Assessing hospital differences in low-risk cesarean delivery metrics in Florida

BACKGROUND

Unnecessary cesarean deliveries lead to increased maternal and neonatal morbidities and mortalities. In 2020, Florida had a cesarean delivery rate of 35.9%, the third highest in the nation. An effective quality improvement strategy to reduce overall cesarean delivery rates is to decrease primary cesarean deliveries in low-risk births (nulliparous, term, singleton, vertex). Of note, 3 nationally accepted hospital measures of low-risk cesarean delivery rates include the nulliparous, term, singleton, vertex; Joint Commission; and Society for Maternal-Fetal Medicine metrics. Comparing metrics is necessary because accurate and timely measurement is essential to support multihospital quality improvement efforts to reduce low-risk cesarean delivery rates and improve the quality of maternal care.

OBJECTIVE

This study aimed to assess differences in hospital low-risk cesarean delivery rates in Florida using 5 different metrics of low-risk cesarean delivery rate based on (1) risk methodology, nulliparous, term, singleton, vertex; Joint Commission; and Society for Maternal-Fetal Medicine metrics, and (2) data source, linked birth certificate and hospital discharge records and hospital discharge records only.

STUDY DESIGN

This was a population-based study of live Florida births from 2016 to 2019 to compare 5 approaches to calculating low-risk cesarean delivery rates. Analyses were performed using linked birth certificate data and inpatient hospital discharge data. The 5 low-risk cesarean delivery measures were defined as follows: nulliparous, term, singleton, vertex birth certificate; Joint Commission-linked used Joint Commission exclusions; Society for Maternal-Fetal Medicine-linked used Society for Maternal-Fetal Medicine exclusions; Joint Commission hospital discharge with Joint Commission exclusions; and Society for Maternal-Fetal Medicine hospital discharge with Society for Maternal-Fetal Medicine exclusions. Nulliparous, term, singleton, vertex birth certificate was based on data from birth certificates and not using linked hospital discharge data. Designated as nulliparous, term, singleton, vertex, it does not exclude other high-risk conditions. The second and third measures (Joint Commission-linked used Joint Commission exclusions and Society for Maternal-Fetal Medicine-linked used Society for Maternal-Fetal Medicine exclusions) use data elements from the full-linked dataset to designate nulliparous, term, singleton, vertex and excluded several high-risk conditions. The last 2 measures (Joint Commission hospital discharge with Joint Commission exclusions; and Society for Maternal-Fetal Medicine hospital discharge with Society for Maternal-Fetal Medicine exclusions) were based on data from hospital discharge data only and not using linked birth certificate data. These measures generally reflect term, singleton, and vertex because parity could not be assessed adequately on hospital discharge data. Hospital differences between these 5 measures were calculated overall and by neonatal intensive care unit level.

RESULTS

Overall, the median of hospital low-risk cesarean rates decreased across the measures, from NTSV-BC 30.7%, to Joint Commission linked 29.1%, and Society for Maternal Fetal Medicine hospital discharge 29.2% with a large decrease to Joint Commission hospital discharge 19.4% and Society for Maternal Fetal Medicine hospital discharge 18.1%. A similar trend was seen by neonatal intensive care unit level. For each of the measures, level II had the highest median low-risk cesarean rates (nulliparous. term, singleton, vertex birth certificate) 32.7%, Joint Commission linked (31.4%), Society for Maternal Fetal Medicine linked: 31.1%, Society for Maternal Fetal Medicine hospital discharge 19.3%), except for level III Joint Commission hospital discharge (20.0%). A comparison of the median number of low-risk births overall and by neonatal intensive care unit level showed a decreasing number across the linked and hospital discharge measures. Again, a wide gap in low-risk cesarean delivery rates was identified between linked measures and hospital discharge measures. However, this gap narrowed as hospital rates increased.

CONCLUSION

Quality monitoring of low-risk cesarean delivery rates measured by the nulliparous, term, singleton, vertex metric using the birth certificate was fairly accurate and provided timely assessment for use by Florida hospitals. The nulliparous, term, singleton, vertex birth certificate rates were comparable with low-risk metrics using the linked data source. Overall, metrics used within the same data source had similar rates, with the Society for Maternal-Fetal Medicine metric having the lowest rates. Across data sources, metrics using hospital discharge data only resulted in substantially underestimated rates because of the inclusion of multiparous women and should be interpreted with caution.

Four vertex technique for correcting urethral prolapse: technique description and cohort study

Introduction/Objectives

This study aims to describe the procedure and effectiveness of the four-vertex technique for correcting urethral prolapse in women.

Methods and Materials

includes a retrospective case series of 17 patients who underwent surgery for urethral prolapse. Two study groups were distinguished based on the presence or absence of pelvic heaviness symptoms. The variables were analyzed, including age, BMI, concomitant diseases, obstetric and gynecological history, time from diagnosis to surgery, and outcomes of treatment.

Results

All patients were postmenopausal, with a mean age at the time of the intervention of 70.41 years, with no differences between groups. Mean BMI was 23.67 kg/m2, higher in the group with a sensation of vaginal heaviness (p = 0.027). Mean time elapsed between diagnosis and operation was 231.58 days, with no differences between groups. Mean childbirth count was 2.29. The most frequent causes for consultation were urethrorrhagia (33.33%) and a bulging sensation (33.33%). After the intervention, 14 patients (82.35%) were asymptomatic, two (11.76%) had dysuria, and one (5.88%) had urinary urgency. Ten patients had pre-surgical urinary incontinence, which was resolved in nine patients. 17.46% subsequently presented pelvic organ prolapse. In three women there was secondary impairment of sexual activity.

Conclusion

The four-vertex technique was effective in resolving symptoms in most patients. However, some patients experienced dysuria, urinary urgency, and pelvic organ prolapse after surgery. Urinary incontinence improved in most patients, but a few required additional treatments with suburethral tape. The study also identified associations between variables and the presence of cystocele, consultation for a bulging sensation, and bleeding from urethral prolapse. Overall, this study sheds light on the challenges and outcomes of surgical treatment for urethral prolapse and provides valuable insights for future research in this area.

Bridges and Vertices in Heteroboranes

A number of (hetero)boranes are known in which a main group atom X 'bridges' a B-B connectivity in the open face, and in such species X has previously been described as simply a bridge or, alternatively, as a vertex in a larger cluster. In this study we describe an approach to distinguish between these options based on identifying the best fit of the experimental {B_x} cluster fragment with alternate exemplar {B_x} fragments derived from DFT-optimized [B_nH_n]^2- models. In most of the examples studied atom X is found to be better regarded as a vertex, having 'a 'verticity' of ca. 60-65%. Consideration of our results leads to the suggestion that the radial electron contribution from X to the overall skeletal electron count is more significant than the tangential contribution.

A series of post-traumatic midline epidural hematoma and review of the literature

BACKGROUND

Supratentorial midline epidural hematoma is rare but challenging in diagnosis and management. Indication for surgery can arise even following hospital admission. Being familiar to the presentation and watching out for direct and indirect signs on axial computed tomography (CT) such as suture diastasis or fracture traversing midline are essential to plan multi-planar CT enabling exact diagnosis including form and mass effect of hematoma.

METHODS

Nine patients with midline epidural hematoma including two pediatric patients underwent surgery between 2013 and 2018. Pre-operative and post-operative patient status, radiological features, and surgical technique were analyzed.

RESULTS

Four patients had deteriorating consciousness levels and two patients had paraparesis. All had fractures traversing midline and epidural hematomas with significant mass effect. They were operated through separated craniotomies around the midline and midline bone strip was used for dural tenting and as support for natural closure of bone flaps. No post-operative complications were developed. All patients were discharged with Glasgow Outcome Score of 5.

CONCLUSION

Because of the rarity of the lesion and small number of patients, definitive conclusions may be misleading but we think that, in experienced hands, midline epidural hematomas can safely be operated on and, preservation of midline bone strip pro-vides easier bleeding control.

A new index for obstetrics safety and quality of care: integrating cesarean delivery rates with maternal and neonatal outcomes

BACKGROUND

Cesarean delivery rates have been used as obstetrical quality indicators. However, these approaches do not consider the accompanying maternal and neonatal morbidities. A challenge in the field of obstetrics has been to establish a valid outcomes quality measure that encompasses preexisting high-risk maternal factors and associated maternal and neonatal morbidities and is universally acceptable to all stakeholders, including patients, healthcare providers, payers, and governmental agencies.

OBJECTIVE

This study aimed to (1) establish a new single metric for obstetrical quality improvement among nulliparous patients with term singleton vertex-presenting fetus, integrating cesarean delivery rates adjusted for preexisting high-risk maternal factors with associated maternal and neonatal morbidities, and (2) determine whether obstetrician quality ranking by this new metric is different compared with the rating based on individual crude and/or risk-adjusted cesarean delivery rates. The single metric has been termed obstetrical safety and quality index.

STUDY DESIGN

This was a cross-sectional study of all nulliparous patients with term singleton vertex-presenting fetuses delivered by 12 randomly chosen obstetricians in a single institution. A review of all records was performed, including a review of maternal high-risk factors and maternal and neonatal outcomes. Maternal and neonatal medical records were reviewed to determine crude and adjusted cesarean delivery rates by obstetricians and quantify maternal and neonatal complications. We estimated the obstetrician-specific crude cesarean delivery rates and rates adjusted for obstetrician-specific maternal and neonatal complications from logistic regression models. From this model, we derived the obstetrical safety and quality index for each obstetrician. The final ranking based on the obstetrical safety and quality index was compared with the initial ranking by crude cesarean delivery rates. Maternal and neonatal morbidities were analyzed as ≥1 and ≥2 maternal and/or neonatal complications.

RESULTS

These 12 obstetricians delivered a total of 535 women; thus, 1070 (535 maternal and 535 neonatal) medical records were reviewed to determine crude and adjusted cesarean delivery rates by obstetricians and quantify maternal and neonatal complications. The ranking of crude cesarean delivery rates was not correlated (rho=0.05; 95% confidence interval, -0.54 to 0.60) to the final ranking based on the obstetrical safety and quality index. Of note, 8 of 12 obstetricians shifted their rank quartiles after adjustments for high-risk maternal conditions and maternal and neonatal outcomes. There was a strong correlation between the ranking based on ≥1 maternal and/or neonatal complication and ranking based on ≥2 maternal and/or neonatal complications (rho=0.63; 95% confidence interval, 0.08-0.88).

CONCLUSION

Ranking based on crude cesarean delivery rates varied significantly after considering high-risk maternal conditions and associated maternal and neonatal outcomes. Therefore, the obstetrical safety and quality index, a single metric, was developed to identify ways to improve clinician practice standards within an institution. Use of this novel quality measure may help to change initiatives geared toward patient safety, balancing cesarean delivery rates with optimal maternal and neonatal outcomes. This metric could be used to compare obstetrical quality not only among individual obstetricians but also among hospitals that practice obstetrics.

Self-Induced Solutal Marangoni Flows Realize Coffee-Ring-Less Quantum Dot Microarrays with Extensive Geometric Tunability and Scalability

Currently, quantum dot light-emitting diodes (QD-LEDs) are receiving extensive attention. To maximize their luminous performance, the uniformity of the QD-LEDs is crucial. Although the spontaneously self-induced solutal Marangoni flow of an evaporating binary mixture droplet has been widely investigated and used to suppress coffee-ring patterns in ink-jet printing technology, unfortunately, ring shapes are still present at the edges, and the Marangoni flow generated by the selective evaporation of volatile liquid components cannot be controlled due to its nonlinear instabilities. In this work, polygonal coffee-ring-less QD microarrays are created using two spontaneous and sequential solutal Marangoni flows. During the initial evaporation, internal circulating flows are controlled by polygonal-shaped droplets. After that, sequential interfacial flows are generated by the captured volatile vapors. A theoretical model and scaling analysis are provided to explain the working mechanisms. It is expected that the newly designed printing system can be applied to the mass production of QD-LEDs.

Is vaginal delivery of a breech second twin safe? A comparison between delivery of vertex and non-vertex second twins

AIM

The aim of this study was to determine the safety of vaginal delivery with a non-vertex second twin when the first twin is in the vertex presentation.

MATERIALS AND METHODS

A retrospective analysis was undertaken, utilizing a cohort of twin gestations in which the presenting twin was vertex and the second twin was either vertex (group A) or non-vertex (group B). We assessed maternal and neonatal outcomes including emergency cesarean delivery, 5-minute Apgar scores, cord arterial pH, NICU admissions, and adverse maternal postpartum outcomes including ICU admissions and the requirement of blood products.

RESULTS

Six hundred and eighty-five women with a vertex presenting twin were admitted to labor and delivery. Three hundred and ninety-five women were included in group A (vertex/vertex) and 290 were included in group B (vertex/non-vertex). No statistically significant differences were found in the 5-minute Apgar scores, cord arterial pH, or in the rates of emergency cesarean deliveries, NICU admission, maternal blood transfusion or ICU admissions.

CONCLUSION

In conclusion, vaginal delivery of a breech second twin when the presenting twin is vertex was found as safe as vaginal delivery of twins in the vertex/vertex presentation.

Factors Associated with Meeting Obstetric Care Consensus Guidelines for Nulliparous, Term, Singleton, Vertex Cesarean Births

Objective  This study aimed to identify factors associated with meeting the Obstetric Care Consensus (OCC) guidelines for nulliparous, term, singleton, and vertex (NTSV) cesarean births. Materials and methods  This was a retrospective case control study of women with NTSV cesarean births between January 2014 and December 2017 at single tertiary care center. Demographics and clinical characteristics were compared between women with NTSV cesarean births which did or did not meet OCC guidelines. A multivariable logistic regression model was used to evaluate the effect of each variable on the odds of meeting OCC guidelines. Results  There were 1,834 women with NTSV cesarean births of which 744 (40.6%) met OCC guidelines for delivery and 1,090 (59.4%) did not. After controlling for confounding factors, the odds of meeting OCC guidelines were increased for in-house providers managing with residents (adjusted odds ratio [aOR] = 2.03, 95% confidence interval [CI]: 1.44-2.87) and without residents (aOR = 1.66, 95% CI: 1.30-2.12), compared with non-in-house providers managing without residents. There was no significant difference in the odds of meeting OCC guidelines for in-house providers managing with or without residents (aOR = 1.23, 95% CI: 0.84-1.79). Conclusion  After adjusting for confounding factors, in-house provider coverage, regardless of resident involvement, is associated with increased odds of NTSV cesarean births meeting OCC guidelines. Key Points Frequency of adherence to OCC guidelines for NTSV cesarean births was 40.6%.Neither patient demographics nor comorbidities was associated with the odds of meeting OCC guidelines.In-house providers are associated with increased odds of meeting OCC guidelines.

Transient opening of tricellular vertices controls paracellular transport through the follicle epithelium during Drosophila oogenesis

Paracellular permeability is regulated to allow solute transport or cell migration across epithelial or endothelial barriers. However, how cell-cell junction dynamics controls paracellular permeability is poorly understood. Here, we describe patency, a developmentally regulated process in Drosophila oogenesis, during which cell vertices in the follicular epithelium open transiently to allow paracellular transport of yolk proteins for uptake by the oocyte. We show that the sequential removal of E-cadherin, N-cadherin, NCAM/Fasciclin 2, and Sidekick from vertices precedes their basal-to-apical opening, while the subsequent assembly of tricellular occluding junctions marks the termination of patency and seals the paracellular barrier. E-cadherin-based adhesion is required to limit paracellular channel size, whereas stabilized adherens junctions, prolonged NCAM/Fasciclin 2 expression, blocked endocytosis, or increased actomyosin contractility prevent patency. Our findings reveal a key role of cell vertices as gateways controlling paracellular transport and demonstrate that dynamic regulation of adhesion and actomyosin contractility at vertices governs epithelial barrier properties.

Development of a New 3D Hybrid Model for Epithelia Morphogenesis

Many epithelial developmental processes like cell migration and spreading, cell sorting, or T1 transitions can be described as planar deformations. As such, they can be studied using two-dimensional tools and vertex models that can properly predict collective dynamics. However, many other epithelial shape changes are characterized by out-of-plane mechanics and three-dimensional effects, such as bending, cell extrusion, delamination, or invagination. Furthermore, during planar cell dynamics or tissue repair in monolayers, spatial intercalation between the apical and basal sides has even been detected. Motivated by this lack of symmetry with respect to the midsurface, we here present a 3D hybrid model that allows us to model differential contractility at the apical, basal or lateral sides. We use the model to study the effects on wound closure of solely apical or lateral contractile contributions and show that an apical purse-string can be sufficient for full closure when it is accompanied by volume preservation.

Hydrocephalus Following Giant Transosseous Vertex Meningioma Resection

Introduction  Meningiomas are among the most common primary intracranial tumors. While well-described, there is limited information on the outcomes and consequences following treatment of giant-sized vertex-based meningiomas. These meningiomas have specific risks and potential complications due to their size, location, and involvement with extracalvarial soft tissue and dural sinuses. Herein, we present four giant-sized vertex transosseous meningioma cases with involvement and occlusion of the sagittal sinus, that postoperatively developed external hydrocephalus and ultimately required shunting. Methods  A retrospective chart review identified patients with large vertex meningiomas that were: (1) large (>6 cm) with hemispheric (no skull base) location, (2) involvement of the superior sagittal sinus resulting in complete sinus occlusion, (3) involvement of dura resulting in a large duraplasty area, (4) transosseous involvement requiring a 5 cm or larger craniectomy for resection of invaded calvarial bone. Results  Tumors were resected in all four cases, with all patients subsequently developing external hydrocephalus which required shunting within 2 weeks to 6 months postsurgery. Conclusion  We believe this may be the first report of the development of hydrocephalus following surgical resection of these large lesions. Based on our observations, we propose that a combination of superior sagittal sinus occlusion and changes in brain elasticity and compliance affect the brain's CSF absorptive capacity, which ultimately lead to hydrocephalus development. We suggest that neurosurgeons be aware that postoperative hydrocephalus can quickly develop following treatment of giant-sized vertex-based meningiomas, and that correction of hydrocephalus with shunting can readily be achieved.

Distribution of polyamines may be altered in different scalp regions of patients with hair loss

Hair loss, from the vertex or front of the head, generally occurs due to increased androgenic steroid levels. Androgenic steroids, particularly testosterone and dihydrotestosterone, are distributed differently across the vertex and occipital regions and are involved in inducing ornithine decarboxylase expression. Therefore, we hypothesized that the distribution of polyamines may be altered in different scalp regions. For the overall metabolic profiling of polyamines in patients with hair loss, a liquid chromatography-mass spectrometry was used. We investigated the differential polyamine levels in different regions of the hair of patients with male pattern baldness and those with female pattern hair loss. The levels of most polyamines were higher in the vertex region than in the occipital region, and N-acetyl polyamine levels differed significantly. We proposed to test our hypothesis by profiling polyamines in human hair fibre to evaluate the distribution of metabolites in various regions of the scalp.

Spontaneous Version of Fetal Presentation in Twin Pregnancies During Third Trimester: Longitudinal Assessment

Little is known about longitudinal changes of the first twin presentation in twin gestations. This is a retrospective cohort study including 411 women who were admitted consecutively and delivered live-born twins at 36 weeks of gestation or more. Longitudinal assessment of the first twin presentation was conducted during gestation and at birth in all cases. Gestational age at antenatal assessment was divided into two intervals: early-third trimester (28-31 weeks) and mid-third trimester (32-35 weeks). Fetal presentation was categorized as vertex or non-vertex. We analyzed change of fetal presentation between antepartum intervals and birth. First twin presentation at early-third trimester had the same presentation at birth in 87.6% (360/411) of the study population. In this 'no change' group, vertex presentation was seen in 95.6% (283/296) and non-vertex was seen in 67.0% (77/115) of cases. In total, 96.1% (395/411) of the study population maintained their presentation between mid-third trimester and birth. Vertex presentation was seen in 98.4% (310/315) and non-vertex was seen in 88.5% (85/96) of cases. When comparing vertex with non-vertex, vertex presentation during third trimester was a more reliable predictor of presentation at birth (p < .001). The only factor that contributed significantly to spontaneous version of the first twin during mid-third trimester and birth was a lower birth weight of the first twin compared with the second twin. In conclusion, first twin presentation with vertex during third trimester is not likely to change into non-vertex at birth. We concluded that vertex presentation in twin gestations at early- and mid-third trimester is very predictable. In contrast, a non-vertex first twin presentation is relatively unstable.

Vaginal delivery in a pregnant woman with cord prolapse, velamentous cord insertion, and fetal vertex presentation: A case report

RATIONALE

We report a rare case of a pregnant woman with cord prolapse, velamentous cord insertion (VCI), and fetal vertex presentation who completed vaginal delivery.

PATIENT CONCERNS

Without having undergone regular antepartum examinations, a 31-year-old pregnant woman, gravida 6, para 4, abortion 1, presented at 37 weeks and 3 days of gestation. She had regular labor pain and bloody show.

DIAGNOSES

Cord prolapse during labor and VCI after delivery.

INTERVENTIONS

Per vaginal examination at 11:20 PM revealed a fully dilated cervix. Thirty minutes later, artificial rupture of the membrane was performed, and an overt prolapsed cord approximately 10-cm long was palpated in the vagina. Fetal heartbeat decelerated to 60 bpm. After fundal pushing for some minutes, a female baby weighing 2130 g was delivered at 11:54 PM with a pediatrician on standby. Apgar scores were 7 (0 minute), 9 (5 minutes), and 10 (10 minutes). The placenta weighed 870 g and was delivered 5 minutes later, and VCI was discovered.

OUTCOMES

Her postpartum course was uncomplicated and both the patient and infant were discharged 3 days later.

LESSONS

A pregnant woman with umbilical prolapse, VCI, and a fetal vertex presentation can successfully deliver a baby through the vagina. Factors contributing to the success of the reported vaginal delivery might have been a small fetus, multipara status, and immediate management.

Neuraxial analgesia to increase the success rate of external cephalic version: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

External cephalic version is a medical procedure in which the fetus is externally manipulated to assume the cephalic presentation. The use of neuraxial analgesia for facilitating the version has been evaluated in several randomized clinical trials, but its potential effects are still controversial.

OBJECTIVE

The objective of the study was to evaluate the effectiveness of neuraxial analgesia as an intervention to increase the success rate of external cephalic version.

DATA SOURCES

Searches were performed in electronic databases with the use of a combination of text words related to external cephalic version and neuraxial analgesia from the inception of each database to January 2016.

STUDY ELIGIBILITY CRITERIA

We included all randomized clinical trials of women, with a gestational age ≥36 weeks and breech or transverse fetal presentation, undergoing external cephalic version who were randomized to neuraxial analgesia, including spinal, epidural, or combined spinal-epidural techniques (ie, intervention group) or to a control group (either intravenous analgesia or no treatment).

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was the successful external cephalic version. The summary measures were reported as relative risk or as mean differences with a 95% confidence interval.

TABULATION, INTEGRATION, AND RESULTS

Nine randomized clinical trials (934 women) were included in this review. Women who received neuraxial analgesia had a significantly higher incidence of successful external cephalic version (58.4% vs 43.1%; relative risk, 1.44, 95% confidence interval, 1.27-1.64), cephalic presentation in labor (55.1% vs 40.2%; relative risk, 1.37, 95% confidence interval, 1.08-1.73), and vaginal delivery (54.0% vs 44.6%; relative risk, 1.21, 95% confidence interval, 1.04-1.41) compared with those who did not. Women who were randomized to the intervention group also had a significantly lower incidence of cesarean delivery (46.0% vs 55.3%; relative risk, 0.83, 95% confidence interval, 0.71-0.97), maternal discomfort (1.2% vs 9.3%; relative risk, 0.12, 95% confidence interval, 0.02-0.99), and lower pain, assessed by the visual analog scale pain score (mean difference, -4.52 points, 95% confidence interval, -5.35 to 3.69) compared with the control group. The incidences of emergency cesarean delivery (1.6% vs 2.5%; relative risk, 0.63, 95% confidence interval, 0.24-1.70), transient bradycardia (11.8% vs 8.3%; relative risk, 1.42, 95% confidence interval, 0.72-2.80), nonreassuring fetal testing, excluding transient bradycardia, after external cephalic version (6.9% vs 7.4%; relative risk, 0.93, 95% confidence interval, 0.53-1.64), and abruption placentae (0.4% vs 0.4%; relative risk, 1.01, 95% confidence interval, 0.06-16.1) were similar.

CONCLUSION

Administration of neuraxial analgesia significantly increases the success rate of external cephalic version among women with malpresentation at term or late preterm, which then significantly increases the incidence of vaginal delivery.

Outcomes of non-vertex second twins, following vertex vaginal delivery of first twin: a secondary analysis of the WHO Global Survey on maternal and perinatal health

BACKGROUND

Mode of delivery remains a topic of debate in vertex/non-vertex twin pregnancies. We used the WHO Global Survey dataset to determine the risk of adverse maternal/perinatal outcomes associated with presentation of the second twin, following vaginal delivery of a vertex first twin.

METHODS

We analysed a derived dataset of twin pregnancies ≥ 32 weeks gestation where the first twin was vertex and delivered vaginally. Maternal, delivery and neonatal characteristics and adverse outcomes were reported by presentation of the second twin. Logistic regression models (adjusted for maternal and perinatal confounders, mode of delivery and region) were developed to determine odds of adverse outcomes associated with presentation.

RESULTS

1,424 twin pregnancies were included, 25.9% of these had a non-vertex second twin and Caesarean was more common in non-vertex presentations (6.2% vs 0.9%, p < 0.001). While the odds of Apgar < 7 at 5 minutes were higher in non-vertex presenting second twins (16.0% vs 11.4%, AOR 1.42 95% CI 1.01-2.00), the odds of maternal ICU admission (4.6% vs 1.7%, AOR 1.30, 95% CI 0.88-1.94), blood transfusion (6.0% vs 3.4%, AOR 1.23, 95% CI 0.67-2.25), stillbirth (7.6% vs 4.7%, AOR 1.15, 95% CI 0.72-1.73), early neonatal death (3.8% vs 2.1%, AOR 1.68, 95% CI 0.96-2.94), and NICU admission (26.6% vs 23.2%, AOR 0.93, 95% CI 0.62-1.39) were not.

CONCLUSION

After a vaginal delivery of a vertex first twin, non-vertex presentation of the second twin is associated with increased odds of Apgar <7 at 5 minutes, but not of other maternal/perinatal outcomes. Presentation of the second twin is not as important a consideration in planning twin vaginal birth as previously considered.

Association between Offset of the Pupil Center from the Corneal Vertex and Wavefront Aberration

Purpose

To investigate the influence of offsets of the pupil center from the corneal vertex on wavefront aberrations in the anterior cornea and the whole eye.

Methods

Both right and left eyes of 103 subjects were measured for the wavefront aberrations in the anterior cornea, along with the offset of the pupil center relative to the corneal vertex, using a Humphrey corneal topographer, and for the wavefront aberration in the whole eye using a WASCA wavefront sensor. Correlations of the pupil center offsets with the Zernike aberrations were tested.

Results

X-axis shift of the pupil center from the corneal vertex was significantly correlated to horizontal coma for both the right (r = 0.54, P<0.0001) and left eyes (r=0.48, P<0.0001) in the cornea, but was weakly correlated to the coma in the whole eye (r=0.17, P=0.04 for OD; and r=0.17, P=0.05 for OS). Significant but weak correlations with the x-axis pupil center shift were also found for several other Zernike aberrations, including the oblique astigmatism, vertical trefoil and secondary astigmatism. Very few Zernike aberrations were significantly correlated to y-axis pupil center shift. Most Zernike aberrations were significantly correlated between the right and left eyes to produce bilateral symmetry in the cornea and the whole eye.

Conclusions

The results suggest that offset of the pupil center from the corneal vertex plays an important role in determining horizontal coma and few other Zernike aberrations. Factors controlling bilateral symmetry of the wavefront aberrations between the two eyes could make important contributions to wavefront aberrations in the human eye.