XIV, 3 Acosta-Sison and Calderon: Pelvimetry 263 
Table IV . — Diagonal conjugate from the point of view of efficiency and 
spontaneous labor in primipo/rse. 
! 
1 Measurement. 
Cases. 
Length 
of 
labor. 
Spontaneous 
labor. 
Operations. 
Indications for 
operation. 
cm. 
H. m. 
P. ct. 
Cases. 
10 to 10. 4 
9 
15 35 
88.88 
8 
Low forceps, 1 
Prolonged labor. 
10. B to 10.9. 
21 
18 42 
97.76 
19 
I Low forceps, 1 
Do. 
[Mid forceps, 1 
Do. 
I Dry labor. 1. 
11 to 11.4 
92 
15 11 
97. 83 
90 
Mid forceps, 2 
Meconium in vagina, 
1 (baby presenting by 
the vertex) 1, 
11. B to 11. 9 
74 
18 60 
98.64 
73 
Mid forceps, 1 | Prolonged labor. 
12 to 12.4 - 
34 
14 62 
94.01 
32 
Mid forceps, 2 
Do. 
12. 6 to 13 
5 
15 02 
100 
6 
Comparing Table IV with Table III on the multiparse, one is 
struck with the apparently greater percentage of spontaneous la- 
bor in primiparee. The cause of this is that in primiparous cases, 
our procedure has been to let nature do all it can before instru- 
mental intervention so as to allow sufficient molding of the head. 
Moreover, many of the operative cases in primiparse are not 
shown here for the reason that we made all of our measurements 
during the puerperium, and in order to avoid infection and 
relaceration of the repaired wounds, a regrettable occurrence in 
many of our earlier cases, we refrained from measuring the 
diagonal conjugate in patients who had been delivered instru- 
•mentally. 
It is interesting to note, however, that the number of cases 
whose diagonal conjugate measures between 11 and 12.4 centi- 
meters forms 87 per cent, which is a slightly greater proportion 
than that of the corresponding measurements in the multipart. 
PELVIC OUTLET 
An eiiort was first made to determine the relationship of the 
intertuberal diameter and the length of the second stage of labor, 
but the results soon demonstrated that this measurement when 
considered alone is of little significance. In cases of contracted 
intertuberal diameter where a prolonged second stage was ex- 
pected it was found that, though the baby was not undersized, 
oftentimes the duration of the second stage was even shorter 
than the average normal. In these cases the posterior sagittal 
