Clinical use of progesterone in human sperm preparation media for increasing IVF success.

RESEARCH QUESTION: Can the addition of progesterone and neurotensin, molecular agents found in the female reproductive tract, after sperm washing increase the fertilization potential of human spermatozoa? DESIGN: (i) Cohort study of 24 men. Spermatozoa selected by swim-up were incubated in either progesterone or neurotensin (0.1-100 µM) for 1-4 h, and hyperactive motility and binding to hyaluronan (0.1-100 µM) were assessed. The effect of progesterone 10 µM on sperm function was assessed in a blinded manner, including: hyperactive motility, binding to hyaluronan, tyrosine phosphorylation, acrosome reaction and oxidative DNA damage. (i) Embryo safety testing [one-cell mouse embryo assay (MEA), endotoxin and sterility counts (n = 3)] in preclinical embryo models of IVF (murine and porcine, n = 7 each model) and a small preliminary human study (n = 4) of couples undergoing standard IVF with oocytes inseminated with spermatozoa ± 10 µM progesterone. RESULTS: Progesterone 10 µM increased sperm binding to hyaluronan, hyperactive motility and tyrosine phosphorylation (all P < 0.05). Neurotensin had no effect (P > 0.05). Progesterone 10 µM in human embryo culture media passed embryo safety testing (MEA, endotoxin concentration and sterility plate count). In preclinical models of IVF, the exposure of spermatozoa to progesterone 10 µM and oocytes to progesterone 1 µM was not detrimental, and increased the fertilization rate in mice and the blastocyst cell number in mice and pigs (all P ≤ 0.03). In humans, every transferred blastocyst that had been produced from spermatozoa exposed to progesterone resulted in a live birth. CONCLUSION: The addition of progesterone to sperm preparation media shows promise as an adjunct to current methods for increasing fertilization potential. Randomized controlled trials are required to determine the clinical utility of progesterone for improving IVF outcomes.

Linkages between the Sustainable Development Goals and health in Somalia.

BACKGROUND: The Sustainable Development Goals (SDGs) adopted in 2015 compromises 17 universal and indivisible goals for sustainable development, however the interactions between the SDGs in Somalia is not known which is vital for understanding potential synergies and trad-offs between the SDGs. Hence, this study aims to identify and classify the linkages between the SDGs with a focus on health and well-being (SDG 3) in Somalia. METHODS: Following the SDG Synergies approach, 35 leading experts from the public and private sectors as well as academia and civil society gathered for a 2-day workshop in Mogadishu and scored the interactions between the individual SDGs on a seven point-scale from - 3 to + 3. From this, a cross-impact matrix was created, and network models were used to showcase the direct and indirect interactions between the SDGs with a focus on SDG 3 (good health and well-being). RESULTS: Many promoting and a few restricting interactions between the different SDGs were found. Overall, SDG 16 (peace, justice, and strong institutions) influenced the other SDGs the most. When second-order interactions were considered, progress on SDG 16 (peace, justice, and strong institutions) showed the largest positive impact on SDG 3 (good health and well-being). SDG 3 (good health and well-being) was heavily influenced by progress on other SDGs in Somalia and making progress on SDG 3 (good health and well-being) positively influenced progress on all other SDGs. CONCLUSION: The findings revealed that in Somalia, the interactions between the SDGs are mostly synergistic and that SDG 16 (peace, justice, and strong institutions) has a strong influence on progress on other SDGs as well as progress on SDG 3 (good health and well-being). This study highlights the need for a multisectoral strategy to accelerate progress on the SDGs in Somalia in general, and particularly SDG 3 (good health and well-being).

Sperm cryopreservation: current status and future developments.

The cryopreservation of spermatozoa is an important reproductive technology for the preservation of fertility in man and animals. Since the serendipitous discovery of glycerol as an effective cryoprotectant in 1947, sperm cryopreservation has undergone many changes in terms of the freezing methods employed, the rates at which samples are frozen and thawed, and the media used to preserve sperm functionality and DNA integrity. An extensive literature survey has been conducted addressing the cryoprotectants employed for both animal and human semen and the freezing protocols utilised. The results indicate that glycerol remains the dominant cryoprotective agent, usually incorporated into a balanced salt solution containing energy substrates, buffers, osmolytes and protein in the form of human serum albumin (human) or skimmed milk (animal). Realisation that some of the damage observed in cryostored cells involves the generation of reactive oxygen species during the thawing process, has prompted many studies to assess the relative merits of incorporating antioxidants into the cryopreservation media. However, in the absence of systematic comparisons, there is currently no consensus as to which antioxidant combination might be the most effective. Utilising our fundamental understanding of cryodamage to optimise cryopreservation protocols for each species will be important in the future.

A comparison between the Felix™ electrophoretic system of sperm isolation and conventional density gradient centrifugation: a multicentre analysis.

PURPOSE: Developing optimized techniques for the isolation of human spermatozoa possessing low levels of DNA damage is an important objective for the ART industry. The purpose of this study was to compare a novel electrophoretic system (Felix™) of sperm isolation with a conventional method involving density gradient centrifugation (DGC). METHODS: Five international ART Centres in Australia, India, Sweden, the USA, and China have collaborated in order to compare the quality of the sperm populations isolated by Felix™ and DGC in terms of processing time, sperm concentration, motility, vitality, and DNA integrity as assessed by 3 methods: SCSA, Halo, and TUNEL. RESULTS: Across all centers, 112 comparisons were performed. Although significant differences were noted between centers in terms of the quality of the semen samples subjected for analysis, overall, both methods were equally capable of isolating populations of spermatozoa exhibiting high levels of vitality and progressive motility. The absolute numbers of spermatozoa recovered were significantly (p < 0.001) lower with the Felix™ device although sperm quality was higher with 4/5 centers reporting a significant improvement in DNA integrity relative to DGC (p < 0.01-p < 0.001). In practical terms, the Felix™ device featured a standardized 6 min preparation time whereas clinical DGC protocols varied from center to center but generally took around 40 min to complete. CONCLUSIONS: The Felix™ device is a positive technical development capable of isolating suspensions of highly motile spermatozoa exhibiting low levels of DNA damage in a fraction of the time taken by conventional procedures such as DGC.

Outcomes of traumatic brain injury in the patient of 60 years and above: a single centre retrospective study.

INTRODUCTION: The elderly is at risk for traumatic brain injury (TBI), but local data on their morbidity and mortality outcomes was lacking. This study aims to assess the outcome in mortality and functional outcome, Glasgow Outcome Scale (GOS) and factors associated with poor outcomes in patients with TBI more than 60 years old. MATERIALS AND METHODS: This single centre retrospective cohort study was carried out involving patients age 60 years old and above with TBI between June 2018 to May 2021. The mortality and GOS at hospital discharge, 30th day, and 90th day of trauma were analysed. The simple logistic regression (SLR) and multiple logistic regression (MLR) were performed to determine factors associated with poor outcomes and mortality. RESULTS: A total of 248 patients were analysed. The mean age was 67.5 ± 6.31 years. 156 (62.9%), 26 (10.5%), and 66 (26.6%) had mild, moderate, and severe TBI, respectively. The overall mortality rate was 9.7% and the median(IQR) GOS score were 4(2); p<0.001 at hospital discharge, 30th day and 90th day. There was significant difference in GOS outcomes after 90 days χ2(2) = 136.76 p<0.001. Upon MLR, there was a significant association of polytrauma, Adj. OR 11.04 (2.503-48.711); p < 0.002 and TBI severity: moderate TBI, Adj. OR 71.44(13.028-391.782); p < 0.001 and severe TBI, Adj OR 2533.51 (213.050-30127.644); p<0.001 towards poor outcome. However, only severity of TBI: moderate TBI, Adj. OR 19.48 (1.899-199.094); p=0.012 and severe TBI, Adj OR 26.42 (2.864-243.722); p=0.004 is associated with mortality. CONCLUSION: Polytrauma and moderate-severe head injury are associated with poor outcomes and moderate-severe head injury is associated with high mortality.

Employing phylogenetic tree shape statistics to resolve the underlying host population structure.

BACKGROUND: Host population structure is a key determinant of pathogen and infectious disease transmission patterns. Pathogen phylogenetic trees are useful tools to reveal the population structure underlying an epidemic. Determining whether a population is structured or not is useful in informing the type of phylogenetic methods to be used in a given study. We employ tree statistics derived from phylogenetic trees and machine learning classification techniques to reveal an underlying population structure. RESULTS: In this paper, we simulate phylogenetic trees from both structured and non-structured host populations. We compute eight statistics for the simulated trees, which are: the number of cherries; Sackin, Colless and total cophenetic indices; ladder length; maximum depth; maximum width, and width-to-depth ratio. Based on the estimated tree statistics, we classify the simulated trees as from either a non-structured or a structured population using the decision tree (DT), K-nearest neighbor (KNN) and support vector machine (SVM). We incorporate the basic reproductive number ([Formula: see text]) in our tree simulation procedure. Sensitivity analysis is done to investigate whether the classifiers are robust to different choice of model parameters and to size of trees. Cross-validated results for area under the curve (AUC) for receiver operating characteristic (ROC) curves yield mean values of over 0.9 for most of the classification models. CONCLUSIONS: Our classification procedure distinguishes well between trees from structured and non-structured populations using the classifiers, the two-sample Kolmogorov-Smirnov, Cucconi and Podgor-Gastwirth tests and the box plots. SVM models were more robust to changes in model parameters and tree size compared to KNN and DT classifiers. Our classification procedure was applied to real -world data and the structured population was revealed with high accuracy of [Formula: see text] using SVM-polynomial classifier.

Should we be measuring DNA damage in human spermatozoa? New light on an old question.

Assessments of sperm DNA damage are controversial because of perceived uncertainties over the relationship with pregnancy and the limited range of therapies available should positive results be returned. In this article, we highlight recent data supporting a chain of associations between oxidative stress in the male germ line, DNA damage in spermatozoa, defective DNA repair in the oocyte, the mutational load carried by the resulting embryo and the long-term health trajectory of the offspring. Any condition capable of generating oxidative damage in spermatozoa (age, obesity, smoking, prolonged abstinence, varicocele, chemical exposures, radiation etc.) is capable of influencing offspring health in this manner, creating a range of pathologies in the progeny including neuropsychiatric disorders and cancer. If sperm DNA damage is detected, there are several therapeutic interventions that can be introduced to improve DNA quality prior to the use of these cells in ART. We therefore argue that infertility specialists should be engaged in the diagnosis and remediation of sperm DNA damage as a matter of best practice, in order to minimize the risk of adverse health outcomes in children conceived using ART.

Heart transplant recipients with confirmed 2019 novel coronavirus infection: The Detroit experience.

A chronic immunosuppressed state as in solid organ transplant recipients is a reported risk factor for the novel 2019 coronavirus infection. Patients with a history of orthotopic heart transplant (OHT) at a tertiary care transplant center in Detroit, Michigan were retrospectively reviewed from March until May 2020. Clinical parameters and outcomes of 5 OHT recipients and one combined heart-lung recipient with confirmed SARS-CoV-2 were obtained. The cohort was predominately African American males with median age of 59 years (interquartile range, 48.25-73.25). All patients were classified as having mild-moderate disease; none required intubation or ICU admission with no deaths. The most common presenting symptoms were fever and shortness of breath 83% (n = 5), followed by cough and chills 67% (n = 4). All admitted patients (n = 5) received hydroxychloroquine and 3 received high-dose steroids. Antimetabolites were held for 2 patients (33.3%). The calcineurin inhibitor trough goal was decreased in only 1 patient; 3 other patients, without change in goal, required calcineurin inhibitor dosage reduction. Two patients requiring readmission presented 7 and 23 days after initial symptoms onset. In conclusion, our experience with OHT patients infected by the SARS-CoV-2 virus did not have an elevated risk of severe infection. Impact of modifying immunosuppression remains unclear.

Farmers' choice of genotypes and trait preferences in tropically adapted chickens in five agro-ecological zones in Nigeria.

This study aimed at determining chicken genotypes of choice and traits preference in chicken by smallholder farmers in Nigeria. Data were obtained from a total of 2063 farmers using structured questionnaires in five agro-ecological zones in Nigeria. Chi square (χ2) statistics was used to explore relationships between categorical variables. The mean ranks of the six genotypes and twelve traits of preference were compared using the non-parametric Kruskal-Wallis H (with Mann-Whitney U test for post hoc separation of mean ranks), Friedman, and Wilcoxon signed-rank (with Bonferroni's adjustments) tests. Categorical principal component analysis (CATPCA) was used to assign farmers into groups. Gender distribution of farmers was found to be statistically significant (χ2 = 16.599; P ≤ 0.002) across the zones. With the exception of Shika Brown, preferences for chicken genotypes were significantly (P ≤ 0.01) influenced by agro-ecological zone. However, gender differentiated response was only significant (P ≤ 0.01) in Sasso chicken with more preference by male farmers. Overall, FUNAAB Alpha, Sasso, and Noiler chicken were ranked 1st, followed by Kuroiler (4th), Shika Brown (5th), and Fulani birds (6th), respectively. Within genotypes, within and across zones and gender, preferences for traits varied significantly (P ≤ 0.005 and P ≤ 0.01). Traits of preference for selection of chicken breeding stock tended towards body size, egg number, egg size, and meat taste. Spearman's rank order correlation coefficients of traits of preference were significant (P ≤ 0.01) and ranged from 0.22 to 0.90. The two PCs extracted, which explained 65.3% of the variability in the dataset, were able to assign the farmers into two groups based on preference for body size of cock and hen and the other ten traits combined. The present findings may guide the choice of appropriate chicken genotypes while the traits of economic importance may be incorporated into future genetic improvement and conservation programs in Nigeria.

Micellar high performance liquid chromatographic method for separation and validation of two anti-hepatitis C- virus drugs in pure form, human plasma and human urine.

OBJECTIVES: In the present study, an eco- friendly micellar liquid chromatographic technique was validated for separation and quantification of two drugs; namely ribavirin (RIV), and sofosbuvir (SBV) in pure form, pharmaceuticals containing them, human plasma and human urine. These drugs are administered co-administered for treatment of Hepatitis C virus (HCV) that causes hepatitis C in humans. MATERIAL AND METHODS: These drugs were separated using Nucleosil 100-5 phenyl column. Sodium dodecyl sulphate (SDS) solution (0.05M, pH 7.0) containing triethylamine (0.3%) and n-butanol (10%) was used as a mobile phase with 1.2 mLmin-1 flow rate and 215nm detection wavelength. Nine minutes were required for resolving the two drugs from the matrix. RESULTS: The method showed good linearity for RIV and SBV with correlation coefficients (r2) more than 0.9996 within the concentration ranges of (20-400) and (40-400) ngmL-1 in pure form, (30-300) and (50-300) ngmL-1 in human plasma and (20-400) and (40-400) ngmL-1 in human urine, respectively. CONCLUSION: The recommended method was applied for examination of RIV and SBV in pure and pharmaceuticals. The obtained results were statistically matched with reported methods with no significant differences. Also, the recommended method was effectively applied for estimation of both drugs in spiked human urine and plasma without purification or extraction steps and real samples of plasma and urine of humans having therapy of RIV and SBV, as well as, performing tablets dissolution-rate tests with satisfactory results.

Genetic diversity of Bm86 sequences in Rhipicephalus (Boophilus) microplus ticks from Mexico: analysis of haplotype distribution patterns.

BACKGROUND: Ticks are a problem for cattle production mainly in tropical and subtropical regions, because they generate great economic losses. Acaricides and vaccines have been used to try to keep tick populations under control. This has been proven difficult given the resistance to acaricides and vaccines observed in ticks. Resistance to protein rBm86-based vaccines has been associated with the genetic diversity of Bm86 among the ectoparasite's populations. So far, neither genetic diversity, nor spatial distribution of circulating Bm86 haplotypes, have been studied within the Mexican territory. Here, we explored the genetic diversity of 125 Bm86 cDNA gene sequences from R. microplus from 10 endemic areas of Mexico by analyzing haplotype distribution patterns to help in understanding the population genetic structure of Mexican ticks. RESULTS: Our results showed an average nucleotide identity among the Mexican isolates of 98.3%, ranging from 91.1 to 100%. Divergence between the Mexican and Yeerongpilly (the Bm86 reference vaccine antigen) sequences ranged from 3.1 to 7.4%. Based on the geographic distribution of Bm86 haplotypes in Mexico, our results suggest gene flow occurrence within different regions of the Mexican territory, and even the USA. CONCLUSIONS: The polymorphism of Bm86 found in the populations included in this study, could account for the poor efficacy of the current Bm86 antigen based commercial vaccine in many regions of Mexico. Our data may contribute towards designing new, highly-specific, Bm86 antigen vaccine candidates against R. microplus circulating in Mexico.

Isolation and Molecular Identification of Microsporidian Pathogen Causing Nosemosis in Muga Silkworm, Antheraea assamensis Helfer (Lepidoptera: Saturniidae).

Microsporidia are intracellular fungal parasites and they are the most common pathogens for sericulture. Microsporidian sp. can cause pebrine, a dreadful disease and lead to destructive disorder in Muga silkworm, Antheraea assamensis Helfer by vertical and horizontal transmission. This disease is the key factor obstructing the developmental progress of Muga culture in India. Nevertheless, molecular identification and characterization of pathogen associated with pebrine disease in A. assamensis is not yet established. Insect bioassay studies revealed that microsporidian infection in Muga silkworm, A. assamensis Helfer significantly reduced (P < 0.005) cocoon weight, pupal weight, shell weight and silk ratios. A new set of PCR primers suitable for amplification of small subunit ribosomal RNA (SSU-rRNA) of microsporidia infecting A. assamensis have been designed. The amplicon was cloned, sequenced and analysed. Microsporidia pathogen of wild silk moth A. assamensis has been identified at genus level as Nosema sp. AA1. Phylogeny of Nosema sp. AA1 was constructed on the basis of SSU-rRNA sequence and it has a close evolutionary relationship with microsporidian pathogens of other wild silkmoths. The arrangement and organization of the rRNA genes inferred that Nosema sp. AA1 belongs to true Nosema group and not to members of the Nosema/Vairimorpha group.

Swim exercise training ameliorates hepatocyte ultrastructural alterations in rats fed on a high fat and sugar diet.

Excessive consumption of carbohydrate and fat increases the risk of liver disease. We hypothesized that swim exercise can protect hepatocytes from ultra-structural damage induced by high cholesterol and fructose diets (HCFD). Rats were either fed with HCFD (model group) or a standard laboratory chow (control group) for 15 weeks before being sacrificed. Swim exercise trained rats started the treatment from the 11th week until the sacrifice day, end of week 15. Blood samples were assayed for biomarkers of liver injury and adiponectin. The harvested liver tissues were examined using transmission electron microscopy (TEM). TEM images revealed substantial damage and accumulation of lipid droplets (steatosis) in the hepatocytes of the model group that was inhibited by swim exercise. In addition, HCFD significantly (p < 0.0005) increased insulin resistance index (HOMA-IR), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), which were effectively (p < 0.02) decreased by a swim exercise to levels comparable to control group. Whereas, swim exercise increased adiponectin levels in HCFD group (p < 0.03). These results show that HCFD-induced hepatic injury is ameliorated by swim training exercise possibly via restoration of a normal blood sugar and lipid, induction of adiponectin and inhibition of inflammatory, and liver injury biomarkers.

Development and application of degradation kinetics of thin layer chromatographic densitometry and conductometric methods for butoconazole nitrate determination.

Two simple methods were developed for determination of butoconazole nitrate (BN). The first developed method was stability-indicating HPTLC-densitometric method (method A) which is based on the quantitative densitometric separation of butoconazole nitrate (BN) from its degradation products on silica gel 60 F254 and measurement of the bands at 290nm. The developed stability study of BN was performed under different stress conditions including oxidative, hydrolytic, thermal and photolytic. Degradation was observed under acidic hydrolytic and oxidative conditions. Moreover, the HPTLC method was used to study the kinetics of BN acid degradation, determining as first order kinetics. The degradation rate constant of BN was found to be 0.076 hr-1 and t 1/2 value was determined at 9.12 hr in acidic medium. The second method (Method B) was conductometric method which is based on the reaction of BN with phosphotungstic acid (PTA) to form an ion associate in 50% methanol-water system. Validation of the proposed methods was carried out. All proposed methods were successfully applied for the commercial dosage form of BN. Statistical analysis of the results has been carried out revealing high accuracy and good precision.

Coelacanth genomes reveal signatures for evolutionary transition from water to land.

Coelacanths are known as "living fossils," as they show remarkable morphological resemblance to the fossil record and belong to the most primitive lineage of living Sarcopterygii (lobe-finned fishes and tetrapods). Coelacanths may be key to elucidating the tempo and mode of evolution from fish to tetrapods. Here, we report the genome sequences of five coelacanths, including four Latimeria chalumnae individuals (three specimens from Tanzania and one from Comoros) and one L. menadoensis individual from Indonesia. These sequences cover two African breeding populations and two known extant coelacanth species. The genome is ∼2.74 Gbp and contains a high proportion (∼60%) of repetitive elements. The genetic diversity among the individuals was extremely low, suggesting a small population size and/or a slow rate of evolution. We found a substantial number of genes that encode olfactory and pheromone receptors with features characteristic of tetrapod receptors for the detection of airborne ligands. We also found that limb enhancers of bmp7 and gli3, both of which are essential for limb formation, are conserved between coelacanth and tetrapods, but not ray-finned fishes. We expect that some tetrapod-like genes may have existed early in the evolution of primitive Sarcopterygii and were later co-opted to adapt to terrestrial environments. These coelacanth genomes will provide a cornerstone for studies to elucidate how ancestral aquatic vertebrates evolved into terrestrial animals.

Effect of Body Mass Index on Outcomes in Left Ventricular Assist Device Recipients.

BACKGROUND AND AIM: Obesity is associated with higher mortality following heart transplantation, but there remains no consensus regarding outcomes in left ventricular assist device (LVAD) recipients. We sought to determine the impact of body mass index (BMI) on outcomes in patients undergoing LVAD implantation. METHODS: This was a single-institution retrospective review, including all patients who received a HeartMate II LVAD or HeartWare HVAD between March 2006 and June 2014. Patients were stratified into three groups based on normal (<25 kg/m(2) ), overweight (25-30 kg/m(2) ), and obese (>30 kg/m(2) ) BMI. RESULTS: Two hundred patients were included in the analysis. Mean BMI was 28.3 kg/m(2) , (27% normal, 36% overweight, and 36.5% obese). Obese patients were younger (51.9 years, p = 0.03) and had higher incidence of diabetes (58.9% vs. 24.1%; p < 0.001) and peripheral vascular disease (16.4% vs. 1.9%; p = 0.03). Normal BMI patients were more likely to undergo LVAD implantation as destination therapy compared to the overweight and obese groups (67% vs. 39% vs. 51%; p = 0.01) and had higher incidence of postoperative stroke/transient ischemic attack (22.2% vs. 6.9% vs. 12.3%; p = 0.04) and postoperative bleeding requiring reoperation (27.8% vs. 12.5% vs. 9.6%; p = 0.01). Survival at one, three, and five years was similar across all BMI groups. BMI was not an independent predictor of overall survival. CONCLUSIONS: Appropriately-selected patients at the extremes of BMI can safely undergo LVAD implantation with no difference in survival. BMI should not in itself be considered a contraindication to LVAD placement.

Paternal obesity negatively affects male fertility and assisted reproduction outcomes: a systematic review and meta-analysis.

This systematic review investigated the effect of paternal obesity on reproductive potential. Databases searched were Pubmed, Ovid, Web of Science, Scopus, Cinahl and Embase. Papers were critically appraised by two reviewers, and data were extracted using a standardized tool. Outcomes were: likelihood of infertility, embryo development, clinical pregnancy, live birth, pregnancy viability, infant development, sperm; concentration, morphology, motility, volume, DNA fragmentation, chromatin condensation, mitochondrial membrane potential (MMP), and seminal plasma factors. Thirty papers were included, with a total participant number of 115,158. Obese men were more likely to experience infertility (OR = 1.66, 95% CI 1.53-1.79), their rate of live birth per cycle of assisted reproduction technology (ART) was reduced (OR = 0.65, 95% CI 0.44-0.97) and they had a 10% absolute risk increase of pregnancy non-viability. Additionally, obese men had an increased percentage of sperm with low MMP, DNA fragmentation, and abnormal morphology. Clinically significant differences were not found for conventional semen parameters. From these findings it can be concluded that male obesity is associated with reduced reproductive potential. Furthermore, it may be informative to incorporate DNA fragmentation analysis and MMP assessment into semen testing, especially for obese men whose results suggest they should have normal fertility.

Prediction of delivery mode by ultrasound-assessed fetal position in nulliparous women with prolonged first stage of labor.

OBJECTIVES: To ascertain if fetal head position on transabdominal ultrasound is associated with delivery by Cesarean section in nulliparous women with a prolonged first stage of labor. METHODS: This was a prospective observational study performed at Stavanger University Hospital, Norway, and Addenbrooke's Hospital, Cambridge, UK, between January 2012 and April 2013. Nulliparous pregnant women with a singleton cephalic presentation at term and prolonged labor had fetal head position assessed by ultrasound. The main outcome was Cesarean section vs vaginal delivery, and secondary outcomes were association of fetal head position with operative vaginal delivery and duration of remaining time in labor. RESULTS: Fetal head position was assessed successfully by ultrasound examination in 142/150 (95%) women. In total, 19/50 (38%) women with a fetus in the occiput posterior (OP) position were delivered by Cesarean section compared with 16/92 (17%) women with a fetus in a non-OP position (P = 0.01). On multivariable logistic regression analysis, the OP position predicted delivery by Cesarean section with an odds ratio (OR) of 2.9 (95% CI, 1.3-6.7; P = 0.01) and induction of labor with an OR of 2.4 (95% CI, 1.0-5.6; P = 0.05). Fetal head position was not associated with operative vaginal delivery or with remaining time in labor. The agreement between a digital and an ultrasound assessment of OP position was poor (Cohen's kappa = 0.19; P = 0.18). CONCLUSION: OP fetal head position assessed by transabdominal ultrasound was significantly associated with delivery by Cesarean section.