Normally the newly born child begins to cry almost immediately after its exit from the vulva. This act indicates the establishment of respiration, which is accompanied by important modifications in the circulatory system.
—J. Whitridge Williams (1903)
In most instances at delivery, the newborn is healthy and vigorous, but at times, special care may be needed. For this reason, the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2017b) recommend that every birth should be attended by at least one qualified individual. This person should be skilled in the initial steps of newborn care and positive-pressure ventilation, and their only responsibility is management of the newborn. This usually is a pediatrician, nurse practitioner, anesthesiologist, nurse anesthetist, or specially trained nurse. However, in their absence, the responsibility for neonatal resuscitation falls to the obstetrical attendant. Thus, obstetricians should be well versed in measures for immediate care of the newborn.
The number and qualifications of personnel who attend the delivery will vary depending on the anticipated risk, the number of babies, and the hospital setting. A qualified team with full resuscitation skills should be present for high-risk deliveries and immediately available for every resuscitation (Wyckoff, 2015). This team should not be on call at home or in a remote area of the hospital. Moreover, team training through frequent simulation practice is recommended for all who may be called to attend deliveries (Perlman, 2015).
TRANSITION TO AIR BREATHING
Immediately following birth, the newborn must promptly convert from placental to pulmonary gas exchange. Pulmonary vascular resistance must fall, pulmonary perfusion must rapidly rise, and unique fetal vascular shunts must begin to close to separate the systemic and pulmonary circulations (Rudolph, 1979). These shunts include the patent ductus arteriosus and patent foramen ovale, described in Chapter 7 (Cardiovascular System). Lung aeration is not only critical for pulmonary gas exchange. Recent studies suggest that it is significantly responsible for initiating cardiovascular changes at birth (Hooper, 2016).
In utero, the fetal lungs are filled with amnionic fluid, which must be cleared quickly for air breathing. This clearance occurs through various means, and the contributions of these mechanisms may depend on gestational age and mode of delivery. First, a large release of fetal adrenaline late in labor stimulates pulmonary epithelial cells to stop secreting and instead to start reabsorbing lung liquid as a result of sodium-channel activation (te Pas, 2008). The contribution of this mechanism is unlikely to be major, as blockade of the receptors for sodium channel activation reduces or delays but does not prevent lung liquid clearance at birth (O’Brodovich, 1990).
As a second method, mechanical forces aid lung fluid clearance during labor. Early reports described compression of the fetal thorax and abdomen as they passed through the birth canal leading to ...