P-358 Effect of endometrial thickness on biochemical pregnancy rate: an analysis of 1534 frozen euploid embryo transfers

Study question

Can a thick endometrial lining measured prior to embryo transfer be considered a protective factor against Biochemical Pregnancy (BP)?

Summary answer

The risk of BP is independent of Endometrial Thickness (EMT), but rather dependent of the type of endometrial preparation and parity.

What is known already

Higher EMT prior to embryo transfer is associated with better clinical outcomes in general, like higher implantation and livebirth, and lower miscarriage rates. But up to our knowledge, no studies evaluated the effect of EMT on BP per say.

Study design, size, duration

This is a two-center retrospective observational study including a total of 1534 euploid Frozen Embryo Transfer (FET) cycles between March 2017 and March 2020 at ART Fertility Clinics Muscat, Oman and Abu Dhabi, UAE. BP is defined as blood beta-hCG >15 mIU/ml on day 12 post FET, that is progressively decreasing, with no evidence of gestational sac on ultrasound.

Participants/materials, setting, methods

The study group consisted of 112 cases of BP, while the control group consisted of the remaining 1422 FET’s that led to different clinical outcomes. EMT was measured by transvaginal ultrasound on the day of progesterone rise (±1 day); that rise was either spontaneous in Natural Cycles (NC), or iatrogenic in Hormone Replacement Therapy (HRT) cycles. Euploidy status of the embryos was assessed by NGS analysis of trophectoderm biopsies. Bivariate and multivariate analyses were conducted.

Main results and the role of chance

There was no difference in mean EMT between the study and the control groups (7.55 vs. 7.68 mm, p = 0.154).

Looking at the association of different variables with the rate of BP, there was no effect of age, BMI, AMH, number of embryos transferred, degree of blastocyst expansion, inner cell mass or trophectoderm grade, day of biopsy, nor presence of blood or mucus on the transfer catheter. However, patients on HRT cycles had significantly higher rates of BP compared to NC (8.42% vs. 4.99%, p = 0.015). Also, those with a previous livebirth had higher rates of BP compared to nulliparous women (8.7% vs. 5.39%, p = 0.014).

The distribution of BP showed that 54.5% occurred with EMT <7.5 mm, 34.8% with EMT 7.5-9 mm, and 10.7% with EMT >9 mm. These represents respectively 8.16%, 6.68%, and 5.94% of the total sample. This decreasing trend of BP with increasing EMT didn’t reach statistical significance (p = 0.429). Univariate analysis comparing the risk of BP in FET’s done with lower and higher EMT to those performed at 7.5-9 mm yielded similar conclusion: OR = 1.24 [0.82-1.88] for <7.5 mm, and OR = 0.88 [0.45-1.72] for >9 mm.

Controlling for different confounders, HRT cycles and multiparity remained as independent risk factors for BP.

Limitations, reasons for caution

Inter-observer variability in EMT measurement and the transfer technique, the retrospective nature of the study, and the lack of data on the mode of delivery of parous women could all have interfered with the conclusion.

Wider implications of the findings

The reduced adverse clinical outcomes with NC shed light on the role of the corpus luteum in the early phases of implantation, and some potential secreted mediators other than progesterone. Besides, the effect of previous deliveries on the endometrium and its receptivity needs further investigation.

Trial registration number

not applicable

Endometriosis and cancer: what do we know?

Endometriosis is the presence of endometriotic tissue outside of the uterus, composed of endometriotic glands and stroma. It affects between 10% to 12% of women in reproductive age. It presents with dysmenorrhea, dyspareunia, chronic pelvic pain, infertility, urinary or digestive symptoms. Diagnosis is based on clinical suspicion, clinical exam, pelvic ultrasound or pelvic magnetic resonance, and confirmed by laparoscopy with pathology studies. Its management is better understood nowadays. However, its association with neoplasia has been questioned for many years. It probably plays a role in the etiology of gynecological cancers, mainly ovarian neoplasia. In our review, we separately compared endometriosis and endometrioma to cancer, in terms of mutual causality, common risk factors, distinction based on histological findings, in addition to molecular and genetic pathways behind this association. This article reviews the English literature for studies on the association between endometriosis and gynecological cancers. Additional reports were collected by systematically reviewing all references from retrieved papers.

In vitro activity of antituberculous agents against Mycobacterium tuberculosis isolates from Bogota, DC (Colombia) evaluated by the ETest

Tuberculosis tests for antimicrobial susceptibility takes weeks. However, delayed therapy, can compromise the patient, as well as lead to an increase in disease incidence. Among infectious diseases, tuberculosis continues to be a leading cause of death in the world. The E-test is a new concept for Minimal Inhibitory Concentrations (MIC) determinations for antimicrobial agents that is based on a predefined antibiotic gradient on a plastic strip calibrated with a continuous logarithmic MIC scale covering 15 two-fold dilutions. MICs of rifampin, isoniazid, and ethambutol were determined by using the E-test (AB BIODISK, Solna, Sweden) for 30 clinical strains of Mycobacterium tuberculosis isolated from four hospitals, and were compared with the Bactec method. To make the inoculum with a turbidity equivalent to a McFarland 3.0 standard, we obtained a sample from an agar surface and the Bactec 460, as described by the manufacturer. Excellent agreement (100% for rifampin, 96.8% for ethambutol, and 90% for isoniazid) was demonstrated between the E-test MIC distributions and the Bactec interpretive criteria for all clinical isolates of M. tuberculosis tested. The E-test appears to be a good alternative method for testing the susceptibility of M. tuberculosis isolates to the three, most-commonly-used therapeutic agents.

Accuracy of fecal lactoferrin and other stool tests for diagnosis of invasive diarrhea at a Colombian pediatric hospital

OBJECTIVES

Estimate under "real life" conditions the operating characteristics of several stool tests for determining whether a diarrheal episode is invasive-inflammatory.

DESIGN

Determination of operating characteristics of diagnostic tests against a standard in a prospectively gathered sample.

SETTING

The emergency room of the largest Social Security Pediatric Hospital in Colombia serving referred and nonreferred patients.

PATIENTS

Stool samples from children attending the emergency room because of acute diarrhea (three or more loose stools per day lasting <7 days). Patients receiving antibiotics or antiparasitic medications were excluded.

INTERVENTIONS

Samples were collected in sterile containers and examined immediately for protozoa, fecal leukocytes, occult blood and lactoferrin. Specimens were inoculated onto culture media for common bacterial fecal pathogens except enteroinvasive Escherichia coli and Clostridium difficile.

MAIN OUTCOME MEASURE

Sensitivity, specificity and likelihood ratios of several cutoff levels for fecal lactoferrin, fecal leukocytes and occult blood.

RESULTS

Stool samples from 500 infants and children with diarrhea were collected. Patients' median age was 2.66 years (range, 0.5 to 13 years), and 261 (52.2%) were males. In 155 (31%) cases enteroinvasive bacteria and/or Entamoeba histolytica were documented. Fecal leukocytes >5 had the best sensitivity (63.2%; 95% confidence interval, 55.4 to 70.5) and specificity (84.3%; 95% confidence interval, 80.2 to 87.9), although not statistically or clinically significantly different from lactoferrin.

CONCLUSIONS

No single test or combination had satisfactory operating characteristics. Nevertheless the use of likelihood ratios derived here can help clinicians identify invasive-inflammatory diarrheal episodes in many instances.

Searching for Lyme disease in Colombia: a preliminary study on the vector

Lyme disease is an infectious multisystemic illness with dermatologic, neurologic, cardiac, and rheumatic manifestations. A total of 4,355 ticks was collected in Colombia, of which 2,805 were identified as Ixodes spp. The midgut contents of 2,600 specimens were fixed on microscope slides and examined by an indirect immunofluorescence assay (IFA) using monoclonal antibodies, anti-ospA H5332, and anti-flagellin 9724. All of the ticks examined by IFA tested negative.

Cytochrome ba3 from Natronobacterium pharaonis--an archaeal four-subunit cytochrome-c-type oxidase

Cytochrome ba3, a terminal oxidase was isolated from the haloalkaliphilic archaeon Natronobacterium pharaonis. NH2-terminal sequence information of two subunits with apparent molecular masses of 40 and 36 kDa was used to generate a DNA probe by polymerase chain reaction. Cloning and sequencing of two overlapping genomic fragments revealed four genes forming a transcriptional unit. The policystronic messenger RNA of this cbaDBAC gene locus was identified by RNA analysis. The genes cbaC and cbaD code for small hydrophobic peptides with 81 and 54 amino acids. The genes cbaB and cbaA code for cytochrome oxidase subunit II (calculated molecular mass = 18.6 kDa) and I (calculated molecular mass = 63.8 kDa) respectively. Five potential CuA ligands for subunit II and six His residues for subunit I located in conserved positions indicate cytochrome ba3 to be a c-type oxidase. Sequence comparison and phylogenetic analysis place the natronobacterial enzyme together with the archaeal quinol oxidase SoxABCD from Sulfolobus acidocaldarius and the eubacterial ba3-type oxidase from Thermus thermophilus into a distinct evolutionary group. All three members are missing residues which are functionally important for vectorial proton translocation. The four-subunit enzyme complex was also identified on the protein level using chromatographic buffers containing ethylene glycol for purification.

[Evaluation of three new culture media: brilliant-glycerol-lactose novobiocin-green agar, modified iron lysin agar and Rambach agar for the isolation of enteropathogenic E. coli, Salmonella sp. in acute gastroenteritis]

BACKGROUND

Acute gastroenteritis (AGE) is one of the most common diseases in children, particularly in those under the age of 5 years in whom a severe picture of hydroelectrolyte imbalance may be triggered accompanied, in most cases, by leukocyte response. The aim of this study was to evaluate three new culture media for the isolation of enteropathogens in infantile diarrhea.

MATERIAL AND METHODS

From April to September, 1993, 170 samples of diarrhea stools from children up to 7 years of age attending pediatric hospitals in Bogota were studied. Three new culture media were used in the isolation of the enteropathogenic bacteria: BGLN, MILA agar, Rambach agar and a conventional agar medium S.S. Biochemical tests were performed to identify the isolated bacteria.

RESULTS

A total of 98.5% of enteropathogenic E. coli was isolated in Rambach agar, which also presented excellent recovery rates of Salmonella sp. (100%) versus S.S> (64.3%) and BGLN (77.2%), respectively. The best selectivity for Shigella sp. was observed with BGLN with a 100% recovery rate. Out of the 170 samples 105 showed a leukocyte count of 70-75% and positive isolation for enteropathogenic bacteria. Six samples with the same leukocyte count did not present enteropathogenic bacteria, with the 59 remaining samples with a 20-25% PMN count being negative for enteropathogenic bacteria.

CONCLUSIONS

The results suggest that the new culture media used in this study may have better recovery rates for enteropathogenic bacteria in acute gastroenteritis. Likewise, a correlation was observed between leukocyte count and isolation enteropathogenic bacteria.

The primary structure of halocyanin, an archaeal blue copper protein, predicts a lipid anchor for membrane fixation

Halocyanin, a small blue copper protein, was isolated from the haloalkaliphilic archaeon Natronobacterium pharaonis. The NH2 terminus was not accessible to Edman degradation. About 70% of the amino acid sequence was determined by protein sequence analysis. The sequence information of two peptides was used for cloning and sequencing the halocyanin gene (hcy). The open reading frame codes for 489 base pairs, which account for a protein with 163 amino acids and a molecular mass of 17,223 Da. The discrepancy between this value and the molecular mass of 15,456 +/- 1.5 Da for the copper-free protein determined by electrospray mass spectrometry can be explained by a post-translational processing of the gene product. The NH2-terminal sequence of the open reading frame contains a motif that is characteristic for prokaryotic lipoproteins. Assuming a similar processing for halocyanin, Cys at position 25 of the primary transcript would be modified by a diphytanyl (glycerol)diether. Subsequently, the precursor is cleaved by a signal peptidase II-like protease and then acetylated at its NH2-terminal alpha-amino group. These modifications would yield a protein with a calculated molecular mass of 15,456 Da. A comparison of the primary structure of halocyanin with a number of other blue copper proteins places it into the plastocyanin-related group.

[Evaluation of screening methods (catalase, sediment, reactive strip and Gram stain) in urinary tract infection in a Colombian university hospital]

BACKGROUND

To evaluate the catalase test as a screening method in urinary tract infection (UTI) versus sediment, reactive strip and Gram.

METHODS

Two hundred forty-five's stain urine samples were prospectively analyzed in the Hospital Universitario San Ignacio de Bogotá (Colombia). The culture was used as a reference test for the evaluation of the screening parameters in UTI patients.

RESULTS

Of the 245 urine samples 45 were discarded. The remaining 200 urine samples were cultured being 100 positive and 100 negative. The former were analyzed by screening methods. The sensitivity and specificity of the catalase test was 97% and 94%, respectively with a positive predictive value of 94% and negative of 97%. The most frequently isolated microorganism was E. coli (84%), followed by Proteus sp. (6%).

CONCLUSIONS

The use of the catalase test in urinary tract infection is a safe, economic and rapid method providing advantages due to its high sensitivity and specificity values, its good correlation with the different parameters evaluated in this study (sediment, strip, Gram's stain), and offers optimum diagnosis in urinary tract infection in developing countries such as Colombia.