P-353 Placenta previa in In Vitro Fertilization and unassisted pregnancies – is there a difference in perinatal outcomes and placental histology?

Study question

Why is In-vitro-fertilization (IVF) an independent risk factor for placenta previa (PP).

Summary answer

While PP in non-assisted pregnancies is probably associated with previous cesarean deliveries (CD), in IVF it is more “sporadic”, and may complicate any index pregnancy.

What is known already

PP is more prevalent following IVF pregnancies as compared with unassisted pregnancies, with an increased risk of three to six-fold according to some authors. The etiology for this increased risk in IVF pregnancies in unclear, and may be related to reproductive procedures performed or to subfertility characteristics which have led to IVF.

Study design, size, duration

A retrospective-cohort study of deliveries with PP between 2008 and 2021. A total of 182 pregnancies were included.

Participants/materials, setting, methods

Placental histopathology, obstetric and neonatal outcomes were compared between IVF and unassisted pregnancies. Included, were singleton deliveries complicated by PP at gestational weeks (GA)> 24. Placental pathology was obtained utilizing the well-accepted Amsterdam criteria.

Main results and the role of chance

Out of 182 pregnancies which were included - 23 IVF pregnancies (IVF group) and 159 in the unassisted pregnancies (Control group). The control group was characterized by higher gravidity (p = 0.007) and parity (p < 0.001), whereas the IVF group- by a higher rate of nulliparity (p < 0.001) and diabetes mellitus (p = 0.04). A higher rate of patients with past CDs was noted in unassisted pregnancies, although not statistically significance (38.9% versus 21.7%, p = 0.10). There was a trend for a lower placental weight in the control group, and a higher incidence of placental weight below the 10thpercentile in this group (47.8% versus 13.9%, p = 0.001). No differences were noted in maternal and fetal vascular lesions. Nevertheless, IVF and unassisted pregnancies entail similar perinatal outcomes in cases of PP.

Limitations, reasons for caution

A major limitation was our small sample size in the IVF group. Despite a power calculation, larger study groups would have possibly allowed for the demonstration of additional differences in outcomes, including previous cesarean deliveries and placenta accreta. Moreover, this limitation prevented us from matching against possible cofounders.

Wider implications of the findings

While a growing proportion of pregnancies worldwide are conceived by IVF, possible iatrogenic side effects should be studied. As PP is of clinical importance, it is essential to diagnose it on time, as well as study the mechanisms and risk factors behind it, which could possibly help with its prevention.

Trial registration number

0282-20-WOMC

P-351 Medical treatment for missed abortion- difference in gestational age based on menstrual dating and on ultrasound criteria, and the correlation to failure

Study question

Does the difference in gestational age based on menstrual dating and on ultrasound criteria correlate with failure rate of medical treatment in missed abortions?

Summary answer

In missed abortions, the difference in gestational age based on menstrual dating and on ultrasound is inversely correlated with failure rate of medical treatment.

What is known already

A number of factors have been reported as predictors for Misoprostol treatment failure, including assisted reproductive treatment, primigravity, and vaginal bleeding prior to treatment.

Increased rates of failure with medical management were also reported with delaying treatment after diagnosis.

Study design, size, duration

This was a retrospective cohort study.

Overall, 778 patients who underwent medical treatment with Misoprostol for missed abortion at our institute, between 07/2015 and 12/2020 were included.

Participants/materials, setting, methods

Inclusion criteria were either anembryonic gestation or embryonic death, as long as pregnancy age, as measured by transvaginal sonography , correlated with 12 weeks gestation or less.

Exclusion criteria included incomplete or septic abortions, multiple pregnancies, and cases that had either irregular period, missing data, or were lost to follow up.

The primary outcome was treatment failure, defined as any need for surgical intervention (elective or emergency Dilation & curettage, or operative hysteroscopy).

Main results and the role of chance

Five hundred and eighty two patients (74.9%) had successful medical treatment, while 196 (25.1%) required surgical intervention.

The gestational age based on menstrual dating and on ultrasound difference (in weeks) was 2.6±1.4 in the success group and 3.1±1.6 in the failure group (p < 0.001).

On multivariant regression analysis, gestational age based on menstrual dating and on ultrasound difference was found to be independently correlated with treatment failure (aOR=1.24, CI 95% (1.01-1.51), p = 0.03).

Limitations, reasons for caution

We did not analyze long term consequences, such as the amount of bleeding, and time to future fertility.

Moreover, patients who were treated at our institute may have been diagnosed and treated for treatment failure in neighboring hospitals and hence lost to follow-up.

Wider implications of the findings

The current study has shown that the difference between gestational age based on menstrual dating and on ultrasound is directly corelated with medical treatment failure.

This data should be taken into account when counseling patients regarding the optimal treatment for first trimester missed abortion.

Trial registration number

not applicable

Prevention of renal injury after induction of ozone tolerance in rats submitted to warm ischaemia

On the basis that ozone (O3) can upregulate cellular antioxidant enzymes, a morphological, biochemical and functional renal study was performed in rats undergoing a prolonged treatment with O3 before renal ischaemia. Rats were divided into four groups: (1) control, a medial abdominal incision was performed to expose the kidneys; (2) ischaemia, in animals undergoing a bilateral renal ischaemia (30 min), with subsequent reperfusion (3 h); (3) O3 + ischaemia, as group 2, but with previous treatment with O3 (0.5 mg/kg per day given in 2.5 ml O2) via rectal administration for 15 treatments; (4) O2 + ischaemia, as group 3, but using oxygen (O2) alone. Biochemical parameters as fructosamine level, phospholipase A, and superoxide dismutases (SOD) activities, as well as renal plasma flow (RPF) and glomerular filtration rate (GFR), were measured by means of plasma clearance of p-amino-hippurate and inulin, respectively. In comparison with groups 1 and 3, the RPF and GFR were significantly decreased in groups 2 and 4. Interestingly, renal homogenates of the latter groups yielded significantly higher values of phospholipase A activity and fructosamine level in comparison with either the control (1) and the O3 (3) treated groups. Moreover renal SOD activity showed a significant increase in group 3 without significant differences among groups 1, 2 and 4. Morphological alterations of the kidney were present in 100%, 88% and 30% of the animals in groups 2, 4 and 3, respectively. It is proposed that the O3 protective effect can be ascribed to the substantial possibility of upregulating the antioxidant defence system capable of counteracting the damaging effect of ischaemia. These findings suggest that, whenever possible, ozone preconditioning may represent a prophylactic approach for minimizing renal damage before transplantation.

Posttranslational regulation of Ty1 retrotransposition by mitogen-activated protein kinase Fus3

Ty1 retrotransposons in Saccharomyces cerevisiae are maintained in a state of transpositional dormancy. We isolated a mutation, rtt100-1, that increases the transposition of genomic Ty1 elements 18- to 56-fold but has little effect on the transposition of related Ty2 elements. rtt100-1 was shown to be a null allele of the FUS3 gene, which encodes a haploid-specific mitogen-activated protein kinase. In fus3 mutants, the levels of Ty1 RNA, protein synthesis, and proteolytic processing were not altered relative to those in FUS3 strains but steady-state levels of TyA, integrase, and reverse transcriptase proteins and Ty1 cDNA were all increased. These findings suggest that Fus3 suppresses Ty1 transposition by destabilizing viruslike particle-associated proteins. The Fus3 kinase is activated through the mating-pheromone response pathway by phosphorylation at basal levels in naive cells and at enhanced levels in pheromone-treated cells. We demonstrate that suppression of Ty1 transposition in naive cells requires basal levels of Fus3 activation. Substitution of conserved amino acids required for activation of Fus3 derepressed Ty1 transposition. Moreover, epistasis analyses revealed that components of the pheromone response pathway that act upstream of Fus3, including Ste4, Ste5, Ste7, and Ste11, are required for the posttranslational suppression of Ty1 transposition by Fus3. The regulation of Ty1 transposition by Fus3 provides a haploid-specific mechanism through which environmental signals can modulate the levels of retrotransposition.

L-arginine supplementation improves venous endothelial cell but not smooth muscle cell dysfunction induced by prolonged diet-induced hypercholesterolemia

Hypercholesterolemia induces venous vasomotor dysfunction. This study examines the endothelial and smooth muscle cell vasoreactivity of external jugular veins from rabbits fed either a normal or a 1% cholesterol diet for 8 weeks with and without L-arginine supplementation (2 g/kg day-1 orally for the last 5 weeks). Isometric tension studies were performed on harvested jugular veins. Concentrations of serum cholesterol were 20-fold higher than controls and serum L-arginine twofold higher than untreated animals. Hypercholesterolemia induced hypersensitivity to norepinephrine (p < .05), bradykinin (p < .05), and histamine (p < .05) with a contractile response to serotonin compared to controls. L-Arginine supplementation decreased bradykinin hypersensitivity but had no effect on the changes in norepinephrine serotonin and histamine responses compared to controls. Hypercholesterolemia interfered with relaxation induced by acetylcholine but with L-arginine, normal acetylcholine-induced, endothelium-dependent relaxation returned (54 +/- 10%, compared to 40 +/- 14% in control veins; p > .05). Non-endothelium-dependent relaxation to sodium nitroprusside of precontracted veins was unaffected by the presence of high cholesterol concentrations. This study suggests that L-arginine therapy may ameliorate hypercholesterolemia-induced functional abnormalities in endothelial cells.

Respiratory health status in swine producers relates to endotoxin exposure in the presence of low dust levels

We conducted an assessment of respiratory health status including questionnaire and spirographic measurements in 54 male swine producers age 36.3 +/- 11.1 years (mean +/- SD) who worked an average of 10.7 +/- 6.3 years in the industry and spent 4.7 +/- 2.1 hours per day in the swine barns, and we also measured atmospheric contaminants including carbon dioxide, ammonia, total dust, respirable dust, and airborne endotoxin. Mean atmospheric dust contaminant levels were as follows: carbon dioxide, 2632 +/- 807 ppm; ammonia, 11.3 +/- 4.2 ppm; total dust, 2.93 +/- 0.92 mg/m3; respirable dust, 0.13 +/- 0.05 mg/m3; and endotoxin, 11,332 +/- 13,492 endotoxin units/m3. Of these, endotoxin related to forced vital capacity (P < .05) and endotoxin x hours per day was related to forced vital capacity (P < .05) and to forced expiratory volume in 1 second (P = .06). Respiratory symptoms and lung function studies did not relate to categories of low, medium, and high exposure to respirable dust. However, categories of endotoxin (available on 46 workers) related to respiratory symptoms (cough, P = .02; chronic bronchitis, P = .06; and to forced vital capacity, P < .01). These data suggest that respiratory health status relates to endotoxin levels but not to dust level exposures in the presence of low dust levels and indicates that control measures should include endotoxin as well as dust control.

Ganglioside-induced CD4 endocytosis occurs independent of serine phosphorylation and is accompanied by dissociation of P56lck

Gangliosides induce a selective and complete modulation of CD4 from the surface of T cells. CD4 down-modulation occurs by CD4 endocytosis. This process is independent of serine phosphorylation of the cytoplasmic tail of CD4 and does not require the association between the tyrosine protein kinase p56lck and the cytoplasmic tail of CD4. Ganglioside-induced CD4 endocytosis is accompanied by the loss of p56lck activity associated with CD4. Sequential immunoprecipitation analysis using an anti-CD4 antibody and an anti-p56lck antiserum showed that this is caused by the dissociation of the enzyme from the cytoplasmic tail of CD4. The kinetics of p56lck dissociation after ganglioside treatment is identical to that of CD4 endocytosis, suggesting that p56lck is displaced in the process of endosome formation. The results indicate that CD4 endocytosis alone can cause the dissociation of the p56lck complex without the requirement for CD4 phosphorylation.

Ganglioside-induced CD4 endocytosis occurs independent of serine phosphorylation and is accompanied by dissociation of P56lck

Gangliosides induce a selective and complete modulation of CD4 from the surface of T cells. CD4 down-modulation occurs by CD4 endocytosis. This process is independent of serine phosphorylation of the cytoplasmic tail of CD4 and does not require the association between the tyrosine protein kinase p56lck and the cytoplasmic tail of CD4. Ganglioside-induced CD4 endocytosis is accompanied by the loss of p56lck activity associated with CD4. Sequential immunoprecipitation analysis using an anti-CD4 antibody and an anti-p56lck antiserum showed that this is caused by the dissociation of the enzyme from the cytoplasmic tail of CD4. The kinetics of p56lck dissociation after ganglioside treatment is identical to that of CD4 endocytosis, suggesting that p56lck is displaced in the process of endosome formation. The results indicate that CD4 endocytosis alone can cause the dissociation of the p56lck complex without the requirement for CD4 phosphorylation.

Correction of hypophosphatemia in patients on hemodialysis using a calcium-free dialysate with added phosphate

Three patients on long term hemodialysis were found to be hypophosphatemic. They were treated using a calcium-free dialysate to which phosphate was added to give a final concentration of 1 or 2 mmol/l. All corrected their low phosphates. Hypocalcemia developed in two patients when the calcium infusion rate was 15 ml/hour of 10% CaCl2. It is recommended that this should be increased to 20 ml/hour. Under these circumstances, correction of hypophosphatemia is possible with the transfer of approximately 30-35 mmol phosphate over a four-hour dialysis.

[Antibody-coated bacteria and quantitative culture in sputum samples from patients with bronchiectasis]

The results of the quantitative culture of sputum samples from patients with bronchiectasis were compared with those obtained in the same samples with the detection of antibody-coated bacteria (ACB), in the acute phase of the disease (group I), after antibiotic therapy (group II), and in the phase of clinical stability (group III). In quantitative cultures at least one potentially pathogen species was isolated, at a concentration of greater than or equal to 10(6) colony forming units/ml in the 7 sputum samples from group I, in 4 of the 5 samples from group II, and in 10 of the 11 samples from group III. The immunofluorescence technique detected ACB in all samples from group I and group II, and in 10 of the 11 from group III. The sample from group III in which ACB were not detected was the same in which potentially pathogen organisms were not detected by culture.

Calcium-free dialyzate: development and applications

A calcium-free, bicarbonate-containing concentrate was prepared for hemodialysis, which, after dilution, gave analyzed concentrations of sodium of 146 mmol/l, Cl 110 mmol/l, HCO3 of 35 mmol/l and pH of 8.3. When compared with standard bicarbonate dialysis, no important differences in blood chemistries, symptoms or signs were seen. The solution has been trouble-free in over 300 dialyses. Total amount of calcium lost uncorrected for time, dialyzer or blood flow was 40.6 +/- 1.1 mmol, n = 62. This loss was replaced by a calcium infusion into the venous line giving 40 mmol calcium over 4 h. The dialyzate calcium loss could be accurately predicted by sampling without collecting the total dialyzate volume. The uses of this concentrate for bicarbonate dialysis, citrate anticoagulation and avoidance of hypercalcemia in patients treated with oral calcium for phosphate binding is discussed.

Chemical industry voluntary test program for phthalate esters: health effects studies

The Chemical Manufacturers' Association voluntary test program on phthalate esters is described, and the results of certain key aspects of the program are presented. Representative phthalate esters were chosen for genotoxicity testing and peroxisome proliferation screening, and di-2-ethylhexyl phthalate (DEHP) and its initial metabolic products were tested in the genotoxicity battery. A comparative metabolism study was performed with DEHP in the mouse, rat, and cynomologus monkey, together with a study of the metabolism of DEHP in the rodent at several dose levels, and after prolonged feeding. A standard test for peroxisome proliferation in the rat, employing 21 days of feeding and several end points is described, based on DEHP as a reference compound. DEHP is shown to be nongenotoxic in the test battery, and its initial major metabolites are also nongenotoxic. A nonlinear dose response with respect to the beta-oxidation of DEHP in the rodent is demonstrated. Quantitative differences exist between the mouse and rat, and the cynomologus monkey with respect to the beta-oxidation of DEHP, beta-oxidation being a much less used pathway in the monkey. The significance of these results in interpreting the hepatocellular carcinogenesis of DEHP in the Fischer 344 rat is discussed.