Historical Development on Fetal Medicine and the Fetus as A Patient
Amos Grünebaum
Laurence B. McCullough
Frank A. Chervenak
Introduction
It was not until the mid-20th century that the fetus was considered a patient.1 Until Cesarean deliveries became somewhat safer for the mother, Cesarean deliveries and forceps were done mostly to save a woman’s life, for example, if the pelvis was contracted, labor was too long, or there was sepsis present.2 Even early fetal diagnoses, such as auscultation of the fetal heart rate or x-rays of the fetus, limited the diagnosis of fetal conditions until the early 1950s.
Auscultation of the Fetal Heart Rate and Diagnosis of Fetal Distress
Auscultation of the fetal heart rate was the first method for evaluating the fetus. In 1818,3 a Swiss surgeon reported the presence of fetal heart tones; 3 years later, Lejuma4 suggested auscultation would be helpful in the diagnosis of twins and the fetal lie and its position. In 1833, Kennedy5 suggested that the fetal heart rate was indicative of “fetal distress.” Such distress, if diagnosed late in pregnancy, could be treated using forceps for delivery. However, it was not until relatively recent times that Cesarean delivery was used to manage fetal distress in labor.
In 1870, Schwartz6 described fetal bradycardia following compression of the fetal head, and in 1885, Schatz7 had provided detailed descriptions of umbilical cord compression.
In 1903, Van Winkel8 was the first to postulate that a fetal heart rate over 160 or below 100 beats per minute was presumptive evidence of “fetal distress.” However, Lund9 believed that tachycardia is not as important as bradycardia. In a series of 250 cases, he found a transient tachycardia during labor in 17.6% and persistent tachycardia in 5.6% without any correlation with fetal distress. In addition to fetal bradycardia, passage of meconium in utero was also considered a sign of “fetal distress” for a long time. In 1927, Freed10 reported on clinical signs of fetal distress during labor.
Perhaps the first time that “fetal indication” for performing a Cesarean delivery was used in the literature was in 1953.11 Thus, the fetus did not become a “patient” worthwhile of intervention and treatment prior to delivery until the mid-20th century when Cesarean deliveries and anesthesia were deemed safe enough and potential benefits of Cesarean deliveries for the fetus and baby outweighed potential maternal risks. Douglas and Stromme,12 in their 1957 text Operative Obstetrics, state that “fetal distress was virtually nonexistent as a cause for Cesarean section on our service [New York Hospital] until 10 years ago.”
In 1953 McCall13 reviewed 8,785 deliveries with 173 cases of “fetal distress.” He said that, “…one or more signs commonly accepted as evidence of fetal distress…[were] fetal heart changes, or meconium, or both.” Fitzgerald and McFarland14 emphasized the significance of bradycardia, arrhythmia, and the expulsion of frank meconium as signs of “fetal distress.” Goodlin15 in 1979 provided an extensive review of the history of fetal monitoring
Amniocentesis
In 1923, Boursier and Gautret16 reported on a patient with polyhydramnios who was treated with “abdominal puncture” removing two liters of amniotic fluid for relief of the polyhydramnios.
In 1964, Goodlin17 reviewed diagnostic abdominal amniocentesis and removal of amniotic fluid. He said that visual inspection of the fluid would be informative: yellow fluid could indicate erythroblastosis, green fluid could indicate “fetal distress,” and dark or reddish black fluid could indicate fetal death. In addition, he said that amniotic fluid analysis could be helpful in estimating fetal age and fetal oxidation. In 1982, Romero18 diagnosed umbilical cord lesions by ultrasound, and in 1985, he confirmed that sonographically monitored amniocentesis was safe to decrease intraoperative complications.19 The same year Hobbins reported on percutaneous blood sampling.20
Rh Disease
A major diagnostic step of diagnosing fetal and subsequent neonatal disease was made by Bevis in 1952.21 He documented a correlation between amniotic fluid nonheme iron (obtained by amniocentesis) and the severity of fetal anemia. This pioneering work was amplified by Liley,22 who in 1961 demonstrated that the spectral peak at 450 mU
reflected the severity of hemolysis. This gave the obstetrician a method with which to follow the patient with Rh sensitization and, in some cases, deliver the fetus prematurely for fetal salvage. The next major step in the treatment of these Rh-sensitized fetuses was also made by Liley, who in 1963 demonstrated that one could successfully treat these anemic fetuses in utero by transfusing blood into the fetal abdomen.23,24
reflected the severity of hemolysis. This gave the obstetrician a method with which to follow the patient with Rh sensitization and, in some cases, deliver the fetus prematurely for fetal salvage. The next major step in the treatment of these Rh-sensitized fetuses was also made by Liley, who in 1963 demonstrated that one could successfully treat these anemic fetuses in utero by transfusing blood into the fetal abdomen.23,24
Amnioscopy and Meconium-Stained Amniotic Fluid
Saling25 was the first in 1962 to publish on the use of amnioscopy to diagnose “hazardous conditions to the fetus” by identifying meconium-stained amniotic fluid through intact fetal membranes. In 1968, Kornacki26 said: “…appearance of meconium in the amniotic fluid without other warning clinical signs forecast fetal asphyxia in 5 of 13 cases.” In 1973, Vujić27 reported on his experience with diagnosis meconium in the amniotic fluid prior to rupture of fetal membranes as a sign of “fetal distress.”
Intrauterine Fetal Blood Sampling
In 1962, Saling28,29 published a report of sampling fetal blood by amnioscopy from the scalp or other presenting part during the course of labor, thus overcoming centuries of ethical and emotional barriers to access the fetus inside the uterus. This was the first documented direct approach to the human fetus before delivery. In his report, “New procedures for examining the fetus during labor: introduction, technique, and basics,” Saling described his pioneering approach to obtaining a fetal scalp blood sample and championed the concept of combining pH with abnormal fetal heart rate pattern to assess the fetal condition shortly after cardiotocography had been introduced for clinical routine use in 1968.
Electronic Fetal Heart Rate Monitoring
In 1951, Caldeyro-Barcia and Alvarez30, from Montevideo, Uruguay, first reported on measuring uterine contractions in labor, and in 1958, they developed a method to measure the effect of uterine contractions on fetal heart rate, which would later become the basis of fetal monitoring. They defined normal and abnormal responses of the fetus through the continuous monitoring of fetal heart rate. During approximately this same period, Hon31,32 was developing methods for continuous recording of the fetal heart rate and, more important, the factors acting in the fetus that altered the fetal heart rate in response to uterine contractions. He identified three basic patterns, early, late, and variable decelerations, which were due to head compression, uteroplacental insufficiency, and umbilical cord compression, respectively. This permitted the attending obstetrician to assign a cause for the fetal heart rate decelerations that had already been described in the 1800s. It also permitted a more individualized therapy for the deceleration: change of position for the variable decelerations and maternal oxygen for the late decelerations. Baseline heart rate change and heart rate variability were also related to specific fetal or maternal conditions.