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Are maternal cortisol levels related to preterm birth?

OBJECTIVE
To examine the evidence related to the relationship between maternal cortisol levels and preterm birth.


DATA SOURCES
A search of Medline, PubMed, and Cumulative Index of Nursing and Allied Health Literature was conducted using the keywords preterm birth, preterm delivery, premature birth, and cortisol.


STUDY SELECTION
Fifteen studies published in English were selected based on the inclusion criteria. There were no limitations on the dates of publication.


DATA EXTRACTION
The data extracted were related to the gestational age at collection of biological samples, time of day at collection, and differences in cortisol levels between preterm and full-term groups.


DATA SYNTHESIS
The majority of the studies suggested that maternal cortisol levels are related to preterm birth. Women with higher levels of cortisol had higher risk of having a preterm birth.


CONCLUSIONS
Researchers can use the findings of this review to develop future studies that examine the relationship between cortisol levels and preterm birth. Health care providers need to assess pregnant women's stress levels more closely and provide appropriate referrals and treatment to ensure that any actions that may possibly lower stress are being taken to reduce the likelihood of preterm birth.