Table 1. The variables used and numbers of responses for each ultrasound scan.

Scan No.	Variables DEL_	No. with gestation	No. with type	No. with Reason	No. with Result	No. “Abnormal”
1	S010-3	7945	5214	7236	8103	3684
2	S020-3	5491	3965	5186	5362	2562
3	S030-3	3013	2063	2828	3014	1349
4	S040-3	1712	1275	1613	1704	789
5	S050-3	1034	798	984	1025	491

[Admissions 6–33 are similarly available.]