Utility of Population Attributable Fraction Assessment in Guiding Interventions to Reduce Low Birthweight in the High-Altitude State of Colorado.

Objectives We evaluated the ability of population attributable fraction (PAF) assessments to alter significant modifiable risks for low birthweight (LBW) and the impact of high altitude as a risk for LBW in Colorado. Methods Logistic regression analysis of birth certificate parameters in 1995-1997 identified risk factors for PAF assessment. PAF for birth at high altitude, multiple births, and LBW in singleton births were determined. Subsequent analysis of singleton LBW risks, using number needed to treat (NNT) analysis, estimated how elimination of major modifiable risk factors could reduce LBW in the study population. Public health interventions were initiated and PAF analysis conducted 12 years afterward to determine the effect of interventions. Results PAF in singleton births revealed low maternal weight gain in pregnancy and maternal smoking as the greatest modifiable attributable risk factors for LBW (12.7/12.5 %, respectively, in 1995-1997 and 12.9/7.1 % in 2007-2009). Significant interaction between these variables resulted in PAF of 34.4 % when the two occurred together in 1995-1997, decreasing to 19.4 % in 2007-2009. NNT analysis of singleton births in 1995-1997 revealed that eliminating low maternal weight gain, smoking, late prenatal care in all women and interpregnancy intervals <1 year in multiparous women reduced LBW by 46.5 %. The respective proportional reductions in PAF of 40.3 and 46.3 % for maternal smoking and weight gain/smoking interaction were associated with a 1.4 % LBW reduction in singleton births between the two study periods. Conclusions for Practice PAF and NNT analyses are valuable tools to predict intervention targets to lower LBW.

The Effect of Omega-3 Docosahexaenoic Acid Supplementation on Gestational Length: Randomized Trial of Supplementation Compared to Nutrition Education for Increasing n-3 Intake from Foods.

OBJECTIVE: DHA supplementation was compared to nutrition education to increase DHA consumption from fish and DHA fortified foods. DESIGN: This two-part intervention included a randomized double-blind placebo controlled DHA supplementation arm and a nutrition education arm designed to increase intake of DHA from dietary sources by 300 mg per day. SETTING: Denver Health Hospitals and Clinics, Denver, Colorado, USA. POPULATION: 871 pregnant women aged 18-40 were recruited between 16 and 20 weeks of gestation of whom 564 completed the study and complete delivery data was available in 505 women and infants. METHODS: Subjects received either 300 or 600 mg DHA or olive oil placebo or nutrition education. MAIN OUTCOME VARIABLE: Gestational length. RESULTS: Gestational length was significantly increased by 4.0-4.5 days in women supplemented with 600 mg DHA per day or provided with nutrition education. Each 1% increase in RBC DHA at delivery was associated with a 1.6-day increase in gestational length. No significant effects on birth weight, birth length, or head circumference were demonstrated. The rate of early preterm birth (1.7%) in those supplemented with DHA (combined 300 and 600 mg/day) was significantly lower than in controls. CONCLUSION: Nutrition education or supplementation with DHA can be effective in increasing gestational length.

Readily treatable reproductive tract infections and preterm birth among black women.

OBJECTIVE: This study sought to quantify the risks of preterm birth that are ascribable to potentially treatable reproductive tract infections among black women in Denver, Colorado. STUDY DESIGN: A secondary analysis was conducted of 4 prospective studies in Denver, Colorado, that included 1038 women who were enrolled at < 29 weeks of gestation and whose cases were followed through delivery. Rates of preterm birth, preterm labor, and preterm premature rupture of membranes were the primary outcomes that were examined. RESULTS: Bacterial vaginosis, infection with Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma hominis, Neisseria gonorrhoeae, and group B streptococcal colonization were more common among black women (P < .01) than among comparators. Preterm birth occurred more often among black women with infections that were being studied (20.4%), compared with uninfected black women (9.5%; relative risk, 2.2; 95% CI, 1.1-4.1). Up to 42% of preterm births among black women were attributable to the presence of bacterial vaginosis, T vaginalis, or C trachomatis alone or in combinations. The risk for preterm birth among infected black women who received Centers for Disease Control and Prevention recommended treatment was reduced significantly (relative risk, 0.16; 95% CI, 0.04-0.66). CONCLUSION: Black women have increased risks of prematurity that are associated with prevalent reproductive tract infections during pregnancy. Preterm birth among similar urban black women could be reduced by > 40% by the screening and treatment of common genitourinary tract infections in pregnancy.