Introduction

A caesarean section (C-section) is a procedure in which a baby is surgically extracted (removed) from the uterus, rather than being born vaginally. This concept describes the methods and definitions used in MCHP research over time to define and identify c-sections, as well as previous cesarean births.

This concept also provides a link to relevant SAS code. Please see the SAS code and formats section containing the following link to: C-Section code from NTK What Works deliverable from 2008 - (internal access only).

NOTE: In MCHP research, the word caesarean has also been spelled cesarean and caesarian. In the Concept Dictionary and Glossary, all these spellings have been modified to "caesarean", to assist in the search functionality.

Data Definition Over Time

Cesarean sections (C-Sections) are identified from hospital discharge abstracts:


• From 1970/71 to 1978/79 ICDA (Adapted) - version 8 procedure codes are used (77.x).
  
• Until March 31, 1987 procedure codes must be used (ICD-9-CM 74.0, 74.1, 74.2, 74.4, 74.9 (74.3 is excluded)).
  
• From April 1, 1987 to March 31, 2004 the OBCSECT field (Hospital Abstract User Manual, Item 40 C.S. Type) or ICD-9-CM procedure codes 74.0, 74.1, 74.2, 74.4, 74.9 (74.3 is excluded) can be used.
  
• Starting April 1, 2004 cesarean sections are identified by CCI code 5MD60^^ (section 5, Obstetrical and Fetal Interventions: MD (birthing), Intervention 60).

In all cases only obstetrical abstracts are used (abstract type 3) where there is an ICD-9-CM diagnosis code V27 (delivery) or ICD-10-CA code Z37 (delivery). Through 1978/79 ICDA-8 code 650-662 may have to be used but this needs to be determined.

When calculating the rates of C-Sections use all maternal birth records in the time period for the denominator, defined by ICD-9-CM diagnosis code V27 or ICD-10-CA code Z37 and an obstetrical abstract type (3).

The type of anaesthsia used can be identified from the HAUM using the OBANAES field (item 40 HAUM anaesthsia). This field is required if diagnosis 2 or 3 is in the range V27.0-V27.9.

0 - Nil,
1 - General/inhalation,
2 - Spinal/epidural, or
4 - Block/pudendal.

In the Discharge Abstract Database (DAD), the type of anaesthsia is identified from Group 11, Field 12 - anaesthetic Technique (inttechXX) for the corresponding delivery procedures (5MD^^):

0 - if for OOH (Out Of Hospital) interventions,
1 - General,
2 - Spinal,
3 - Epidural,
4 - Combined general and neuraxial (epidural or spinal),
5 - other nerve block (including intravenous regional anaesthsia, neuroleptic),
6 - Monitored anaesthsia care (monitoring by an anaesthetist with or without anaesthetist giving sedation or analgesia: with or without local anaesthsia),
7 - local anaesthsia (no anaesthetist present) includes topical,
8 - no anaesthetic,
9 - other anaesthetic not monitored by an anaesthetist (includes intravenous sedation, nitrous oxide/nitronox).

Previous Cesarean Birth

In Heaman et al. (2012), a woman was considered to have had a previous cesarean birth by the presence of one or more of the following codes:


• ICD-9-CM: 654.20, 654.21, 654.23; OR
  
• ICD-10-CA: O34.201, O34.203, O34.209, O34.291, O34.293, O34.299, O75.701, O75.703, O75.709.

In MCHP Research

Several MCHP deliverables have investigated and reported on caesarean section. For more information, see the following sections in our deliverables:


• section 10.11 Caesarean Section (C-Section) in The Manitoba RHA Indicators Atlas: Population-Based Comparison of Health and Health Care Use deliverable by Martens et al. (2003)
  
• section 3.3 Caesarean Sections in the Manitoba Child Health Atlas Update deliverable by Brownell et al. (2008)
  
• section 4.6 Cesarean Birth in the Perinatal Services and Outcomes in Manitoba deliverable by Heaman et al. (2012)
  
• section 10.6 Caesarean Section Rate in The 2019 RHA Indicators Atlas deliverable by Fransoo et al. (2019)