This study was aimed to identify the determinants of failed oxytocin induction among
women who gave birth at five referral hospitals of Amhara Regional State. The multivariable model indicated that the odds of having failed oxytocin induction
were found to be 2.47 times higher among women who had emergency induction compared
with counterparts (AOR=2.47, 95%, CI:(1.31 ,4.68)). The finding of our study is in
contrast to a study conducted in Jimma university which discovered emergency oxytocin induction had no association
with failed oxytocin induction (
11
</a>). This might be related to difference in sample size and study design. Moreover,
the discrepancy can be explained by variation in the proportion of intermediate bishop
score between studies; 198 (59%) in our study and 68 (24.8%) in the study conducted
in Jimma university hospital.</p>
With regards to bishop score, the multivariable analysis indicated that women who
had pre induction intermediate bishop score were 11.77 times more likely to experience
failed oxytocin induction compared with women who had favorable bishop score. The
finding of our study is in agreement with studies conducted in Jimma and USA (
11
</a>). This might be because of the dependency of oxytocin induction on cervical status.
There is less preparation of the pelvis in terms of cervical dilatation, effacement,
consistency, station of the presenting part and position of the cervixes which leads
to failed oxytocin induction (<a href="#_ENREF_12">
12
</a>, <a href="#_ENREF_13">
13
</a>). This discrepancy could be due to the difference in sample size and health service
practice in which the presence of subjectivity in assessing bishop score. </p>
With regards to parity, being primiparous was found to be a significant predictor
of failed oxytocin induction in our study. The odds of having failed oxytocin induction
were found to be 6.24 times higher than those multi parous mothers (AOR: 6.24, 95%, CI: (3.32, 11.73)). The is consistent with different studies at Hawassa, Jimma, Pakistan and Norway
(
6
</a>, <a href="#_ENREF_11">
11
</a>, <a href="#_ENREF_12">
12
</a>, <a href="#_ENREF_14">
14
</a>) . This could be explained by primiparous women are different from multiparous women
in pre-induction cervical effacement as well as response to ripening methods. In addition
primiparous women have no labor experience hence the rate of cervical collagen fiber
dissolution is hard to attain among primiparous women , beside this primiparous uterus
could be less sensitive for oxytocin(<a href="#_ENREF_15">
15
</a>).</p>
The odds of failed oxytocin among mothers whose age ≤30 years were 2.16 times higher
than counterparts (AOR: 2.16, 95%, CI: (1.13, 4.16)). This study supported by a study done at Pakistan (
6
</a>) but not supported by studies (<a href="#_ENREF_9">
9
</a>, <a href="#_ENREF_11">
11
</a>, <a href="#_ENREF_12">
12
</a>) . This is possibly explained by difference in study population. </p>
Conclusion
Women with ages of ≤30 years, having intermediate bishop score, and those who had
unplanned oxytocin induction were more likely to encounter failed induction. Appropriate
cervical preparations (ripening) shall be considered before commencing induction of
labor.
Limitations
The following limitations shall be put into consideration while taking the findings
of this study. Due to retrospective nature of the study recall bias might be a concern.
The study is conducted at referral hospitals which might not be representative to
the general population. Efforts were made to minimize recall bias by complementing
interview with medical chart review.