Echocardiographic determination of resting haemodynamics and optimal positioning in term pregnant women

Maternal posture-physiology interactions in human pregnancy: a narrative review

There are several well-known medical conditions in which posture and gravity interact with natural history, including pregnancy. In this review, we provide a comprehensive overview of interactions between maternal posture and maternal physiology and pathophysiology at rest during pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 644 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We present a narrative review of the resulting literature and highlight discrepancies, research gaps, and potential clinical implications. We organize the results by organ system and, commencing with the neurological system, proceed in our synthesis generally in the craniocaudal direction, concluding with the skin. The circulatory system warranted our greatest and closest consideration-literature concerning the dynamic interplay between physiology (heart rate, stroke volume, cardiac output, blood pressure, and systemic vascular resistance), pathophysiology (e.g., hypertension in pregnancy), and postural changes provide an intricate and fascinating example of the importance of the subject of this review. Other organ systems discussed include respiratory, renal, genitourinary, gastrointestinal, abdominal, and endocrine. In addition to summarizing the existing literature on maternal posture-physiology interactions, we also point out gaps and opportunities for further research and clinical developments in this area. Overall, our review provides both insight into and relevance of maternal posture-physiology interactions vis à vis healthcare's mission to improve health and wellness during pregnancy and beyond.

Impact of maternal posture on fetal physiology in human pregnancy: a narrative review

In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.

Point of care maternal ultrasound in obstetrics

Ultrasound is the hallmark imaging modality traditionally used by obstetricians for fetal diagnosis and surveillance. The COVID-19 pandemic highlighted the role of point of care ultrasound for expeditious assessment of the maternal cardiopulmonary status. The familiarity of obstetricians with ultrasound, coupled with the availability of ultrasound equipment without the need to transport the patient, make point of care ultrasound particularly valuable in the labor and delivery unit. The rising contribution of cardiopulmonary disorders to maternal morbidity and mortality carves out many potential applications for point of care ultrasound during labor and delivery. Obstetricians have access to the technology and the skills to obtain the basic views required to assess for the presence of pulmonary edema, ventricular dysfunction, or intra-abdominal free fluid. Point of care ultrasound can be used routinely for the evaluation of pulmonary complaints or in the assessment of hypotension and may play an essential role in the diagnosis and management of life-threatening emergencies such as shock, an amniotic fluid embolism, or cardiac arrest. We reviewed the currently established point of care ultrasound protocols for the evaluation of cardiopulmonary complaints through the lens of the obstetrician. We call on educators and academic leaders to incorporate maternal point of care ultrasound teachings into existing curricula. Point of care ultrasound is of enormous value for providers with limited access to diagnostic imaging or subspecialty providers. With the growing complexity of the obstetrical population, acquiring the clinical skills to meet these evolving needs is a requisite step in the ongoing efforts to reduce maternal morbidity and mortality.

Effect of positioning on blood pressure measurement in pregnancy

Blood pressure is the key vital sign to detecting hypertensive disorders in pregnancy. The importance of taking blood pressure properly was recently underscored by the publication of updated ACC/AHA guidelines for measuring blood pressure in patients. However, the recommended position of seating with arms and back supported is not always feasible to achieve clinically, especially for inpatient women who are pregnant. Therefore, it is clinically important to understand the effects of alternative patient positioning on blood pressure measurements. We conducted a review of studies which considered patient position on the effect of blood pressure in pregnancy. This review demonstrates that clinically significant differences may occur based on patient positioning. Despite the small number of primary studies that include pregnant women, notable reductions in blood pressure measurements have been observed in the left lateral recumbent position, a common position during labor or during monitoring, in comparison to measurements taken in the supported seated position. Ultimately, these differences could affect the clinical management of patients and care should be taken to document and consider the position in which the reading was taken.

Cardiopulmonary resuscitation in special circumstances

Cardiopulmonary resuscitation prioritises treatment for cardiac arrests from a primary cardiac cause, which make up the majority of treated cardiac arrests. Early chest compressions and, when indicated, a defibrillation shock from a bystander give the best chance of survival with a good neurological status. Cardiac arrest can also be caused by special circumstances, such as asphyxia, trauma, pulmonary embolism, accidental hypothermia, anaphylaxis, or COVID-19, and during pregnancy or perioperatively. Cardiac arrests in these circumstances represent an increasing proportion of all treated cardiac arrests, often have a preventable cause, and require additional interventions to correct a reversible cause during resuscitation. The evidence for treating these conditions is mostly of low or very low certainty and further studies are needed. Irrespective of the cause, treatments for cardiac arrest are time sensitive and most effective when given early-every minute counts.

Supine hypotensive syndrome of pregnancy: A review of current knowledge

Since the first description of supine hypotensive syndrome in the 1950s, its potentially detrimental effects on otherwise healthy women during late pregnancy have become a persistent challenge in obstetric practice. Establishing a 15° left lateral tilt during labour and caesarean section is a fundamental principle of obstetric care, universally adopted and upheld by current guidelines and recommendations. Reassessment of the original landmark studies in the light of current physiological and anatomical knowledge questions adherence to this standard in clinical practice. The modern practice of providing vasopressor support during caesarean delivery under neuraxial anaesthesia appears to negate any potential negative effects of a maternal full supine position. Recent MRI studies provide evidence as to the cause of supine hypotension and the physiological effects of different maternal positions at term. This review highlights current data on the acute supine hypotensive syndrome in contrast to traditional knowledge and established practice.