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Preterm Birth and Social Support during Pregnancy: a Systematic Review and Meta-Analysis.

BACKGROUND
Additional social support is often recommended for women during the prenatal period to optimise birth outcomes, specifically to avoid preterm birth. Social support is thought to act in one of two ways: by reducing stress and anxiety, or by providing coping mechanisms for women with high stress. However, evidence in this area is mixed. The purpose of this meta-analysis is to determine if low levels of social support are associated with an increased risk for preterm birth.


METHODS
Six databases were searched for randomised control trials and cohort studies regarding social support and preterm birth with no limits set on date or language. Inclusion criteria included the use of a validated instrument to measure social support, and studies conducted in high-income or high-middle-income countries.


RESULTS
There were 3467 records retrieved, 16 of which met the inclusion criteria. Eight studies (n = 14 630 subjects) demonstrated a pooled odds ratio (OR) of 1.22 (95% CI 0.84, 1.76) for preterm birth in women with low social support compared with high social support. Among women with high stress levels, two studies (n = 6374 subjects) yielded a pooled OR of 1.52 (95% CI 1.18, 1.97). The results of six studies could not be pooled due to incompatibility of outcome measures.


CONCLUSIONS
There is no evidence for a direct association between social support and preterm birth. Social support, however, may provide a buffering mechanism between stress and preterm birth.