Interpretation
The incidence of PTSD following traumatic childbirth varied in different countries. Two studies[31,32] reported that in the resource-poor countries, women of reproductive age typically have socioeconomic and health challenges that interplay in mutually reinforcing ways, and indeed the incidence of common perinatal mental disorders in low-income and lower-middle-income countries were higher than in high-income countries[33]. According to this systematic review, a subgroup analysis for different countries, the incidence of PTSD following traumatic childbirth in Asia was highest, including in Turkey[22]and in Iran[25]; meta-regression analysis also indicated that Asia was different from other countries such as Europe[23,24,26], Oceania[27,30], and North America[28,29] in the incidence of PTSD following traumatic childbirth. One study[34] has found that a PTSD development was associated with childbirth in a non-western culture, which may be related to the economic development, cultural background, and medical level of different countries in the treatment of postpartum women.
Currently, there are no specific assessment tools for screening for traumatic birth. A review [35]reported that most studies were based on the DSM-A criterion, while a few were based on self-report from postpartum women. Therefore, this study conducted a subgroup analysis to determine the impact of the two different types of assessment tools on the incidence of PTSD in postpartum women after a traumatic birth. The result found that the incidence of screening using the DSM-A was higher than self-report. An RCT has shown that the assessment scale based on DSM-A criterion was validated by psychiatrists for effectiveness in screening for traumatic birth and compatibility with the definition of traumatic birth[36]. Moghadam et al [37] also confirmed the rationality and validity of this scale. However, compared with the self-report, participants were only asked whether they would describe their birth as traumatic (yes/no) [25,27,30], lacking reliability and effectiveness. Therefore, it is considered that based on DSM-A assessment scale is more stringent for screening traumatic childbirth, and the included participants are more likely to develop postpartum PTSD.
Two types of PTSD assessment scales, including structured interview diagnostic scales and self-assessment scales are widely used in the world and have good reliability and validity. In this systematic review of subgroup analysis, we found that different assessment tools for postpartum PTSD women after traumatic childbirth could develop different incidences. However, meta-regression analysis did not show that the difference in assessment tools for postpartum PTSD were the source of heterogeneity. A previous systematic review[18]has shown that the impact of measurement type on postnatal PTSD rate estimates was not detectable, and Grekin et al[38]have indicated that differences in incidence were not found between studies that used self-report and clinical assessment measures to diagnose PTSD. These results should be treated with a degree of caution. This may be since above half of included studies used self-assessment scales[22-24,27-30] to assess PTSD symptoms, so making it difficult to reveal differences between the two methods, which is an limitation of the current research. Therefore, further research should target the evaluation effects of different assessment scales on postpartum PTSD.
Although lacking reliable evidence of significant changes between the incidence of postpartum PTSD after traumatic birth and assessment tools, the incidence at different time points might provide some insights into the course of postpartum PTSD.
In this study, we also found that the PTSD rate was highest in postpartum 1-4months and the incidence declined gradually over time, which coincided with a systematic review by Dikmen-Yildiz[18]. While, Andersen et al[39] has reported that the incidence of PTSD was 1.3% - 2.4% at 1-2 months postpartum and 0.9% - 4.6% at 3 - 12 months postpartum, suggesting that the rate of PTSD increase gradually over time. Thus, it can be considered that there are certain differences in the results of measuring the incidence of postpartum PTSD at different time points. However, the results on the relationship between several key time points and PTSD incidence are different. This might be related to differences in participants and study sites, or during postpartum PTSD, part of women might develop acute PTSD symptoms (3 months postpartum), delayed PTSD symptoms (6 months postpartum), or self-healing.
From this systematic review, due to the limited number of studies included in the measurement of PTSD at 1-4 and 1-12 months postpartum, we were short of sufficient evidence to support its relationship with the rate of postpartum PTSD. Hence, this result should be critically treated. Meanwhile, the relationship between the rate of postpartum PTSD and the evaluation time points should be further researched to provide a basis for the subsequent measurement of postpartum PTSD. In addition, the evaluation time of traumatic birth was the same as PTSD, and it was not analyzed in this systematic review. However, previous studies[40,41] also have shown that the evaluation time of traumatic birth should be measured within 48h or 72h after birth to avoid retrospective bias that results from a too long time.
This systematic review demonstrated that postpartum women whose babies were hospitalized in NICU (neonatal intensive care unit) had the highest incidence of PTSD. However, the evidence recommendation grade of this result was not sufficient to support those postpartum women whose babies were hospitalized in NICU had the greatest influence on the rate of PTSD because only one study[29] was included in the subgroup analysis, although Grekin et al[38]indicated that infant complications, including NICU hospitalization, had a large association with postpartum PTSD symptoms. Therefore, a series of related studies can be performed to explore the impact of neonatal complications, a moderating variable, on the incidence of postpartum PTSD after traumatic birth, and provide ideas for reducing the rate of postpartum PTSD.