Abstract:
BACKGROUND: Birth weight is the most important factor determining the survival,
healthy growth, and development of a newborn. The healthy intrauterine existence of the
fetus depends on the adequate function of the placenta. The placenta is a feto-maternal organ
that has two components: a fetal part that develops from the chorionic sac and a maternal part
derived from the endometrium. Preeclampsia causes morphological changes in the placenta
and fetal hypoxia leading to intrauterine growth restriction which contributes to low birth
weight.
OBJECTIVES: To compare the birth weight of newborn, gross placental morphology and
their determinant factors among pre-eclamptic and normotensive mothers delivered at
Butajira General Hospital, 2020.
METHODS: A comparative cross-sectional study was conducted from September 15 to
December 15, 2020, at Butajira General Hospital. A consecutive sampling technique was
used to select study subjects. Informed consent was taken from mothers under the study and a
total of 158 placentas (79 pre-eclamptic and 79 normotensives) were collected after delivery
in the labor room. The placental diameter and thickness were measured, the number of
cotyledons was counted and the shape of the placenta was noted. The weight of the placenta
and newborn was measured on a standard weight scale. EPI data version 4.2 was used to
enter the data and the data were analyzed by SPSS version 22. An independent sample t-test
was used to compare the mean differences of the groups. Pearson correlation test was used to
investigate the correlation of birth weight with placental morphology in normotensive and
preeclamptic pregnant mothers.
RESULTS: Birth weight of newborn and placental morphometric measurements were
significantly (<0.05) less in the pre-eclamptic group as compared with the normotensive
group. The mean birth weight in the pre-eclamptic group was 2.89±0.389 kg and
3.331±0.0.359 kg in the normotensive group (p<0.001). The mean placental weight,
thickness, diameter, and number of cotyledons among the pre-eclamptic group were
446.72±83.86 g, 1.74±0.19 cm, 15.61±1.82 cm, and 16.7±1.77 respectively. The mean
placental weight, thickness, diameter, and number of cotyledons among the normotensive
group were 576.86±130.91 g, 2.03±0.31 cm, 18.91±2.43 cm, and 19.25±3.04 respectively.
The placental shape had no significant difference between the two groups (p> 0.05). There ii
was a significant positive correlation between birth weight and placental weight (r=0.636,
p<0.001) in pre-eclamptic and (r=0.456, p<0.001) in normotensive groups. The risk of low
birth weight was two times more likely to occur in the pre-eclamptic group than in the
normotensive group [AOR =2.87 (95%CI =0.72-11.56)]. Low placental weight in pre eclamptic mothers was four times more likely to occur in at [AOR=4.26; (95% CI= 1.79-
10.135)] than in normotensive mothers.
CONCLUSIONS: Most of the placental morphometric parameters except the placental
shape in the preeclampsia group were found significantly different between normotensive and
pre-eclamptic groups. Birth weight of the newborn was also significantly lower in pre eclampsia group than the normotensive group. Placental weight had a significant positive
correlation with birth weight in both normotensive and pre-eclamptic groups. Preeclampsia,
nullparity, maternal age (20-24 years), male sex newborn, and BMI <18.5 kg/m
2
identified as
the determining factors for birth weight and placental morphometric parameters. Lower
placental weight and birth weight were positively associated with preeclampsia. Therefore,
health professionals must screen preeclampsia as early as possible to manage it and reduce its
complications.