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Alternatively cholesterol hoax 60 pills abana sale, the surviving twin can be seriously damaged (see Embryonic and Fetal Demise) cholesterol levels in food buy abana 60pills visa. In contrast to structural malformations foods for high cholesterol diet buy abana us, chromosomal anomalies are not more frequent among multiples cholesterol levels in pregnancy 60pills abana visa. Each member of the multiple gestation has the same maternal ageependent risk for trisomy 21. By probability calculations, the risk for a mother that one of her twins will have trisomy 21 is greater, however, than that of a mother of a singleton who is at the same age. A 32-year-old mother of twins has approximately the same risk of one infant with trisomy 21 as a 35-year-old mother of a singleton. In addition, echocardiography and Doppler velocimetry can detect structural and functional cardiovascular anomalies. In multichorionic multiples, reduction is accomplished by ultrasound-guided intracardiac injection of potassium chloride. All invasive procedures (amniocentesis, chorionic villus sampling, and reduction methods) are associated with the risk of 5% to 10% of membrane rupture and loss of the entire pregnancy. When one twin is anencephalic, the risk of reducing this twin should be weighed against the risk of endangering the normal fetus by preterm birth. First it is possible that the twins share unequal placental territories that inevitably lead to discordant growth. Twin-twin transfusion syndrome is seen mainly (or only) in the diamniotic variety. The hypovolemia of the donor is manifested by poor micturition (absent bladder and oligohydramnios on ultrasound scan) and signs of growth restriction. Conversely the hypervolemic recipient is surrounded by polyhydramnios and manifests signs of cardiac overload ranging from tricuspid regurgitation to cardiac insufficiency and hydrops fetalis. No single therapy has emerged as a treatment of choice with significantly better short-term results, which puts the clinician in a difficult position vis-is the patient. More recent data suggest, however, that longterm outcomes are better with laser occlusion than with amnioreduction (see Chapter 14). However, most authorities maintain that laser treatment after 27 to 28 weeks is too risky and advocate elective preterm delivery thereafter. The early loss of one twin was eventually designated "vanishing" twin syndrome to denote the disappearance of an embryonic structure during the first trimester. The true frequency of vanishing twin syndrome is unknown because many twin gestations remain unnoticed unless sonography is performed at an early stage. One estimate of frequency of vanishing twin syndrome comes from iatrogenic conceptions: Spontaneous reduction of one or more gestational sacs or embryos occurred before the 12th week of gestation in 36% of twin, 53% of triplet, and 65% of quadruplet gestations. Historically it was believed that some ill-defined thromboplastin-like material is transfused from the dead to the live fetus-the twin embolization syndrome. The theory was that these emboli might cause fetal death or result in end-organ damage, such as brain and kidney lesions. In the early 1990s, after meticulous postmortem examinations, the embolic theory was replaced by the ischemic theory, which postulates that blood is acutely shunted from the live twin to the low-resistance circulation of the deceased fetus, causing acute hypovolemia, ischemia, and end-organ damage in the survivor. The chance of serious damage in the survivor is significant and estimated to be 20% to 30%, although more recent estimations suggest lower figures. Data suggest that acute blood loss occurs just before the time of death of the surviving twin, and it is unlikely that immediate delivery of the surviving twin could decrease the associated high mortality and morbidity rates. Because we are unable to predict accurately which case is going to deteriorate over time, waiting may mean delivery of more mature twins who are in a worse or worsening condition. In addition, discordant fetal conditions remote from term pose difficult ethical questions: Waiting increases the risk for fetal death and long-term morbidity for the ailing twin, whereas pregnancy termination by cesarean section exposes both twins to the risk of preterm delivery. The neonates may present with some of the problems that the twins acquired in utero, such as cardiac decompensation and renal problems. The donor twin might be acutely distressed, with severe anemia and hypovolemic shock necessitating transfusion or exchange of blood products, or both. The recipient occasionally requires partial dilution exchange and support for cardiac failure (see Chapter 89). Thereafter, during the third trimester, growth curves of multiples show a clear decelerating trend compared with the growth curve of singletons. The limited uterine capacity to nurture multiples leads to growth aberrations (see Chapter 16). When one analyzes a large series of multiples, one rarely finds that all members of the set have the same birth weight. Some variation is expected between siblings, and the magnitude of the difference-the degree of discordance-must be incorporated in the definition. The most common definition of discordance is the percent definition, whereby the birth weight disparity is calculated as a percentage of the larger infant. The definition does not refer to the actual size of the twins, however, and it can assign the same degree of discordance. The cumulative frequency19 shows that about 75% of twins exhibit less than 15% discordance, about 20% are 15% to 25% discordant, and about 5% are more than 25% discordant. Clinicians usually employ the same percent definition used for twins and calculate the difference between the largest and smallest triplet of each set, although this scheme ignores the middle-sized triplet and the true intertriplet relationship. A new description was developed in which the relative birth weight of the middle triplet was defined. The frequencies of different types of triplet discordance did not change with gestational age, suggesting three distinct types of discordant growth in triplets that are independent of gestational age (average values-symmetric 57%, high-skew 30%, low-skew 13%). It has been determined, however, that at lower levels of discordance either twin can be the smaller, but the likelihood of the second-born twin being the smaller increases with increasing discordance levels. In the lowest levels (probably <25%), discordance seems to be related to the normal variation expected from the natural dissimilarities between siblings. In the highest level (probably >35%), discordance seems to be related to the exhausted uterine environment and reflects growth restriction.

By some interpretations cholesterol total buy cheap abana 60pills on-line, malpractice is also considered a type of breach of contract with the patient cholesterol medication for stroke buy abana 60 pills low price, so the defendant is technically being accused of committing a tort and violating contract law cholesterol levels requiring statins order 60 pills abana with amex. Lawyers cholesterol test not fasting effects generic 60pills abana with mastercard, accountants, physicians, and other professionals are held to a certain level of conduct. The trial court ruled, and the Kansas Supreme Court agreed, that the delivering physician had a duty to inform the woman of her hepatitis B status. The Supreme Court stated, "A physician who has a doctorpatient relationship with a pregnant woman who intends to carry her fetus to term and deliver a healthy baby also has a doctor-patient relationship with the fetus. On many transports, the responsible physician at the receiving facility is not physically present with the transport team. The receiving physician often begins to offer clinical advice, however, when first contact is initiated by the referring facility. The referring physician and the receiving physician may have a duty to the patient. The receiving physician may have no duty to the patient, however, if the receiving physician is acting more in the role of a consultant. The husband sued the receiving hospital, alleging negligent advice given over the phone. The court determined that there was no physician-patient relationship between the receiving physician and the pregnant woman. Because the receiving physician was acting more in the role of a consultant and the referring physician was free to make his own management decisions, the court ruled that the receiving physician did not have a duty to the pregnant woman. The court determined that no duty existed between the receiving facility and the patient. If a neonatologist has privileges only at hospital A, and the physician is called and refuses to attend a high-risk delivery at hospital B, the physician likely would have no professional relationship with the pregnant woman or her infant at hospital B. The neonatologist cannot breach his or her duty if no duty to the defendant exists. This concept of duty is separate from the moral or ethical obligation to provide care. Does a physician caring for a pregnant woman have a duty to the newborn even after the infant is born and being cared for by another physician Many of these issues have to do with licensure, credentialing, and reimbursement as well as liability. For example, a physician based in state A who cares for a patient via telemedicine located in state B may be found to be practicing without a license and subject to disciplinary action in state A as well as medically liable in state B. Colorado, for example, requires that "Any health benefits provided through telemedicine shall meet the same standard of care as for in-person care. There is little question that telemedicine has significant potential to improve quality and access to care for patients, especially in underserved areas. Given the legal risks, however, it is important to seek legal counsel and be aware of relevant laws and regulations. In contrast to this case, if a neonatologist is formally consulted and speaks with a family and makes recommendations concerning management, there may be a duty to the mother and her infant. Judicial decisions also seem to hinge on whether or not a consulting physician is recommending a specific course of therapy or merely making suggestions that the original physician either can follow or can ignore. Generally it is not difficult for a plaintiff to establish that a clinician had a duty to the patient. Usually the physician has provided care to the patient, and the plaintiff easily establishes that the duty requirement has been met. Especially in the case of hospital-based physicians, such as neonatologists, the element of "duty" is generally established. In many malpractice suits involving obstetricians, perinatologists, and neonatologists, considerable emphasis is placed on this element. If the defense can prove that the physician acted within the standard of care, the plaintiff cannot successfully maintain a malpractice action. In Brownsville Pediatric Associates v Reyes,20 a pediatrician was found liable for substandard ventilator management. In this case, the neonatologist apparently provided all necessary referrals and documentation, and she was not named in the resulting suit. Among the determining factors, courts seem to evaluate the formality of the consultation and the presence or absence of contact between the parties. Given the facts, the court concluded that no physician-patient relationship existed between the neonatologist and the family. The court concluded that the neonatologist did not prescribe a course of treatment, but rather gave recommendations that could be accepted or rejected by the obstetrician. The lay juror understands that one should not walk down the street with closed eyes because someone else could be injured as a result. In medical malpractice cases, however, the lay juror generally does not have a grasp of "reasonable care under the circumstances. To serve as an expert witness, an individual must have specific knowledge and training that qualifies him or her to serve in this capacity. The Rhode Island statute,68 for example, states "only those persons who by knowledge, skill, experience, training, or education qualify as experts in the field of the alleged malpractice. It is the role of the expert witnesses to educate the jury so that the jurors have a grasp of what is (and is not) reasonable care under the circumstances. After the expert witnesses are examined and cross-examined, it is up to the jury (or arbitrators) to decide whether the clinician committed a breach in the standard of care.

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As the obturator nerve enters the thigh cholesterol level medication required proven 60 pills abana, it divides into two branches cholesterol test black coffee cheap abana american express, an anterior branch and a posterior branch high cholesterol foods bananas buy discount abana 60 pills, which are separated by the adductor brevis muscle: the posterior branch descends behind the adductor brevis muscle and on the anterior surface of the adductor magnus muscle ideal cholesterol ratio ldl hdl generic abana 60 pills without a prescription, and supplies the obturator externus and adductor brevis muscles and the part of adductor magnus that attaches to the linea aspera. The anterior branch descends on the anterior surface of the adductor brevis muscle and is behind the pectineus and adductor longus muscles-it supplies branches to the adductor longus, gracilis, and adductor brevis muscles, and often contributes to the supply of the pectineus muscle, and cutaneous branches innervate the skin on the medial side of the thigh. Ps oas and iliacus mus cles Obturator nerve Obturator externus mus cle Pos terior branch Anterior branch Pectineus mus cle Adductor brevis mus cle Cutaneous branch Adductor longus mus cle Branch to adductor magnus from pos terior branch Gracilis mus cle Adductor magnus mus cle Sciatic nerve the sciatic nerve is a branch of the lumbosacral plexus (spinal cord segments L4-S3) and descends into the posterior compartment of thigh from the gluteal region. It innervates all muscles in the posterior compartment of thigh and then its branches continue into the leg and foot. In the posterior compartment of thigh, the sciatic nerve lies on the adductor magnus muscle and is crossed by the long head of biceps femoris muscle. Proximal to the knee, and sometimes within the pelvis, the sciatic nerve divides into its two terminal branches: the tibial nerve and the common bular nerve. These nerves travel vertically down the thigh and enter the popliteal fossa posterior to the knee. The tibial nerve supplies branches to all muscles in the posterior compartment of thigh (long head of biceps. The detailed movements of the knee joint are complex, but basically the joint is a hinge joint that allows mainly exion and extension. The joint consists of: the articulation between the femur and tibia, which is weight bearing, and the articulation between the patella and the femur, which allows the pull of the quadriceps femoris muscle to be directed anteriorly over the knee to the tibia without tendon wear. Articular surfaces the articular surfaces of the bones that contribute to the knee joint are covered by hyaline cartilage. The major surfaces involved include: the two femoral condyles, and the adjacent surfaces of the superior aspect of the tibial condyles. The surfaces of the femoral condyles that articulate with the tibia in exion of the knee are curved or round, whereas the surfaces that articulate in full extension are at. The articular surfaces between the femur and patella are the V-shaped trench on the anterior surface of the distal end of the femur where the two condyles join and the adjacent surfaces on the posterior aspect of the patella. The joint surfaces are all enclosed within a single articular cavity, as are the intra-articular menisci between the femoral and tibial condyles. The tibial nerve descends through the popliteal fossa, enters the posterior compartment of leg, and continues into the sole of the foot. The tibial nerve innervates: all muscles in the posterior compartment of leg, all intrinsic muscles in the sole of the foot except for the rst two dorsal interossei muscles, which are innervated by the deep bular nerve, and skin on the posterolateral side of the lower half of the leg and lateral side of the ankle, foot, and little toe, and skin on the sole of the foot and toes. The common bular nerve supplies the short head of biceps femoris in the posterior compartment of thigh and then continues into the lateral and anterior compartments of leg and onto the foot. The common bular nerve innervates: all muscles in the anterior and lateral compartments of leg, Menisci There are two menisci, which are brocartilaginous C-shaped cartilages, in the knee joint, one medial (medial meniscus) and the other lateral (lateral meniscus). Both are attached at each end to facets in the intercondylar region of the tibial plateau. The medial meniscus is attached around its margin to the capsule of the joint and to the tibial collateral ligament, whereas the lateral meniscus is unattached to the capsule. The menisci are interconnected anteriorly by a transverse ligament of the knee. The lateral meniscus is also connected to the tendon of the popliteus muscle, which passes superolaterally between this meniscus and the capsule to insert on the femur. The menisci improve congruency between the femoral and tibial condyles during joint movements where the surfaces of the femoral condyles articulating with the tibial plateau change from small curved surfaces in exion to large at surfaces in extension. The two cruciate ligaments, which attach in the intercondylar region of the tibia below and the intercondylar fossa of the femur above, are outside the articular cavity, but enclosed within the brous membrane of the knee joint. Anteriorly, the synovial membrane is separated from the patellar ligament by an infrapatellar fat pad. On each side of the pad, the synovial membrane forms a fringed margin (an alar fold), which projects into the articular cavity. In addition, the synovial membrane covering the lower part of the infrapatellar fat pad is raised into a sharp midline fold directed posteriorly (the infrapatellar synovial fold), which attaches to the margin of the intercondylar fossa of the femur. The synovial membrane of the knee joint forms pouches in two locations to provide low friction surfaces for the movement of tendons associated with the joint: the small subpopliteal recess. The apex of this bursa is attached to the small articularis genus muscle, which pulls the bursa away from the joint during extension of the knee. Other bursae associated with the knee, but not normally communicating with the articular cavity include the subcutaneous prepatellar bursa, deep and subcutaneous infrapatellar bursae, and numerous other bursae associated with tendons and ligaments around the joint. The deep and subcutaneous infrapatellar bursae are on the deep and subcutaneous sides of the patellar ligament, respectively. Pos terior cruciate ligament Patella Anterior cruciate ligament Fibular collateral ligament Tendon of popliteus mus cle Lateral menis cus Proximal tibiofibular joint Patellar ligament Infrapatellar fat. Femur Patella Menis cus Tibia Flat Round A Surface for articulation with patella Intercondylar region Anterior cruciate ligament Menis cus B Patella Flat s urfaces for articulation with tibia in extens ion Pos terior cruciate ligament Round s urfaces for articulation with tibia in flexion Lateral menis cus Popliteus tendon Infrapatellar fat Trans vers e ligament Patellar ligament J oint caps ule C Medial menis cus. Vas tus medialis mus cle Vas tus lateralis mus cle Iliotibial tract Fibular collateral ligament Patellar ligament Gracilis Sartorius Popliteus mus cle Quadriceps femoris tendon Tibial collateral ligament Semitendinos us Semimembranos us tendon Oblique popliteal ligament A B. Fibrous membrane the brous membrane of the knee joint is extensive and is partly formed and reinforced by extensions from tendons of the surrounding muscles. In general, the brous membrane encloses the articular cavity and the intercondylar region. Laterally, the external surface of the brous membrane is separated by a space from the bular collateral ligament and the internal surface of the brous membrane is not attached to the lateral meniscus. Anteriorly, the brous membrane is attached to the margins of the patella where it is reinforced with tendinous expansions from the vastus lateralis and vastus medialis muscles, which also merge above with the quadriceps femoris tendon and below with the patellar ligament. The upper end of the popliteus muscle passes through an aperture in the posterolateral aspect of the brous membrane of the knee and is enclosed by the brous membrane as its tendon travels around the joint to insert into the lateral aspect of the lateral femoral condyle.

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These paired venous channels cholesterol lowering drugs chart order generic abana from india, which begin as small veins natural cholesterol lowering foods supplements safe 60pills abana, come together at or just superior to the hyoid bone nutrition top 10 cholesterol lowering foods purchase abana 60pills otc. Once formed cholesterol ratio of 2.1 buy discount abana 60pills on-line, each anterior jugular vein descends on either side of the midline of the neck. Inferiorly, near the medial attachment of the sternocleidomastoid muscle, each anterior jugular vein pierces the investing layer of cervical fascia to enter the subclavian vein. Occasionally, the anterior jugular vein may enter the external jugular vein immediately before the external jugular vein enters the subclavian vein. Often, the right and left anterior jugular veins communicate with each other, being connected by a jugular venous arch in the area of the suprasternal notch. Anterior triangle of the neck the anterior triangle of the neck is outlined by the anterior border of the sternocleidomastoid muscle laterally, the inferior border of the mandible superiorly, and the midline of the neck medially. It is further subdivided into several smaller triangles as follows: the submandibular triangle is outlined by the inferior border of the mandible superiorly and the anterior and posterior bellies of the digastric muscle inferiorly. The submental triangle is outlined by the hyoid bone inferiorly, the anterior belly of the digastric muscle laterally, and the midline. The muscular triangle is outlined by the hyoid bone superiorly, the superior belly of the omohyoid muscle, and the anterior border of the sternocleidomastoid muscle laterally, and the midline. Clinical app Central venous access In most instances, access to peripheral veins of the arm and the leg will suf ce for administering intravenous drugs and uids and for obtaining blood for analysis. Stylohyoid mus cle Pos terior belly of digas tric mus cle Submandibular triang le Each of these triangles contains numerous structures that can be identi ed as being within a speci c triangle, passing into a speci c triangle from outside the area, originating in one triangle and passing to another triangle, or passing through several triangles while passing through the region. A discussion of the anterior triangle of the neck must therefore combine a systemic approach, describing the muscles, vessels, and nerves in the area, with a regional approach, describing the contents of each triangle. Anterior belly of digas tric mus cle Subme ntal triang le Hyoid bone Mus c ular triang le Superior belly of omohyoid mus cle Sternocleidomas toid mus cle Caro tid triang le Po s the rio r triang le Trapezius mus cle Muscles the muscles in the anterior triangle of the neck (Table 8. Muscles inferior to the hyoid are infrahyoid muscles and include the omohyoid, sternohyoid, thyrohyoid, and sternothyroid. Suprahyoid muscles the four pairs of suprahyoid muscles are in the submental and submandibular triangles (Table 8. The stylohyoid muscle arises from the base of the styloid process and passes anteroinferiorly to attach to the lateral area of the body of the hyoid bone (Table 8. The digastric muscle has anterior and posterior bellies connected by a tendon, which attaches to the body of the hyoid bone (Table 8. Because of this arrangement, the muscle has multiple actions depending on which bone is xed. The mylohyoid muscle is superior to the anterior belly of the digastric and, with its partner from the opposite side, forms the oor of the mouth (Table 8. The mylohyoid muscle supports and elevates the oor of the mouth and elevates the hyoid bone. The geniohyoid muscle is superior to the oor of the oral cavity and is not generally considered a muscle of the anterior triangle of the neck; however, it can be regarded as a suprahyoid muscle. Infrahyoid muscles Hyoid bone Thyroid cartilage Omohyoid mus cle Cricoid cartilage Sternohyoid mus cle Internal jugular vein Thyrohyoid mus cle Common carotid artery Sternothyroid mus cle the four infrahyoid muscles are in the muscular triangle (Table 8. Because of their appearance, they are sometimes referred to as the "strap muscles. This muscle consists of two bellies with an intermediate tendon and is in both the posterior and anterior triangles of the neck. The thyrohyoid muscle is deep to the superior parts of the omohyoid and sternohyoid (Table 8. The thyrohyoid muscle depresses the hyoid, but when the hyoid is xed it raises the larynx. Lying beneath the sternohyoid and, in continuity with the thyrohyoid, the sternothyroid is the last muscle in the infrahyoid group (Table 8. Vessels Passing through the anterior triangle of the neck are the common carotid arteries and their branches, the external and internal carotid arteries. Associated with this arterial system are the internal jugular vein and its tributaries. Carotid system Common carotid arteries the common carotid arteries are the beginning of the carotid system. The left common carotid artery begins in the thorax as a direct branch of the arch of the aorta and passes superiorly to enter the neck near the left sternoclavicular joint. Both right and left common carotid arteries ascend through the neck, just lateral to the trachea and esophagus, within a fascial compartment (the carotid sheath). Near the superior edge of the thyroid cartilage each common carotid artery divides into its two terminal branches-the external and internal carotid arteries. At the bifurcation, the common carotid artery and the beginning of the internal carotid artery are dilated. Another accumulation of receptors in the area of the bifurcation is responsible for detecting changes in blood chemistry, primarily oxygen content. Internal carotid arteries After its origin, the internal carotid artery ascends toward the base of the skull. It gives off no branches in the neck and enters the cranial cavity through the carotid canal in the petrous part of the temporal bone.

The list of clinical scenarios in which it has been utilized includes the evaluation of the fetal middle cerebral artery in cases of red blood cell isoimmunization cholesterol medication grapefruit effective abana 60pills,20 monochorionic twins with twin-twin transfusion syndrome total cholesterol level definition 60pills abana with amex,28 the screening and diagnosis of congenital cardiac anomalies cholesterol bumps purchase 60 pills abana fast delivery, and the diagnosis of congenital vascular anomalies cholesterol hypertension medication order abana mastercard. However, the primary utility of Doppler sonography is in the evaluation of a fetus with possible intrauterine growth restriction. In normal pregnancies or when the fetus has demonstrated normal growth, there is no current role for Doppler sonography of fetal vessels because they have not been found to convey benefit in a low-risk population. Although more extreme biometric deviations are usually pathologic, many fetuses with ultrasound weight estimations at the fifth to tenth percentile will be small but healthy. In these cases, either the ultrasound weight estimation is incorrect or the true birth weight is less than 10% but the fetus is just an otherwise healthy outlier of the normal weight distribution. Doppler sonography of fetal vessels in these circumstances can potentially identify the fetuses that are healthy, thus avoiding iatrogenic prematurity and additional antenatal testing. In cases of suspected growth restriction, abnormal blood flow in the umbilical artery is associated with increased risk of perinatal morbidity and mortality. A Cochrane review of 11 randomized trials showed a trend toward decreased perinatal mortality with the use of Doppler assessment of the umbilical artery in high-risk pregnancies. Pathologic placental processes such as thrombosis and infarction decrease the relative size of the placental vascular bed and increase placental vascular resistance. As placental vascular resistance increases, there is a progressive diminution of blood flow during diastole, resulting in an altered ratio of systolic (S) and diastolic (D) blood flow that can be detected with Doppler sonography (Figure 13-3). Numerically, this can be quantified as either the systolic/diastolic (S/D) ratio, resistance index ([S-D]/S), or pulsatility index ([S-D]/average blood flow). Abnormal umbilical artery Doppler S/D ratios imply placental vascular pathology, although the test does not otherwise specifically address the immediate state of fetal oxygenation or health. Many individuals with mild elevations of the S/D ratio will deliver healthy babies at term, which is why Doppler sonography is discouraged in low-risk patients or those with normal fetal biometric evaluations. Additionally, the fetal status can be evaluated through Doppler sonography of additional fetal vessels beyond the umbilical artery. Turan and colleagues serially evaluated 104 fetuses with uteroplacental insufficiency and growth restriction and performed sonography on the middle cerebral artery, umbilical artery and vein, and ductus venosus until the patient was delivered. In response to increasing hypoxia, blood flow is diverted away from nonvital organs such as the kidney (resulting in oligohydramnios) and preferentially toward vital organs such as the brain, a process referred to as cephalization. The increased cerebral blood flow can be reflected in a decreasing pulsatility index in the fetal middle cerebral artery (Figure 13-5). The absence of cephalization can be reassuring, although it should be noted that it can sometimes be absent in critically ill fetuses that have lost the ability to preferentially direct their blood flow. More severe degrees of hypoxia eventually generate myocardial decompensation, which can be evaluated through the Doppler evaluation of the ductus venosus and umbilical artery. Just as jugular Figure 13-5 Ultrasoundimageofthefetalcerebralvasculature,with Doppler visualization of the middle cerebral artery and measurement ofthepeaksystolicvelocity. Noninvasive tests to predict fetal anemia: a study comparing Doppler and ultrasound parameters. When present these can be an ominous finding, with delivery often being necessitated within a few days. While normal Doppler results in a fetus with concerning biometric measurements signal that a pregnancy can safely continue, the optimal management of a fetus with abnormal Doppler studies is far from clear. If other tests of fetal well-being (nonstress test, biophysical profile) are not reassuring, then delivery is usually indicated. Likewise, abnormal Doppler results can be used to guide the frequency of antepartum testing. On the other hand, many fetuses with absent or reverse umbilical artery diastolic flow can safely remain in utero for even several weeks. When corrected for congenital anomalies and unpredictable causes of intrauterine death, the rate of stillbirth in the tested population (after antepartum testing with normal results) has been reported to be approximately 1. The false-positive rate is more difficult to ascertain because a positive test usually results in obstetric intervention, significantly decreasing the likelihood of intrauterine death. There was a significant inverse linear association, however, between biophysical profile score and these markers, and all fetuses with scores of 0 had at least one of these markers at delivery. Labile conditions may merit more frequent testing; the frequency is left to the discretion of the physician. Clinically, one should always give consideration to maternal illness as a cause of nonreassuring fetal status. For example, if the mother is acidemic from any etiology, placental equilibration will eventually lead to acidemia in an otherwise healthy fetus, which in turn can lead to abnormal antenatal testing results. In such circumstances, the appropriate course of action is to correct the maternal condition first and not to necessarily directly intervene on behalf of the fetus despite the nonreassuring antenatal testing. The fetal status will improve as the maternal status is improved, thus avoiding iatrogenic delivery, and cesarean sections or other efforts to deliver the fetus may not be safe if the mother is critically ill. Evaluation of the Intrapartum Fetus the process of labor and delivery is a period of significant metabolic stress for both the laboring mother and her baby, although in the great majority of cases these stressors are easily tolerated and labor results in a perfectly healthy mother and child. In some cases, however, the process is tolerated poorly and the fetus develops a degree of acidosis that places it at risk of multiorgan dysfunction or even death. What is more easily and often evaluated, however, is decreased oxygenation or pH in the peripheral blood, referred to respectively as hypoxemia and acidemia. These are what is measured when the blood from the umbilical artery and vein is sampled after delivery, and thus serve as common surrogate outcomes in clinical research. Although significant hypoxemia will eventually lead to tissue-level hypoxia and acidosis, the presence of the former does not necessarily guarantee the latter. Although hypoxemia and acidemia can be easily evaluated by laboratory methods, determining the presence or absence of hypoxia or acidosis is more complex and often involves physical and clinical more so than laboratory assessments. Another important differentiation is between respiratory and metabolic acidosis in the fetus and neonate. The concept of a "respiratory" acidosis in a fetus may seem unusual, because they are not literally using their lungs to exchange air, although the same concepts that are useful outside of the uterus can be applied to the transplacental exchange of oxygen and carbon dioxide.

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