Management of Spontaneous Vaginal Delivery.

Pregnancy dating is determined by the patient's last menstrual period or an ultrasound measurement. A full-term pregnancy is considered 37 weeks' gestation or more. Spontaneous labor begins when regular painful uterine contractions result in a cervical change. Active labor begins at 6 cm dilation and is marked by more predictable, accelerated cervical change. In the absence of pregnancy complications, intermittent fetal auscultation may be considered as an alternative to continuous electronic fetal monitoring, which is associated with a high false-positive rate. Intravenous antibiotic prophylaxis is indicated in patients with group B streptococcus colonization or those at high risk to prevent newborn early-onset group B streptococcus. The likelihood of vaginal delivery is increased by providing continuous nonmedical support during labor, encouraging mobility, and using a peanut ball with epidural analgesia. Neuraxial analgesia is more effective for pain control than systemic opioids and is associated with fewer adverse effects. Delayed pushing during the second stage of labor has risks but does not affect the mode of delivery. Routine oropharyngeal suctioning of the newborn is not recommended, even with meconium-stained amniotic fluid. Delayed cord clamping reduces newborn anemia. Prevention of postpartum hemorrhage in patients at risk includes prophylactic uterotonic administration and controlled cord traction. Perineal lacerations that alter anatomy or are not hemostatic should be repaired. (Am Fam Physician. 2024;109(6):525-532.

Dysmenorrhea.

Dysmenorrhea is common and usually independent of, rather than secondary to, pelvic pathology. Dysmenorrhea occurs in 50% to 90% of adolescent girls and women of reproductive age and is a leading cause of absenteeism. Secondary dysmenorrhea as a result of endometriosis, pelvic anatomic abnormalities, or infection may present with progressive worsening of pain, abnormal uterine bleeding, vaginal discharge, or dyspareunia. Initial workup should include a menstrual history and pregnancy test for patients who are sexually active. Nonsteroidal anti-inflammatory drugs and hormonal contraceptives are first-line medical options that may be used independently or in combination. Because most progestin or estrogen-progestin combinations are effective, secondary indications, such as contraception, should be considered. Good evidence supports the effectiveness of some nonpharmacologic options, including exercise, transcutaneous electrical nerve stimulation, heat therapy, and self-acupressure. If secondary dysmenorrhea is suspected, nonsteroidal anti-inflammatory drugs or hormonal therapies may be effective, but further workup should include pelvic examination and ultrasonography. Referral to an obstetrician-gynecologist may be warranted for further evaluation and treatment.

Thrombotic responses of endothelial outgrowth cells to protein-coated surfaces.

There is significant clinical need for viable small-diameter vascular grafts. While there are many graft biomaterials in development, few have been clinically successful. Evaluation of grafts with a clinically relevant model is needed to drive development. This work examined extracellular matrix coatings on the thrombotic phenotype of endothelial outgrowth cells (EOCs). EOCs were tested on flat plates and tubular grafts. Flat plate studies examined collagen I, collagen IV, fibronectin and α-elastin coatings. EOCs attached or proliferated more readily on collagen I and fibronectin surfaces as determined by total DNA. The production of activated protein C (APC) by EOCs was also dependent on the surface coating, with collagen I and fibronectin displaying a higher activity than both collagen IV and α-elastin on flat plate studies. Based on these results, only collagen I and fibronectin coatings were tested on expanded polytetrafluoroethylene (ePTFE) in the ex vivo model. Tubular samples showed significantly greater tissue factor pathway inhibitor gene expression on collagen I than on fibronectin. Platelet adhesion was not significantly different, but EOCs on collagen I produced significantly lower APC than on fibronectin, suggesting that differences exist between the flat plate and tubular cultures. Overall, while the hemostatic phenotype of EOCs displayed some differences, cell responses were largely independent of the matrix coating. EOCs adhered strongly to both fibronectin- and collagen-I-coated ePTFE grafts under ex vivo (100 ml/min) flow conditions suggesting the usefulness of this clinically relevant cell source, testing modality, and shunt model for future work examining biomaterials and cell conditioning before implantation.

Structural and cellular characterization of electrospun recombinant human tropoelastin biomaterials.

An off-the-shelf vascular graft biomaterial for vascular bypass surgeries is an unmet clinical need. The vascular biomaterial must support cell growth, be non-thrombogenic, minimize intimal hyperplasia, match the structural properties of native vessels, and allow for regeneration of arterial tissue. Electrospun recombinant human tropoelastin (rTE) as a medial component of a vascular graft scaffold was investigated in this study by evaluating its structural properties, as well as its ability to support primary smooth muscle cell adhesion and growth. rTE solutions of 9, 15, and 20 wt% were electrospun into sheets with average fiber diameters of 167 ± 32, 522 ± 67, and 735 ± 270 nm, and average pore sizes of 0.4 ± 0.1, 5.8 ± 4.3, and 4.9 ± 2.4 µm, respectively. Electrospun rTE fibers were cross-linked with disuccinimidyl suberate to produce an insoluble fibrous polymeric recombinant tropoelastin (prTE) biomaterial. Smooth muscle cells attached via integrin binding to the rTE coatings and proliferated on prTE biomaterials at a comparable rate to growth on prTE coated glass, glass alone, and tissue culture plastic. Electrospun tropoelastin demonstrated the cell compatibility and design flexibility required of a graft biomaterial for vascular applications.

Mechanical property characterization of electrospun recombinant human tropoelastin for vascular graft biomaterials.

The development of vascular grafts has focused on finding a biomaterial that is non-thrombogenic, minimizes intimal hyperplasia, matches the mechanical properties of native vessels and allows for regeneration of arterial tissue. In this study, the structural and mechanical properties and the vascular cell compatibility of electrospun recombinant human tropoelastin (rTE) were evaluated as a potential vascular graft support matrix. Disuccinimidyl suberate (DSS) was used to cross-link electrospun rTE fibers to produce a polymeric recombinant tropoelastin (prTE) matrix that is stable in aqueous environments. Tubular 1cm diameter prTE samples were constructed for uniaxial tensile testing and 4mm small-diameter prTE tubular scaffolds were produced for burst pressure and cell compatibility evaluations from 15 wt.% rTE solutions. Uniaxial tensile tests demonstrated an average ultimate tensile strength (UTS) of 0.36±0.05 MPa and elastic moduli of 0.15±0.04 and 0.91±0.16 MPa, which were comparable to extracted native elastin. Burst pressures of 485±25 mm Hg were obtained from 4mm internal diameter scaffolds with 453±74 µm average wall thickness. prTE supported endothelial cell growth with typical endothelial cell cobblestone morphology after 48 h in culture. Cross-linked electrospun rTE has promising properties for utilization as a vascular graft biomaterial with customizable dimensions, a compliant matrix and vascular cell compatibility.