모성연령과 출산순위의 변화가 저체중아 출생률에 미친 영향

Impact of Changes in Maternal Age and Parity Distribution on Low Birth Weight Incidence Rate

모성연령 및 출산순위의 변화가 출생시 체중에 미치는 영향을 알아보기 위하여 부산시내 1개 대학병원, 5개 종합병원,1개 병원, 1개 의원, 1개 조산소에서 분만된 1977년 7,786건과 1987년 8,671건의 단태아를 대상으로 산실의 분만대장에서 출생시 체중, 모성연령 그리고 출산순위를 조사하였다. 모성 연령은 1977년에 25-29세가 56.4%, 30-34세가 18.8%였으나 1987년에는 25-29세가 65.1%, 30-34세가 21.6%로 증가하였으며, 24세이하군과 35세 이상군의 출생아 비율은 감소하였다. 출산순위별 분포는 1977년에 1,2순위 출생아가 각각 56.9%, 28.8%였는데 1987년에는 각각 59.9%, 36.8%로 증가한 반면 3,4순위는 1977년에 10.6%, 3.6%에서 1987년에 각각 2.8%, 0.5%로 감소하였다. 저 체중아 출생률은 1977년에 5.3%였는데 1987년에는 4.0%였고, 이 가운데 직접표준화법을 응용하여 추정한 모성연령 및 출산순위별 변화가 저체중아 출생률 감소에 기여한 것은 10.7% 이었다. 나머지 89.3%는 모성 연령 및 출산순위별 저 체중아 출산률의 감소에 기인한 것이다.

The objective of this study was to examine the impact of changes in maternal age and parity distribution on birth weight. The study population included 7,786 single live births in 1977 and 8,671 single live births in 1987 delivered at 9 medical facilities in Pusan. Data were obtained from the delivery record. The proportion of infants born to the mothers of 25-29 years increased from 56.475 in 1977 to 65.1% in 1987 and the proportion to the mothers of 30-34 years increased from 18.8% in 1977 to 21.6% in 1987. In the same period, the proportions of 1st and 2nd birth order were increased from 56.9% and 28.8% to 59.9% and 36.8%, respectively. The proportion of infants born to the age group of ${\leq}24\;and\;35{\leq}$ years were decreased in 1987. The proportion of births of the third or higher birth order was decreased from 14.2% in 1977 to 3.3% in 1987. Low birth weight (<2500gm) incidence rate was 5.3% in 1977 and it was decreased to 4.0% in 1987. It was estimated that changes in maternal age-parity distribution accounted for 10.7% of the decreased in low birth weight incidence rate. Rest of the change (89.3%) was attributed to the reduction of age-parity specific low birth weight incidence rate. Application of the direct adjustment method was considered to be an adequate tool for evaluating the impact of family planning on neonatal health.