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BMC Pregnancy and Childbirth May 2009The vast majority of global stillbirths occur in low- and middle-income countries, and in many settings, the majority of stillbirths occur antenatally, prior to the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The vast majority of global stillbirths occur in low- and middle-income countries, and in many settings, the majority of stillbirths occur antenatally, prior to the onset of labour. Poor nutritional status, lack of antenatal care and a number of behaviours increase women's risk of stillbirth in many resource-poor settings. Interventions to reduce these risks could reduce the resulting burden of stillbirths, but the evidence for the impact of such interventions has not yet been comprehensively evaluated.
METHODS
This second paper of a systematic review of interventions that could plausibly impact stillbirth rates covers 12 different interventions relating to behavioural and socially mediated risk factors, including exposures to harmful practices and substances, antenatal care utilisation and quality, and maternal nutrition before and during pregnancy. The search strategy reviewed indexed medical journals on PubMed and the Cochrane Library. If any eligible randomised controlled trials were identified that were published after the most recent Cochrane review, they were added to generate new meta-analyses. Interventions covered in this paper have a focus on low- and middle-income countries, both because of the large burden of stillbirths and because of the high prevalence of risk factors including maternal malnutrition and harmful environmental exposures. The reviews and studies belonging to these interventions were graded and conclusions derived about the evidence of benefit of these interventions.
RESULTS
From a programmatic perspective, none of the interventions achieved clear evidence of benefit. Evidence for some socially mediated risk factors were identified, such as exposure to indoor air pollution and birth spacing, but still require the development of appropriate interventions. There is a need for additional studies on culturally appropriate behavioural interventions and clinical trials to increase smoking cessation and reduce exposure to smokeless tobacco. Balanced protein-energy supplementation was associated with reduced stillbirth rates, but larger well-designed trials are required to confirm findings. Peri-conceptional folic acid supplementation significantly reduces neural tube defects, yet no significant associated reductions in stillbirth rates have been documented. Evidence for other nutritional interventions including multiple micronutrient and Vitamin A supplementation is weak, suggesting the need for further research to assess potential of nutritional interventions to reduce stillbirths.
CONCLUSION
Antenatal care is widely used in low- and middle-income countries, and provides a natural facility-based contact through which to provide or educate about many of the interventions we reviewed. The impact of broader socially mediated behaviors, such as fertility decision-making, access to antenatal care, and maternal diet and exposures like tobacco and indoor air pollution during pregnancy, are poorly understood, and further research and appropriate interventions are needed to test the association of these behaviours with stillbirth outcomes. For most nutritional interventions, larger randomised controlled trials are needed which report stillbirths disaggregated from composite perinatal mortality. Many antepartum stillbirths are potentially preventable in low- and middle-income countries, particularly through dietary and environmental improvement, and through improving the quality of antenatal care - particularly including diagnosis and management of high-risk pregnancies - that pregnant women receive.
Topics: Air Pollution, Indoor; Birth Intervals; Causality; Circumcision, Female; Dietary Supplements; Evidence-Based Medicine; Female; Fetal Death; Global Health; Health Services Accessibility; Humans; Pregnancy; Pregnancy Complications; Prenatal Care; Prenatal Nutritional Physiological Phenomena; Risk Reduction Behavior; Stillbirth; Tobacco Use Cessation
PubMed: 19426466
DOI: 10.1186/1471-2393-9-S1-S3 -
American Journal of Obstetrics and... Dec 2005This is a systematic review of the literature on the causes of stillbirth and clinical opinion regarding strategies for its prevention. (Review)
Review
OBJECTIVE
This is a systematic review of the literature on the causes of stillbirth and clinical opinion regarding strategies for its prevention.
STUDY DESIGN
We reviewed the causes of stillbirth by performing a Medline search limited to articles in English published in core clinical journals from January 1, 1995, to January 1, 2005. Articles before this date were included if they added historical information relevant to the topic. A total of 1445 articles obtained, 113 were the basis of this review and chosen based on the criterion that stillbirth or fetal death was central to the article.
RESULTS
Fifteen risk factors for stillbirths were identified and the prevalence of these conditions and associated risks are presented The most prevalent risk factors for stillbirth are prepregnancy obesity, socioeconomic factors, and advanced maternal age. Biologic markers associated with increased stillbirth risk are also reviewed, and strategies for its prevention identified.
CONCLUSION
Identification of risk factors for stillbirth assists the clinician in performing a risk assessment for each patient. Unexplained stillbirths and stillbirths related to growth restriction are the 2 categories of death that contribute the most to late fetal losses. Late pregnancy is associated with an increasing risk of stillbirth, and clinicians should have a low threshold to evaluate fetal growth. The value of antepartum testing is related to the underlying risk of stillbirth and, although the strategy of antepartum testing in patients with increased risk will decrease the risk of late fetal loss, it is of necessity associated with higher intervention rates.
Topics: Abruptio Placentae; Birth Weight; Comorbidity; Female; Fetal Death; Humans; Infertility; Lupus Erythematosus, Systemic; Maternal Age; Obesity; Pregnancy; Pregnancy Complications; Pregnancy, Multiple; Pregnancy-Associated Plasma Protein-A; Risk Factors; Stillbirth; Thrombophilia; United States
PubMed: 16325593
DOI: 10.1016/j.ajog.2005.03.074