Gene Lee

Transplacental Supply of Mannose and Inositol in Uncomplicated Pregnancies Using Stable Isotopes

OBJECTIVE The aim of this study was to determine relative contributions of transplacental flux vs. fetal production for inositol and mannose in normal term pregnancies. STUDY DESIGN Seven term uncomplicated pregnancies undergoing cesarean section were infused with (13)C- and (2)H-labeled isotopes of glucose, inositol, and mannose until a steady state was achieved. Maternal and fetal concentrations of labeled and unlabeled glucose, mannose, and inositol were measured using gas chromatography/mass spectroscopy. The fetomaternal molar percentage excess ratio was calculated for each glucose, mannose, and inositol. RESULTS The fetomaternal molar percentage excess ratio of mannose in the fetal artery (F(artery)/M) was 0.99 [97.5% confidence interval (CI), 0.91-1.07] and in the fetal vein (F(vein)/M), 1.02 (97.5% CI, 0.95-1.10). Both were not significantly different from 1.0, consistent with transplacental supply. The fetomaternal ratios for glucose were similar to mannose (fetal artery, 0.95; 97.5% CI, 0.84-1.15; and fetal vein, 0.96; 97.5% CI, 0.85-1.07). The fetomaternal ratio for inositol was significantly less than 1.0 (fetal artery, 0.08; 97.5% CI, 0.05-0.12; fetal vein, 0.12; 97.5% CI, 0.06-0.18), indicating little transplacental flux and significant fetal production. CONCLUSION In normal term pregnancies, fetal mannose and glucose concentrations are dependent upon maternal transplacental supply. Fetal inositol is not dependent upon transplacental supply.

Effect of Prostaglandin E2 on Multidrug Resistance Transporters In Human Placental Cells

Prostaglandin (PG) E2, a major product of cyclooxygenase (COX)-2, acts as an immunomodulator at the maternal-fetal interface during pregnancy. It exerts biologic function through interaction with E-prostanoid (EP) receptors localized to the placenta. The activation of the COX-2/PGE2/EP signal pathway can alter the expression of the ATP-binding cassette (ABC) transporters, multidrug resistance protein 1 [P-glycoprotein (Pgp); gene: ABCB1], and breast cancer resistance protein (BCRP; gene: ABCG2), which function to extrude drugs and xenobiotics from cells. In the placenta, PGE2-mediated changes in ABC transporter expression could impact fetal drug exposure. Furthermore, understanding the signaling cascades involved could lead to strategies for the control of Pgp and BCRP expression levels. We sought to determine the impact of PGE2 signaling mechanisms on Pgp and BCRP in human placental cells. The treatment of placental cells with PGE2 up-regulated BCRP expression and resulted in decreased cellular accumulation of the fluorescent substrate Hoechst 33342. Inhibiting the EP1 and EP3 receptors with specific antagonists attenuated the increase in BCRP. EP receptor signaling results in activation of transcription factors, which can affect BCRP expression. Although PGE2 decreased nuclear factor κ-light chain-enhancer of activated B activation and increased activator protein 1, chemical inhibition of these inflammatory transcription factors did not blunt BCRP up-regulation by PGE2. Though PGE2 decreased Pgp mRNA, Pgp expression and function were not significantly altered. Overall, these findings suggest a possible role for PGE2 in the up-regulation of placental BCRP expression via EP1 and EP3 receptor signaling cascades.

Increased trophoblast expression of NFAT5/TonEBP in pre-eclamptic placentas and hyperosmolar-treated BeWo cells.

OBJECTIVES To assess the concentrations of inositol and sorbitol, and determine the expression of related osmolyte factors [nuclear factor of activated T cells 5, also known as tonicity responsive binding protein (NFAT5/TonEBP); sodium myo-inositol transporter (SLC5A3); and aldose reductase] in placentas of pre-eclamptic (PE) patients and trophoblast BeWo cells subjected to hypertonic stress in vitro. STUDY DESIGN Control and PE placentas were collected. BeWo cells were cultured and subjected to a hyperosmolar solution for 4h. Western blot analysis was performed on NFAT5, SLC5A3, aldose reductase and ERK proteins. High-performance liquid chromatography was used to determine the levels of inositol and sorbitol in cell lysates. RESULTS Compared with control placentas, PE placentas showed higher levels of inositol and NFAT5, and lower levels of SLC5A3. Treated BeWo cells showed higher levels of inositol, sorbitol, NFAT5 total protein, SLC5A3 and aldose reductase, and increased ERK activation compared with control BeWo cells. CONCLUSIONS Hyperosmolar conditions increase the expression of NFAT5 in PE placentas and BeWo cells, and may account for the increased osmolyte levels. NFAT5 may accomplish this through aldose reductase and SLC5A3 in trophoblast cells.

Does the use of fetal fibronectin in an algorithm for preterm labor reduce triage evaluation times

Abstract Objective: To determine the effectiveness of a novel algorithm based on fetal fibronectin (FFN) for management of preterm labor (PTL). Methods: A randomized trial was performed on patients who presented with symptoms of PTL at 24–34 weeks. Patients were randomized to algorithms with cervical exams only versus cervical exams plus FFN. In this algorithm, physicians had to discharge patients with a negative FFN result. The primary outcome was the evaluation time for triage. The secondary outcomes were admission to the hospital for PTL, preterm birth <34 weeks and preterm birth <37 weeks. Results: A total of 76 patients were enrolled and randomized (control n = 32, FFN n = 44). There were no differences in triage time, hospital admissions or preterm deliveries (PTDs) between the two groups. Conclusion: An algorithm based on FFN for management of PTL does not reduce evaluation times for triage, hospital admissions or PTDs.

Is an isolated ventricular septal defect detected before 24 weeks on ultrasound associated with fetal aneuploidy

Abstract Objective: Whether the isolated VSD (i-VSD) is associated with aneuploidy to the same degree as a more severe heart anomaly is unclear. Our objective was to determine the likelihood of aneuploidy in pregnancies at a tertiary referral center when an i-VSD is detected before 24 weeks. Methods: A retrospective chart review of all detailed anatomy ultrasounds before 24 weeks performed at the University of Kansas Medical Center from 08/23/2006 to 06/07/2012 was conducted. A complete evaluation of the fetal heart was accomplished using gray scale and spectral/color Doppler examinations. The outcomes of each pregnancy were reviewed for any diagnoses of aneuploidy. Odds ratios were calculated. Results: A total of 4078 pregnancies with complete obstetric and neonatal data were reviewed. The prevalence of an i-VSD was 2.7% (112/4078). The odds ratio of aneuploidy when an i-VSD was present was (OR: 36.0, 95% CI: 5.0, 258.1). This odds ratio remained large when either an abnormal or unknown serum screen was present. Conclusion: The presence of an i-VSD present before 24 weeks does increase the risk of fetal aneuploidy. Whether a normal serum screen or first trimester screen for aneuploidy negates the association of an i-VSD with aneuploidy still remains undetermined.

A retrospective study comparing outcomes in a midwestern US population after introduction of IADPSG guidelines for gestational diabetes

Abstract Objective: More evidence is required to endorse the 1-step approach for gestational diabetes mellitus (GDM) for clinical practice. Since 2010, our department has pragmatically allowed faculty to self-select the guidelines they use to screen and diagnose GDM. We sought to compare the maternal and neonatal outcomes from these two simultaneous cohorts. Study design: We performed a retrospective cohort study of all singleton pregnancies delivered between October 2011 and –November 2013 at our hospital. Patients were excluded if they had preexisting diabetes, were not screened or screened inappropriately, or their fetus had congenital anomalies. Patients were grouped by their screening strategy, and maternal and neonatal outcomes were analyzed. Results: The 1-step group had a higher incidence of GDM (21.6% versus 5.0%). Initial results suggested higher rates of neonatal hypoglycemia, phototherapy for hyperbilirubinemia, and a lower rate of gestational HTN. After adjustment, these differences disappeared, but a lower rate of large for gestational age (LGA) infants was discovered (adjusted odds ratios (aOR) 0.78). Conclusion: The picture remains unclear as to whether the 1-step approach is associated with significantly improved outcomes compared with the 2-step approach. We did find a lower risk for a LGA infant in our 1-step cohort, but it is unlikely that the 1-step approach would be cost-effective due to the absence of other improved outcomes.

Pregnancy outcomes after cerclage placement in nulliparous women with a short cervix on transvaginal ultrasonography

Abstract Objective: Little is known about pregnancy outcomes associated with a short cervix and cerclage placement in nulliparous women. Methods: An electronic query of our ultrasound database was used to identify patients whose cervical length measured < 25 mm between 16–24 weeks of gestation. Any nulliparous women, with no prior pregnancy lasting beyond 13 weeks 6 d gestational age, were included in the analysis. The primary outcome was the interval of time from the diagnosis of a short cervix (<25 mm) to the time of delivery. Results: Our query identified 70 patients for analysis. The interval of time from diagnosis of a short cervix to delivery was observed to be 85 d (12.1 weeks) in the cerclage group and 116 d (16.6 weeks) in the expectantly managed group (p = 0.02). In those women receiving a cerclage, there was a statistically significant risk of spontaneous preterm birth <32 weeks gestational age (R.R. 6.7 [95% CI 1.45–30.6]). Conclusions: The impact of a short cervix is largely unknown in patients with an uncomplicated obstetrical history. Our investigation would suggest that in this subset of patients, cerclage would not be beneficial in preventing preterm delivery.

Regulation of human placental drug transporters in HCV infection and their influence on direct acting antiviral medications

INTRODUCTION The objectives of this study were to determine how HCV infection affects placental drug transporters, and to determine the role of drug transporters on the cellular accumulation of direct-acting antiviral drugs in human trophoblasts. METHODS Eighty-four ABC and SLC transporter genes were first screened in normal and HCV infected pregnant women using PCR profiler array. The changes in expression were confirmed by qPCR and Western blot. The impact of selected drug transporters on the cellular accumulation of radiolabeled antiviral drugs sofosbuvir, entecavir, and tenofovir was measured in primary human trophoblasts (PHT) and BeWo b30 cells in the presence or absence of transporter-specific inhibitors. PHT were then treated with CL097, ssRNA40, and imquimod to determine the impact of Toll-like receptor (TLR) 7/8 activation on drug transporter expression. RESULTS The expression of the ABC efflux transporters ABCB1/P-gp and ABCG2/BCRP was increased in placenta of women with HCV, while the nucleoside transporters SLC29A1/ENT1 and SLC29A2/ENT2 remained unchanged. The accumulation of sofosbuvir and tenofovir was unaffected by inhibition of these transporters in trophoblast cells. Entecavir accumulation was decreased by the inhibition of ENT2. P-gp and BCRP inhibition enhanced entecavir accumulation in BeWo b30, but not PHT. Overall, there was little effect of TLR7/8 activation on these drug transporters, and the accumulation of entecavir in PHT. DISCUSSION The data suggest that expression of placental drug transporters and selection of antiviral drug may impact fetal drug exposure in pregnancies complicated by HCV infections.