Vital statistics of premature and low birthweight infants in Tainan area.

Birth weight and gestational age are strongly associated with perinatal mortality and morbidity. This study was conducted to survey the vital statistics of premature and low birthweight infants in the Tainan area. Between July 1991 and April 1992, fifteen medical institutions were included on a voluntary basis: eight from level I (obstetric specialty clinic), six from level II (regional hospital), and one from level III (tertiary care center). A total of 14,307 deliveries were enrolled, accounting for about 60% of the total delivery for that year in the area. The proportions of delivery among level I, II and III were 52%, 41% and 7%, respectively. The incidence of premature singleton live birth was 4.6%, and the percentages of gestation between 20-27 weeks, 28-31 weeks and 32-37 weeks were 0.2%, 0.6% and 3.8%, respectively. The premature births accounted for 3.5%, 4.8% and 11.3% of live births at the level I, II and III hospitals, respectively. The incidence of low birthweight and very low birthweight singleton live births was 4.4% and 0.5%, respectively. The low birthweight births accounted for 3.5%, 4.5% and 11.1% of live births at the level I, II and III hospitals, respectively. The data revealed that the higher the level of hospital, the higher incidences of premature and low birthweight infant. Teenage mothers (< 20 year of age) had higher low birthweight rate. The risk of having low birthweight infants decreased progressively in mothers of age < 20 (6.3%), 20-24 (5.4%), 25-29 (4.1%) and 30-34 (3.8%), whereas it became higher in mothers older than 35 (4.8%). Conclusion: The incidence of premature and low birthweight births in the Tainan area was low. Teenager or those with maternal age older than 35 year were high risk groups for producing these infants.