Risk Factors for Low Birth Weights of Pregnant Women Receiving Prenatal Care at Yan Ta Khao Hospital - ปัจจัยที่มีผลต่อการคลอดทารกน้ำหนักน้อยของหญิงตั้งครรภ์ที่ฝากครรภ์ในโรงพยาบาลย่านตาขาว จังหวัดตรัง

Abstract

The objective of this cross-sectional descriptive study was to find out the factors influencing
low birth weight of newborns and its incidence for the sake of controlling, improving and solving
the low birth weight problems of newborns as well as supporting further development plan of maternal
and child health promotion. In this study, 422 cases of pregnant women receiving pre and post
natal care at Yan Ta Khao hospital, Trang province were included. Several independent variables
including 1) fundamental information of mother (before pregnancy weight, education, occupation,
religion, marital status, history of abortion, underlying diseases) and 2) the factors related to medical
and health care during pregnancy (gestational age of the first prenatal care, pregnant weight
gain, a number of prenatal cares, hematocrit of the first prenatal care, antenatal hematocrit, pregnancy
complications and gestational age at birth) were statistically analyzed with respect to the
weights of newborn infants as a dependent variable. Descriptive statistics, chi-square, odds ratio and
95%CI were used in data analysis.
The results reveal that the average age of the pregnant women was 26 years, while those with
the age below 20 years accounted for 20.4 percent. Most of them were Buddhist and in a farming
with high school graduates and living with husbands (94.5%). It was reported that 42.9 percent
were primipara and 17.1 percent had history of abortion. Anemia and asthma were the first and
second underlying diseases accounting for 2.1 percent and 1.4 percent, respectively. With respect to
gestational ages of the first prenatal care, 64.2 percent of them were lower than 12 weeks. The
pregnant women with the weights before pregnancy lower than 45 kilograms accounted for 14.7
percent. Of all cases, 99.1 percent received prenatal care more than or equal to 4 times. There were
14.9 percent which hematocrit at birth lower than 33 percent. The most complications found during
pregnancy were anemia (14.5%), and the proportion of gestational age at delivery below 36 weeks
were only 0.9 percent. There were 35.1 percent which their weights gained during pregnancy below
10 kilograms. The incidence of lower-birth weight than 2,500 grams was only 8.8 percent.
The factors which statistically related significantly to low birth weight at 95% confidence
interval, were pre-pregnancy weights less than 45 kilograms (p 0.001, OR 3.007, 95%CI 1.425,
6.346), pregnant weight gained lower than 10 kilograms (p 0.002, OR 2.666, 95%CI 1.345, 5.285),
hematocrit at delivery (p 0.004, OR 2.709, 95%CI 1.263, 5.811) and gestational age at delivery
lower than 36 weeks (p 0.001, OR 10.943, 95%CI 1.495, 80.07). To prevent low birth weight, it
should therefore emphasize both maternal care before pregnancy to gain weight greater than or
equal to 45 kilograms and antenatal care to gain weight at least 10 kilograms during pregnancy and
to have hematocrit higher than 33 percent as well as to take care of gestational age at delivery
greater than 36 weeks.
Key words: risk factors, low birth weight, pregnant women