Colorado Prenatal Program Targeted at Specific Risk Factors Helps Reduce the Incidence of Low Birth Weight

Susan London

First published online:

Programs targeting specific factors that can increase a woman’s risk of having a low-birth-weight infant may help reduce the incidence of this outcome, according to a study of women in Colorado participating in a targeted risk reduction prenatal program.1 Nine percent of smokers who quit while pregnant had low-birth-weight infants, compared with 14% of those who did not quit. Similarly, among women who had not gained an adequate amount of weight before enrolling in the program, 7% of those who eventually gained sufficient weight, but 17% of those who did not, bore low-birth-weight infants. In addition, a larger proportion of participants who resolved all of their risks while pregnant than of those who had resolved none of them had infants who were low-birth-weight (7% vs. 13%).

The researchers analyzed data from the Colorado Prenatal Plus program, a multidisciplinary, Medicaid-funded program that complements medical prenatal care and aims to improve birth outcomes. Women can participate if they are Medicaid-eligible and are at high risk for having a low-birth-weight infant. The program aims to identify specific risk factors for this outcome and target them by providing nutritional and mental health services, and services promoting healthy lifestyles (including smoking cessation). Women receive services during visits or contacts with staff throughout pregnancy. The study focused on three risk factors and their resolution by the end of pregnancy: smoking, for which resolution was defined as self-reported smoking cessation; inadequate prenatal weight gain, for which resolution was defined as achievement of weight within the recommended range; and psychosocial problems (such as depression, domestic violence or homelessness that caused severe stress), for which resolution was defined as addressing these problems so that they no longer existed or no longer caused severe stress.

Analyses were based on 2,377 women who received Prenatal Plus services in 2002 and remained in the program through delivery. Most were Hispanic (46%) or white (43%). One-third (31%) were teenagers, and three-fourths (74%) were single. Half (54%) had had fewer than 12 years of education.

When they enrolled in the program, 43% of women smoked, 57% had gained an inadequate amount of weight during the pregnancy and 81% had psychosocial problems. Moreover, 24–47% had some combination of two of the risk factors, and 20% had all three. By the end of their pregnancy, 51% of smokers had quit, 62% of women with inadequate weight gain had achieved their recommended weight and 55% of women with psychosocial problems had addressed them. Among women who had entered the program with two risk factors, 30–37% resolved both risks before giving birth, and among women who had had all three risk factors, 20% resolved all of them.

Overall, 10% of women gave birth to an infant with a low birth weight (less than 2,500 g). Among women who had initially smoked, a significantly smaller proportion of those who quit than of their counterparts who continued smoking delivered a low-birth-weight infant (9% vs. 14%). Similarly, among women who initially had had an inadequate weight gain, a smaller proportion of those who achieved their recommended weight than of those who did not had an infant who was low-birth-weight (7% vs. 17%). Resolution of psychosocial problems was not associated with the incidence of this outcome.

Among women who had entered the program with two risk factors, significantly smaller proportions of those resolving both risks (5–9%) than of those resolving neither (15–21%) gave birth to low-birth-weight infants. Among women who had had all three risk factors at enrollment, the proportion was markedly smaller among women who resolved all of the risks than among their counterparts who resolved none (3% vs. 19%). Finally, a smaller proportion of women who resolved all of their risks (regardless of number) during pregnancy than of those who resolved none had low-birth-weight infants (7% vs. 13%).

Four in 10 women received the full package of Prenatal Plus services (at least 10 visits or contacts), while the rest received a partial package. Larger proportions of those who received the full package of services than of those who received fewer services were able to resolve all of their risks (47% vs. 39%) or at least some of them (34% vs. 29%).

In contrast to most standard prenatal interventions, the researchers observe, the targeted and multidisciplinary intervention of the Prenatal Plus program reduces the rate of low birth weight among infants born to women at high risk for this outcome. While ensuring access to multidisciplinary support services is one consideration in improving maternal and infant health, they point out, the design of these services is just as important. "Interventions are more likely to influence birth outcomes if they are targeted to the resolution of specific risks," they contend.

—S. London


1. Ricketts SA, Murray EK and Schwalberg R, Reducing low birthweight by resolving risks: results from Colorado’s Prenatal Plus program, American Journal of Public Health, 2005, 95(11):1952–1957.