Parameters Of Fetal Development Research Articles

English

Angylocalyx oligophyllus (Fabaceae) is a shrub used traditionally to treat diabetes mellitus and intestinal parasites. Although it is also used by pregnant women, no scientific study has yet revealed its effects on pregnancy. This work aimed to assess the toxic effects of A. oligophyllus leaves aqueous extract on pregnancy, reproduction and fetal development in pregnant rats. The acute toxicity of the A. oligophyllus leaves aqueous extract was firstly performed in female non-pregnant rats. Then, pregnant rats were divided into a control and three test groups receiving, respectively distilled water and A. oligophyllus leaves aqueous extract doses (50, 100 and 200 mg/kg) by gavage for 20 days (from pregnancy screening day). The daily body masses of pregnant rats and the 21st-day relative organs masses were measured for assessing the pregnancy progress. The numbers of corpora lutea, implantation sites, live and dead fetuses and calculated pre-and-post implantation loss for appreciating the reproduction, and the fetuses’ masses for fetal development assessment, were recorded on the 21st day. Acute administration of the A. oligophyllus leaves aqueous extract (2000 mg/kg) did not cause any death or adverse effect in non-pregnant female rats. The LD50 was estimated higher than 2000 mg/kg. Pregnancy and reproductive parameters did not vary significantly between plant extract-treated rats and control. However, although fetal development parameters did not change significantly between the groups, the percentages of small (SGA) and large (LGA) pups for the gestational age were higher in rats treated with the dose extract of 200 mg/kg, compared to control (20 and 11%, respectively). Current data showed that the A. oligophyllus leaves aqueous extract does not impair motherhood and reproduction. Nevertheless, limitation of the dose is recommended during treatment in pregnant women to avoid adverse effect on fetal development. Key words: Angylocalyx oligophyllus, toxic effects, pregnancy, embryo-fetal development.

Ultrasonographic parameters of fetal well-being and development in alpacas

In this study, a database of fetal and maternal parameters was developed in pregnant alpacas from 120 days of gestation to term for evaluation of fetal well-being and development. Ten pregnancies were examined every 2 weeks from 120 to 300 days of gestation, then weekly until parturition. Five more pregnancies were evaluated weekly during the last 4 weeks prepartum. Maternal weight and heart rate were recorded. Indicators of fetal well-being (mean, minimum, and maximum fetal heart rate, fetal movement, and tone), development (size of the aorta, thorax, abdomen, stomach, kidney, head, eye orbit, radius, and umbilical vessels), and uterine environment (combined thickness of the uterus and placenta, depth and character of allantoic and amnionic fluids) were assessed using transabdominal ultrasound. Reference values and fetal growth curves were created. Weights of the cria, fetal membranes, and dam at parturition were associated with parameters of fetal growth. Mean (R2 = 0.65), minimum (R2 = 0.57), and maximum (R2 = 0.64) fetal heart rate decreased from midgestation to term (P < 0.0001). Fetal activity also decreased as pregnancy advanced (P < 0.0001). Fetal presentation was anterior in all fetuses by 10 months. Increases in depth of allantoic (R2 = 0.11) and amniotic (R2 = 0.02) fluid, combined thickness of the uterus and placenta (R2 = 0.31), and maternal weight (R2 = 0.09) were significantly but poorly associated with gestation length. All parameters of fetal development were positively associated with gestational age (P < 0.0001). Size of the aorta (R2 = 0.88), abdomen (R2 = 0.87), kidney (R2 = 0.83), and thorax (R2 = 0.82) provided the best estimates of gestational age. Birth weight was associated with the size of the aorta (R2 = 0.71), kidney (R2 = 0.61), and radius (R2 = 0.73) (P < 0.05). This information might be of value in the assessment of fetal well-being and development in alpacas.

Imprinted gene expression in fetal growth and development

Experimental studies showed that genomic imprinting is fundamental in fetoplacental development by timely regulating the expression of the imprinted genes to overlook a set of events determining placenta implantation, growth and embryogenesis.We examined the expression profile of 22 imprinted genes which have been linked to pregnancy abnormalities that may ultimately influence childhood development. The study was conducted in a subset of 106 placenta samples, overrepresented with small and large for gestational age cases, from the Rhode Island Child Health Study.We investigated associations between imprinted gene expression and three fetal development parameters: newborn head circumference, birth weight, and size for gestational age. Results from our investigation show that the maternally imprinted/paternally expressed gene ZNF331 inversely associates with each parameter to drive smaller fetal size, while paternally imprinted/maternally expressed gene SLC22A18 directly associates with the newborn head circumference promoting growth. Multidimensional Scaling analysis revealed two clusters within the 22 imprinted genes which are independently associated with fetoplacental development. Our data suggest that cluster 1 genes work by assuring cell growth and tissue development, while cluster 2 genes act by coordinating these processes. Results from this epidemiologic study offer solid support for the key role of imprinting in fetoplacental development.

Alterations of placental cytochrome P450 1A1 and P-glycoprotein in tobacco-induced intrauterine growth retardation in rats1

To investigate the alterations of placental P-glycoprotein (P-gp) and cytochrome P450 1A1 (CYP1A1) at different gestational days (GD), and to explore the possible significance of placental P-gp and CYP1A1 in tobacco smoke-induced intrauterine growth retardation (IUGR) in rats. An IUGR model was produced by passive tobacco smoking from GD7 to parturition (GD21) and predicted using fetal development parameters. Placental structure and function were monitored by observing pathological alteration and antioxidative function, including the content of malondialdehyde and the activities of superoxide dismutase and catalase (CAT). The expressions of CYP1A1 and P-gp (mdr 1a and mdr 1b) were detected using a reverse transcription polymerase chain reaction and immunohistochemistry. Placental pathological changes occurred and the malondialdehyde content increased, whereas the activities of superoxide dismutase and CAT lowered, when compared to their controls. In the rat placenta of the tobacco group, the level of CYP1A1 mRNA increased significantly; the level of mdr1a mRNA increased significantly at GD21 but not at GD14, whereas the level of mdr1b mRNA in different term remained stable; the expression of P-gp increased significantly only in full-term placenta. The expression of placental CYP1A1 and P-gp increased in tobacco-induced IUGR. Overexpression of placental CYP1A1 can attribute to the metabolism of tobacco and the generation of reactive metabolites, which can trigger IUGR. As a compulsory mechanism, upregulation of P-gp might decrease tobacco exposure to a developing fetus with IUGR.

Development of deciduous mandibular incisors related to developmental stages in the mandible.

On the basis of morphological and histochemical studies of 71 human mandibles from the former half of prenatal life, five stages (D I to D V) in the development of the deciduous mandibular incisors are described. These stages are related partly to general parameters of fetal development, such as M age (menstrual age), CRL (crown-rump length), CNO (composite number of ossified bones in hand and foot) and partly to stages in the skeletal development of the symphysis menti (SM I to SM V). The investigation revealed close relationship between the development of the deciduous mandibular incisors and the skeletal development of the deciduous mandibular incisors and the skeletal development of the mandible in the region of the incisors. No such relationship was found between the development of the deciduous mandibular incisors and general parameters of fetal development.