Seminars in perinatology
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The optimal mode of delivery when periviable birth is anticipated has been the subject of considerable discussion. Potentially, cesarean delivery could avert intrapartum fetal trauma and asphyxia and allow timed delivery to assure readiness of neonatal intensive care resources. However, cesarean delivery in the early preterm period commonly necessitates a classical vertical uterine incision involving the fundus with its associated acute and long-term risks to the mother and future pregnancies. ⋯ Randomized controlled trials of adequate size regarding this issue are lacking. Data from retrospective and observational studies do not support routine cesarean delivery for all early preterm infants. Cesarean delivery may offer survival advantage to the periviable growth-restricted infant regardless of fetal presentation and appears to offer survival benefit to the malpresenting fetus.
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Seminars in perinatology · Dec 2013
ReviewPeriviable births: epidemiology and obstetrical antecedents.
Confusion in terminology and non-standardized definitions can arguably be classified as the most important characteristics that lead to disparate study findings. While such situations abound in all of perinatal epidemiology, the study of "periviable birth" is a classic case in point. The most common term used to describe periviable birth has been extremely low birthweight (ELBW), often defined as newborns with birthweight below 1000g; yet, we identified 11 other descriptors for periviable birth. ⋯ Six clinical interventions before delivery that may improve outcomes include transfer of patient to a tertiary center, administration of antenatal corticosteroids, tocolytics, or antibiotics after premature rupture of membranes, assessment of fetal well-being with electronic fetal heart rate monitoring, and willingness to perform a cesarean delivery after the limit of viability is reached. While there is an accessible predictive model for mortality and long-term morbidities for newborns delivered at 22-25 weeks with weights of 400-1000g, it is hampered by the need to know the birthweight. In addition to reaching a consensus regarding what birthweight-gestational age thresholds determine a periviable birth, the acute need to optimize neonatal outcomes remains a paramount target worthy of future research, and efforts to advance obstetrical medicine are needed to minimize the likelihood of its occurrence.
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Seminars in perinatology · Dec 2013
ReviewPrevention of periviable birth: bed rest, tocolysis, progesterone, and cerclage.
The periviable period is associated with a rapid improvement in both mortality and morbidity with increasing gestational age. Therapies that can prolong gestation have the potential for markedly improving outcome compared to later in pregnancy. ⋯ These therapies are discussed relative to the periviable period exploring available data and possible impact on perinatal outcome. Studies specifically evaluating therapeutic interventions during the periviable period are lacking.
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Seminars in perinatology · Dec 2013
Periviable births: communication and counseling before delivery.
The potential delivery of an extremely premature infant presents a clinical situation that raises a complex combination of medical, social, ethical, religious, and economic issues. It is a unique medical encounter such that it is not all about "curing" the patient. ⋯ These decisions include but are not limited to place and mode of delivery, resuscitation decisions, and palliative management. Given the urgency of the situation, the emotionally charged nature of the decision, and the relative unpredictability prior to presentation, this particular situation poses unique challenges for all involved and mandates the need to have carefully constructed guidelines and processes for care and counseling that meet the needs of all involved.