Role of psychotherapy on antenatal depression, anxiety, and maternal quality of life: A meta-analysis

Optimizing Psychological Health Across the Perinatal Period: An Update on Maternal Cardiovascular Health: A Scientific Statement From the American Heart Association

Perinatal psychological health conditions (eg, perinatal depression, anxiety) are some of the leading causes of maternal mortality in the United States and are associated with adverse pregnancy outcomes, long-term cardiovascular outcomes, and intergenerational effects on offspring neurodevelopment. These risks underscore the importance of addressing maternal psychological health as a key determinant of perinatal cardiovascular health. Thus, it is vital to recognize the spectrum of perinatal psychological health and to provide guidance for both patients and clinicians on screening and management options across the perinatal period. In this scientific statement from the American Heart Association, we redefine maternal cardiovascular health to include psychological health, provide robust evidence on the association of psychological health with cardiovascular outcomes, highlight the social and environmental underpinnings, and finally, offer guidance about how to integrate psychological health into maternal cardiovascular health with a specific focus on the perinatal period (ie, pregnancy through 1 year postpartum). We also describe opportunities for creating care delivery models that recurrently address perinatal psychological health in cardio-obstetric care, using behavioral and pharmacological interventions, with an emphasis on better integration of psychological health care, longer postpartum follow-up, and opportunities for evaluating the comparative effectiveness of these models with stakeholder partners.

Integrating WHO thinking healthy programme for maternal mental health into routine antenatal care in China: a randomized-controlled pilot trial

Background

Women with perinatal depression and their children are at increased risk of poor health outcomes. Integrating evidence based non-stigmatizing interventions within existing health systems is crucial to reducing psychosocial distress during pregnancy and preventing perinatal depression. This study aimed to evaluate the feasibility of the World Health Organization (WHO) endorsed cognitive-behavior therapy-based Thinking Healthy Programme (THP), delivered by antenatal nurses in China.

Methods

A two-arm pilot randomized controlled pilot trial was conducted to assess the feasibility and of the adapted Chinese version of the Thinking Healthy Programme (THP) among various stakeholders. We recruited pregnant women between 25- and 34-weeks' gestation from two pregnancy schools within the two public sector Hospitals in Xian. Participants in the intervention group attended five face to face sessions of THP facilitated by antenatal nurses. This intervention used cognitive behavior therapy principles to offer psychoeducation, behavioral activation, problem-solving strategies, and social support. In the control group, participants received standard care, which included routine pregnancy education classes led by antenatal nurses. We assessed depressive symptoms using the Patient Health Questionnaire-9 (PHQ-9) at baseline, after the intervention and 4-6 weeks post-intervention, along with evaluations of anxiety, perceived social support, and health-related quality of life.

Results

Among the 737 pregnant women screened, 267 (30.26%) scored ≥5 on the PHQ-9. Out of these, 85 were eligible and consented to participate, with 42 assigned to the intervention group and 43 to the control group. Eighty participants (94.1%) completed the final assessments. Our primary findings indicated that this nurse-delivered intervention was feasible to integrate into routine antenatal care and was well-received by both the women and the delivery agents. Although the study was not designed to detect differences between the intervention and control groups, we observed positive trends towards reductions in anxiety and depressive symptoms favoring the intervention arm. No serious adverse events were reported. This trial is registered in the Chinese Clinical Trial Registry with the registration number ChiCTR1900028114.

Conclusions

We conclude that this intervention, grounded in the well-established WHO Thinking Healthy Programme, is both feasible and acceptable to stakeholders. It merits a definitive randomized trial to assess its effectiveness and cost-effectiveness across various settings.

Clinical Trial Registration

ChiCTR1900028114.

New treatments: Opportunities and challenges

Across the spectrum of perinatal mental illness, there exist a variety of effective treatments. However, the available treatments are not always matched to the presentation, resources, constraints, or values of each patient. Furthermore, provider, local, and systemic factors complicate access to current treatment options. New and emerging approaches offer the potential of more effective treatment for specific perinatal psychiatric disorders. From neuroactive steroid medications to accelerated psychotherapy interventions, recent innovations have demonstrated enhanced efficacy on a faster timeline. Optimally, these developments will also lower barriers to care but this is not necessarily true. We review novel and upcoming interventions across perinatal mental illness and place them in the context of existing treatments and common challenges.

Efficacy and safety of a mineral and vitamin treatment on symptoms of antenatal depression: 12-week fully blinded randomised placebo-controlled trial (NUTRIMUM)

BACKGROUND

Broad-spectrum micronutrients (minerals and vitamins) have shown benefit for treatment of depressive symptoms.

AIMS

To determine whether additional micronutrients reduce symptoms of antenatal depression.

METHOD

Eighty-eight medication-free pregnant women at 12-24 weeks gestation, who scored ≥13 on the Edinburgh Postnatal Depression Scale (EPDS), were randomised 1:1 to micronutrients or active placebo (containing iodine and riboflavin), for 12 weeks. Micronutrient doses were generally between recommended dietary allowance and tolerable upper level. Primary outcomes (EPDS and Clinical Global Impression - Improvement Scale (CGI-I)) were analysed with constrained longitudinal data analysis.

RESULTS

Seventeen (19%) women dropped out, with no group differences, and four (4.5%) gave birth before trial completion. Both groups improved on the EPDS, with no group differences (P = 0.1018); 77.3% taking micronutrients and 72.7% taking placebos were considered recovered. However, the micronutrient group demonstrated significantly greater improvement, based on CGI-I clinician ratings, over time (P = 0.0196). The micronutrient group had significantly greater improvement on sleep and global assessment of functioning, and were more likely to identify themselves as 'much' to 'very much' improved (68.8%) compared with placebo (38.5%) (odds ratio 3.52, P = 0.011; number needed to treat: 3). There were no significant group differences on treatment-emergent adverse events, including suicidal ideation. Homocysteine decreased significantly more in the micronutrient group. Presence of personality difficulties, history of psychiatric medication use and higher social support tended to increase micronutrient response compared with placebo.

CONCLUSIONS

This study highlights the benefits of active monitoring on antenatal depression, with added efficacy for overall functioning when taking micronutrients, with no evidence of harm. Trial replication with larger samples and clinically diagnosed depression are needed.

Screening, Assessment, and Treatment of Perinatal Mental Health in Obstetrical Settings

Perinatal mood and anxiety disorders (PMADs) are common, yet obstetricians receive little training prior to independent practice on screening, assessing, diagnosing, and treating patients with depression and anxiety. Untreated PMADs lead to adverse pregnancy and fetal outcomes. Obstetricians are in a unique position to address PMADs. The following serves as a resource for addressing PMADs in obstetric practice.

Treatment and Management of Mental Health Conditions During Pregnancy and Postpartum: ACOG Clinical Practice Guideline No. 5

PURPOSE

To assess the evidence regarding safety and efficacy of psychiatric medications to treat mental health conditions during pregnancy and lactation. The conditions reviewed include depression, anxiety and anxiety-related disorders, bipolar disorder, and acute psychosis. For information on screening and diagnosis, refer to American College of Obstetricians and Gynecologists (ACOG) Clinical Practice Guideline Number 4, "Screening and Diagnosis of Mental Health Conditions During Pregnancy and Postpartum" (1).

TARGET POPULATION

Pregnant or postpartum individuals with mental health conditions with onset that may have predated the perinatal period or may have occurred for the first time in pregnancy or the first year postpartum or may have been exacerbated in that time.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one specialist in obstetrics and gynecology and one maternal-fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by two authors from the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes recommendations on treatment and management of perinatal mental health conditions including depression, anxiety, bipolar disorders, and acute postpartum psychosis, with a focus on psychopharmacotherapy. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Psychological treatment of perinatal depression: a meta-analysis

BACKGROUND

Depression during pregnancy and after the birth of a child is highly prevalent and an important public health problem. Psychological interventions are the first-line treatment and, although a considerable number of randomized trials have been conducted, no recent comprehensive meta-analysis has evaluated treatment effects.

METHODS

We used an existing database of randomized controlled trials of psychotherapies for adult depression and included studies aimed at perinatal depression. Random effects models were used in all analyses. We examined the effects of the interventions in the short and long term, and also examined secondary outcomes.

RESULTS

Forty-three studies with 49 comparisons and 6270 participants between an intervention and control group were included. The overall effect size was g = 0.67 [95% confidence interval (CI) 0.45~0.89; numbers needed-to-be-treated = 4.39] with high heterogeneity (I2 = 80%; 95% CI 75~85). This effect size remained largely unchanged and significant in a series of sensitivity analyses, although some publication bias was found. The effects remained significant at 6-12 months follow-up. Significant effects were also found for social support, anxiety, functional limitations, parental stress and marital stress, although the number of studies for each outcome was low. All results should be considered with caution because of the high levels of heterogeneity in most analyses.

CONCLUSIONS

Psychological interventions are probably effective in the treatment of perinatal depression, with effects that last at least up to 6-12 months and probably also have effects on social support, anxiety, functional impairment, parental stress, and marital stress.

Health-Related Quality of Life Among Chinese Pregnant Women in the Third Trimester Based on Theory of Unpleasant Symptoms: A Complex Network Analysis

Health-related quality of life (HRQOL) is the result of complex interactions between many different factors. But few studies to date have explored the structure of HRQOL. This study aimed to investigate the complex inter-relationship between HRQOL and influencing factors using network analysis. In all, 624 Chinese pregnant women in third trimester were recruited through recruiting sampling. We used regularized network analysis to create a complex network. The relationship with mother-in-law was the most central node followed by relationship with partner. We found the comorbidity of anxiety and depressive symptoms using network analysis. Physical- and mental-related quality of life were a "bridge node" connecting psychological factors with physiologic factors. The present network analysis highlights the strong link between relationship with mother-in-law or partner and HRQOL, which is also a unique phenomenon under Chinese culture. This analysis provides key variables for future intervention or improvement of pregnant women' HRQOL.

Effect of transcranial direct current stimulation on postpartum depression: A study protocol for a randomized controlled trial

Postpartum depression (PPD) is a complex combination of physiological, emotional, and behavioral alterations associated with postpartum chemical, social, and psychological variations. It does harm to the relationship between family members that could potentially last for years. However, standard depression treatments are not ideal for PPD, and the outcomes of these treatments are debatable. Transcranial direct current stimulation (tDCS) is an emerging technology that could provide patients with PPD with a safe and non-pharmacological treatment. tDCS can relieve depression by directly stimulating the prefrontal cortex through the excitatory effect of the anode. It may also ease depression indirectly by promoting the production and release of the neurotransmitter GABA. The mechanism of tDCS makes it an ideal therapeutic approach to treat PPD, although it has not been widely used, and its effect has not been evaluated systematically and effectively. A double-blind, randomized controlled trial will be conducted involving 240 tDCS-naive patients with PPD, who will be randomly divided into two groups. One group will receive routine clinical treatment and care with active tDCS, and the other group will receive routine clinical treatment and care with sham tDCS. Each group of patients will receive a 3-week intervention during which they will receive 20 min of active or sham tDCS 6 days per week. The Montgomery-Åsberg Depression Rating Scale will be administered before the intervention as a baseline and on each weekend throughout the intervention phase. Before and after the intervention, the Perceived Stress Scale and the Positive and Negative Affect Schedule will be evaluated. Side effects and abnormal reactions will be recorded during each treatment. As antidepressants are banned in the study, the results will not be affected by drugs and will therefore be more accurate. Nonetheless, this experiment will be conducted in a single center as a small sample experiment. Therefore, future studies are required to confirm the effectiveness of tDCS in treating PPD.

The Fibrinolytic System in Peripartum Depression

The relationship between depression and reduced fibrinolytic activity reflects the role of tissue plasminogen activator and plasmin in brain remodeling underlying resilience, depression remission, and reward processing, rather than the dissolution of fibrin clots. Individuals who experience depression demonstrate hippocampal and prefrontal cortex atrophy, as well as impaired neuronal connectivity. Brain-derived neurotrophic factor (BDNF), synthesized as a precursor that is activated through cleavage by tissue plasminogen activator and plasmin, influences adult neurogenesis and neuronal plasticity in the hippocampus and prefrontal cortex. Depression is associated with decreased brain levels of BDNF, due to reduced activity of tissue plasminogen activator and plasmin. Tissue plasminogen activator and plasmin also mediate the release of dopamine, a neurotransmitter implicated in motivation and reward. Peripartum depression defines a depressive episode that occurs during pregnancy or in the first month after delivery, reinforcing the concept that postpartum depression may be a continuum of antenatal depression. This article describes the fibrinolytic status in the healthy brain, in stress and depression, emphasizing the links between biological markers of depression and defective fibrinolysis. It also discusses the association between hypofibrinolysis and risk factors for perinatal depression, including polycystic ovary syndrome, early miscarriage, preeclampsia, stressful life events, sedentariness, eating habits, gestational and type 2 diabetes, and antithyroid peroxidase antibodies. In addition, it reviews the evidence that antidepressant medications and interventions as diverse as placebo, psychotherapy, massage, video game playing, regular exercise, dietary modifications, omega 3 fatty acid supplementation, neurohormones, and cigarette smoking may reduce depression by restoring the fibrinolytic activity. Last, it suggests new directions for research.

Cognitive behavioral therapy in perinatal mental health: An overview of systematic reviews

AIM

The purpose of this study was to determine whether cognitive behavioral therapy (CBT) started in pregnancy can prevent depression and anxiety.

METHODS

We conducted an overview review by selecting systematic reviews (SRs) that compared CBT with usual care, no CBT, or interventions other than CBT in perinatal women. We restricted the review to studies that included randomized controlled trials. The results of included SRs were descriptively integrated according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Seven SRs met our eligibility criteria. One SR was limited to CBT interventions, whereas others included psychoeducation and interpersonal psychotherapy. There was some variation in the number of sessions and timing of CBT, and whether there was a postpartum intervention. Five SRs showed that CBT reduced depression compared with usual care, an educational intervention, or no intervention. One SR that analyzed the effect on anxiety found that psychotherapy, including CBT, reduced anxiety compared with usual care or no intervention.

DISCUSSION

CBT starting from pregnancy may be effective as a preventive intervention for postpartum depression and anxiety, although the degree of effectiveness varied.

CONCLUSIONS

This overview review aimed to clarify whether CBT is effective in preventing depression and anxiety from pregnancy. CBT may be effective in reducing perinatal depression and anxiety.

Patterns of peripartum depression screening and detection in a large, multi-site, integrated healthcare system

The purpose of this study was to examine peripartum depression (PD) screening patterns within and across the prenatal and postpartum periods and assess the incidence of new positive screens during standard screening protocol timepoints to inform practice, particularly when limited screenings can be conducted.This is a retrospective observational study of women screened for PD through a large, integrated health system using the Edinburgh Postnatal Depression Scale (EPDS) within their obstetrics and pediatric practices. Pregnancies with an EPDS score for at least one obstetric and one pediatric appointment between November 2016 and October 2019 were included (n = 3240). The data were analyzed using chi-squared test, Student's t-test, and binary logistic regression analyses. An EPDS score of 10 or higher was considered a positive screen.The positive screening rate for this cohort was 18.5%, with a prenatal positive rate of 9.9% and a postpartum positive rate of 8.6%. Single relationship status showed a higher rate of PD overall. Two thirds of women were not screened until their third trimester, resulting in delayed detection for an estimated 28% of women who ultimately screened positive. Few new positive screens (1.3%) were detected after 9 weeks postpartum in women who had completed all recommended prior screens.Obstetric providers should screen for PD as early in pregnancy as possible and continue to screen as often as feasible regardless of previous negative EPDS scores. Prioritizing screening more often in pregnancy and before 9 weeks postpartum is optimal to avoid delays in detection and intervention.

Psychological Interventions for Prenatal Anxiety in Latinas and Black Women: A Scoping Review and Recommendations

Anxiety symptoms are common among pregnant women worldwide. In the United States, prenatal anxiety symptoms tend to be elevated among Black and Latin American women as compared to non-Latina White women. Despite the high prevalence of anxiety and associations with adverse maternal and offspring outcomes, interventions have not been developed or tailored sufficiently to Black women or Latinas who need efficacious treatment. This article provides a scoping review of articles published since 2017 that test the effects of randomized and non-randomized psychological interventions designed to reduce prenatal anxiety in samples comprised primarily of ethnic/racial minority women. We also review published protocols of planned psychological interventions to reduce prenatal anxiety in order to highlight novel approaches. In addition to summarizing intervention efficacy and participant acceptability, we highlight gaps in the literature which, if addressed, could improve perinatal mental health equity. Finally, we discuss future directions in prenatal anxiety intervention science beginning preconception including intervention design and prevention models.

Associations of physical activity, sedentary behavior and sleep duration with anxiety symptoms during pregnancy: An isotemporal substitution model

BACKGROUND

Studies have evidenced the close relationships between movement behavior [physical activity (PA), sedentary behavior (SB), and sleep duration)] and anxiety. Capturing 24 h of these maternal movement behaviors during pregnancy is necessary to understand their relationships.

METHODS

In a cross-sectional study design, a total of 946 prenatal women filled Pregnancy Physical Activity Questionnaire-Chinese version, Pregnancy-Related Anxiety Questionnaire, and 7-item Generalised Anxiety Disorders scale between May 2020 and April 2021. An Isotemporal Substitution Model was used to estimate the per-hour effects of replacing one behavior.

RESULTS

Replacing moderate-to-vigorous PA(MVPA), light PA (LPA), or SB with sleep could reduce both general and pregnancy-specific anxiety (LPA, B = -0.61∼-0.37, P ≤ 0.01; MVPA, B = -0.35, P = 0.03; SB, B = -0.45∼-0.34, P ≤ 0.01). Replacing SB with MVPA could reduce pregnancy-specific anxiety in the group without adequate sleep duration (SB, B = -0.62,95%CI = -1.13∼-0.17). As for the types of PA, replacing household, occupational or inactivity PA with transportation PA or sleep duration reduced general anxiety (household PA: B = -0.51, 95%CI = -0.73∼-0.29, P < 0.001; occupational PA: B = -0.48, 95%CI = -0.69∼-0.27, P < 0.001; inactivity: B = -0.45, 95%CI = -0.68∼-0.24, P < 0.001). Replacing household PA, occupational PA, or inactivity with transport PA was associated with improved general anxiety (household: B = -0.33, 95%CI = -0.64∼-0.03, P = 0.29; occupational PA: B = -0.31, 95%CI = -0.62∼-0.003, P = 0.35; inactivity: B = -0.28, 95%CI = -0.56∼-0.01, P = 0.33).

LIMITATIONS

A cross-sectional study design and self-reported measurement limits the reliability of study.

CONCLUSION

Longer time spent in sleep and MVPA may mitigate the negative effects of SB on anxiety.

Digitalized Cognitive Behavioral Interventions for Depressive Symptoms During Pregnancy: Systematic Review

BACKGROUND

Studies have shown a high prevalence of depression during pregnancy, and there is also evidence that cognitive behavioral therapy (CBT) is one of the most effective psychosocial interventions. Emerging evidence from randomized controlled trials (RCTs) has shown that technology has been successfully harnessed to provide CBT interventions for other populations. However, very few studies have focused on their use during pregnancy. This approach has become increasingly important in many clinical areas due to the COVID-19 pandemic, and our study aimed to expand the knowledge in this particular clinical area.

OBJECTIVE

Our systematic review aimed to bring together the available research-based evidence on digitalized CBT interventions for depression symptoms during pregnancy.

METHODS

A systematic review of the Web of Science, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, Embase, PsycINFO, Scopus, ClinicalTrials.gov, and EBSCO Open Dissertations databases was carried out from the earliest available evidence to October 27, 2021. Only RCT studies published in English were considered. The PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-analyses) guidelines were followed, and the protocol was registered on the Prospective Register of Systematic Reviews. The risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

The review identified 7 studies from 5 countries (the United States, China, Australia, Norway, and Sweden) published from 2015 to 2021. The sample sizes ranged from 25 to 1342 participants. The interventions used various technological elements, including text, images, videos, games, interactive features, and peer group discussions. They comprised 2 guided and 5 unguided approaches. Using digitalized CBT interventions for depression during pregnancy showed promising efficacy, with guided intervention showing higher effect sizes (Hedges g=1.21) than the unguided interventions (Hedges g=0.14-0.99). The acceptability of the digitalized CBT interventions was highly encouraging, based on user feedback. Attrition rates were low for the guided intervention (4.5%) but high for the unguided interventions (22.1%-46.5%). A high overall risk of bias was present for 6 of the 7 studies.

CONCLUSIONS

Our search only identified a small number of digitalized CBT interventions for pregnant women, despite the potential of this approach. These showed promising evidence when it came to efficacy and positive outcomes for depression symptoms, and user feedback was positive. However, the overall risk of bias suggests that the efficacy of the interventions needs to be interpreted with caution. Future studies need to consider how to mitigate these sources of biases. Digitalized CBT interventions can provide prompt, effective, evidence-based interventions for pregnant women. This review increases our understanding of the importance of digitalized interventions during pregnancy, including during the COVID-19 pandemic.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42020216159; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=216159.

Resilience mediates the effect of self-efficacy on symptoms of prenatal anxiety among pregnant women: a nationwide smartphone cross-sectional study in China

Background

Prenatal anxiety is one of the most prevalent mental disorders during pregnancy. This study assessed the prevalence of prenatal anxiety and examined whether resilience could play the mediating role in the association between self-efficacy and symptoms of prenatal anxiety among pregnant women in China.

Methods

A nationwide smartphone cross-sectional study was carried out in three cities (Shenyang of Liaoning Province, Zhengzhou of Henan Province and Chongqing Municipality) in China from July 2018 to July 2019. The questionnaire consisted of questions on demographic characteristics, the Generalized Anxiety Disorder Scale (GAD-7), the Chinese version of General Self-efficacy Scale (GSES), and the 14-item Wagnild and Young Resilience Scale (RS-14). A total of 665 pregnant women were recruited in this study. A hierarchical multiple regression model was employed to explore the associate factors and mediators of symptoms of prenatal anxiety. A structural equation model was employed to test the hypothesis that resilience mediates the association between self-efficacy and symptoms of prenatal anxiety.

Results

The prevalence of symptoms of prenatal anxiety was 36.4% in this study. Self-efficacy was negatively correlated with symptoms of prenatal anxiety (r = -0.366, P < 0.01). Resilience had a significant positive correlation with self-efficacy (r = 0.612, P < 0.01) and had a negative correlation with symptoms of prenatal anxiety (r = -0.427, P < 0.01). The hierarchical multiple regression model indicated that self-efficacy and resilience were the main factors associated with symptoms of prenatal anxiety and contributed to 11.9% and 6.3% to the variance of symptoms of prenatal anxiety, respectively. Resilience served as a mediator between self-efficacy and symptoms of prenatal anxiety (a*b = -0.198, Bias-corrected and accelerated bootstrap 95% Confidence interval: -0.270, -0.126).

Conclusions

Self-efficacy was a negative predictor of symptoms of prenatal anxiety among pregnant women. Moreover, resilience mediated the relation between self-efficacy and symptoms of prenatal anxiety among pregnant women in China. It was observed in this study that psychological interventions might be beneficial for pregnant women to relieve symptoms of prenatal anxiety through improved self-efficacy and resilience.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03911-5.

Current Resources for Evidence-Based Practice, November 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of diversity in the maternity care workforce and commentaries on reviews focused on burnout in midwifery and a cross-national comparison of guidelines for uncomplicated childbirth.