ceive. As a result, the proportion of premature infants born to mothers of higher socioeconomic status may be rising. Some data have raised the concern that infants conceived by the use of ART are more likely to be born premature or of low birth weight. Achieving access to high-quality prenatal and obstetric care for all women, regardless of socioeconomic status, race, or ethnicity, would help the realization of justice for pregnant women and neonates.

In a population-based study of birth outcomes in North Carolina (1993 to 1997), it was found that Hispanic and white women had similar rates of infant mortality, low birth weight, and prematurity but that African American women had significantly higher rates of all adverse outcomes. In that study, Hispanic women had less education than African American women but had prenatal care patterns similar to those of African American women. Hispanic women also had significantly lower rates of daily tobacco use than white or African American women. The authors could not explain why, despite similar rates of use of prenatal care use, Hispanic women had significantly better birth outcomes than African American women. They did suggest that health behaviors such as smoking may be an important difference with respect to birth outcomes (91).

In an observational study from Arizona, adolescents had a greater incidence of delivering LBW infants, with 2 percent of their deliveries being VLBW, whereas the rate was 1.1 percent among women at least 19 years old (p = 0.002) (92).

In a large population-based study in New Zealand spanning the years from 1980 to 1999, it was found that the overall rates of premature births rose from 4.3 to 5.9 percent; however, the largest increase was among families living in the least-deprived areas (a 71.9 percent increase, from 3.2 to 5.5 percent). The authors concluded that preterm births were still on the rise, potentially because of changes in ultrasound dating techniques, changes in the definition of viability, decreased numbers of stillbirths, and increased rates of assisted conception. They also concluded that the social gradient in preterm birth had disappeared, with possible reasons including changes in maternal age and parity and women’s participation in the workforce (93).

The ethical conduct of clinical research involving children was recently reviewed by the Institute of Medicine in a report published in 2004 (94). Overall, the regulations (referred to as Subpart D) and the associated ethical framework are appropriate for research involving premature infants.

Although the topic is not unique to neonatology, several themes have been the subject of investigation and commentary in the context of neonatal research. These include (a) the prospect of direct benefit to an infant from