This study contributes several useful insights. First, to our knowledge, this is one of the first studies to show evidence of intergenerational effects of child maltreatment and violence during pregnancy on mothers’ mental distress and the health of their infants in Vietnam. Evidence from our birth cohort extends the fairly limited international research into violent trajectories from childhood to pregnancy; clearly, these phenomena share many risk factors [58]. Second, this study shows the risk differences and pathway effects of p-IPV severity upon maternal wellbeing and infant health outcomes. The longitudinal data allowed us to investigate causal relationships via various robust models (i.e. AIPW estimators) to address the missing data issue. Importantly, findings from this study reinforce the long-term consequences of child abuse throughout the lifespan and its impact on maternal wellbeing.
Our study suggests the pattern of p-IPV in Central Vietnam (14% of emotional IPV and 3.3% of physical and sexual IPV) is similar to the global prevalence (13.8%–physical P-IPV, 8%–sexual P-IPV, and 28.4%–emotional P-IPV) [3]. A recent national study examining violence against women in Vietnam found a similar prevalence of physical p-IPV (3.4%) [59]. However, this prevalence was lower than the findings of studies with Vietnamese mothers in our recent review (30% for emotional p-IPV and 5% for physical IPV) [19] and lower than the prevalence among women in a survey in northern Vietnam (35.3%) [23] and among female patients seeking fertility treatment in a southern city (16.8% for emotional violence, 7.3% for physical violence, and 12.4% for sexual violence) [60]. This difference might reflect the significant influence of Buddhist values of kindness, belief in karma, non-violence and Nirvana (the state of peace and happiness, achieved after giving up three poisons of greed, hatred, and delusion), which are especially strong in the contemporary population of Hue City [61]. Future studies with randomized sampling throughout the diverse nation of Vietnam to further understand which contextual factors significantly contribute to the apparently lower prevalence of p-IPV in the central region.
At the individual level, a clear implication to emerge from the analysis is the cumulative and prolonged harmful effects of CM, p-IPV victimization, witnessing parental IPV, and growing up amid family dysfunctions. The effects were apparent for adverse birth outcomes and mental health difficulties during pregnancy. Women who reported a history of CM were more likely to experienced p-IPV. The detrimental effect of p-IPV and childhood trauma then doubled the risk of poor maternal mental health and adverse birth outcomes. This is consistent with other research in South Africa [62]. The intergenerational effect of victimization is also consistent with studies that show women who have experienced multiple adverse events have more stress and trauma-related symptoms in the last trimester than women with low exposure [63] and a dose-response relationship was found between multiple incidents of abuse and the highest levels of psychological distress[64]. Particularly, a recent survey found that women who suffered severe IPV had a 4.5-fold increased likelihood of LBW and PTB infants, compared to those with low-level IPV exposure. p-IPV is strongly associated with antepartum hemorrhage, which puts the unborn baby at increased risk of PTB, LBW and long-term health complications in early childhood [65].
The findings at the interpersonal level, while preliminary, suggest that greater partner support during pregnancy can help to reduce the onset of p-IPV. Our findings broadly support the work of other studies that link partner connectedness with maternal wellness [66, 67], pregnancy outcomes [68], and IPV exposure[18]. Partner support may have a buffering effect to improve maternal wellbeing and birth outcome via promoting mothers' personal feeling of security, relationship stability and marital satisfaction [69]. A low level of partner support can be an important indicator of inadequate caring, listening and understanding that contributes to emotional neglect and abuse [70].
At structural levels, we found the important predictors of p-IPV included neighborhood disorder and non-partner social support. Exposure to neighborhood disorder could contribute to a higher risk of both p-IPV and mental distress. This result aligns with Beyer’s (2015) findings that higher perceived neighborhood disorder is associated with increased IPV [71], especially “street” crime [72] or neighborhood disorganization (e.g., drug trading, shootings). Both IPV and CM are high in areas with neighborhood disorders and residential instability [73]. Based on a review of 36 studies, Voith (2017) suggested that the effect of neighborhood disadvantage might interact with the individual’s subjective disorder to contribute to IPV perpetration [27]. A 24-year longitudinal study also suggested that people perceived more positive neighborhoods as less likely places to experience IPV and individual experiences of violence are reinforced by the observing of neighborhood risk factors (e.g. alcohol or drug misuse, neighborhood violence observed) [74]. Negative views of human behaviors and conflict relationships can be fostered during pregnancy by a perception of threatening and dangerous environments that turn to feelings of isolation and powerlessness and trigger physiological responses (e.g. anxiety, anger, fear and depression) [75]. Our findings underscore the importance of contextual factors related to neighborhood disadvantages and how women can be protected against violence by improving neighborhood safety in future intervention toward ending violence. Future work focusing on a series of protective and promotive neighborhood factors could potentially reduce the trajectory of p-IPV, build resilience for survivors of IPV, and promote a harmonic family and optimal child development [25].
Perceived social support is a potential protective factor for p-IPV, as it fully mediated the effects of the history of ACE and perceived partner support during pregnancy. Our analysis found that women who perceived a high level of social support had less antenatal distress and a lower risk of p-IPV. This finding aligns with previous studies that suggest poor social support magnifies the harm from IPV [76]. Low family support may double the risk of repeated IPV episodes [77]. Notably, social support was strongly associated with partner support via possible interference of influential family members in the patriarchal system. The positive impact of social support suggests that enhancing social support might be beneficial to improving maternal mental health and reducing the burden of ACE exposure and further investigation should focus on how family, friends and social disadvantage may influence children's development via violent intimate relationships [25].
This paper contributes to debates concerning the inter-generational transmission of IPV in relation to social attitudes that tolerate child corporal punishment. Violence experienced by mothers may lead to harsh parental educational practice. A previous study suggested that children whose mothers experienced IPV have double the risk of being exposed to psychological aggression and using violent methods (e.g. shouting or slapping) to discipline their children [14]. Similar results were found in UNICEF’s Multiple Indicator Cluster Survey in 21 LMICs, [15], which showed that women who experienced childhood corporal punishment are twice as likely to have a positive attitude toward IPV acceptability. Longitudinal data have also suggested dose-response between higher level of IPV exposure with higher degrees of spanking parental behavior [78]. This current study revealed that four in five women (74.67%) endorsed spanking children. However, this study did not find a significant risk difference between attitude to child spanking and p-IPV victimization. This unexpected finding can be explained by the small number of women who experienced p-IPV (22 participants) and the pervasive proportion of women supporting child spanking (75%). Thus, our sampling power may not have been able to detect a small difference. This hypothesis is supported by the fact that corporal punishment is prevalent among Vietnamese parents, as three in four children aged 1–14 experience corporal punishment or violent discipline [79]. Further, corporal punishment is more common during school age in Vietnam [80]. “Tiger parenting” practice is a common violent parental discipline toward high academic performance for children, and is especially more frequently in urban high-income families in Vietnam [81]. Hence, a further study could assess the long-term effects of p-IPV on perception toward corporal punishment and pathways to physical punishment behaviors using a larger sample size.
One of our unexpected findings was the negative direct effect of physical child abuse history on instrumental/surgery delivery (e.g. C-section or forceps or vacuum). This is a controversial topic with mixed evidence. A systematic review of 43 studies found minimal effects of childhood abuse experienced on a high level of instrumental/surgery delivery (i.e. forceps, vacuum extraction or cesarean section [82], while a recent study found that women who were sexually or physically abused in childhood had a higher level of fear of childbirth and were more likely to experience a complicated vaginal birth. Specifically, women raped in childhood had a considerable greater risk for C-section (OR 15.7, 95% CI 5.0–49.1) or assisted vaginal birth (OR 13.1, 95% CI 4.9–34.5) [83] or more difficult pregnancies and delivery [84]. It is difficult to explain this unexpected result; however, it may be related to the high proportion of planned C-section among abused women [85], perhaps due to worry about their infant’s health [86]. In the Vietnamese cultural context and contemporary central Vietnam, some women may believe that a child may be born dead as punishment or karma [87].
There are limitations to this study due to reliance on subjective self-reported data and possible recall bias especially for childhood experience events that may have occurred one to three decades earlier. However, the self-administered questionnaire via tablet to assist confidentiality may have encouraged participants to disclose their adverse experiences more openly than in face-to-face interviews [88]. Additionally, the sample size is a significant limitation for the external validity of this study. However, we believe that the bootstrapping technique and AIPW modeling may have helped to estimate robust SE values and avoid type I error in testing risk differences. Further, although convenience sampling could limit generalizability, the participants were recruited from eight out of 27 commune health centers in Hue City; thus, the sample was diverse and may be similar to urban settings in central Vietnam. Finally, this study was unable to examine some other forms of violence that could be experienced during a woman’s life span (e.g. bullying, dating violence) that may be harmful to pregnant women. Future birth cohort studies should include more comprehensive measurement of traumatic events.