Discussion
MAIN FINDINGS
Although the studies identified by the quantitative search provided varied results, eight out of the 12 studies found mode of birth to be significantly associated with maternal development of symptoms of PTSD postnatally. Meta-analysis showed that PTSD symptoms were worse in women who had CS compared to those who had VD (p=0.005). Symptoms were also worse in women who had EmCS than in those who had either SVD (p<0.001) or ElCS (p<0.001). The significant difference between EmCS and ElCS may have confounded the first analysis which pooled these two CS groups. Evidence showed that women who had CS births worried more about the safety of their baby and felt less satisfied overall with their birthing experience , a finding which reflects the literature indicating that women may perceive CS as more traumatic than VD .
All of the midwives interviewed by Nyberg et al. reported being asked by women with postnatal PTSD for an ElCS in a subsequent pregnancy, but did not believe that this was the optimum mode of birth for this group of women. The other included qualitative study compared the experiences of women who did and did not develop symptoms of PTSD after an EmCS . Women who did not develop PTSD felt more supported by staff and more involved with the decision to proceed to a caesarean. This study suggests that although EmCS may be associated with an increased likelihood of postnatal PTSD, compassionate care and ensuring that women are involved in decision-making can mediate against this effect.
The importance of the impact of inadequate support from staff during labour and birth on women with PTSD supported findings from Nyberget al. This study reported that many women with postnatal PTSD later told specialist midwives that they felt a lack of support and control during the birth resulting in their PTSD . These findings provide some insight into how a perceived lack of support from labour ward staff could have a considerable detrimental effect on maternal mental health outcomes. NICE guidelines recommend that women are offered the opportunity to talk about their birth experiences at every postnatal contact, which may mitigate against this. No studies were found which evaluated the role of support from partners, families and peers as a potential mitigating factor against PTSD. This is an important avenue for future research.
STRENGTHS AND LIMITATIONS
This is the first systematic review and meta-analysis to combine information from small and medium sized studies, and present synthesised findings about the association of birth mode and maternal postnatal PTSD, reducing the uncertainty that is associated with each single study. However, there are several limitations. There was an issue with the inclusion criterion of “live, term, singleton births”. Six of the included studies did not specify this within their paper, and although efforts were made to contact authors to verify this, only three replied to confirm their paper met this criterion. This left three studies included on a benefit of the doubt basis .
The meta-analysis compiled the most relevant clinical information, utilising robust statistical methods to synthesise the evidence on birthing methods and PTSD symptoms. A statistician (DG) performed both MA and NMA to utilise all direct and indirect information. A potential limitation with this was the assumption of equivalence in the measures used in the difference studies and the follow-up points. If these assumptions fail to hold then they may have introduced heterogeneity into the studies. A meta-analysis of SMDs assumes the populations of each study contain equivalent variation.
CONCLUSION
Although there was some variation in the studies, an overall conclusion can be made that mode of birth has an impact on PTSD in the postnatal period. Women who have emergency CS and instrumental VD might be at an increased risk, although it is important to note that women with all types of birth experience go on to develop PTSD, and the disorder is not limited to those who had a birth that would be deemed traumatic from a clinical perspective. Qualitative data indicated that although elective CS may not be associated with postnatal PTSD, they might have a negative impact on women with pre-existing postnatal PTSD. Support and involvement in decision-making from staff during labour may have a protective effect against women who experience emergency obstetric intervention, but more work must be done to confirm the above findings.