Birth weight distribution as an indicator of environmental effects on fetal development

Birth weight, body length, and cranial circumference in newborns with cleft lip or palate

OBJECTIVE

This paper reports on birth weight, body length, body mass index, and cranial circumference at birth of infants with cleft lip and/or palate born between 1973 and 1992.

METHODS

Data were obtained from two nationwide Swedish health registries. Infants with syndromes, twins, and infants with immigrant parentage were excluded from the study. Comparisons were made with all singleton births with the same exclusion criteria (n = 2,031,140).

RESULTS

The body dimensions of infants with isolated cleft lip (n = 865) were found not to differ from those of control subjects, but infants with isolated cleft palate (n = 811) or cleft lip and palate (n = 1139) were found to be lighter and shorter than control subjects. Also, infants with the Pierre Robin sequence (n = 121) had a tendency to be lighter and shorter than control subjects, but these differences did not reach statistical significance despite the large study population.

Poverty levels and children's health status: study of risk factors in an urban population of low socioeconomic level

To test the hypothesis that the low socioeconomic population living in shanty towns in Porto Alegre presents different levels of poverty which are reflected on its health status, a cross-sectional study was designed involving 477 families living in Vila Grande Cruzeiro, Porto Alegre, Brazil. The poverty level of the families was measured by using an instrument specifically designed for poor urban populations. Children from families living in extreme poverty (poorest quartile) were found to have higher infant mortality rate, lower birth weights, more hospitalizations, and higher malnutrition rates, in addition to belonging to more numerous families. Thus, the shanty town population of Porto Alegre is not homogeneous, and priority should be given to the more vulnerable subgroups.

Different effects of maternal and paternal education on early mortality in Norway

In order to separate the effects of maternal and paternal education on pregnancy outcome, a total population of 97,526 single, firstborn infants and their parents was studied. Census information from 1980 was linked to the Medical Birth Registry for 1978-82. Children of parents with high education (> 12 years) were the most likely to survive the first year of life. There was a linear association between parental education and infant mortality. Examining parental education jointly, it was found that the father's educational level had the greatest impact on stillbirth. Mother's educational level seemed to be more closely associated with postneonatal mortality. Possible mechanism to explain the association between educational level and infant mortality are discussed.

The outcome and experiences of first pregnancy in relation to the mother's childbirth knowledge: the Finnish Family Competence Study

The possible influence of the expectant mother's knowledge of childbirth on the outcome and experience of pregnancy and labour was investigated by means of a postpartum questionnaire in 1238 primiparae. The mothers were divided into two groups according to their basic childbirth knowledge. At birth, the conditions of newborns were equal in both groups when judged by Apgar scores. The low knowledge level group had small-for-gestational-age babies more frequently and these babies were also treated in the paediatric ward more frequently than those in the high knowledge group. The latter group was significantly more critical towards the staff of the delivery room and the postnatal ward; the fathers of this group were also present at delivery significantly more frequently. The low knowledge level group was significantly more unwilling to have another pregnancy in the near future or ever. The results indicate that low childbirth knowledge is associated with a poorer pregnancy outcome. It is a message to antenatal care staff of the need for support, supplementary education and careful obstetric surveillance. Low childbirth knowledge may imply a set of problems, including those in interparental relationship, socio-economic situation and need for close surveillance and improved education.

Reproductive outcome after anesthesia and operation during pregnancy: a registry study of 5405 cases

To define the risk of adverse reproductive outcomes after nonobstetric operations during pregnancy, we linked data from three Swedish health care registries, the Medical Birth Registry, the Registry of Congenital Malformations, and the Hospital Discharge Registry, for the years 1973 to 1981. Adverse outcomes examined were the incidences of (1) congenital anomalies, (2) stillborn infants, (3) infants dead at 168 hours, and (4) infants with very low and low birth weights. There were 5405 operations in the population of 720,000 pregnant women (operation rate, 0.75%). The incidences of congenital malformations and stillbirths were not increased in the offspring of women having an operation. However, the incidences of very-low- and low-birth-weight-infants were increased; these were the result of both prematurity and intrauterine growth retardation. The incidence of infants born alive but dying within 168 hours also was increased. No specific types of anesthesia or operation were associated with increased incidences of adverse reproductive outcomes. The cause of these outcomes was not determined.

Socio-economic variables and pregnancy outcome. Birthweight in singletons

The effect of various social indicators on birthweight in singletons was studied in Sweden with the use of a medical birth registry to which census information was linked. Two years were studied: 1976 births linked to the 1975 census, and 1981 births linked to the 1980 census. The strongest social indicator affecting birthweight was family situation: whether the woman cohabited or not. After standardization for this variable, effects were still seen for occupation and type of housing. They were not secondary to maternal age or parity. By using cohabitation status, enhanced with other social indicators, two groups were selected: one privileged and one underprivileged. Distributions of birthweight and pregnancy duration in the two groups were compared with those formed in women being neither privileged nor under privileged and also working outside the home (because occupation entered the definitions of the two former groups). There were marked differences: underprivileged women had shorter pregnancy duration and, at term, their infants weighed slightly less than those of privileged women. These differences remain after standardization for maternal age and parity.

Outcome of pregnancy in relation to irregular and inconvenient work schedules

The relation between irregular and inconvenient working hours and the outcome of pregnancy was studied among women employed at a hospital in Sweden some time between 1980 and 1984. A questionnaire was distributed to 807 women; 81% replied. The pregnancies were divided into six groups with respect to work schedules during pregnancy. A slightly, but not significantly, increased risk of miscarriage was found in women who worked irregular hours or rotating shifts compared with women who worked only during the day (RR = 1.44, 95% confidence interval 0.83-2.51). Infants of non-smoking mothers who worked irregular hours had significantly lower birth weights than infants of non-smoking women working day time only. This difference was largest at birth order 2+. Similar results were found for infants of this birth order whose non-smoking mothers worked evenings or rotating shift.