Participants
The study was performed between December 2017 and May 2019, and was proposed to 266 pregnant women receiving prenatal care as outpatients at the Gynecology Clinic of the University Hospital of Udine (Italy): 55 women (20.7%) refused to participate and the final sample comprised 211 participants. The sample size of this study was determined according to Mundfrom et al. [27] that reported a minimum sample size for conducting factor analysis of three to ten times the number of variables (see also: [28]).
Inclusion criteria were age over 18 years, Italian fluency, and absence of pregnancy complications (as routinely evaluated during gynecological visits) until the research assessment. Of the 211 eligible women, 70 were in the first trimester (1-13 weeks), 71 were in the second trimester (14-25 weeks), and 70 were in the third trimester (26-40 weeks).
Socio-demographic and general characteristics of the sample are detailed in Table 1.
Measures
The socio-demographic data were collected with a patient form, including information on age, education, employment status, marital status, number of previous pregnancies, week of pregnancy, and patient medical history. Four psychometric instruments were used.
NuPCI (Revised Prenatal Coping Inventory)
The Italian translation of the revised version of the Prenatal Coping Inventory was used [10, 11]. Two of the authors (MB and CP) translated the original NuPCI in Italian, with the Authors’ permission, using the forward-backward procedure: one researcher translated the items in Italian and the second back-translated them. After performing the translations, the authors revised the Italian version in order to have a final instrument as similar as possible to the original NuPCI, but also adapted to the Italian cultural contest. Both translators are native Italian speakers fluent in English.
The questionnaire includes 42 items, rated on a five-point scale from zero (“Never”) to four (“Very often”). According to the factors reported by Hamilton and Lobel [11], three scales were considered: Planning-Preparation (PP; that includes 15 items: 1, 2, 3, 5, 11, 12, 13, 14, 17, 19, 23, 24, 34, 39, and 42), Avoidance (A; 11 items: 4, 7, 10, 18, 20, 26, 27, 30, 31, 37, and 38) and Spiritual-Positive Coping (SPC; 6 items: 6, 9, 16, 33, 36, and 41); higher scale scores correspond to a more frequent use of the specific coping style. In this English version the Planning-Preparation scale showed a Cronbach’s alpha of 0.82, 0.85 and 0.86 in early, mid-, and late pregnancy, respectively. The Avoidance scale showed a Cronbach’s alpha of 0.77, 0.79, and 0.80. Lastly, the Spiritual-Positive scale showed a Cronbach’s alpha of 0.73, 0.78, and 0.77 [11]. Moreover, the NuPCI subscales showed good validity, in association with a measure of coping strategies, the Way of Coping Questionnaire (WCQ): Planning-Preparation scale was associated with the WCQ Problem-Solving scale (r=+0.542, p<0.01), Avoidance scale was associated with Emotional-Solving scale (r=+0.606, p<0.01), and Spiritual-Positive Coping scale was associated with Problem-Solving scale (r=+0.231, p<0.01).
The Italian version of NuPCI used in this study can be requested by contacting the corresponding author.
NuPDQ (Revised Prenatal Distress Questionnaire)
The NuPDQ is the revised version of the Prenatal Distress Questionnaire [10], developed by Lobel et al. [7]. Initially, NuPDQ had three different forms (i.e., for early-, mid- and late-pregnancy), and it was subsequently modified to include all the items regardless of the pregnancy period [16].
It includes 18-items evaluating the level of PSS. The first 17 items are rated on a three-point scale from zero (“Never”) to two (“Very often”). The last item is rated zero-one (“Yes”/“No”). The NuPDQ provides a prenatal stress score ranging from zero to 35 (i.e., the sum of the item scores). This instrument showed good reliability (Cronbach's coefficient alpha 0.55-0.79) and validity, considering the association with other instruments [18].
For this study, the NuPDQ was translated to Italian using the same forward-backward procedure adopted for the NuPCI. The Authors’ permission was also obtained.
The Italian version of NuPDQ used in this study can be requested by contacting the corresponding author.
Brief-COPE (Coping Orientation to the Problems Experienced)
The Brief-COPE is a 28-item self-report questionnaire designed to measure effective and ineffective ways of coping with stressful life events [4]. It is a short self-report instruments that showed good validity and reliability worldwide; it was translated in several languages, including Italian [29]. The original instrument includes 14 subscales, that showed a good reliability (subscales Cronbach’s alpha range between 0.50 and 0.90) [4]: Self-distraction, Active coping, Denial, Substance use, Emotional support, Use of instrumental support, Behavioral disengagement, Venting, Positive reframing, Planning, Humor, Acceptance, Religion, and Self-blame. According to previous research [9], the scores may also be summarized by two global coping styles: Avoidant Coping (derived by the subscales of Denial, Substance use, Venting, Behavioral disengagement, Self-distraction, and Self-blame) and Approach Coping (Active coping, Positive reframing, Planning, Acceptance, Seeking emotional support, and Seeking informational support). Compared to Approach Coping, Avoidant Coping is shown to be less effective at managing anxiety [30]. Moreover, other different measurement models have been proposed. Cooper and collaborators [31] identified three general coping styles (Problem-focused, Emotion-focused, and Dysfunctional coping) while Meyer [32] grouped the 14 original subscales in two styles: Adaptive and Maladaptive coping (see also: [33]). We have adopted this latter partition.
STAI (State-Trait Anxiety Inventory, Y form)
The STAI [34] comprises separate self-report scales for measuring state and trait anxiety. The State anxiety scale (STAI, Form Y-1) consists of 20 statements that evaluate how respondents feel “right now, at this moment”. The Trait anxiety scale (STAI, Form Y-2) consists of 20 statements that assess how people generally feel. It is a well validated instrument (the Cronbach’s alpha coefficients for trait and state anxiety scales revealed a high reliability in female adults, 0.91 and 0.93 respectively) [34], used worldwide. We used the Italian version of the STAI [35].
Data analysis
Continuous measures were summarized using means and standard deviation (SD). Between-group differences were analyzed using analysis of variance, or Kruskal-Wallis’ test, when the assumption of homogeneity of variance was violated. For statistically significant results post-hoc analyses were conducted using Tukey’s honest significance test. Partial omega-square (ω2P) was used for effect-size estimations, conventionally considering effects as medium-size when ω2P was between 0.06 and 0.15. Pearson’s product-moment correlation coefficient (r) was also calculated.
For categorical measures, between group comparisons were performed using χ2-test.
Shapiro-Wilk’s test was used to evaluate normality of distribution of NuPCI scales and NuPDQ scores.
The internal consistency of NuPCI scales was assessed using Cronbach's coefficient alpha (ɑC). Internal consistency is good when ɑC ≥0.8 and acceptable when ɑC ≥0.6. Also, maximum-likelihood exploratory factor analyses (EFAs) were conducted for each scale. Unidimensionality was evaluated as the proportion of variance explained by the 1st factor and the ratio between 1st and 2nd eigenvalue extracted (i.e., expected to be >3). Confirmatory factor analyses (CFAs) were conducted first testing the original NuPCI measurement model (i.e., with 32 items organized on 3 orthogonal scales). The measurement model was then modified excluding three items and allowing correlated factors. The diagonally weighted least squares estimator, suitable for five-levels ordinal items, were used and robust test was preferred. A model fit was considered acceptable for a ratio between model’s χ2 and degrees of freedom less than two, a Comparative Fit Index (CFI) and Tucker-Lewis’ Index (TLI) greater than 0.900, and a Root Mean Square Error of Approximation (RMSEA) less than 0.050.
To investigate the effects of NuPCI scales on the NuPDQ score, a multiple linear regression was fitted.
To check the assumption for the use of multiple linear regression, Mardia’s multivariate skewness and kurtosis coefficients were calculated and Breusch-Pagan’s test for multivariate heteroskedasticity was used.
Variance inflation factors were calculated, considering acceptable values below two. The ability of coping strategies (NuPCI scales) to predict Apgar score was estimated in by-trimester samples. Multiple linear regression models with covariates only (i.e., week of pregnancy, age of participant, status of primigravida, and presence of previous miscarriage) were compared with models including also NuPCI scales (best-fit χ2-test). Then, NuPDQ scores were introduced in the selected models, evaluating their possible moderating effect. We excluded from those analysis two women who lost their baby before birth and three participants with twin-delivery.
The 95% confidence intervals used to evaluate the statistical significance of item-loadings in EFAs and those reported for ɑC and ω2P were calculated with a bootstrapping procedure (using 10,000 replication samples).
The level of statistical significance was set at ɑ=0.05. Since a total of 22 independent scales were included (i.e., three from NuPCI, NuPDQ, 16 from Brief-COPE, and two from STAI), in correlation analysis statistical significance was considered for p≤0.002, possibly indicating as close to statistical significance those correlations that did not survive to this correction.
All analyses were conducted using R-3.6.3 [36], using Lavaan 0.6-6 library in conducting CFAs [37].