Introduction

Pregnancy-induced hypertension (PIH) affects 6%–10% of pregnant women worldwide (Kintiraki et al., 2015; Walle & Azagew, 2019) and is a major cause of maternal and fetal death (Wu et al., 2015). This condition involves the development of gestational hypertension and preeclampsia after 20 weeks of pregnancy (Walle & Azagew, 2019). PIH is defined as two occasions of systolic blood pressure (BP) greater than or equal to 140 mmHg or of diastolic BP greater than or equal to 90 mmHg (Muti et al., 2015). The risk factors for PIH include advanced maternal age, primiparity, multiple pregnancy, use of assisted reproduction techniques, being overweight, diabetes mellitus (gestational or otherwise), previous history of PIH, and chronic hypertension (Liu et al., 2018; Zhuang et al., 2019). In Taiwan, PIH is the second leading cause of maternal death (Wu et al., 2015). The incidence of preeclampsia has significantly increased from 0.87% to 1.21%, and the relative risk of developing this complication increases incrementally with age. Hypertensive disorders associated with pregnancy remain a significant challenge for obstetricians in Taiwan because of ongoing changes in society and culture such as the rise in mean maternal age at first birth (Chan et al., 2015).

Women with PIH face increased risks of placental abruption, organ failure, and disseminated intravascular coagulation (Kintiraki et al., 2015). In addition, women with a history of severe preeclampsia may experience headaches, left upper quadrant pain, visual impairment, fatigue, and memory and concentration disturbances after delivery more frequently than women without this history (Brusse et al., 2008). Other long-term risks associated with PIH include atherosclerosis and cardiovascular disease (Watanabe et al., 2015), midlife development of Type 2 diabetes (Timpka et al., 2018), and intracranial hemorrhage (Lin et al., 2016). Furthermore, the fetuses of mothers with PIH face increased risks of intrauterine growth retardation, premature birth, being small for gestational age, and intrauterine death (Kintiraki et al., 2015; Muti et al., 2015). In a study of 17,933 fetal deaths in Norway, 9.2% occurred during the pregnancies of women with hypertensive disorders (Ahmad & Samuelsen, 2012).

Women with PIH also face elevated vulnerability to psychological and physical problems (Abedian et al., 2015; Zhang et al., 2013) that may impact fetal health significantly, even to the point of being life-threatening (Leeners et al., 2008). Evidence has shown that women with PIH experience more stress than healthy pregnant women, and women with preeclampsia often experience higher anxiety and stress levels than pregnant women without preeclampsia (Brusse et al., 2008; Hayase et al., 2014; Thiagayson et al., 2013). The results of previous studies have associated anxiety in early pregnancy with risk of preeclampsia and found that one in four women with preeclampsia experience anxiety problems during their subsequent pregnancy (Habli et al., 2009; Rubertsson et al., 2014). In one study, 67.5% of women with preeclampsia were unaware that they were experiencing this condition before becoming pregnant or being diagnosed, most did not consider it to be a potentially life-threatening condition for mothers, half feared that it threatened the life of their fetuses, and the overwhelming majority (95%) expressed a desire to learn more about it (Frawley et al., 2020).

It has also been reported that women who experience psychological distress during pregnancy may be at increased risks for preterm birth and delivery of low-birth-weight babies. Thus, researchers have emphasized the importance of providing appropriate prenatal mental health support (Glover, 2014; Staneva et al., 2015). Certain relaxation techniques have been shown to be effective in helping pregnant women control anxiety. For example, a randomized, controlled trial involving women in their second trimester found that the experimental group, which participated in a 7-week program involving 90 minutes of relaxation training targeting breathing and muscles, had mean postintervention anxiety and stress levels that were significantly lower than those in the routine-care control group (Bastani et al., 2005). Similarly, Toosi et al. (2017) conducted a study on women receiving in vitro fertilization who participated in a 4-week program of relaxation training that included 10–20 minutes of specific techniques at the end of the course. The training emphasized finding a quiet environment, doing mental preparation, maintaining a passive attitude, remaining comfortable, and relaxing muscles throughout the body, with the experimental group achieving a significant decrease in anxiety at posttest. However, little research has focused on relaxation techniques that are specifically designed to reduce maternal anxiety or stress in women with PIH (Damodaran, 2015).

Prenatal care during pregnancy is recommended to improve maternal and fetal outcomes, especially during high-risk pregnancies (Till et al., 2012). This care requires case management, which has been defined as “a collaborative process of assessment, planning, facilitation, care coordination, evaluation, and advocacy for options and services to meet an individual's and family's comprehensive health needs through communication and available resources to promote quality, cost-effective outcomes” (Case Management Society of America, 2016). During high-risk pregnancies, case management involves the implementation of systematic, long-term care strategies and includes follow-up consultation to manage risk and reduce morbidity and mortality (Soares & Higarashi, 2019). Maternity case management usually involves screening for diseases and social risks, ongoing contact with case managers, and resource referrals. Curry et al. (2006) conducted a nurse case management study targeting pregnant women at risk for abuse. Women were randomly assigned to the routine-care control group or the experimental group, with members of the latter group provided with videos, telephone access to a nursing case manager, and individualized nursing case management. The findings suggest that nursing case management approaches that assess pregnant women's needs and support their choices may effectively reduce self-perceived stress.

Case management has also proved effective in improving the birth weight of infants and reducing the incidence of preterm births (Slaughter et al., 2013), reducing the frequency at which babies are hospitalized in the neonatal intensive care unit, the healthcare costs associated with pregnancy, and the number of women experiencing high-risk pregnancies (Hutti & Usui, 2004). Moreover, the findings of several studies indicate that case management improves maternal behavior with respect to maintaining and engaging in HIV care at 1-year postpartum (Anderson et al., 2017; Schwartz et al., 2015) and to reducing alcohol consumption and the incidence of fetal alcohol spectrum disorders (de Vries et al., 2015; May et al., 2013). However, as previously noted, little information is available regarding the effectiveness of case management interventions designed to address the needs of women with PIH.

Therefore, the purpose of this study was to evaluate the effect of an antepartum case management program on stress, anxiety, and pregnancy in women in Taiwan with PIH. The primary aim was to assess the impact of an antepartum case management program on the stress and anxiety experienced by pregnant women. The secondary aim was to assess the impact of the program on pregnancy outcomes. Thus, the following research questions were formulated:

What are the effects of an 8-week antepartum case management program on the stress and anxiety experienced by women with PIH? What are the effects of an 8-week antepartum case management program on pregnancy outcomes in women with PIH, including infant birth weeks, infant birth weight, number of medical visits, and frequency of hospitalization? Methods Design and Setting

A quasi-experimental approach was used to evaluate the effects of a case management program for women with PIH in terms of stress, anxiety, and pregnancy outcomes. Sixty-two women diagnosed with PIH were recruited from the obstetrics and gynecology clinics at a medical center in southern Taiwan and randomly assigned to either the experimental group or the control group. The experimental group received a case management program, and the control group did not. All of the participants were assessed using the same stress, anxiety, and pregnancy outcome measures. The outcomes were calculated by comparing the differences between measurements taken before the intervention (pretest) and measures taken at 8 weeks after the intervention (posttest).

Participants

Women who met the following criteria were invited to participate: (a) diagnosed by a physician within the previous 20–28 weeks as having PIH (including preeclampsia), (b) ≥ 18 years old, (c) free of other major health problems, and (d) able to communicate in Mandarin. Otherwise, qualified individuals with psychiatric conditions or a history of medical–surgical disease, maternal abuse, substance abuse, or multiple pregnancies, as determined via a medical records review, were excluded. In addition, those who had experienced other complications during pregnancy such as bleeding, gestational diabetes, uterine contracture, or rupture of membrane were excluded. Using the F test in G*Power software Version 3.1.6, with the assumptions α = .05, effect size = 0.3, power level = 0.80, and two groups (Chiu, 2007), a minimum sample size of 56 was determined. Using a presumed attrition rate of 10%, a total minimum sample size of 62 was determined for this study. Eighty-three women with PIH met the inclusion criteria for this study, of which 72 were recruited and 62 completed the 8-week program.

Intervention

The case management program for women with PIH was developed after an extensive review of the literature and discussions with experts. The case management program team consisted of physicians, the head nurse, the nursing faculty, and one nurse case manager. Two professors with specialties in maternal nursing and health education were also recruited to serve as the planning committee. The three key components of the case management program were (a) education related to PIH, including its etiology, complications, management, and self-care; (b) instruction in relaxation techniques, including explanations and demonstrations of the various steps; and (c) telephone follow-up evaluations every 2 weeks to identify difficulties faced by the participants, monitor their relaxation practice, and answer questions. A booklet describing case management for PIH, inclusive of all materials in the health education program, was developed and distributed to the participants for their use as a guide.

The case management process for this study included (a) screening and recruitment by the case manager to identify women meeting the eligibility criteria; (b) assessment and monitoring of the participants' weight, height, BP, blood sugar, urine glucose, proteinuria, bleeding, uterine contracture, and rupture of membrane; (c) implementation of the program, including discussion of the concept of PIH and its etiology, managing symptoms, self-management and monitoring, hospital resources, and relaxation techniques; and (d) evaluation and follow-up consultation by telephone regarding the condition of the pregnant women, weeks of gestation, and the numbers of hospitalizations and visits to clinics or hospitals. Whereas the experimental group participated in the case management program, the control group received the standard care protocol provided by Taiwanese clinics.

Measurements

The measurements included demographic and clinical information, BP, pregnancy outcomes, and self-reported stress and anxiety.

Demographic and clinical information

The demographic data collected from participants included age, education, and marital status. The clinical information that was collected included the participants' pregnancy, childbirth, and PIH histories and any current PIH symptoms such as edema and proteinuria.

Blood pressure

BP was measured 5 minutes before the patients took a rest and 15 minutes afterward using a calibrated, automated, and oscillometric-validated device. All of the measurements were performed by the same researcher at the same time of day at a controlled room temperature.

Pregnancy outcomes

The main concern in this study was to evaluate the pregnancy outcomes of the participants, which included infant birth weeks, infant birth weight, number of hospitalizations, and number of medical visits. Infant birth weeks was defined as the gestational week of birth. Infant birth weight was defined as the weight of the newborn at birth. Number of hospitalizations was defined as the number of participants hospitalized because of PIH. Number of clinic or hospital visits (apart from routine prenatal care) was further subcategorized by reason, including high BP, symptoms related to PIH, and emergency treatment.

Pregnancy stress

The Pregnancy Stress Rating Scale developed by Chen et al. (1983) was used to evaluate prenatal stress. This scale consists of five domains: stress related to concerns about maternal and fetal safety through pregnancy, labor, and childbirth; newborn care and changes in family relationships; maternal role identification; seeking social support; and physical appearance and changes in function. The participants were asked to rate 30 items keyed to pregnancy-related stressors based on their levels of concern and distress on a Likert scale ranging from 1 (definitely not concerned or distressed) to 5 (very severe concern and distress). The total possible score was 150, with higher scores correlating with higher levels of prenatal stress. This instrument showed good internal consistency (α = .91) and supporting convergent and discriminate validities (Chen et al., 1983; Chiu, 2007).

Anxiety

Anxiety was measured in this study using one part of the State-Trait Anxiety Inventory (STAI) developed by Spielberger. Twenty items were used to measure state anxiety (STAI-State), which indicated the current feelings of the participants on a 4-point Likert scale ranging from 1 (not at all) to 4 (very much so); the scores ranged from 20 to 80 for both state anxiety scales, with higher scores correlating with the intensity of the respondents' anxiety. This questionnaire has shown good reliability (Cronbach's α = .830; Delgado et al., 2016).

Procedure

Ethical approval for this study was obtained from the institutional review board of university hospital (B-ER-105-388). The data were collected from January 2017 to January 2018. A nurse with more than 10 years of professional experience served as the case manager and conducted the case management and relaxation course training classes. Eligible participants referred by their physicians were invited to participate. Written informed consent was obtained from the participants after explaining the study thoroughly. The participants were randomly assigned to either the experimental group or the control group. Those assigned to the experimental group were instructed to fill out the pretest measure, which included demographic and clinical information, information related to pregnancy stress, and the state anxiety questionnaires, which took about 20 minutes to complete. Next, these participants received one-on-one health education related to PIH for about 30 minutes and spent 20 minutes on the relaxation techniques. The intervention was conducted for an 8-week period, and every participant received a copy of the aforementioned PIH case management booklet. The posttest, administered after the intervention, gathered data on pregnancy stress, state anxiety, number of medical visits, and number of hospitalizations. By contrast, the participants who were assigned to the control group received routine care and completed both the pretest and posttest measures. Information on infant birth weeks and infant birth weight was obtained from the participants' medical records. All of the data collected were treated confidentially, and the participants were informed that they were free to withdraw from the study at any time and for any reason without affecting their treatment or care.

Ethical Considerations

The confidential information associated with this study was stored on a password-protected computer in a locked cabinet. The researchers explained the purpose, process, and method of the study to the participants along with their related rights and interests. Signed, informed consent was obtained from all of the participants before data collection. To maintain the principle of equality, the members of the control group had access to routine hospital care during their pregnancies. To further ensure the confidentiality and privacy of participants, all data were anonymously encoded and not publicly disclosed.

Data Analysis

The data were analyzed using SPSS for Windows software Version 25.0 (IBM Inc., Armonk, NY, USA). Descriptive statistical analysis served to describe the study variables and the demographic and clinical characteristics of the participants. Independent t tests or Mann–Whitney U tests were used for the continuous variables, and chi-square tests or Fisher exact tests were used for the categorical variables to examine the homogeneity between the experimental and control groups. In addition, paired-sample t tests were used to compare intragroup differences in the outcome variables between T1 and T2, and generalized estimation equations were used to evaluate the differences in the changes between the groups (p < .05) between pretest and posttest.

Results

Seventy-two qualified individuals consented to participate in the study, with 10 lost to follow-up for reasons including transfer to another hospital, inability to complete the intervention, or being moved away from the area. Thus, data for 62 participants were available for analysis, including 31 in the experimental group and 31 in the control group. No significant intergroup differences were identified in terms of either demographics (Table 1) or clinical-related information.

Table 1 - Demographic and Clinical Information, by Group (N = 62) Variable Total (N = 62) Experimental Group (n = 31) Control Group (n = 31) p n % n % n % Age (years; M and SD) 35.1 4.5 34.8 4.9 35.4 4.1 .639 Marital status 1.000  Married 58 93.5 29 93.5 29 93.5  Not married 4 6.5 2 6.5 2 6.5 Educational level .155  High school or less 17 27.4 11 35.5 6 19.4  Post-high school 45 72.6 20 64.5 25 80.6 Religious .189  Yes 23 37.1 14 45.2 9 29.0  No 39 62.9 17 54.8 22 71.0 Employed (n = 60) .142  Yes 38 63.0 15 52.0 23 74.0  No 22 37.0 14 48.0 8 26.0 Health insurance (n = 60) .416  Yes 54 90.0 25 86.0 29 94.0  No 6 10.0 4 14.0 2 6.0 Gestational weeks (M and SD) 24.4 2.5 24.3 2.3 24.5 2.7 .835 Hypertensive disorder subtype .309  Gestational hypertension 30 48.0 13 42.0 17 54.0  Mild or severe preeclampsia 32 52.0 18 58.0 14 46.0 Previous deliveries .611  0 32 51.6 17 54.8 15 48.4  ≥ 1 30 48.4 14 45.2 16 51.6 Previous preterm deliveries 1.000  0 55 88.7 28 90.3 27 87.1  1 7 11.3 3 9.7 4 12.9 Previous PIH experience .562  Yes 16 25.8 9 29.0 7 22.6  No 46 74.2 22 71.0 24 77.4 SBP (mmHg; M and SD) 146.6 8.8 147.3 10.6 145.8 6.7 .488 DBP (mmHg; M and SD) 88.6 9.1 88.7 9.1 88.6 9.3 .989 Edema .297  Yes 24 38.7 14 45.2 10 32.3  No 28 61.3 17 54.8 21 67.7 Proteinuria .544  Yes 14 22.6 8 25.8 6 19.4  No 48 77.4 23 74.2 25 80.6

Note. PIH = pregnancy-induced hypertension; SBP = systolic blood pressure; DBP = diastolic blood pressure.

Levels of stress and anxiety did not differ significantly between the two groups at either pretest or posttest (Table 2). In the experimental group, the mean score for stress during pregnancy decreased significantly, from 62.3 (SD = 15.8) at pretest to 52.5 (SD = 8.8; p < .001) at posttest, and the mean score for anxiety status declined significantly from 40.0 (SD = 12.8) at pretest to 36.9 (SD = 10.0) at posttest (p = .003). In the control group, no significant improvement was observed for either stress or anxiety status. In terms of intergroup comparisons, the posttest mean anxiety score was significantly lower in the experimental group than in the control group (p = .03). In terms of posttest pregnancy outcomes, no significant differences were found between the two groups with respect to infant birth weeks, infant birth weight, number of medical visits, or number of hospitalizations.

Table 2 - Stress, Anxiety, and Pregnancy Outcomes, by Group (N = 62) Variable Experimental Group (n = 31) Control Group (n = 31) p M SD M SD Pregnancy Stress Rating Scale  Pretest 62.3 15.8 59.5 13.5 .457  Posttest 52.5 8.8 56.6 15.0 .238   p Value < .001 .317 State Trait Anxiety Inventory-State  Pretest 40.0 12.8 41.5 10.8 .610  Posttest 36.9 10.0 42.6 10.3 .030   p Value .003 .550 Pregnancy outcomes  Infant birth weeks 36.3 2.38 37.4 2.2 .082  Infant birth weight (grams) 2639.1 660.1 2857.0 622.6 .190  Number of medical visits 5.2 1.9 5.1 1.3 .646  Frequency of hospitalization 0.4 0.6 0.3 0.4 .353

The interactions between the groups and time were analyzed using a generalized estimation equation analysis of the changes in stress and anxiety after the case management intervention (Table 3). The results showed that posttest stress (Pregnancy Stress Rating Scale) scores were significantly lower in the experimental group (B = −8.92, p = .013) than in the control group. Moreover, group and time interaction effects were observed on the anxiety (STAI-State) score (B = −4.69, p = .031).

Table 3 - Generalized Estimating Equation Analysis of Changes in PSRS and STAI-S From Baseline (T1) to 8 Weeks (T2) Variable PSRS STAI-S B 95% Wald CI p B 95% Wald CI p Low High Low High (Intercept) 33.80 9.80 57.80 .006 28.49 11.03 45.95 .001 Time  8 weeks (T2) vs. baseline (T1) −1.48 −6.88 3.91 .590 1.29 −2.60 5.18 .510 Group  Experimental vs. control 3.97 −2.54 10.49 .230 −1.74 −7.25 3.75