Thyrotropin-releasing hormone added to corticosteroids for women at risk of preterm birth for preventing neonatal respiratory disease

Neonatal morbidity and mortality for preterm in breech presentation regarding the onset mode of labor

PURPOSE

To assess severe neonatal morbidity and mortality in induced labor in preterm breech deliveries, compared to spontaneous labor.

METHODS

This is a retrospective study conducted in a tertiary university center in France. Women with single live breech pregnancy between 28 + 0 and 36 + 6 weeks gestation were included. We excluded situations with medical contraindication to vaginal delivery and fetal malformations. We compared women with an unfavorable cervix, who had an indication for deliver and could receive cervical ripening to induce labor, to women in spontaneous labor. The primary outcome was a composite criterion of severe neonatal morbidity and mortality including perinatal death, traumatic event during delivery, Apgar score at 5-min < 4, moderate or severe encephalopathy, seizures within the first 24 h, Intra-Ventricular Hemorrhage grade 3 or 4, necrotizing enterocolitis grade 2 or 3.

RESULTS

We included 212 patients: 64 in the induced labor group and 136 in the spontaneous labor group. In the induced labor group, 45.3% of patients delivered vaginally, and 86% in spontaneous labor group. The neonatal morbidity and mortality rate were similar in both groups: 4.7% in the induced labor group, and 5.2% in the spontaneous labor group, p = 0.889, aOR = 1.5 (0.28-8.28).

CONCLUSION

Nearly half of the patient who received induction of labor delivered vaginally. The onset mode of labor does not appear to have an effect on severe neonatal morbidity and mortality in preterm breech fetuses. Induction of labor could be an option for patients in this setting.

The prevention and management strategies for neonatal chronic lung disease

INTRODUCTION

Survival from even very premature birth is improving, but long-term respiratory morbidity following neonatal chronic lung disease (bronchopulmonary dysplasia (BPD)) has not reduced. Affected infants may require supplementary oxygen at home, because they have more hospital admissions particularly due to viral infections and frequent, troublesome respiratory symptoms requiring treatment. Furthermore, adolescents and adults who had BPD have poorer lung function and exercise capacity.

AREAS COVERED

Antenatal and postnatal preventative strategies and management of infants with BPD. A literature review was undertaken using PubMed and Web of Science.

EXPERT OPINION

There are effective preventative strategies which include caffeine, postnatal corticosteroids, vitamin A, and volume guarantee ventilation. Side-effects, however, have appropriately caused clinicians to reduce use of systemically administered corticosteroids to infants only at risk of severe BPD. Promising preventative strategies which need further research are surfactant with budesonide, less invasive surfactant administration (LISA), neurally adjusted ventilatory assist (NAVA) and stem cells. The management of infants with established BPD is under-researched and should include identifying the optimum form of respiratory support on the neonatal unit and at home and which infants will most benefit in the long term from pulmonary vasodilators, diuretics, and bronchodilators.

Trial of labor following cesarean in preterm deliveries: success rates and maternal and neonatal outcomes: a multicenter retrospective study

PURPOSE

To evaluate the rates of vaginal birth after cesarean (VBAC) among parturients attempting preterm trial of labor following a cesarean delivery (TOLAC) vs. term TOLAC.

METHODS

A multicenter historic cohort study was conducted at two university-affiliated centers between August 2005 and March 2021. Parturients in their second delivery, attempting TOLAC after a single low segment transverse cesarean delivery were included. We retrospectively examined computerized medical records of all preterm (< 37 weeks) and term (37-42 weeks) births. Multifetal gestations and postterm deliveries (≥ 42 weeks) were excluded. A univariate analysis was conducted, followed by a multivariate analysis.

RESULTS

4865 second deliveries following previous cesarean were identified: 212 (4.4%) preterm and 4653 (95.6%) term. Hypertensive disorders, diabetes and fertility treatments were significantly more prevalent in the preterm group. VBAC rate was significantly lower in preterm group (57.5 vs 79.7%., p < 0.01), including both spontaneous and vaginal-assisted deliveries. In multivariate analysis, preterm TOLAC was independently associated with TOLAC failure [adjusted odds ratio 2.24, [95% confidence interval 1.62-3.09]. Overall, maternal outcomes were favorable. Rates of uterine rupture, re-laparotomy and postpartum hemorrhage were comparable between groups. Neonatal outcomes were less favorable among the preterm group; however, preterm vs. term TOLAC was not associated with low 5 min Apgar score (aOR 1.76, 95% CI 0.92-3.40).

CONCLUSION

In our study, VBAC rates were lower in preterm compared to term deliveries. Maternal outcomes were comparable. Neonatal outcomes were less favorable in the preterm group, more likely due to prematurity than delivery mode.

Maternal hormonal milieu influence on fetal brain development

An adverse maternal hormonal environment during pregnancy can be associated with abnormal brain growth. Subtle changes in fetal brain development have been observed even for maternal hormone levels within the currently accepted physiologic ranges. In this review, we provide an update of the research data on maternal hormonal impact on fetal neurodevelopment, giving particular emphasis to thyroid hormones and glucocorticoids. Thyroid hormones are required for normal brain development. Despite serum TSH appearing to be the most accurate indicator of thyroid function in pregnancy, maternal serum free T4 levels in the first trimester of pregnancy are the major determinant of postnatal psychomotor development. Even a transient period of maternal hypothyroxinemia at the beginning of neurogenesis can confer a higher risk of expressive language and nonverbal cognitive delays in offspring. Nevertheless, most recent clinical guidelines advocate for targeted high-risk case finding during first trimester of pregnancy despite universal thyroid function screening. Corticosteroids are determinant in suppressing cell proliferation and stimulating terminal differentiation, a fundamental switch for the maturation of fetal organs. Not surprisingly, intrauterine exposure to stress or high levels of glucocorticoids, endogenous or synthetic, has a molecular and structural impact on brain development and appears to impair cognition and increase anxiety and reactivity to stress. Limbic regions, such as hippocampus and amygdala, are particularly sensitive. Repeated doses of prenatal corticosteroids seem to have short-term benefits of less respiratory distress and fewer serious health problems in offspring. Nevertheless, neurodevelopmental growth in later childhood and adulthood needs further clarification. Future studies should address the relevance of monitoring the level of thyroid hormones and corticosteroids during pregnancy in the risk stratification for impaired postnatal neurodevelopment.

Hampered Lung Maturation in Methimazole-Induced Hypothyroidism in Fetal Chicken: Morphological and Molecular Correlates to Human Fetal Development

BACKGROUND

Molecular understanding of lung development is crucial for developing therapies and diagnostic tools. Animal models with altered thyroid hormone signaling provide mechanistic insight into thyroid-dependent neonatal lung disease. Repression of Klf2 (Krüppel-like factor 2), a suggested T3 target gene, is associated with disrupted lung development in mice. Klf2 is proposed to be specifically involved in type I pneumocyte differentiation.

OBJECTIVES

To explore mechanisms of thyroid-dependent lung disease, we studied developing chicken fetuses with experimentally induced hypothyroidism.

METHODS

Morphology and the expression of a panel of molecules linked to Klf2 were assessed using histology, immunohistochemistry, Western blot and qPCR.

RESULTS

Methimazole injections at E14 hampered lung maturation. The effects of methimazole were evident in several tissue compartments, and impacted on both pneumocyte and vascular differentiation, suggesting cellular and molecular pleiotropy.

CONCLUSIONS

Concomitant expression changes in a panel of selected microRNAs regulated by Klf2 suggest importance in lung development. These microRNAs may thus represent potential clinical targets and diagnostic and prognostic tools in thyroid-dependent lung disease.