Socio-demographic, reproductive and obstetric characteristics of study participants
A total of 216 pregnant women participated in the study in four hospitals. A total of 3162 mothers have delivered in JUMC during the study period of which 302 mothers undergo induction making prevalence of induction 9.5% at JUMC. Mean age of study participants is 26 years and is similar among the two study groups. One third 78 (36.1%) of the study participants are rural dwellers.
Overall mean gestational age at delivery for all participants was 39.4 weeks which is also the same for the two study groups. Majority 176(82%) of the inductions were undergone on emergency basis. The top three indications for IOL in this study were PROM 128 (59.3%), hypertensive disorders of pregnancy (HDP) 49 (22.7%) and post-term pregnancy 27 (12.5%) while the others accounted for 12 (5.6%). The indication for IOL is similar among the two study groups. Majorities of the participants enrolled in LDG 65(60.2%) have favorable bishop score at initiation of induction unlike those enrolled in HDG which was observed only in 14(13%) (Table2)
Table 1: Socio-demographic characteristics of the participants in four hospitals, October 1, 2017 to May 30, 2018
Socio-demographic variables
|
Type of oxytocin regimen
|
Total No (%)
N=216
|
High dose
(N=108)
|
Low dose
(N=108)
|
Age of respondent
|
Mean Age (+SD)
|
26.1 + 4.5
|
25.95+4.56
|
26.02 + 4.526
|
< = 19
|
4(3.7)
|
5(4.6)
|
9(4.2)
|
20-29
|
76(70.4)
|
81(75.0)
|
157(72.7)
|
>30
|
28(25.9)
|
22(20.4)
|
50(33.1)
|
Religion
|
Muslim
|
50(46.3)
|
29(29.6)
|
79(36.6)
|
Orthodox
|
44(40.7)
|
42(39.8)
|
86(39.8)
|
Protestant
|
14(13)
|
29(19.9)
|
43(19.9)
|
Others
|
0(0)
|
8(7.4)
|
8(3.8)
|
Occupation of respondent
|
House wife
|
66(61.1)
|
57(52.8)
|
123(57)
|
Gov’t employee
|
30(27.8)
|
25(23.1)
|
55(25.5)
|
Merchant
|
7(6.5)
|
7(6.5)
|
14(6.5)
|
Farmer
|
1(0.9)
|
9(8.3)
|
10(4.6)
|
Student
|
2(1.9)
|
6(5.6)
|
8(3.7)
|
Others
|
2(1.9)
|
4(3.7)
|
6(2.7)
|
Labor outcomes (induction to delivery time, mean oxytocin concentration, rate of CS, Rate of instrumental delivery, induction success)
Mean induction to delivery time was 5.9 hours for HDG and 6.3 hours for LDG. Induction was successful in 61.1% and 72.2 % of study participants among HDG and LDG while it is failed in 17.6 % and 15.7% of mothers in the two groups respectively. Rates of C/S are 42 (38.8%) and 30 (27.8%) while that of instrumental delivery are 16 (14.8%) and 5 (4.6%) among HDG and LDG respectively. Indications for C/S in decreasing order were failed induction 19 (45%), Non reassuring fetal heart rate patterns (NRFHRP) 19 (45%) and CPD 4 (10%) among HDG while failed induction 17(56.7%), CPD 7(23.3%) and NRFHRP 6(20%) are among LDG. NRFHRP as an indication of instrumental delivery is observed in 37.5% and 20% of participants enrolled in HDG and LDG respectively. Inadequate uterine contraction as a reason for failed induction was observed in 10% and 30% of HDG and LDG respectively (Table3). Both successful induction (p-value=0.083) and cesarean delivery (P-value=0.083) didn’t show significant relation with use of different oxytocin regimens. Only instrumental vaginal delivery (P-value=0.012) and vaginal delivery (P-value=0.002) had relation with use of different oxytocin regimens (Table4).
Table 2: Reproductive and Obstetric characteristics of the participants in four hospitals, October 1, 2017 to May 30, 2018
Variables
|
Categories
|
Type of oxytocin regimen
|
|
High dose NH=108
|
Low dose (NL=108)
|
Total (N=216)
|
Parity
|
Nullipara
|
56(51.9)
|
32(29.6)
|
88(40.7)
|
Parous
|
52(48.1)
|
76(70.4)
|
128(59.3)
|
Type of induction
|
Elective
|
22(20.4)
|
18(16.7)
|
40(18.5)
|
Emergency
|
86(79.6)
|
90(83.3)
|
176(81.5)
|
Bishop score before induction
|
Unfavorable
|
94(87)
|
43(39.8)
|
137(63.4)
|
Favorable
|
14(13)
|
65(60.2)
|
79(36.6)
|
Mean GA at Delivery
|
Mean GA
|
39.34+1.8
|
39.36+1.7
|
39.35+1.8
|
Gestational Age
|
Term
|
95(88)
|
94(87)
|
189(87.5)
|
Post term
|
13(12)
|
14(13)
|
27(12.5)
|
History of previous successful induction
|
YES
|
5(4.6)
|
11(10.2)
|
16(7.4)
|
NO
|
103(95.4)
|
97(89.8)
|
200(92.6)
|
Misoprostol use for Ripening
|
YES
|
40(37)
|
57(52.8)
|
97(44.9)
|
NO
|
68(63)
|
51(47.2)
|
119(55.1)
|
ARM done
|
YES
|
27(25)
|
18(16.7)
|
45(20.8)
|
NO
|
81(75)
|
90(83.3)
|
171(79.2)
|
Table 3: Outcome of pregnant women undergoing IOL with high dose and low dose oxytocin regimen in four hospitals, October 1, 2017 to May 30, 2018.
Variables
|
Categories
|
Type of oxytocin regimen
|
Total (N=216)
|
High dose NH=108
|
Low dose (NL=108)
|
Induction to delivery time
|
Mean duration
|
5.9+1.8
|
6.27+2.74
|
6.07+2.32
|
Maximum Oxytocin concentration in mu/min
|
Mean concentration
|
77.6+24.5
|
22+12.5
|
49.8+33.9
|
Mode of delivery
|
VD
|
50(46.3)
|
73(67.6)
|
123(56.9)
|
CS
|
42(38.9)
|
30(27.8)
|
72(33.3)
|
· For failed Induction
|
19(45.2)
|
17(56.7)
|
36(50)
|
· For NRFHRP
|
19(45.2)
|
6(20)
|
25(34.7)
|
· For CPD
|
4(9.6)
|
7(23.3)
|
11(15.3)
|
Instrumental delivery
|
16(14.8)
|
5(4.6)
|
21(9.7)
|
· For Shortening SSOL
|
7(43.8)
|
4(80)
|
11(52.4)
|
· For NRFHRP
|
7(43.8)
|
1(20)
|
8(36.4)
|
· For Prolonged SSOL
|
2(12.5)
|
0(0)
|
2(11.2)
|
Reason for Failed induction
|
No cervical change
|
17(89.5)
|
12(70.6)
|
29(80.6)
|
Inadequate Uterine contraction
|
2(10.5)
|
5(29.4)
|
7(19.4)
|
Average length of hospital stay in days
|
Mean duration
|
2.0+1.5
|
2.7+1.5
|
2.4+1.6
|
Weight of neonate in grams
|
2500-3999
|
103(95.4)
|
89(82.4)
|
192(88.9)
|
> 4000
|
5(4.6)
|
19(17.6)
|
24(11.1)
|
Successful induction
|
Yes
|
66 (61.1)
|
78 (72.2)
|
144(66.7)
|
No
|
42 (38.9)
|
30 (27.8)
|
72(33.3)
|
Table 4: Labor outcomes among participants who received high dose and low dose oxytocin regimen in four hospitals, October 1, 2017 to May 30, 2018.
Labor Outcome Variables
|
Response
|
Type of Oxytocin Regimen
|
P- Value
|
High Dose
N (%)
|
Low Dose
N (%)
|
Instrumental vaginal Delivery
|
Yes
|
16 (14.8)
|
5(4.6)
|
0.012
|
No
|
92 (85.2)
|
103(95.4)
|
Vaginal delivery
|
Yes
|
50(46.3)
|
73(67.6)
|
0.002
|
No
|
58(53.7)
|
35(32.4)
|
C/S Delivery
|
Yes
|
42 (38.9)
|
30(27.8)
|
0.083
|
No
|
66 (61.1)
|
78(72.2)
|
Successful induction
|
Yes
|
66 (61.2)
|
78 (72.2)
|
0.083
|
No
|
42 (38.8)
|
30 (27.8)
|
Factors affecting success of induction
On Bivariate logistic regression analysis age, residence and family income of the respondent, previous history of successful induction, cervical ripening with misoprostol, type of oxytocin regimen, gestational age at delivery and neonatal weight did not show any kind of association with successful induction of labour. However, previous parity [COR 2.1, 95%CI 1.2, 3.7], bishop score at initiation of oxytocin [COR 3.4, 95%CI 1.7, 6.7], type of induction [COR 0.4, 95%CI 0.2, 0.7] and performing ARM [COR 3.3, 95%CI 1.4, 7.9] were associated with successful IOL at P-Value < 0.05. (Table5).
On multivariable logistic regression analysis, the variables remained in the model were having favourable bishop score at initiation of oxytocin [AOR 4.0, 95% CI 1.9, 8.5], elective type of induction [AOR 0.2,95%CI 0.1,0.4] , performing ARM [AOR 10.1,95%CI 3.2, 32.2 ], neonatal weight of < 4000gm [AOR 4.3, 95%CI 1.6, 11.6] and being parous [AOR 2.1, 95%CI 1.1,4.0] were found to be statistically significant. (Table5).
Table 5: Multivariate Logistic Regression of factors associated with success of induction in four hospitals October 1, 2017 to May 30, 2018.
VARIABLES
|
RESPONSE
|
Successful Induction
|
COR(95%CI)
|
P –value
|
AOR
(95%CI)
|
P-Value
|
Yes
|
No
|
Age of respondent
|
< = 19
|
4(44.4)
|
5(55.6)
|
1
|
|
1
|
|
20-29
|
103(65.6)
|
54(34.4)
|
2.4(0.6, 9.2)
|
.209
|
1.9(0.4,9.9)
|
0.43
|
>30
|
37(74)
|
13(26)
|
3.6(0.8,15.3)
|
.088
|
2.6(0.5,15.2)
|
0.28
|
Residence
|
Urban
|
87(63)
|
51(37)
|
0.6(0.3, 1.2)
|
.134
|
0.6(0.3,1.29)
|
0.19
|
Rural
|
57(73.1)
|
21(26.9)
|
1
|
|
1
|
|
Oxytocin regimen
|
High dose
|
66(61.1)
|
42(38.9)
|
0.6(0.3, 1.1)
|
.084
|
0.6(0.3,1.53)
|
0.29
|
Low dose
|
78(72.2)
|
30(27.8)
|
1
|
|
1
|
|
Previous successful induction
|
YES
|
14(87.5)
|
2(12.5)
|
3.8(0.8, 17.1)
|
.085
|
1.6(0.3,9.02)
|
0.58
|
NO
|
130(65)
|
70(35)
|
1
|
|
1
|
|
Gestational age at delivery
|
Term
|
129(68.3)
|
60(31.7)
|
1.7(0.8, 3.9)
|
.194
|
0.6(0.1,2.9)
|
0.48
|
Post-term
|
15(55.6)
|
12(44.4)
|
1
|
|
1
|
|
Ripening with misoprostol
|
YES
|
59(60.8)
|
38(39.2)
|
0.6(0.4, 1.1 )
|
.101
|
0.4(0.1,1.1)
|
0.06
|
NO
|
85(71.4)
|
34(28.6)
|
1
|
|
|
|
Previous Parity
|
Parous
|
94(73.4)
|
34(26.6)
|
2.1(1.2, 3.7 )
|
.012
|
2.1(1.1,4.0)
|
.024
|
Nulliparous
|
50(56.8)
|
38(43.2)
|
1
|
|
1
|
|
Bishop score before induction
|
Favorable
|
65(82.3)
|
14(17.7)
|
3.4(1.7, 6.7 )
|
.000
|
4.1(2.0, 8.8 )
|
.00
|
Unfavorable
|
79(57.7)
|
58(42.3)
|
1
|
|
1
|
|
Type of induction
|
Elective
|
19(47.5)
|
21(52.5)
|
0.4(0.2,0.7)
|
.005
|
0.2(0.1,0.5)
|
.001
|
Emergency
|
125(71)
|
51(29)
|
1
|
|
1
|
|
ARM done
|
YES
|
38(84.4)
|
7(15.6)
|
3.3(1.4, 7.9)
|
.006
|
7.8(2.7, 22.6)
|
.00
|
NO
|
106(73.6)
|
65(90.3)
|
1
|
|
1
|
|
Neonatal weight in gm
|
< 4000
|
132(68.8)
|
60(31.2)
|
2.2(0.9, 5.2)
|
.071
|
4.3(1.6, 11.6)
|
.005
|
>4000
|
12(50)
|
12(50)
|
1
|
|
1
|
|