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 ... -  《-》

[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》

World Health Organisation multicentre randomised trial of supplementation with vitamins C and E among pregnant women at high risk for pre-eclampsia in populations of low nutritional status from developing countries.

Villar J ，Purwar M ，Merialdi M ，Zavaleta N ，Thi Nhu Ngoc N ，Anthony J ，De Greeff A ，Poston L ，Shennan A ，WHO Vitamin C and Vitamin E trial group ... -  《-》

Multimicronutrient supplementation for undernourished pregnant women and the birth size of their offspring: a double-blind, randomized, placebo-controlled trial.

Gupta P ，Ray M ，Dua T ，Radhakrishnan G ，Kumar R ，Sachdev HP ... -  《archives of pediatrics & adolescent medicine》

Periconception folic acid supplementation, fetal growth and the risks of low birth weight and preterm birth: the Generation R Study.

Timmermans S ，Jaddoe VW ，Hofman A ，Steegers-Theunissen RP ，Steegers EA ... -  《-》