Cesarean effects on adolescents’ birth experiences: counterfactual analysis

Abstract Introduction The birth experience of adolescents is understudied even though they are a particularly vulnerable population to experience a negative birth event, given that they exhibit many known risk factors. Objective To ascertain whether a cesarean birth mediates the impact of infant complications on the birth experience of adolescent mothers. Methods Using a secondary analysis of data collected from 303 postpartum adolescents previously evaluated for depression and post-traumatic stress, we employed counterfactual causal analysis to determine if delivery type mediated the birth experience at different levels of depression. Noted limitations pertain to methodological assumptions and computational feasibility as well as potential sample bias. Results We found that the mediating effect of delivery mode depended on the adolescent’s depression level as well as on the specific operationalization of the birth experience. At low levels of depression, the odds of a negative birth appraisal were reduced by around 30% when operationalized as a single item subjective rating. In contrast, at high levels of depression, the odds of a negative birth experience increased by 80% when operationalized as an Impact of Event Scale (IES) subconstruct. Conclusion Depression level plays a pivotal role in moderating how delivery mode mediates the birth experience. The direction of impact also depends on how the birth experience is operationalized.


Introduction
A woman's birth experience is multidimensional and complex, defined by an interplay of tangible events and resulting perceptions. One way of assessing the birth experience is via a conscious perceptual rating.
Other methods of assessment are based on responses addressing different aspects of the experience, including detection of subjective distress and trauma impact.
Adolescent mothers are a particularly vulnerable population to report a negative birth event, given an increased likelihood to experience several recognized risk factors observed among adult samples. Specific risks include depression, prior trauma, a lack of information/ awareness of events taking place during labor and birth, feelings of loss of control and powerlessness, limited support, unanticipated pain levels, and infant complications. [1][2][3][4][5][6] Type of birth has also received attention as a factor that influences a woman's perception of birth and distress level. 1,2 More than 32% of women in the United rates continue to rise worldwide. 7 A common reason for a primary CB is fetal distress, but several other reasons exist. 8 Experiencing either a planned or unplanned CB can evoke negative birth feelings of varying distress levels. 1,9,10 Systematic reviews have noted the influence of type of delivery upon the development of posttraumatic stress symptoms and post-traumatic stress disorder (PTSD). [11][12][13] Yet, contrary studies either offer no evidence supporting operative birth as an important predictor of a negative birth experience, 6,[14][15][16] or show preference for a CB. 17 Despite the inconsistent findings available in the literature, a link has been identified between CB distress and birth perception, and a negative perception of birth has been recognized as an independent risk factor for the development of PTSD. 12,18,19 Symptoms reflective of PTSD are associated with poor mother-infant bonding, future infertility, an increased fear of childbirth and voluntary CBs in subsequent pregnancies. 1,20,21 Adolescents are recognized to be more prone to experience prenatal and postpartum depression, infant complications, and prior traumas than adults. [22][23][24][25][26][27] Demographic data such as age (younger) and race/ethnicity may also indirectly impact one's birth experience. 19 Specifically, minority adolescents may be more prone to report a negative birth experience because of an increased prevalence of several risk factors, 28 and notably Black childbearing adult women have been shown to be at exceptional risk for a CB. 29 In the Unites States, while comparable CB rates for adolescents and adults are reported at around one in three, adolescents globally are at greater risk for a CB. 29 It is known that the "typical" birth experience for women with birth complications is at risk of being more negative than the birth experience of women without infant complications. 19 It is also known that the "typical" delivery mode for women with infant complications may be a CB. 8 The question we set out to address is whether the typical delivery mode mediates the impact of infant complications on the birth experience, perhaps mitigating the expected negative outcome. To come closer to the counterfactual technical formulation that follows, our goal was to contrast two different If a woman gives birth vaginally when expecting or preferring a CB, increased PTSD may result. 33 ) Last, given the known contribution of depression upon the birth experience 11,12 and noted ethnic/racial disparities related to our variables of interest, 28-31 these two variables were identified as relevant to the analysis as potential confounders. Further, we treated depression as a moderator variable, so that the overall problem we address is one of "moderated mediation," i.e., one in which the mediated effects vary with levels of depression. (We provide technical definitions of these terms below.) Our previous analyses with this dataset informed our decision to exclude other potential confounders that did not show correlative relationships with the main variables in the current study.

Counterfactual causal analysis
Our research question called for an analysis of "moderated mediation," i.e., we hypothesized that there

Variables and expectations of interest
We adopted the following nomenclature in the of which have been associated with a negative birth experience. 12 We note that both these confounders come temporally before the birth experience, which adds to the plausibility of their causal role.

Applying the counterfactual approach
This analysis centers on the "counterfactual," or "potential outcome," Y i (x), which denotes the potential outcome that would have been observed for subject i had the treatment variable X been set to the value x, where a value of 0 or 1 denotes respectively the control and treatment groups. In our case, the "treatment" group refers to adolescent mothers with infant complications. The counterfactual concept inherent here is due to the fact that only one of x = 1 or 0 will be observed for any one individual; i.e., we only observe an adolescent in one of the two states (infant complications or no infant complications).
Since we wish to consider the same individual at both values, we focused on average effects (denoted by An example dataset is provided in Table 2 :

Accommodating a binary mediator
The case in which the mediator is itself binary, as is the case here, has also been extensively discussed in the mediation literature. [46][47][48] In this case, the process of The TNIE can also be expressed in terms of an odds ratio (Equation 7).
The estimated indirect effect and direct effects for a binary outcome usually have non-normal sampling distributions so that a non-symmetric confidence is needed. 34 As such, we obtained bootstrap confidence intervals using 1,000 bootstrap draws with maximumlikelihood estimation in the analysis to follow.

Operationalization of the outcome variable
Here we consider two different aspects of the birth experience measured as birth perception and subjective distress. The first is a straightforward single indicator variable (0 to 10) of the adolescent's overall appraisal (rating) of the experience from 1 (great) to 10 (awful).
Appraisal of the birth experience has been assessed using a one-item measure in several previous studies, with a suggested cutoff of > 6 as indicative of a traumatic birth appraisal. 6,49 The second aspect of birth is based on the Impact of Event Scale (IES). 50

Results
The results for the two estimated models are shown in Tables 3 and 4, respectively. Given that our main interest was in true causal effects that may further vary over a range of moderator values, we emphasize that the two tables do not convey this key information and that our inferences are instead to be drawn from the reported TNIE effects. That being said, the directional effects of the predictors were at least consistent with findings from other studies. In particular, infant complications were predictive of a negative birth appraisal (Table 3), and also were more likely to lead to a CB. Also, Black adolescents were more likely to indicate a negative birth appraisal. By contrast, the results reported in Table 4 show that infant complications did not exhibit a direct effect on avoidance, although an adolescent's level of depression did have such a direct effect.
It is not obvious from these estimates that there was any mediation effect of delivery type on either of     These results were replicated using the prenatal rating measure of depression as the moderator. As with the case above, where birth appraisal was the outcome variable, only for the adolescents who indicated they were "usually happy" did a CB mitigate the impact of infant complications on the birth appraisal evaluation.
Likewise, in the case of the avoidance outcome measure, adolescents who were more depressed during pregnancy (specifically here, those who were in the range "sometimes happy" to "always sad") indicated higher avoidance scores after a CB.

Assumptions and limitations
The main assumptions and limitations here are of two types; the first pertaining to the causal effect methodology and the second pertaining to our specific research design and sample. Assumptions of the counterfactual approach were summarized by VanderWeele & Vansteelandt. 55 These mostly pertain to the need to control for variables that simultaneously affect any pair among the treatment, mediator and outcome variables. We sought to address these issues by the inclusion of confounder variables in our analysis.
In addition, these confounders, (prior trauma and ethnicity/race) must not be affected by the exposure (infant complications), which in our case is assured by the natural temporal ordering of these variables. We been recognized and studies are being conducted to aid in its reduction 7 ; yet, minimal advance has been seen related to hospital policy and state legislation supporting mandatory education and/or routine assessment of depression for childbearing women. 62,63 Given the fact that the present findings illustrate an interaction between depression and delivery mode as an influence on both birth appraisal and avoidance, and

Conclusion
Using counterfactual causal analysis, we found evidence that delivery type does indeed exhibit a mediating impact on the birth experience of adolescent mothers with infant complications, but that the size and direction of this effect depends in turn on how the birth experience is operationalized as well as on existing levels of depression. Specifically, we found opposite effects when the outcome was measured in terms of a conscious appraisal of the overall birth experience as compared to a subjective distress "avoidance" reaction.
For adolescent women with low levels of depression, a CB leads to a better birth appraisal than it would without a CB. Yet for adolescent women with moderate to high levels of depression, a CB leads to a higher avoidance reaction than would without a CB. In summary, both potential positive and negative perceptions emerge from giving birth by CB, depending on depression levels, and essential assessments of high-risk adolescents can guide immediate and future assessments and treatment.

Disclosure
No conflicts of interest declared concerning the publication of this article.