Serum Gonadotropins Before, at the Inception of, and Following Human Pregnancy

Rb, Jaffe; Lee, Pa; Ar, Midgley

doi:10.1210/jcem-29-9-1281

Cited by 119 publications

(45 citation statements)

References 5 publications

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“…6), a two compartment model can be shown to characterize the vast bulk of E2 clearance, with a mean second ti of 6-7 hr and a range of from 6 to 8 hr. The E2 concentration reached follicular phase levels by 14-35 hr, similar to the fall of progesterone (23,24) at a time when plasma HCG levels remained quite high (32,33). These data directly support the view that HCG does not stimulate estrogen secretion by the ovary of pregnancy.…”

Section: Discussionsupporting

confidence: 72%

The plasma estradiol as an index of fetoplacental function

Tulchinsky¹,

Korenman²

1971

J. Clin. Invest.

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A B S T R A C T A radioligand assay has been developedfor the measurement of unconjugated 17j#-estradiol in as little as 0.01 ml of pregnancy plasma employing rabbit uterine cytosol as specific binder and activated charcoal as nonspecific adsorbant. Large numbers of samples could be processed simultaneously at relatively little expense and results were obtainable within 3 hr. The procedure was sensitive to 1 ng/ml. No diurnal or positional variations were found. Values from 250 unselected normal patients showed a constantly rising mean plasma E2 from 18 to 35 wk gestation from 4.5 to 14 ng/ml. From 35 to 40 wk, mean E2 rose only to 15 ng/ml and the range of values increased substantially. When 22 normal pregnant subjects were followed serially, rising levels of plasma E2 were found with no significant fall ever seen. By contrast, patients exhibiting fetal distress generally had falling or reduced E2 levels. However, 3 cases of Rh isoimmunization had elevated or normal E2 concentrations even after clearcut evidence of fetal demise. A decrease of 45% in E2 concentration was associated with intraamniotic instillation of hypertonic saline prior to delivery supporting the view that placental conversion of maternal adrenal precursors is responsible for about half of the Ea production in pregnancy. The postpartum clearance of endogenous E2 was measured and found to fit a two compartment model with mean half-time of 22 min and 7 hr. Follicular phase levels of E2 were attained by 35 hr postpartum. The concentration of unconjugated E2 in pregnancy plasma correlated as well with the state of the placenta as other placental hormone measurements and holds promise of being a rapid, inexpensive, and reliable method of following patients with high-risk pregnancies in a variety of clinical settings.

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Section: Discussionsupporting

confidence: 72%

The plasma estradiol as an index of fetoplacental function

Tulchinsky¹,

Korenman²

1971

J. Clin. Invest.

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“…Furthermore, hCG proteins and RNAs are more expressed in early than in late firsttrimester placental tissues. These observations might contribute to the higher level of hCG in maternal serum during the first trimester (20). A Fig.…”

Section: Discussionmentioning

confidence: 92%

“…Maintenance of pregnancy during early gestation depends on the synthesis of hCG, which prevents regression of the corpus luteum (16), allowing the maintenance of ovarian progesterone secretion (20). In addition to its wellestablished endocrine role, hCG has a role in human trophoblast differentiation in a paracrine manner, as well as fusion (40) and invasion (14), and in angiogenesis (3,41).…”

mentioning

confidence: 99%

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Comparative expression of hCG β-genes in human trophoblast from early and late first-trimester placentas

Cocquebert

Berndt

Segond

et al. 2012

American Journal of Physiology-Endocrinology and Metabolism

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Human chorionic gonadotropin (hCG) displays a major role in pregnancy initiation and progression and is involved in trophoblast differentiation and fusion. However, the site and the type of dimeric hCG production during the first trimester of pregnancy is poorly known. At that time, trophoblastic plugs present in the uterine arteries disappear, allowing unrestricted flow of maternal blood to the intervillous space. The consequence is an important modification of the trophoblast environment, including a rise of oxygen levels from about 2.5% before 10 wk of amenorrhea (WA) to ∼8% after 12 WA. Two specific β-hCG proteins that differ from three amino acids have been described: type 1 (CGB7) and type 2 (CGB3, -5, and -8). Here, we demonstrated in situ and ex vivo on placental villi and in vitro in primary cultures of human cytotrophoblasts that type 1 and 2 β-hCG RNAs and proteins were expressed by trophoblasts and that these expressions were higher before blood enters in the intervillous space (8–9 vs. 12–14 WA). hCG was immunodetected in villous mononucleated cytotrophoblasts (VCT) and syncytiotrophoblast (ST) at 8–9 WA but only in ST at 12–14 WA. Furthermore, hCG secretion was fourfold higher in VCT cultures from 8–9 WA compared with 12–14 WA. Interestingly, VCT from 8–9 WA placentas were found to exhibit more fusion features. Taken together, we showed that type 1 and type 2 β-hCG are highly expressed by VCT in the early first trimester, contributing to the high levels of hCG found in maternal serum at this term.

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“…After implantation, hCG is the first trophoblast signal detected in the maternal blood and is used as a diagnostic marker of pregnancy. hCG and its free β subunit are detected in the maternal blood from the 4 second week of pregnancy with peak levels at twelve weeks and then gradually decrease; α hCG levels increase progressively up to term (12). Maintenance of pregnancy during the first trimester depends on the synthesis of hCG, which prevents regression of the corpus luteum (13) allowing the maintenance of ovarian progesterone secretion (1).…”

Section: Introductionmentioning

confidence: 99%

Human Chorionic Gonadotropin Expression in Human Trophoblasts from Early Placenta: Comparative Study Between Villous and Extravillous Trophoblastic Cells

Handschuh¹,

Gadrey²,

Tsatsaris³

et al. 2007

Placenta

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Human trophoblast differentiates into two pathways: extravillous cytotrophoblasts (EVCT) that invade the uterus wall and villous cytotrophoblasts (VCT) that fuse to form the syncytiotrophoblast (ST) involved in placental exchanges and endocrine function. It is established that hCG is produced and secreted by the ST into the maternal compartment where it plays a key endocrine role and stimulates ST formation in an autocrine manner. Herein, we investigated hCG expression in early placentas by immunohistochemistry using different antibodies. We then compared hCG secretion by primary cultures of VCT and EVCT isolated from the same first trimester human chorionic villi. In situ hCG was immunodetected in EVCT all along their invasive differentiating pathway excepted in cells near the stromal core of the proximal column. hCG expression was confirmed in vitro by immunocytochemistry and hCG secretion quantified in cell supernatants. Interestingly, whereas hCG secretion increased during VCT differentiation into ST (from 60 to 350 UI/L/µg DNA), EVCT secretion remained constant and at a high level during the same culture period (160 UI/L/µg DNA). Our data demonstrated that in addition to the ST, invasive EVCT also expressed and secreted high levels of hCG, suggesting a specific paracrine and/or autocrine role for hCG from EVCT origin.3

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Serum Gonadotropins Before, at the Inception of, and Following Human Pregnancy

Cited by 119 publications

References 5 publications

The plasma estradiol as an index of fetoplacental function

The plasma estradiol as an index of fetoplacental function

Comparative expression of hCG β-genes in human trophoblast from early and late first-trimester placentas

Human Chorionic Gonadotropin Expression in Human Trophoblasts from Early Placenta: Comparative Study Between Villous and Extravillous Trophoblastic Cells

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