EVIDENCE FOR INDEPENDENT REGULATORS OF ORGAN MATURATION IN FETAL RABBITS

PEDIATRICS ◽  
1971 ◽  
Vol 47 (1) ◽  
pp. 57-64
Author(s):  
Robert V. Kotas ◽  
Barry D. Fletcher ◽  
John Torday ◽  
Mary Ellen Avery

The degree of organ development bears a relationship to gestational age, but in a given infant not all organs need be at the same stage of development. The range of variation of organ maturation can be best studied in an animal with a large litter, such as the rabbit, in which gestation can be precisely timed. Body weight, ossification centers, and lung "maturity," defined as distensibility and stability on deflation, were all measured. Marked variations within a litter allowed study of the relationships between them. Body weight and the number of ossification centers were closely correlated at the same gestational age (R = 0.88, p 001). Ossification centers were less well correlated with gestational age. Lung "age," on the other hand, was more closely related to gestational age than body weight. A single injection of the fetus with 9-fluoroprednisolone, a glucocorticoid, at 24 days resulted in an acceleration of lung maturation, defined in terms of distensibility and the presence of surfactant by 26 to 27 days. No increase in lung weight took place. Similarly, the glucocorticoid had no effect on body size or the number of ossification centers, suggesting that regulators of maturation of these organs are independent.

1987 ◽  
Vol 62 (6) ◽  
pp. 2141-2146 ◽  
Author(s):  
C. R. Comer ◽  
J. S. Grunstein ◽  
R. J. Mason ◽  
S. C. Johnston ◽  
M. M. Grunstein

To test the hypothesis that endogenous opioids modulate fetal lung development, separate groups of pregnant rabbits received daily injections of saline, morphine (1 mg/kg body wt), or the opioid antagonist naloxone (0.4 and 5.0 mg) for 10 days during their last trimester of pregnancy. The corresponding groups of fetuses were then delivered prematurely on day 28 of gestation (term approximately 31 days) and evaluated with respect to differences in body weight, lung weight, and the ratios of wet to dry lung weight and lung dry weight to body weight, the static inflation and deflation air and saline pressure-volume (P-V) characteristics of the lungs, and lung morphology. Mean values for body weight, lung weight, and the ratios of lung wet to dry weight and lung dry weight to body weight were not significantly different among the saline control (C), morphine (M)-, and naloxone (NLX)-treated fetuses. On the other hand, the fetal air P-V curves varied significantly (P less than 0.001), wherein the M-treated group depicted increased lung distensibility and alveolar stability on lung deflation, whereas the opposite was obtained in the NLX-treated fetuses. Moreover, morphometric analyses demonstrated that the mean alveolar air space-to-tissue ratio in lungs from M-treated fetuses were significantly greater than that observed either in C or in NLX-treated fetuses (P less than 0.05); however, the air space-to-tissue ratio did not significantly vary between the C and NLX-treated animals. These observations provide new evidence that endogenous opioids enhance fetal lung maturation.


PEDIATRICS ◽  
1972 ◽  
Vol 49 (3) ◽  
pp. 400-405
Author(s):  
H. William Taeusch ◽  
N. S. Wang ◽  
Mary Ellen Avery

A skin score was constructed from the study of histological specimens from 38 rabbit litters removed during the last third of gestation. The score increased predictably with increasing gestational age. Changes in body weight occurring within litters of the same gestational age did not affect the score. This pattern of development is similar to that previously described for fetal rabbit lung. In 16 fetuses, 1 mg of hydrocortisone was injected 2 days before delivery on day 28 of gestation. Although lung age is known to be accelerated by steroid injection, the skin score was not advanced. Therefore, maturational indices of lung and skin while normally parallel and independent of body weight variation, are affected differently by an altered steroid environment.


1980 ◽  
Vol 48 (3) ◽  
pp. 505-510 ◽  
Author(s):  
L. Frank ◽  
J. Summerville ◽  
D. Massaro

Isoxsuprine, a beta-sympathomimetic agent used clinically to delay premature parturition and to possibly accelerate fetal lung maturation, was administered to pregnant rats at 48 and 24 h prior to delivery. Newborn rats were placed in 96-98% O2 (or room air) to determine if the prenatal isoxsuprine treatment compromised their tolerance to prolonged hyperoxic exposure. (Exogenous catecholamines are known to exacerbate O2 toxicity in adult animals). Survival of the isoxsuprine-treated pups in O2 (52%) was no different than for control neonates exposed to hyperoxia for 7 days (57%) (P = 0.22). Body weight, lung weight, lung protein, and DNA content of the newborns were also not altered by the prenatal isoxsuprine treatment. Lung antioxidant enzyme activities for superoxide dismutase, catalase, and glutathione peroxidase were the same at birth in the isoxsuprine-treated and control rat pups, and the enzyme activities increased in response to hyperoxic exposure in each group to an equivalent degree. Thus, in utero treatment with isoxsuprine had no apparent adverse effect on newborn rats exposed to a prolonged O2 challenge.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiajia Jing ◽  
Yiheng Dai ◽  
Yanqi Li ◽  
Ping Zhou ◽  
Xiaodong Li ◽  
...  

Abstract Background Antenatal corticosteroids (ACS) treatment is critical to support survival and lung maturation in preterm infants, however, its effect on feeding and growth is unclear. Prior preterm delivery, it remains uncertain whether ACS treatment should be continued if possible (repeated course ACS), until a certain gestational age is reached. We hypothesized that the association of single-course ACS with feeding competence and postnatal growth outcomes might be different from that of repeated course ACS in very-low-birth-weight preterm infants. Methods A multicenter retrospective cohort study was conducted in very-low-birth-weight preterm infants born at 23–37 weeks’ gestation in South China from 2011 to 2014. Data on growth, nutritional and clinical outcomes were collected. Repeated course ACS was defined in this study as two or more courses ACS (more than single-course). Infants were stratified by gestational age (GA), including GA < 28 weeks, 28 weeks ≤ GA < 32 weeks and 32 weeks ≤ GA < 37 weeks. Multiple linear regression and multilevel model were applied to analyze the association of ACS with feeding and growth outcomes. Results A total of 841 infants were recruited. The results, just in very-low-birth-weight preterm infants born at 28–32 weeks’ gestation, showed both single and repeated course of ACS regimens had shorter intubated ventilation time compared to non-ACS regimen. Single-course ACS promoted the earlier application of amino acid and enteral nutrition, and higher rate of weight increase (15.71; 95%CI 5.54–25.88) than non-ACS after adjusting for potential confounding factors. No associations of repeated course ACS with feeding, mean weight and weight increase rate were observed. Conclusions Single-course ACS was positively related to feeding and growth outcomes in very-low-birth-weight preterm infants born at 28–32 weeks’ gestation. However, the similar phenomenon was not observed in the repeated course of ACS regimen.


1972 ◽  
Vol 27 (2) ◽  
pp. 305-312 ◽  
Author(s):  
Sharad V. Apte ◽  
Leela Iyengar

1. The body composition was determined of forty-one fetuses of different gestational ages born to mothers belonging to a low socio-economic group of the population.2. With increasing gestational age the water content fell from 88% at 28 weeks to 76% at term; the fat content increased from 2.1% to 11.2% and the protein content increased from 6.9 to 9.3%.3. The changes in body composition were more closely related to body-weight than to gestational age.4. The calcium, Phosphorus and magnesium contents of the body per unit fat-free weight progressively increased with gestational age, and at term the values appeared to be considerably lower than those reported in the literature. The Ca:P ratio was constant at different body-weights.5. The body iron content per unit of fat-free weight increased marginally with increasing gestational age. The value was almost 30% lower than the values reported from elsewhere.6. It is suggested that chemical composition and nutrient stores of the developing foetus can be considerably influenced by the state of maternal nutrition.


2018 ◽  
Vol 52 (21) ◽  
pp. 1386-1396 ◽  
Author(s):  
Margie H Davenport ◽  
Victoria L Meah ◽  
Stephanie-May Ruchat ◽  
Gregory A Davies ◽  
Rachel J Skow ◽  
...  

ObjectiveWe aimed to identify the relationship between maternal prenatal exercise and birth complications, and neonatal and childhood morphometric, metabolic and developmental outcomes.DesignSystematic review with random-effects meta-analysis and meta-regression.Data sourcesOnline databases were searched up to 6 January 2017.Study eligibility criteriaStudies of all designs were eligible (except case studies and reviews) if published in English, Spanish or French, and contained information on the relevant population (pregnant women without contraindication to exercise), intervention (subjective/objective measures of frequency, intensity, duration, volume or type of exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’)), comparator (no exercise or different frequency, intensity, duration, volume, type or trimester of exercise) and outcomes (preterm birth, gestational age at delivery, birth weight, low birth weight (<2500 g), high birth weight (>4000 g), small for gestational age, large for gestational age, intrauterine growth restriction, neonatal hypoglycaemia, metabolic acidosis (cord blood pH, base excess), hyperbilirubinaemia, Apgar scores, neonatal intensive care unit admittance, shoulder dystocia, brachial plexus injury, neonatal body composition (per cent body fat, body weight, body mass index (BMI), ponderal index), childhood obesity (per cent body fat, body weight, BMI) and developmental milestones (including cognitive, psychosocial, motor skills)).ResultsA total of 135 studies (n=166 094) were included. There was ‘high’ quality evidence from exercise-only randomised controlled trials (RCTs) showing a 39% reduction in the odds of having a baby >4000 g (macrosomia: 15 RCTs, n=3670; OR 0.61, 95% CI 0.41 to 0.92) in women who exercised compared with women who did not exercise, without affecting the odds of growth-restricted, preterm or low birth weight babies. Prenatal exercise was not associated with the other neonatal or infant outcomes that were examined.ConclusionsPrenatal exercise is safe and beneficial for the fetus. Maternal exercise was associated with reduced odds of macrosomia (abnormally large babies) and was not associated with neonatal complications or adverse childhood outcomes.


2014 ◽  
Vol 9 ◽  
Author(s):  
Gloria Pelizzo ◽  
Maurizio Ballico ◽  
Maria Chiara Mimmi ◽  
José Louis Peirò ◽  
Mario Marotta ◽  
...  

Background: Tracheal occlusion (TO) stimulates lung growth in fetuses affected with congenital diaphragmatic hernia (CDH) although the processes involved in lung maturation still remain unknown. The objective of this study was to evaluate the metabolomic profile of amniotic fluid (AF) following TO in fetal lamb model in order to obtain an indirect view of mechanisms involved in pulmonary reversal hypoplasia and biochemical maturity in response to fetal TO. Methods: Liquid Chromatography Mass Spectrometry was performed on lamb AF samples at: age I (70 days’gestation); age II (102 days’ gestation); age III (136 days’ gestation). CDH was induced at age I and TO at age II. Results: Betaine, choline, creatinine were found significantly increased during gestation in the control group. The CDH group showed choline (p =0.007) and creatinine (p =0.004) decreases during pregnancy. In the TO group choline and creatinine profiles were restored. Conclusions: Alveolar tissue and fetal global growth ameliorated after TO. Metabolomics provided useful information on biochemical details during lung maturation. Metabolomic profiling would help to identify the best time to perform TO, in order to increase survival of CDH affected patients.


2021 ◽  
Vol 12 (2) ◽  
pp. 35-41
Author(s):  
Anastasia V. Budalova ◽  
Natalia V. Kharlamova ◽  
Galina N. Kuzmenko

Background. Currently, the development of medicine in the field of perinatology is aimed at improving the quality of medical care for newborns, especially those born prematurely. Premature newborns are most likely to develop hemorrhagic disorders, which often aggravates their condition and determines high morbidity and mortality. On modern hematological analyzers, it has become possible to evaluate a larger number of blood parameters, including platelet parameters, however, there are a small number of studies devoted to the study of platelet parameters in premature newborns. The aim was to study the morphofunctional features of platelets in premature newborns with very low and extremely low body weight. Materials and methods. The study included 78 newborns born at 2534 weeks of gestation, with a body weight of less than 1500 grams. On the 3rd5th day of life, a clinical blood test was performed on the Advia 2120i hematological analyzer (Siemens), with the determination of platelet parameters: PLT, 103 cells/l, PCT, %, PDW, %, Large Plt, 103 cells/l, MPC, g/dl, MRM, pg. Results. In newborns with ELBW, a decrease in the number and granularity of platelets in the blood, an increase in the average dry mass of platelets was found. Newborns with intrauterine growth retardation have a reduced platelet count and reduced thrombocrit. In premature newborns with a gestational age of 2527 weeks, blood circulation of platelets with a reduced volume was established, and in newborns who were born at a gestational age of 3234 weeks with increased granularity. In the absence of antenatal prevention of respiratory distress syndrome in newborns, there is a decrease in thrombocrit, the number of platelets, including large forms in the blood. In premature newborns born in a state of severe asphyxia, a decrease in platelet granularity was noted. The use of high concentrations of O2 in the oxygen-air mixture during respiratory therapy leads to a decrease in the number of platelets in the blood. Conclusions. Factors determining the morphofunctional state of platelets in premature newborns were established: the presence of a full course of antenatal prevention of respiratory distress syndrome of newborns, gestational age, the severity of asphyxia at birth, as well as the concentration of O2 in the oxygen-air mixture used in respiratory therapy. Newborns with ELBW have a reduced platelet count, low-granulated platelets, and an increased average dry platelet mass. Newborns with intrauterine growth retardation have a reduced number of platelets and thrombocrit in the blood. The revealed morphofunctional features of platelets allow us to clarify the nature of changes in the platelet link of hemostasis in premature newborns for the timely prevention of complications during the underlying disease.


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