[Risk factors for low birth weight and intrauterine growth retardation in Santiago, Chile].

An epidemiologic case-control study to ascertain the determinants of low birthweight was carried out in Santiago, Chile, from January to December 1989. The cases were defined as livebirths < 2500 g. The controls were livebirths > or = 2500 g of birthweight. All cases and a random sample (1:1) of controls were selected among 8,254 singleton births occurring at the El Salvador Hospital in the Eastern area of Santiago. These deliveries represented 50% of institutional deliveries in the area. Home deliveries (2%) and private hospital deliveries were not included in the study. Information was obtained from hospital medical records by six trained medical students. Some information could not be obtained from the hospital medical records. Thus the second step in data collection was the tracking of all the selected subjects to their referring neighborhood health centers. For the analysis, the data were divided into 3 case (outcome) categories: 453 subjects were the total case group. From these, 153 were the IUGR case group and 300 were the LBW preterm case group. The general control group consisted of 605 normal birthweight infants. 565 were the IUGR control group and 40 were the preterm control group. A total of 25 risk factors showed a significant crude odds ratio for at least one of the groups. In the multivariate logistic regression analysis eight variables: No. of pregnancies, previous adverse outcomes, previous LBW, pregnancy maternal weight, No. of visits, month of first prenatal care visit, maternal smoking and intrahepatic cholestasis of pregnancy, were significantly associated with LBW after adjustment by confounding. Eight risk factors: IUGR in previous pregnancies, Previous adverse outcome, Maternal smoking, intrahepatic cholestasis, maternal pregnancy weight, maternal height, month first prenatal visit, No. of visit, were significant to IUGR. Only two variables: pregnancy weight, divorced mother, were significantly associated with low birth weight in the preterm group. The most relevant risk factors were included in stepwise logistic regression models carried out for the outcome LBW for the general group, term group and preterm group, in order to adjust by confounding. Adjusted odds ratios were then obtained. Prenatal care related factors and maternal adverse obstetric factors were at higher significance for LBW in the general and IUGR groups. Only nutritional factors were related to LBW in preterm group. Women who delivered a LBW or IUGR infant were more likely to have fewer pregnancies, a history of previous LBW, lower prepregnancy weight and lower gestational weight gain. ICP was associated with an elevated risk of LBW that was independent of gestational age.

Vega J ，Sáez G ，Smith M ，Agurto M ，Morris NM ... -  《REVISTA MEDICA DE CHILE》

Risk factors of intrauterine growth retardation: a study of an urban population in Poland.

The main objective of the study was to examine the role of selected socio-occupational factors on the development of intrauterine growth retardation (IUGR) in the urban population of Lódź, Poland. An epidemiological model of the case-control study was employed. Both the cases and controls were recruited from the female population covered by obstetric services in district hospitals during 1 January-30 June 1992. A group of cases included 92 females who delivered IUGR children, the control group-438 mothers of term born eutrophic babies. The presence of the relationship between IUGR manifestation and selected variables was initially assessed using the unadjusted odds ratio (OR). The variables described as significant were considered in the logistic regressions models, separately for all women and those with previous pregnancies. A comparison of the groups of cases and controls has revealed a significant excess of risk of delivering an IUGR child by mothers with the following characteristics: marital status-single, low educational level, low height (less than 1.60 m) low prepregnancy weight and low maternal weight gain. An elevated risk of delivering an IUGR child was found in the group of women who reported to have their first contact with the physician after 12 weeks of pregnancy. An adverse effect of prolonged vaginal bleeding was observed. Women who recently lost their job, compared to those employed continuously during pregnancy, were at an increased risk of IUGR. Cigarette smoking appeared to be the most important variable affecting the evaluated pregnancy outcome. For the women smoking 6-10 and more than 10 cigarettes a day, the risk of delivering an IUGR child was found to be almost 4 and 7 times, respectively, higher than for non-smokers. A logistic regression covering all the above mentioned maternal characteristics was employed. Only four of them proved to be significant: low maternal weight gain, prolonged vaginal bleeding, smoking and the marital status-single. The process of preventing IUGR and its consequences requires more effective activities aimed at increasing the level of health education and stimulating the development of appropriate, health-oriented behaviour.

Kalinka J ，Hanke W ，Szymczak W 《Central European Journal of Public Health》

Maternal weight, height and risk of poor pregnancy outcome in Ahmedabad, India.

This paper explores the relationships between maternal weight, height and poor pregnancy outcome using a data set from a case-control study of low birth weight (LBW) and perinatal mortality in Ahmedabad, India. Maternal height and weights were compared between mothers of 611 perinatal deaths, 644 preterm-LBW, and 1465 normal birth weight controls as well as 617 small-for-gestational age (SGA) and 1851 appropriate-for-gestational-age (AGA) births. Weight and height were much lower in this population compared to western standards. Low weight and height were associated with increased risk of perinatal death, prematurity and SGA. After adjusting for confounders, maternal weight remained significantly associated with poor pregnancy outcomes, whereas height was only weakly associated. Attributable risk estimates show that low weight is a much more important contributor to poor outcome than low height. Improvement in maternal nutritional status could lead to substantial improvement in birth outcome in this population.

Mavalankar DV ，Trivedi CC ，Gray RH 《INDIAN PEDIATRICS》

Low birth weight in urban Harare.

1. To measure the incidence of low birth weight from all institutional deliveries in a defined catchment area of urban Harare. 2. To estimate the relative proportions of preterm and small for gestational age (SGA). The study was descriptive and was conducted during the last three months of 1986. The low risk maternity units in three high density suburbs, Highfield, Glen Norah and Glen View and the referral centre Harare Central Hospital. All babies born to women residing in the study areas in the maternity clinics and those transferred to the referral hospital were identified and weighed. For low birthweight babies gestation was estimated by the Dubowitz method and perinatal outcome was recorded. During the three month study period in 1986, 2,056 babies in total were born; 223 (10.8%) of which were low birthweight. Of these 65 (44%) were preterm and 55 (37%) were SGA. The findings show a lower percentage of low birthweight and SGA babies than in many developing countries but higher than the norm for developed countries. The study demonstrates a need for resources to prevent low birthweight delivery and improve care for low birthweight babies.

Sanders JA ，Fawcus SR ，Sanders DM ，Foster G ，Chinhara B ... -  《-》

Iron but not folic acid supplementation reduces the risk of low birthweight in pregnant women without anaemia: a case-control study.

To assess whether iron and folic acid supplementation reduce the risk of low birthweight (LBW) in women without anaemia. Case-control study. University Hospital of Cantabria. Cases were 322 mothers without anaemia delivering a singleton infant of less than 2500 g. Controls were 934 mothers without anaemia delivering a term non-small-for-gestational-age infant. Data on iron and folic acid supplementation were obtained from prenatal chart record and personal interview. Data on risk factors for LBW were also gathered. Agreement between the two sources of information was good (82% for folic acid and 94% for iron). Odds ratios yielded from the two sources were very close. Folic acid only (15 mg/day) was unrelated to LBW, whereas iron supplementation (80 mg ferrous sulphate) was associated with a lower risk of LBW (odds ratio (OR) 0.58, 95% CI 0.34 to 0.98), adjusted for smoking, maternal education, body mass index, obstetric diseases during pregnancy, weight gain during pregnancy, and previous LBW. The results of iron plus folic acid were similar to those for iron (OR 0.56, 95% CI 0.33 to 0.96). There was a significant trend towards a lower risk of LBW (p<0.001) with the duration of iron supplementation. After stratifying by the type of LBW, the trend was also significant for any kind of LBW. Iron supplementation is associated with a lower risk of LBW in pregnant women without anaemia.

Palma S ，Perez-Iglesias R ，Prieto D ，Pardo R ，Llorca J ，Delgado-Rodriguez M ... -  《-》