what was the last time that patient 17694 was diagnosed with 31-32 comp wks gestation?
select diagnoses_icd.charttime from diagnoses_icd where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = '31-32 comp wks gestation' ) and diagnoses_icd.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 17694 ) order by diagnoses_icd.charttime desc limit 1