The current study was conducted to assess the prevalence and factors associated with low fifth minute Apgar score among newborns delivered by CS at WSUCSH. The proportion of low fifth minute Apgar score in this study was 26.5% (95% CI: 22.7–31.1). Our study was in line with study conducted at Debre Tabor General Hospital, North Central Ethiopia (28.3%) and Arbaminch General hospital in southern Ethiopia (31.5%) [9, 10]. However, the prevalence of LAS in our study was lower than the prevalence in Jimma zone public hospitals, south west Ethiopia (47.5%) and Iran (58.8%) [11, 12]. This variation might be due to differences in sample size and study setting.
In this study: PIH, type of CS, APH, type of anesthesia, incision to delivery time, meconium stained amniotic fluid and low birth weight (< 2.5kg) were found to be significantly associated with low Apgar score among newborns delivered by CS at WSUCSH.
Type of anesthesia was significantly associated with the risk of developing low Apgar score, accordingly new born whose mothers underwent general anesthesia[AOR = 3.37;95% CI(1.72‒6.62)] showed significant association with LAS, as compared with new born whose mothers underwent spinal anesthesia. This finding is consistent with the study conducted at Arbaminch general hospital, southern Ethiopia[9] and Abbasi Shaheed hospital, Pakistan [13]. This could be explained by anesthetic drugs given during general anesthesia cross the placenta and cause fetal depression.
Those newborns delivered from mothers who underwent emergency CS were about 2.17 times (AOR = 2.17; 95% CI: 1.13 ‒ 4.15) more likely to have LAS than those delivered from mothers whom underwent elective CS. This finding was supported by study conducted at Rabat, Morocco [14]. This might be due to the fact that either most of the mothers come with complications or the decision to for CS might be late after they develop complications.
A data from multivariate analysis also showed that babies born when skin incision to delivery time was above three minutes was 5.27 times (AOR = 5.27; 95% CI: 2.20‒12.60) more likely to have LAS compared to those with skin incision to delivery time < = 3. This is in line with study conducted at Gandhi memorial hospital, Ethiopia[15]. The low Apgar score when skin incision to delivery time is prolonged might be due to decrease in blood pressure because of supine hypotension syndrome or effect of anesthetic drugs. This causes decrease in uteroplacental circulation and causes LAS.
Meconium stained amniotic fluid also had a significant association with the occurrence of low Apgar score. Specifically, newborns delivered with meconium stained amniotic fluid were 3.07 times (AOR = 3.07, 95% CI: 1.32 ‒ 7.12) more likely to develop low Apgar score compared with that of their counter parts. This finding is compatible with studies from Gonder, Northwest Ethiopia[16] and India [17]. This might be due to the reason, newborns delivered from mothers with meconium stained amniotic fluid are more predisposed to aspirate it and fill smaller airways and alveoli in the lung. This can lead to airway obstruction and limited lung movement. Then due to poor gas exchange birth asphyxia evidenced by low Apgar score could occur.
This study revealed that neonates born to mothers with PIH were 4.58 times more likely to have LAS than their counterparts [AOR = 4.58:95% CI (1.75‒11.92)]. This is in line with studies done in Lemlem Karl general hospital, Northern Ethiopia[18], Sweden and India [19, 20] This might be due to, PIH causes placental ischemia. Placenta may bleed or it may begin to separate from the wall of the uterus prematurely. This cause limited transfer of oxygen or nutrients to the fetus. If any of these complications occurs, fetal distress may develop ultimately leads to LAS.
Odds of LAS increased about 3.96 times more comparing newborns from mothers with APH to those who do not have the event (AOR = 3.96 95%CI:1.75‒8.94). This is in line with studies conducted at Addis Ababa, Ethiopia [21], Tigray Ethiopia [22] and Indonesia[8] The possible explanation could be because of the consequence of antepartum bleeding. If APH occurs there will be decreased blood flow from mother to fetus through placenta, so that the hypoxemia can occur in the fetus. This condition can lead to birth asphyxia; this in turn leads to LAS.
Moreover, this study also revealed newborns born with low birth weight were eight times more likely to have LAS AOR = 8.17(95% CI:1.03‒64.59). This study is agreeable with studies done at Asella teaching referral hospital, south eastern Ethiopia [23] and Pakistan [24]. This could be explained by the fact that small babies might suffer difficult breathing and might develop difficulty in cardiopulmonary transition and perinatal asphyxia which predisposes the newborns to different complications including LAS.