Apgar reported 2,096 births over seven and a half months at Sloane Hospital.
Of 1,760 available anaesthesia charts, 1,021 liveborn infants had received
the new rating and 712 had not. Sixteen per cent of anaesthesia records were
missing, chiefly births with pudendal block or “natural childbirth”—the
cases Apgar herself said would have provided the best control group. She
also stated that most subgroups were too small for statistical analysis
(Apgar 1953).
Within that selected series, infants born by spontaneous or low-forceps
delivery averaged 8.4, compared with 6.8 after caesarean section. Among 141
rated caesarean births, the average was 8.0 after spinal anaesthesia and 5.0
after general anaesthesia with cyclopropane and oxygen. These figures made
differences visible, but the observational groups also differed in labour,
indication, maternal risk, and other circumstances. They could generate
questions about practice; they did not by themselves prove that the
anaesthetic method caused every difference.
The paper's labour was collective even though it had one author. Apgar
described obstetric house staff using the ratings and acknowledged nurse
Rita Ruane for technical assistance with data collection, as well as H. C.
Taylor Jr. for encouragement. Later studies formally brought together
anaesthesia, obstetric, paediatric, laboratory, and nursing expertise.