Research Article - Annals of Experimental Biology ( 2023) Volume 11, Issue 2
Received: 28-Mar-2023, Manuscript No. aeb-23-93249; Editor assigned: 29-Mar-2023, Pre QC No. aeb-23-93249 (PQ); Reviewed: 31-Mar-2023, QC No. aeb-23-93249 (Q); Revised: 03-Apr-2023, Manuscript No. aeb-23-93249 (R); Published: 10-Apr-2023
Background and Objective: Induction of labor refers to the stimulation of contractions before the labor starts spontaneously, with or without ruptured membranes. The present study aimed to compare the maternal outcomes of induced versus spontaneous labor.
Methodology: A comparative study was conducted in Maternity Teaching Hospital in Erbil city from February 2020 to February 2021. Using purposive (non-probability) sampling techniques, 240 pregnant women (120 with induced labor and 120 with spontaneous labor) were recruited into the study. Through direct interviews, a proper researcher-designed questionnaire was utilized to collect the required data. The collected data were analyzed using descriptive and inferential statistical approaches.
Results: There were significant to highly significant differences between the two delivery methods in terms of maternal outcomes, emergency cesarean section, postpartum blood loss, need for blood transfusion, uterine atony, perennial laceration, and postpartum hospital stay.
Conclusion There was the significance to a highly significant difference in maternal outcomes between induced and spontaneous labor.
Induction of labor; Spontaneous labor; Outcome
Spontaneous labor refers to birth without clinical intervention and the pregnant women do not have induction of labor, epidural anesthesia, spinal anesthesia, general anesthesia, assisted vaginal delivery (with forceps and/or ventouse), and cesarean delivery. Women will experience spontaneous labor if they do not take prostaglandins, oxytocin, artificial rupture of membrane, or balloon catheters for labor induction [1].
Induction of labor is a procedure used to stimulate uterine contractions during pregnancy before labor begins on its own, and it initiates when a birth benefits the mother or the fetus and compensates for the risks of a continuing pregnancy [2]. Induction of labor often begins with cervical ripening which includes softening and loosening of the cervix in the preparation for labor and delivery [3]. Cervical ripening is defined as the precursor to the onset of labor, in which the cervix becomes soft, either naturally or as a result of physical or pharmacological interventions [4].
Indications for induction of labor include postdate, gestational hypertension, chorioamnionitis, premature rupture of membrane, preeclampsia, maternal conditions (e.g., chronic hypertension and diabetes mellitus), and neonate conditions (e.g., oligohydramnios and severe neonate growth restriction) [5,6]. Both pharmacological (prostaglandins and oxytocin) and mechanical (balloon catheters) agents are used for the induction of labor [7]. When these methods are used individually, the incidence of cesarean delivery decreases in women undergoing induction [8]. Oxytocin, the hormone that stimulates uterine contractions, is less effective in cervical ripening and is usually used alone to induce labor when the cervix is favorable (Bishop’s degree >6) or after cervical ripening by prostaglandins or mechanical methods [9]. Misoprostol (prostaglandin E1 analog) is broadly used to induce labor [6]. Induction of labor brings about many potential complications for mothers and newborns, while mechanical methods are associated with the fewest number of harmful effects [9].
Women undergoing induction of labor may be at a higher risk of cesarean section [10]. Pharmacological methods of induction of labor are associated with possible risks, such as uterine tachysystole with or without changing the neonate heart rate, uterine rupture, fetus distress, and maternal morbidity and mortality. The incidence of these adverse events is dependent on the agent used for induction, dose, and other factors [11]. Induction of the postdate is associated with an increased risk of overall C/S due to failure to progress, chorioamnionitis, labor dystocia, uterine rupture, reduced risk of developing oligohydramnios, and meconium-stained amniotic fluid. Induction of labor does not cause postpartum hemorrhage, shoulder dystocia, or meconium aspiration [12]. Induction of labor at 39 weeks of gestation results in lower rates of cesarean delivery, maternal morbidity, newborn morbidity, stillbirths, and newborn deaths [13].
Induction of labor represents the most common interventional procedure in obstetrics. It is applied in 20% to 25% of all pregnancies in Korea [14]. The prevalence of induction of labor in Finland is very low compared to other developed countries, and the rate of successful induction in Finland is slightly higher than in Ethiopia but is comparable to regional rates when induction failure is very low compared to local and regional institutions. Bishop score, which is based on cervical favourability before induction, has been used to predict whether induction of labor leads to a successful vaginal delivery or not. The low cervical score has been associated with failure of induction, prolonged labor, and a high rate of cesarean deliveries [15]. Bishop’s score is a remarkable predictor of the success of induction [16]. In the United States of America and the United Kingdom, about 23% of all deliveries are by induction of labor, while the counterpart figure in Latin America is 11.4% [17].
Using a quantitative comparative design, the present study was conducted among full-term pregnant women admitted to the Maternity Teaching Hospital in Erbil city from February 2020 to February 2021. The ethical approval has been obtained from the ethical approval committee of Hawler Medical University /Nursing college that consists of (Assistant .Prof DR. Siyamand Hasan Muhedin, ,Assistant.Prof DR..Runak Neamatulla Husin, L.DR..Zhyan Abdulla, L.Salar Saidi Husin, L.Banaz sediq Smail) and the head of committee (Assistant Prof. Dr.Abdulqader Husin ) Then a verbal consent has been obtained from the samples after informed them about the questionnaire items, We didn’t need written consent from participants because we dealing with them by asking questions they answer after getting agreement from them this is allowed by our university, the ethical committee in nursing college(Assistant .Prof DR. Siyamand Hasan Muhedin, Assistant.Prof DR..Runak Neamatulla Husin, L.DR..Zhyan Abdulla, L.Salar Saidi Husin, L.Banaz sediq Smail) and the head of committee (Assistant Prof. Dr.Abdulqader Husin ) approved that , in case of dealing with participants by drugs ,substances, herbal and some kinds of food need written consent. The guidelines outlined in the Declaration of Helsinki were followed so the participants to didn’t expose themselves to any risk. The sample size was determined by power and sample size estimation software (Version 3.0.43). For this purpose, the following data were fed into the software: The rate of vaginal delivery which was set at 83.6% and 67.6% among the spontaneous labor group and the induction group, respectively, the alpha error that was set at 0.05, and the beta error that was set at 20% (power 80%) [18]. Accordingly, the estimated sample size was 112 women in the spontaneous labor group and 112 women in the induced labor group. Therefore, 240 women have recruited: 120 women for the induced group and 120 for the spontaneous group. The inclusion criteria were live singleton fetus, vertex presentation, gestational age after 37 gestational weeks, cases indicated induction of labor (in the induced group), and uncomplicated cases (convulsion, severe bleeding, and shock). The exclusion criteria were mal-presentation, abnormal placentation, intrauterine neonate death, gestational age less than 37 gestational weeks, women who did not have a chronic disease or any medical problems, previous cesarean section, uncooperative patient, and multiple pregnancies. Required data were gathered through a proper questionnaire aimed at collecting data on the pregnant women’s socio-demographic characteristics. The questionnaire consisted of two sections. Section 1 was used to gather data on the pregnant women’s demographic characteristics, including age (classified into 16-23, 24-31, 32-39, and >40 age groups), educational level (including illiterate, able to read and write, primary school, secondary school, and college or institute), residency (including urban, suburban, and rural), occupation (including government employee, private employee, self-employment, student, and housewife), income, smoking, and secondary smoker. Section 2 was utilized to collect data on anthropometric measurement, BMI according to the World Health Organization (WHO, 2011) (BMI was classified as follows: Underweight<18.5 kg/m², Normal weight 18.5 kg/m²-24.9 kg/m², Overweight 25.0 kg/m²-29.9 kg/m², Moderate obesity (class I) 30.0 kg/m² – 34.9 kg/m², Severe (gross) obesity (class II) 35.0 kg/m²-39.9 kg/m², and Very severe (morbid) obesity (class III) ≥ 40 kg/m²), and maternal outcomes (including emergency cesarean section delivery, blood loss , need for blood transfusion, uterine atony, need for uterotonics after delivery, perennial laceration, postpartum stay in the hospital, admission to ICU, hysterectomy, and status at discharge).
Table 1 shows the demographic data obtained from the study participants with induced and spontaneous labor. As indicated, about half of the induced group (49.1%) was aged between 16 years and 23 years, and 43.3% of the spontaneous group was aged between 24 years and 31 years. Regarding the educational level, 26.6% of the women in the induced group were primary school graduates, and 30% in the spontaneous group were illiterate. Most of the women in the induced group 45% lived in rural areas, and 43.3% in the spontaneous group lived in urban areas. Regarding their occupation, most of the women in both study groups (97.5%) were housewives. The results revealed that 76.7% of women in the induced group and 70% in the spontaneous group were not satisfied with their income. Regarding their BMI, 34.2% of the women in the induced and spontaneous groups were overweight. In terms of their smoking status, non-smokers made up the majority proportion (96.7%) of the induced women and 100% of the spontaneous women; however, 50.8% of the women in the induced group and 63.3% in the spontaneous group were secondary smokers.
| Characteristics | Induced labor | Spontaneous labor | ||
|---|---|---|---|---|
| f | % | f | % | |
| Age | ||||
| 16 years-23 years | 59 | 49.1 | 31 | 25.8 |
| 24 years-31 years | 33 | 27.5 | 52 | 43.3 |
| 32 years –39 years | 26 | 21.7 | 32 | 26.7 |
| 40 and more years | 2 | 1.7 | 5 | 4.2 |
| Total | 120 | 100 | 120 | 100 |
| Level of education | ||||
| Illiterate | 28 | 23.3 | 36 | 30 |
| Able to Read and Write | 17 | 14.2 | 19 | 15.8 |
| Primary School | 32 | 26.6 | 35 | 29.2 |
| Secondary School | 26 | 21.7 | 20 | 16.7 |
| College or Institute | 17 | 14.2 | 10 | 8.3 |
| Total | 120 | 100 | 120 | 100 |
| Residency | ||||
| Urban | 35 | 29.2 | 52 | 43.3 |
| Suburban | 31 | 25.8 | 27 | 22.5 |
| Rural | 54 | 45 | 41 | 34.2 |
| Total | 120 | 100 | 120 | 100 |
| Occupation | ||||
| Government Employee | 1 | 0.8 | 3 | 2.5 |
| Student | 2 | 1.7 | 0 | 0 |
| Housewife | 117 | 97.5 | 117 | 97.5 |
| Total | 120 | 100 | 120 | 100 |
| Income | ||||
| Satisfied | 28 | 23.3 | 36 | 30 |
| Non-satisfied | 92 | 76.7 | 84 | 70 |
| Total | 120 | 100 | 120 | 100 |
| MBI | ||||
| Underweight | 0 | 0 | 0 | 0 |
| Normal Weight | 14 | 11.7 | 20 | 16.6 |
| Overweight | 41 | 34.2 | 41 | 34.2 |
| Obesity | 40 | 33.3 | 38 | 31.7 |
| Morbid Obesity | 25 | 20.8 | 21 | 17.5 |
| Total | 120 | 100 | 120 | 100 |
| Smoking | ||||
| Yes | 4 | 3.3 | 0 | 0 |
| No | 116 | 96.7 | 120 | 100 |
| Total | 120 | 100 | 120 | 100 |
| Secondary Smoking | ||||
| Yes | 59 | 49.2 | 44 | 36.7 |
| No | 61 | 50.8 | 76 | 63.3 |
| Total | 120 | 100 | 120 | 100 |
Table 2 shows the differences between maternal outcomes regarding methods of labor (induced and spontaneous labor). There was significance to a highly significant difference between the scores of the items of the maternal outcomes (Emergency C/S, vital signs, Amount of blood loss after delivery, blood transfusion needed, number of blood pints, Uterine atony, perennial laceration, postpartum stay) with regards to the method of delivery (induced and spontaneous labor) except the items; (postpartum uterotonic use, ICU admission, admission causes, hysterectomy, and pt. discharge status) which they have not computed because the similar answer in both groups.
| Maternal Outcomes | Induced labor | Spontaneous labor | chi-square value | p-value | ||
|---|---|---|---|---|---|---|
| f | % | f | % | (Sig) | ||
| Emergency C/S | ||||||
| Yes | 16 | 13.3 | 0 | 0 | 16 | <0.001 HS |
| No | 104 | 86.7 | 120 | 100 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Pulse beats/min. | ||||||
| 70-80 | 39 | 32.5 | 57 | 47.5 | 5.857 | 0.021 |
| 81-91 | 43 | 35.8 | 36 | 30 | S | |
| 92-102 | 38 | 31.7 | 27 | 22.5 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Temperature°C | ||||||
| 36-37 | 43 | 35.8 | 83 | 69.2 | 26.734 | <0.001 HS |
| 37.1-38.1 | 77 | 64.2 | 37 | 30.8 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Blood Pressure | ||||||
| Hypotension | 37 | 30.8 | 3 | 2.5 | 93.995 | <0.001 HS |
| Normal BP. | 44 | 36.7 | 115 | 95.8 | ||
| Hypertension | 39 | 32.5 | 2 | 1.7 | ||
| Total | 120 | 100 | 0 | 0 | ||
| Amount of blood loss after delivery | ||||||
| <500 ml | 57 | 47.5 | 103 | 85.8 | ||
| 500 ml-999 ml | 39 | 32.5 | 15 | 12.6 | 42.872 | <0.001 HS |
| 1000 ml -1499 ml | 1 | 0.8 | 0 | 0 | ||
| 1500 ml-1999 ml | 10 | 8.3 | 1 | 0.8 | ||
| 2000 ml -2499 ml | 7 | 5.8 | 0 | 0 | ||
| 2500 ml -2999 ml | 6 | 5.1 | 1 | 0.8 | ||
| 3000 ml + more | 0 | 0 | 0 | 0 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Blood Transfusion Needed | ||||||
| Yes | 23 | 19.2 | 2 | 1.7 | ||
| No | 97 | 80.8 | 118 | 98.3 | 19.691 | <0.001 HS |
| Total | 120 | 100 | 120 | 100 | ||
| No. of Blood Pints | ||||||
| >No Pint | >97 | > 80.8 | > 118 | > 98.3 | ||
| >1 Pint | >16 | > 13.3 | > 2 | > 1.7 | 19.94 | <0.001 HS |
| >2 Pints | >6 | > 5.1 | > 0 | > 0 | ||
| >3 Pints | >1 | > 0.8 | > 0 | > 0 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Uterine atony | ||||||
| Yes | 18 | 15 | 0 | 0 | ||
| No | 102 | 85 | 120 | 100 | 19.459 | <0.001 HS |
| Total | 120 | 100 | 120 | 100 | ||
| Postpartum Uterotonic Use | ||||||
| >Yes | >120 | > 100 | > 120 | > 100 | ||
| >No | >0 | > 0 | > 0 | > 0 | . | NC |
| Total | 120 | 100 | 120 | 100 | ||
| Perennial Laceration | ||||||
| 1st Degree | 21 | 17.5 | 21 | 17.5 | ||
| 2nd Degree | 17 | 14.3 | 7 | 5.8 | ||
| 3rd Degree | 31 | 25.8 | 9 | 7.5 | ||
| 4th Degree | 22 | 18.3 | 3 | 2.5 | 94.975 | <0.001 HS |
| No Laceration | 13 | 10.8 | 80 | 66.7 | ||
| C/S | 16 | 13.3 | 0 | 0 | ||
| Total | 120 | 100 | 120 | 100 | ||
| Postpartum Stay | ||||||
| < 12 hours | 55 | 45.8 | 118 | 98.3 | ||
| 12 hours | 20 | 16.7 | 0 | 0 | ||
| 24 hours | 25 | 20.8 | 2 | 1.7 | 82.535 | <0.001 HS |
| > 24 hours | 20 | 16.7 | 0 | 0 | ||
| Total | 120 | 100 | 120 | 100 | ||
| ICU Admission | ||||||
| Yes | 0 | 0 | 0 | 0 | ||
| No | 120 | 100 | 120 | 100 | . | NC |
| Total | 120 | 100 | 120 | 100 | ||
| Causes of ICU Admission | ||||||
| No Causes | 120 | 100 | 120 | 100 | . | |
| Total | 120 | 100 | 120 | 100 | NC | |
| Hysterectomy | ||||||
| Yes | 0 | 0 | 0 | 0 | . | |
| No | 120 | 100 | 120 | 100 | NC | |
| Total | 120 | 100 | 120 | 100 | ||
| Pt. Discharge Status | ||||||
| Alive | 120 | 100 | 120 | 100 | ||
| Dead | 0 | 0 | 0 | 0 | . | NC |
| Total | 120 | 100 | 120 | 100 | ||
Table 1 analyze the data on the women’s demographic variables revealed that nearly half of the women in the induced group were aged 16 years -23 years, while the majority of the women in the spontaneous group were aged 24 years - 31 years. These results are consistent with the study conducted in Italy by Poma who reported the majority of the participants in the induced group were within the age group of 16 years-23 years and 24 years -31 years in the spontaneous group [19].
Percentage distribution of the women’s level of education revealed that the majority of the induced group were primary school graduates. This finding is inconsistent with the results of the previous study carried out in Nigeria by Lawani who reported that the majority of the induced group were tertiary graduates [20]. The present study showed that the majority of the women in the spontaneous group were illiterate. This finding is in line with that of the study conducted by Tarimo who reported similar results [21].
According to the data on the women’s residency, a large proportion of the induced women lived in rural areas. This finding disagrees with those of a descriptive observational study which was conducted in Sulaymaniyah City, Iraq by Mohammed who reported that the majority of the induced group lived in urban areas [22]. It also disagrees with the results of a study carried out in Ethiopia which indicated that the majority of the induced group lived in urban areas [16]. However, a large proportion of the women in the spontaneous group lived in urban areas. This finding is in disagreement with those of the study conducted in Spain by Marco-Gracia who found that the highest proportion of women resided in rural areas [23].
Concerning the participants’ occupations, the results of the current study indicated that the highest proportion of both study groups were housewives. This finding is persistent with those of an earlier study conducted by Yisma who demonstrated similar results [24]. Similarly, the results of another study conducted by Lueth showed that the highest proportion of both study groups were housewives [16].
According to the percentage distribution of the women’s income, three-quarters of both groups were dissatisfied with their income. This finding is consistent with those of a study performed in Brazil by Velho who mentioned that most of the participants in both groups did not have a satisfactory income [25].
Measuring the participants’ BMI showed that the highest proportion of the women in both groups was overweight. This finding is supported by those of the studies conducted by Hermesch, Addo, and O’Dwyer who reported that the highest percentage of the participants were overweight [26-28].
Percentage distribution of the women’s smoking status showed that the majority proportion for the induced group were nonsmokers. This finding is in line with those of the study conducted in Sweden by Wennerholm who reported that the majority of the participants did not smoke. None of the spontaneous women in the present study smoked [29]. This finding is similar to those of a previous study conducted by Attanayake who reported similar results. However, this finding is not in line with those of the study conducted by Zanardo who reported that a small proportion of the spontaneous sample smoked [30, 31].
The results of the present study showed that there was a highly significant difference between the (Emergency C/S) and delivery method at p-value<0.001 (Table 2). A similar finding was reported in a study conducted by Jonsson who mentioned that the C/S rate in induced labor was over twofold greater than spontaneous labor (p<0.001). However, this finding is in contrast with those of a study carried out by Skeith who found that there was no significant difference between induction of labor and spontaneous labor in terms of the risk of C/S (p-value=0.052).
The results obtained from the data on post-partum blood loss revealed that there was a highly significant difference between postpartum blood loss and method of delivery at p- value<0.001. This finding is similar to those found in a previous study by Al-Turiahi who mentioned that compared to spontaneous labor, induction of labor was associated with a higher risk of post-partum blood loss (p<0.001). This finding is also supported by Khireddine who found that compared to spontaneous labor, induction of labor was associated with a higher risk of post-partum blood loss (p<0.01). The results of another study conducted by Al-Zirqi showed that there was a highly significant difference between post-partum blood loss and induction and spontaneous delivery at p- value<0.001. This finding is in contrast with those of a study conducted by Skeith who found that there was no significant difference between induction of labor and spontaneous labor in terms of the risk of post-partum blood loss (p-value=0.083).
The results of the present study also revealed a highly significant difference between the delivery methods regarding perineal laceration (p-value<0.001). This finding is consistent with those of a previous study conducted by Thangarajah who reported that perineal laceration was significantly higher in the induction of the labor group (p=0.002). However, this finding disagrees with that of the study conducted in Bangladesh by Ferdous and Rahman who reported that there was no statistically significant difference between delivery methods regarding perineal laceration (p-value >0.05 ).
In the current study, it was found that there was a highly significant difference between the induced and spontaneous groups in terms of blood transfusion needed. This finding is in disagreement with those of a study conducted by Alalem who reported no significant differences between induced and spontaneous methods regarding blood transfusion needed (p-value=0.087).
It was also found that there was a highly significant difference between induced and spontaneous methods in terms of uterine atony (p-value<0.001). This finding is in contrast with those of the study conducted by Thangarajah who found that the two groups were not significantly different regarding their uterine atony.
The results of the present study showed a significant difference between the induced and spontaneous labor women in terms of their postpartum stay in the hospital. This finding is in agreement with the results of the study by Sujata who reported significantly different postpartum hospital stays at the hospital following induced and spontaneous labor (p- value=0.0001).
The results of the present study demonstrated that postpartum uterotonic use, ICU admission, admission causes, hysterectomy, and pt. discharge status was similar in both groups; therefore, they were not computed. This finding is not supported by Guerra who reported that compared to spontaneous labor, labor induction is associated with higher rates of some maternal complications, including the need for uterotonic drugs in the postpartum, hysterectomy, admission to an intensive care unit, and longer hospital stays [17]. According to ICU admission, which was not computed, this finding is supported by Gimovsky who mentioned similar findings.
In the present study, it was concluded that the majority of the induced group aged 16 years-23 years, graduated from primary school, lived in rural areas, were housewives, were not satisfied with their income, and were overweight, while the majority of the spontaneous group aged 24 years -31 years, were illiterate, lived in urban areas, were not satisfied with their income, and were overweight. The results showed that induction of labor is associated with an increased risk of cesarean delivery, postpartum blood loss, uterine atony, third-degree laceration, and prolonged postpartum hospital stay compared with spontaneous labor. In comparison with spontaneous labor, induced labor is associated with poorer maternal and neonate outcomes.producing Streptomyces sp. Secondary metabolites produced by these strains can be used to treat various bacterial and fungal diseases.
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