The present study shows that the new documentation protocol delivers more comprehensive information regarding perineal lacerations compared with the current obstetric record system, ObstetriX, when used in primiparous women. The new protocol appears to specifically diagnose second-degree perineal lacerations to a greater extent than ObstetriX, which implies that the incidence of these perineal lacerations might be systematically underestimated. We could not see any difference in the ability to diagnose third-degree perineal tears, but the new protocol gave more comprehensive information regarding suturing. The agreement between the new protocol and ObstetriX was generally good when comparing labial lacerations, vaginal ruptures, and episiotomies.
Strengths and limitations
To our knowledge, this is the first validation of a protocol for documentation of perineal lacerations. The lack of a previously validated protocol implies that we do not know the true incidence of perineal lacerations when comparing the two documentation methods, which is a limitation. The index method used in this study, ObstetriX, is far from suitable as a reference method for documentation of perineal trauma because of the substantial lack of information. Many of the estimates of diagnostic accuracy suggested for use in validation of health administrative data, such as sensitivity and specificity [
11], were thus considered inappropriate to use. The ideal reference method would be clinical examination by experts in perineal rupture classification, but this method was not practically possible to implement. Due to this lack of a previously validated protocol, validation against the current obstetric medical record system in Sweden was considered acceptable. Since the Royal College of Obstetricians and Gynecologists classification of perineal rupture was used, the results may be transferred to an international context.
We studied the documentation for 187 women, which is a sufficient number to make a statistical comparison of the documentation methods except for third- and fourth-degree perineal tears, where the numbers were too small to compare with statistical methods. The fact that no power calculation was made when planning the study is a limitation. A considerably larger study sample would be required to achieve the power to compare the documentation methods regarding third- and fourth-degree perineal tears, but that was judged not feasible within a reasonable period of time. The study only includes one obstetric unit, which possibly limits the external validity; however, we have no specific reason to believe that the result would change if we repeated the study in another obstetric unit. The fact that documentation was made by the same person in both ObstetriX and the new documentation protocol for each woman indicates that the differences observed are due to the different configurations of the protocols and are not random.
There was a loss of 87 women who were eligible for the study but for unknown reasons were not included. It is possible that in many cases the reason for non-inclusion was that the midwife or obstetrician was not aware of the study; however, it is hard to completely rule out any form of selection bias.
We found that the new documentation protocol had better coverage in terms of information on perineal lacerations. This might because this protocol specifically asks if there was a perineal laceration and, if so, what degree of perineal laceration there was. Conversely, in ObstetriX, accessible information about the degree of perineal laceration is only generated if the documentation protocol “Suturing of delivery-related injury” is used, which was only the case if the laceration was sutured by an obstetrician rather than a midwife. Since the majority of second-degree perineal lacerations are sutured by midwives, no diagnosis is registered in those cases. The documentation protocol of ObstetriX only includes classification into second-, third-, and fourth-degree perineal tears, but not first-degree perineal tear, so there is no information about these lacerations in ObstetriX.
The new documentation protocol appears to diagnose second-degree perineal tears to a greater extent than ObstetriX. The current Swedish documentation method might systematically underestimate second-degree perineal lacerations, which is unfortunate given the increasing research interest in these lacerations. Second-degree perineal lacerations might cause future morbidity if not sutured correctly or if complicated, for example, by an infection. Additionally, second-degree perineal tears might hide an occult sphincter rupture, which is another reason why these lacerations merit further attention [
4]. Overall, the two documentation methods appear to have acceptable agreement on diagnosis of third-degree perineal lacerations; however, we refrained from calculating agreement and testing for statistically significant differences regarding these lacerations, as the numbers of cases were too small.
Overall, the agreement is good between the two documentation methods regarding labial tears, vaginal rupture, and episiotomy. The two documentation methods seem to give equally comprehensive information about labial lacerations. In the documentation protocol, labial tears are specified as those requiring suturing, which is not the case in ObstetriX. To some extent, this might explain the cases where ObstetriX and the new documentation protocol disagree. In the case of vaginal rupture and episiotomy, the new documentation protocol gives more information than ObstetriX. This may be because the new protocol focuses more specifically on the perineal and vaginal trauma that has occurred compared with the protocol “Delivery care 1” in ObstetriX.
One could expect that the information obtained from a documentation protocol that asks specific and detailed questions about obstetric perineal trauma would be even more complete than this study showed. The fact that the new documentation protocol was filled in on a physical sheet of paper might partly explain this. A computerized documentation protocol with mandatory questions that cannot be signed before all necessary tick boxes are filled in would increase coverage of information even more.
To our knowledge, a validated protocol for documentation of obstetric perineal laceration in a research context has been lacking. In the present study, we have developed and validated a new documentation protocol which has proved to be suitable for scientific purposes. The current Swedish documentation method, on the other hand, appears to systematically underestimate the incidence of second-degree perineal tears. The increasing demand for health care organizations to follow up quality of care makes this new protocol useful to implement in future obstetric record systems.