Placental transport and metabolism
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Hormones are produced by the placenta and released to the mother and fetus. These include peptides, steroids, glycoproteins, and cytokines. Progesterone and placental lactogen have effects on the mother, which promote glucose delivery to the fetus (2). The placental variant of growth hormone (GHv) and IGF-1 and IGF-2 may influence nutrient provision by endocrine effects on maternal metabolism and/or paracrine effects on placental potential for simple and facilitated diffusion (16,17). Binding of these hormones to placental receptors can change placental clearance of analogs of glucose and amino acids in vivo and in vitro (18). Maternal levels and placental expression of GHv are decreased in pregnancies with growth-restricted fetuses, implicating changes in placental endocrine function as a cause rather than a result of abnormal fetal growth (19).
Obstetric Management of Intrauterine Growth Retardation
Asim Kurjak, John M. Beazley in Fetal Growth Retardation: Diagnosis and Treatment, 2020
The placenta being the live anchor of the fetus serves several important functions.135 Fetal oxygen and nutritional demands are met and waste products are excreted. The production of various hormones and proteins in the placenta have been employed to measure placental function.136,137 The substances most commonly used for fetal surveillance are oestriol and human placental lactogen as they are considered to reflect best fetal condition.138,139 The early enthusiasm, that placental function tests could reliably diagnose deterioration in fetal health, have not been borne out, and placental function tests can presently only be used as an adjunct to other means in the management of the fetus with IUGR.140–142
Steroid Receptors in the Pregnant Uterus*
Gabor Huszar in The Physiology and Biochemistry of the Uterus in Pregnancy and Labor, 2020
The question of whether the placenta is a target organ for E and P remains controversial. The issue is complicated by the fact that the placenta is a source of the hormones, as well as a potential target. As indicated previously, this presents considerable methodologie problems in the detection of the receptor sites in the face of competition for the sites from endogenous hormones. Nevertheless, several studies have demonstrated high affinity binding components in placental cytosols, in a number of species. In both rats and rabbits, putative E and P receptors have been identified in the placenta,57-59 while the detection of high affinity binding of the synthetic progestin [3H] R5020 in human placental cytosols60 was not always successful. This may have been due to occupation of the binding sites by unlabeled P because, in a subsequent study,61 the [3H] R5020 binding was detected in placental cytosols after incubation at higher temperatures, which would facilitate exchange between the radiolabeled ligand and endogenous hormone. Definitive answers regarding the presence of E receptors in the human placenta await studies of nuclear binding.
Pathology of the Placenta in Singletons after Assisted Reproductive Technology Compared to Singletons after Spontaneous Conception: A Systematic Review
Published in Fetal and Pediatric Pathology, 2023
Urška Belak, Bojana Pinter, Helena Ban Frangež, Mojca Velikonja, Sara Korošec
Currently, there is evidence that there are more pathological lesions of the placenta in pregnancies after IVF, especially in the ICSI group. There are higher rates of retroplacental and marginal hematoma (p = 0.04), greater thickness (p = 0.02), higher overall rates of vascular and anatomical pathology (p < 0.001) and higher rates of marginal (p = 0.001) and membranous (p = 0.02) umbilical cord insertions than in placentas from pregnancies without ART. Unfortunately, we do not know how anatomical and vascular changes affect the placenta, its function and neonatal outcomes. There is not yet a clear correlation between ultrasound, anatomical and vascular changes in the placenta that correspond to actual findings at postpartum examination. Further prospective studies on different ultrasound features of the placenta compared to anatomical and pathological examination of the placenta after birth are needed.
Effects of different doses of estrogen on ER expression and ovarian function in patients with unexplained recurrent abortion
Published in Gynecological Endocrinology, 2022
Yamin Qiu, Jie Lin, Qing Xu, Linhua Zeng, Chao Liu
Fertilized egg implantation and normal pregnancy are affected by many factors, especially the development of the uterus, the level of estrogen and progesterone, and the level and specificity of ER and PR. The combination of ER and estrogen can act on the decidua tissue, regulate the function of the placenta, and maintain the growth and development of both. The PR binds to progesterone to maintain normal pregnancy [9,10]. Therefore, the ER and PR are essential for maintaining a normal pregnancy. The role of estrogen and progesterone is closely related. Only when estrogen exists and is combined with the corresponding ER, the hormone signal is converted into a series of intracellular chemical reactions, and progesterone and PR can play their due physiological effects, so the difference in ER expression may affect pregnancy outcome [11–13]. Experts have confirmed that the expression level of ER and PR in the cytoplasm and nucleus of the decidual tissue of URSA patients is extremely low, and some scholars call it primary endometrial defect, and this kind of endometrial defect exists even when hormone levels are normal and no pathological changes are found in the endometrium [5,14,15]. When the expression of ER and PR in the decidua tissue decreases, the physiological functions of the corresponding hormones are affected, which can cause embryonic death or abortion [16,17]. Li [5] showed that supplementation of estradiol in the early follicular phase and supplementation of progesterone in the luteal phase can increase the content of receptors in the endometrium and improve endometrial responsiveness.
Anti-Mullerian hormone levels in spontaneous pregnancies with hyperemesis gravidarum
Published in Journal of Obstetrics and Gynaecology, 2022
Banuhan Şahin, Gizem Cura Şahin, Andrea Tinelli
The HG incidence is highest at the beginning of pregnancy when hormones are produced by the placenta and the corpus luteum and, therefore, it has been emphasised that endocrine factors are potentially involved in the HG development. In fact, circulating ovarian and placental hormones are strongly associated with the increasing serum level of human chorionic gonadotropin (hCG) from the very beginning of pregnancy, and it is high influent in the HG pathophysiology (Lagiou et al. 2003). Both high and low progesterone concentrations have been shown to contribute to the HG development (Kleine et al. 2017). Oestrogen continuously increasing throughout the pregnancy could play a role in HG pathogenesis, since HG is more common in obese women and in the first trimester, where oestrogen levels are very high (Goodwin et al. 1992). In a study on the HG aetiology, Taşkın et al. reported that cellular immunity was activated by high oestradiol and high progesterone levels (Taşkın et al. 2009). As reported in the literature, the authors’ study showed that serum oestradiol and progesterone levels were higher in pregnant women with HG diagnosis than in the control group, but the difference did not reach a statistical significance.
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