The relationship between pregnancy wantedness and adverse pregnancy outcomes was studied using data from 2,828 mothers who participated in the Missouri Maternal and Infant Health Survey. The wantedness of a pregnancy was measured using traditional classifications of mistimed and unwanted, as well as additional measures gauging how the woman felt about the pregnancy while she was pregnant. Fifty-eight percent of the very low birth weight infants and 59% of the moderately low birth weight infants resulted from unintended pregnancies, as did 62% of the normal-birth-weight infants. Logistic regression showed that mothers of very low birth weight infants were significantly more likely than those who had a normal-weight baby to report that they had felt unhappy about the pregnancy (odds ratio of 1.53). Very low birth weight was also associated with early denial of the pregnancy (1.54). Odds ratios associating these two unwantedness categories with low-birth-weight babies were higher among Medicaid recipients than among women not receiving Medicaid. Associations between very low birth weight and the denial variable were also significant among white women when very low birth weight outcomes were compared with normal outcomes, but there was no significant association among black women. There were no significant associations between low birth weight and the traditional unwantedness variables.
PIP: This study examines the relationship between pregnancy wantedness and adverse pregnancy outcomes among 2828 mothers who participated in the Missouri Maternal and Infant Health Survey. The survey was designed as a population-based case-control study of very low birth weight infants born to Missouri residents during December 1, 1989, and March 31, 1991. Infants of moderate and normal birth weight were the controls. Stillbirths were included, but multiple pregnancies were excluded. 36% of the sample were in-patients, 38% were Black, 62% were White, 23% were teenagers, 54% were in their 20s, 52% were married, and 52% lived in a major metropolitan area. 45% of mothers qualified for Medicaid. 779 women gave birth to a low birth weight infant, 799 gave birth to a moderately low birth weight infant, and 800 gave birth to a normal birth weight infant. 450 infants were stillbirths. Pregnancy wantedness was defined by traditional measures of mistimed and unwanted pregnancies as used in the NSFG and some newer measures, such as feelings about being pregnant. Six measures were used: unintended (mistimed and unwanted), mistimed, unwanted, unhappy about the pregnancy, unsure about the pregnancy, and denial of the pregnancy. Logistic regression analysis reveals that the odds of a pregnancy being unwanted if the baby was of low birth weight were greater for the following factors: smoking during pregnancy, maternal age, race, education, health status, pre-pregnancy weight-for-height, parity, infant mortality, and in-patient status at the survey date. The sample included 42% of mistimed pregnancies, and 15% each reported the pregnancy as unwanted, unhappy, or a denial. Birth weight outcomes did not vary by age or race. Low birth weight did not differentiate the wantedness of pregnancies using the timing-wantedness scale, but did distinguish on the happiness scale and denial measures.