Abstract:
Preterm delivery is the most important cause of infant mortality and mobility.
The first part of this study is a historical cohort study with the objective to determine
the incidence of preterm delivery among mulliparous women at Ramathibodi hospital
during 1 January 30 December 2005. The second part is a case control study with
the objective to determine risk factors of preterm delivery. During the study period,
there were 2,542 pregnant women who came to register for the first time. For those
who failed to follow-up an attempt to contact was made by mail or telephone.Overall,
68.6 % of women who registered had known outcomes of pregnancy (59.9% delivery,
8.7% abortion). Descriptive statistics were percentage, mean and standard deviation.
Analytical statistics including odds ratio with 95% confidence intervals, chi square
test, and logistic regression analysis were used to determine risk and association
between factors and preterm delivery. SPSS+ PC program was used for statistical
analysis.
The results of the study showed that the incidence of preterm delivery was
12.48%. Most preterm deliveries occurred at gestational ages of34-36weeks(7.16%).
About 1-2% occurred at gestational ages of less than 28 wks(2.23%), 28-
30wks(1.12%) and 31-33wks(1.97%). The case control study included 190 cases of
preterm delivery and 190 cases of control. The controls were selected from pregnant
women who came to register on the same day just after the test cases and delivered at
full term. From univariate analysis, the significantly associated factors were maternal
height≤155 cms, mean weight gain≥1kg/wk, civil employment, hemoglobin<10g%
and medical complication before delivery. However from multiple logistic regression
analysis only premature rupture of membranes and maternal height were factors
significantly associated with preterm delivery.
In conclusion, incidence of preterm delivery at Ramathibodi hospital is
comparable to other studies. Risk factors of preterm delivery are found to be difficult
to change or are resistant to intervention. However, these finding could be applied to
screen pregnant women, to advise them on and prepare services to prevent and care
for preterm delivery.