Prenatal Maternal Stress and Prematurity: A Prospective Study of Socioeconomically Disadvantaged Women

Medical risks only predict one half to two thirds of adverse pregnancy outcomes. Even though elevated levels of epinephrine and norepinephrine reduces bloodflow and oxygen to the fetus, which may inhibit fetal growth and precipitate labor, studies that have explored stress factors related to low birthweight and premature delivery have found mixed. Researchers Lobel, Dunkel-Schetter, and Scrimshaw (1992) pursued the relationship between stress and adverse pregnancy outcomes in greater detail in their study of disadvantaged women. They looked at stress more holistically than previous studies and found stronger relationships.

The first major difference between this and previous studies was that Lobel et al. integrated biomedical data and psychosocial data, as opposed to just one or the other. They also looked at the relationship between weeks of gestation and birthweight, which many researchers...

These researchers' operationalization of the stress construct for their study was more explicit than other researchers', and they sought to eliminate the misidentification of medical complications during pregnancy as an adverse birth outcome. The final issue with previous research they tried to rectify was the misuse of statistical tests and analyses.
The construct the researchers tested, in conjunction with biomedical data about pregnancy risk factors, was stress -- specifically the response to the stimulus of life events, emotional state anxiety, and perceived stress. Even though the test sample was fairly homogenous, they also examined the effect social class, age, ethnicity, race, marital status, parity (whether this was the first child or not) and socioeconomic status on birth outcomes.

The sample consisted of 130 women receiving prenatal care at a public clinic with a sliding pay scale (so pretty much all low-income women). Minors were excluded from the study, so…