Association of Fatigue and Preterm Birth in Active Duty Military

Objective: The purposes of this study were to: 1) describe the internal and external environmental demands of fatigue correlates in pregnant military women, and 2) determine the relationship between fatigue at 22-26 weeks gestation and the incidence of preterm labor and birth in military women.

Design: The study design was longitudinal, prospective, multi-site descriptive study in order to correct deficiencies in previous studies which included retrospective designs and insufficient power (numbers) to detect differences in women who delivered preterm and those who did not.

Po12ulation, Sam12le, Setting: Sampling included pregnant active duty women from 4 military treatment facilities in the United States. Between September 1995 to December 1996. Inclusion criteria included those designed to minimize confounders for preterm labor and delivery such as no history of preterm delivery. Using variables from the Environmental Demands Fatigue Model as the organizing framework, fatigue, sleep disturbance, life changes (stressors), support systems as well as demographic variables were examined. The outcome measure was defined as preterm was delivery at less than 37 weeks gestation. The sample consisted of 359 women, predominantly White (62%), enlisted (91 %), Navy (72%) with a mean age of 23.9 years.

Method: Data were collected prospectively at 22-26 weeks gestation by questionnaires including the Profile of Moods States, Visual Analog Scale-Fatigue, Sleep Disturbance Scale, Life Events Questionnaire, Support Behavior Index, and Occupational Fatigue Index (OFI). A fatigue diary was completed over 2 consecutive work days and mailed back to the Principal Investigator. Telephone follow up of hours worked per week was conducted until the participants delivered. Postpartum charts were reviewed for pregnancy outcomes

Findings: Hierarchical linear regression models with 11 variables explained 36% of the variance in fatigue while 14 variables explained 30% of the variance in energy. Independent variables making unique contributions to fatigue severity perception were sleep disturbance, negative life events and role demands. Hierarchical logistic regression models revealed no significant relationship between preterm birth (9.5%) and fatigue severity or occupational fatigue but a trend toward lower fatigue severity (X2 = 3.78, p=.0552) and posture subscale of the OFI (X2=2.39, p=.12) with preterm labor (13.6%). When placed in multivariate models, neither fatigue or occupational fatigue were related to preterm labor and birth. However, officer rank was associated with both preterm labor (OR=2.75, 95% CI=1.08, 6.98) and preterm birth (OR=4.14, 95% CI=1.54, 11.08). Low sleep disturbance (OR=2.36, 95% CI=1.09, 5.07) and negative life events (OR=1.05, 95% CI=1.01, 1.08) were also related to preterm labor.

Conclusions: These findings suggest that the military woman who is at risk for preterm labor is a high energy officer experiencing stress and that fatigue is protective against premature birth. Clinical Implications: The results support investigation of interventions which examine the pregnant officer and activities in a high energy group which may lead to preterm labor.

Final Report is available on NTRL at: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB2002107...