Objective: To test the effect of telephone calls from registered nurses to low-income pregnant women on the rates of low birth weight (LBW) and preterm births.
Methods: A total of 1554 women receiving prenatal care in a public clinic who met study criteria and who consented were assigned randomly to intervention and control groups. Women in the intervention group received telephone calls from a registered nurse, one or two times weekly from 24 weeks' through 37 weeks' gestation. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated.
Results: Low birth weight rates were 10.9% in the intervention group and 14.0% in the control group (RR 0.75; 95% CI 0.55, 1.03; P = .072). For gestational age less than 37 weeks, rates were 9.7 in the intervention group and 11.0 in the control group (RR .87; 95% CI 0.62, 1.22; P = .415). In the subgroup of low-income black women 19 years of age and older, a statistically significant difference was found in preterm birth rates before 37 weeks (8.7% in the intervention group versus 15.4% in the controls [RR 0.56; 95% CI 0.38, 0.84; P = .004]).
Conclusion: There was no difference in LBW or preterm births between intervention and control groups in the total sample. In a secondary analysis of black subjects 19 years of age and older, there was a significant difference in preterm birth rates.