Fetomaternal production and transfer of progesterone and uridine in sheep

Risk Factors in Fetal Ovarian Cysts for Postnatal Adverse Outcomes

AIM

To investigate the natural history of fetal ovarian cysts and elucidate the risk factors for postnatal adverse outcomes in fetal ovarian cysts.

METHODS

The study subjects were 18 cases with ovarian cysts prenatally diagnosed using ultrasonography at our hospital between 2007 and 2020. The subjects were classified by cyst characteristics according to echogenic patterns [simple cyst (S) and complex cyst (C)], changes in echogenic patterns (S-to-S, S-to-C, and C-to-C), and diameters (<40 and ≥ 40 mm). Clinical parameters and outcomes were compared between S and C patterns, S-to-S and S-to-C patterns, and <40 and ≥ 40 mm diameters.

RESULTS

Cases with S and C patterns (15 and 3, respectively) had median gestational ages of 35 and 36 weeks, respectively, and maximum cyst diameters of 36 and 57mm, respectively. The number of cases with S-to-S, S-to-C and C-to-C patterns were 11, 4 and 3, respectively. The maximum cyst diameter in cases with S-to-C patterns (58 mm) was larger than that in cases with S-to-S patterns (34 mm) (P<0.05). Placental weight in cases with cysts >40 mm and/or cyst expansion was greater than that in cases with neither or both conditions (P<0.05). Spontaneous resolution (before and after birth) occurred in 8 of 9 and 3 of 9 cases with maximum cyst diameters <40 and ≥ 40 mm, respectively. Ovarian function was lost in 2 cases with S-to-C patterns and in 2 cases with C-to-C patterns.

CONCLUSION

Cases with cyst diameters ≥ 40 mm and/or cyst expansion during the late third trimester had greater placental weight and more postnatal adverse outcomes.

Global metabolomic profiling reveals hepatic biosignatures that reflect the unique metabolic needs of late-term mother and fetus

OBJECTIVE

Gestational disorders including preeclampsia, growth restriction and diabetes are characterized, in part, by altered metabolic interactions between mother and fetus. Understanding their functional relevance requires metabolic characterization under normotypic conditions.

METHODS

We performed untargeted metabolomics on livers of pregnant, late-term C57Bl/6J mice (N = 9 dams) and their fetuses (pooling 4 fetuses/litter), using UPLC-MS/MS.

RESULTS

Multivariate analysis of 730 hepatic metabolites revealed that maternal and fetal metabolite profiles were highly compartmentalized, and were significantly more similar within fetuses (ρ_average = 0.81), or within dams (ρ_average = 0.79), than within each maternal-fetal dyad (ρ_average = - 0.76), suggesting that fetal hepatic metabolism is under distinct and equally tight metabolic control compared with its respective dam. The metabolite profiles were consistent with known differences in maternal-fetal metabolism. The reduced fetal glucose reflected its limited capacity for gluconeogenesis and dependence upon maternal plasma glucose pools. The fetal decreases in essential amino acids and elevations in their alpha-keto acid carnitine conjugates reflects their importance as secondary fuel sources to meet fetal energy demands. Whereas, contrasting elevations in fetal serine, glycine, aspartate, and glutamate reflects their contributions to endogenous nucleotide synthesis and fetal growth. Finally, the elevated maternal hepatic lipids and glycerol were consistent with a catabolic state that spares glucose to meet competing maternal-fetal energy demands.

CONCLUSIONS

The metabolite profile of the late-term mouse dam and fetus is consistent with prior, non-rodent analyses utilizing plasma and urine. These data position mouse as a suitable model for mechanistic investigation into how maternal-fetal metabolism adapts (or not) to gestational stressors.

Progesterone as a Postnatal Prophylactic Agent for Encephalopathy Caused by Prenatal Hypoxic Ischemic Insult

Brain damage caused by hypoxic ischemic insult during the perinatal period causes hypoxic ischemic encephalopathies (HIEs). Therapeutic hypothermia is indicated for HIE, but because the therapeutic burden is large for its limited therapeutic effectiveness, another strategy is needed. Progesterone (P4) plays a neuroprotective role through the actions of its metabolite, allopregnanolone (Allo), on P4 receptor, γ-aminobutyric acid type A receptors or both. We examined the therapeutic potential of P4 using a newborn rat model of HIE. Fetal rats were exposed to transient ischemic hypoxia by 30-minute bilateral uterine artery clamping on gestational day 18. After spontaneous birth, newborn pups were subcutaneously injected with P4 (0.10 or 0.01 mg), medroxyprogesterone acetate (MPA; 0.12 mg), or Allo (0.10 mg) through postnatal days (PDs) 1 to 9. Brain damage in the rats was assessed using the rotarod test at PD50. The HIE insult reduced the rats' ability in the rotarod task, which was completely reversed by P4 and Allo, but not by MPA. Histological examination revealed that the HIE insult decreased neuronal (the cortex and the hippocampal CA1 region) and oligodendroglial cell density (the corpus callosum) through PD0 to PD50. The axon fiber density and myelin sheath thickness in the corpus callosum were also reduced at PD50. The time-course study revealed that P4 restored oligodendroglial cells by PD5, which was followed by neuroprotective action of P4 that lasted long over the injection period. These results suggest that P4 protects the neonatal brain from HIE insult via restoration of oligodendroglial cells.

Progesterone and estradiol suppress human mononuclear cell cytotoxicity

Fetal trophoblast is generally resistant to lysis by cytotoxic cells. We hypothesized that progesterone and estrogens secreted by the trophoblast act at the choriodecidual interface where they are present in high concentrations to provide a local, paracrine immunosuppressive effect on cellular cytotoxicity. Using peripheral blood mononuclear cells as effector cells in a cytotoxicity assay, we evaluated the effects of progesterone, estrone, estradiol and estriol, either alone or in combination, on cellular cytotoxicity. Both progesterone and estradiol suppressed cytotoxicity in a dose-dependent manner. Estrone, estriol, pregnenolone and cholesterol had no effect. A synergistic suppression of cytotoxicity was observed when estrone, estradiol, estriol and progesterone were combined. We speculate that trophoblast production of progesterone and estradiol may be an important local immunosuppressive mechanism contributing to fetal survival.

Measurement of unidirectional transplacental flux: a simplified method

A simple method for determining unidirectional transplacental flux in the in vitro perfusion (transfer factor analysis) has been derived from a general treatment of non-compartmental analysis describing transfer between two accessible pools. This method was validated by comparison of the unidirectional transfer fractions for Evans Blue in a two-pool hydraulic model with the true transfer fractions determined from the pump flow rates in the model. There was excellent agreement between calculated and true transfer fractions. Transfer fractions obtained using this method were also compared to the fractions determined by a previously described technique, deconvolution analysis, for a hydraulic model in which a third, inaccessible pool was interposed between the two accessible pools. Good agreement was found between the two methods. Similar agreement was found for the fractional transfer of [14C]L-lactate in the in vitro perfused human placenta, calculated using transfer factor and deconvolution analysis. The sample collection and data processing are much simpler using the former method but the quality of information obtained is reduced accordingly.

Concentrations of deoxycorticosterone, deoxycorticosterone sulfate, and progesterone in maternal venous serum and umbilical arterial and venous sera

The present investigation was conducted to evaluate the potential for the transfer of deoxycorticosterone (DOC) and deoxycorticosterone sulfate (DOC-SO4) from the fetal to the maternal compartment in near-term human pregnancy. To do so we measured progesterone, DOC, and DOC-SO4 in maternal venous serum and in umbilical arterial and venous sera. The levels of DOC and DOC-SO4 in maternal serum were significantly correlated to each other and to those of progesterone in maternal serum. However, there was no correlation between the levels of DOC or DOC-SO4 in umbilical arterial or venous sera and those of these steroids in maternal serum. Although there was no difference in the concentrations of DOC in umbilical arterial or venous serum, there was a highly significant difference in the umbilical arterial and venous concentrations of DOC-SO4. We conclude that the potential exists for DOC-SO4 from umbilical arterial plasma to enter trophoblasts where it could be hydrolyzed to DOC. The DOC so formed could then be redistributed primarily to the maternal but also to the fetal compartment.

Contribution of maternal circulation to blood-borne progesterone in the fetus. II. Studies on sheep

Catheters were placed in maternal and fetal vessels in four ewes in the last month of gestation. Tritiated progesterone (P) was infused at a constant rate into a maternal peripheral vein. Specific activities and endogenous concentrations of P were measured in blood samples drawn from a maternal artery and either a fetal femoral artery or an umbilical vein. Comparison of the specific activities of P in fetal and maternal samples revealed that direct secretion of the placental hormone into the umbilical vein accounted for 90 to 93 per cent of the hormone in the fetal circulation. Estimates of the rates of production of P in the fetal circulation, obtained by multiplying metabolic clearance rates previously reported and concentrations of P in a fetal femoral artery, indicate that placental P is preferentially secreted toward the maternal circulation.