A Case-Control Study on the Risk Factors of the Low Birth Weight

저체중아(低體重兒) 출산 관련요인에 관한 사례-비교군 연구

Low birth weight baby, defined as the baby born with less than or equal to 2,500g of body weight by WHO has been a great concern in the fold of maternal and child health since the low birth weight is a major cause of high perinatal mortality. Any measure to prevent the low birth weight baby is most desirable not only for saving the life of a baby but also for levelling up the health of the whole society. The authors attempted to figure out how some known maternal risk factors are related to the low birth weight and to measure their strengh of associations in terms of relative risk using hospital birth records. For this study, hospital birth records of 66 low birth weight cases and sex-parity matched 198 normal controls were chosen from Kangnam St. Mary's Hospital, Catholic Medical Center, and the data were analyzed in regards to several maternal factors. The risk factors studied were mother's age, mother's ABO blood type, previous histories of abortion, low birth weight baby, fetal wastage, and maternal diseases represented by anemia, hypertension, proteinuria, and glucosuria. The results obtained in this study were as follows: 1. The mean body weight of the cases and controls were 1,955g and 3,251g, respectively, and the heights were 41cm for cases and 50cm for controls. Mean gestation periods of cases and controls were 34 weeks and 39 weeks, respectively. 2. Young mother(less than or equal to 20 years of age) or old mother(more than or equal to 30 years of age) experienced more frequently the delivery of low birth weight babies than mothers in between 21 and 29 years of age. But the difference was not statistically significant. 3. Mothers whose blood type was O tended to have slighty higher frequency of low birth weight babies while B mothers have lower frequency. But the difference was not statistically significant too. 4. Those mothers who had experienced low birth weight baby in the past tended to give more births of low birth weight babies. This factor is even statistically significant and the relative risk of the prior experience of low birth weight was 6.7. 5. Mothers with experience of fetal losses and mothers of more than two pregnancies had higher frequency of low birth weight than the mothers with no fatal losses and of first pregnancy, but the difference was not statistically significant. 6. Statistically significant higher frequency of low birth weight were found in mothers with hypertension(odds ratio=4.07), anemia(odds ratio=22,33), and proteinuria(odds ratio=2.79). In summary, these study results strongly suggest that in order to prevent the low birth weight, special care should be made when the mother is too young or too old, and when the mother has experienced deliveries of low birth weight and fetal deaths. Medical control for the maternal diseases such as anemia and hypertension is also needed before or during the pregnency.