnant women who are at risk of preterm birth for the maturation of cardiopulmonary function. Preterm and low-birth-weight infants often experience liver dysfunction after birth because their livers are immature. However, the effects of prenatal GC administration on the liver remain unclear. We aimed to investigate the effects of prenatal GC administration on the maturation of liver hepatocytes in preterm rats.

METHODS AND RESULTS

Dexamethasone (DEX) was administered to pregnant Wistar rats on gestational days 17 and 19 before cesarean section. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to determine the mRNA levels of albumin, hepatocyte nuclear factor-4 alpha (HNF4α), hepatocyte growth factor (HGF), thymus cell antigen 1 (Thy-1), cyclin B, and Cyclin-dependent kinase 1 (CDK1) in the liver samples. Immunohistochemical staining and enzyme-linked immunosorbent assay were performed to examine protein production. The hepatocytes enlarged because of growth and prenatal DEX administration. Albumin, HNF4α, and HGF levels increased secondary to growth and prenatal DEX administration. The levels of the cell cycle markers cyclin B and CDK1 gradually decreased during growth and with DEX administration.

CONCLUSIONS

The results suggest that prenatal GC administration leads to hepatocyte maturation via expression of HNF4α and HGF in preterm fetuses.

Fetal lung regeneration using stem cell-derived extracellular vesicles: A new frontier for pulmonary hypoplasia secondary to congenital diaphragmatic hernia

The poor outcomes of babies with congenital diaphragmatic hernia (CDH) are directly related to pulmonary hypoplasia, a cosndition characterized by impaired lung development. Although the pathogenesis of pulmonary hypoplasia is not fully elucidated, there is now evidence that CDH patients have missing or dysregulated microRNAs (miRNAs) that regulate lung development. A prenatal therapy that supplements these missing/dysregulated miRNAs could be a strategy to rescue normal lung development. Extracellular vesicles (EVs), also known as exosomes when of small dimensions, are lipid-bound nanoparticles that can transfer their heterogeneous cargo (proteins, lipids, small RNAs) to target cells to induce biological responses. Herein, we review all studies that show evidence for stem cell-derived EVs as a regenerative therapy to rescue normal development in CDH fetal lungs. Particularly, we report studies showing that administration of EVs derived from amniotic fluid stem cells (AFSC-EVs) to models of pulmonary hypoplasia promotes fetal lung growth and maturation via transfer of miRNAs that are known to regulate lung developmental processes. We also describe that stem cell-derived EVs exert effects on vascular remodeling, thus possibly preventing postnatal pulmonary hypertension. Finally, we discuss future perspectives and challenges to translate this promising stem cell EV-based therapy to clinical practice. This article is protected by copyright. All rights reserved.

The effects of betamethasone on clinical outcome of the late preterm neonates born between 34 and 36 weeks of gestation

Background

Prenatal corticosteroid administration in preterm labor is one of the most important treatments available to improve neonatal outcomes; however, its beneficial effects on late preterm infants (after the 34th week of gestation) remained unknown. We aimed to assess the effects of betamethasone on the clinical condition of the late preterm infants born between 34 and 36 weeks of gestation.

Methods

This retrospective cohort study was performed on 100 consecutive infants born between 34 and 36 weeks of gestation and received betamethasone before delivery as the cases and 100 neonates with the same delivery conditions but without receiving betamethasone. All neonates were followed up within hospitalization to assess the neonatal outcome.

Results

The neonates receiving betamethasone suffered more from respiratory distress syndrome (49% versus 31%, p = 0.008, RR = 1.59 95% CI (1.12–2.27)) and requiring more respiratory support (71% versus 50%, p = 0.002, RR = 1.43 95% CI (1.13–1.80)) as compared to the control group. There was no difference between the two groups in other neonatal adverse events or death.

Conclusion

the use of betamethasone in the late preterm period (after 34 weeks of gestation) has no beneficial effects on lung maturity or preventing neonatal adverse outcomes, even may lead to increase the risk for RDS and requiring respiratory support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04246-x.