Spontaneous cesarean scar dehiscence during pregnancy: A case report and review of the literature

Abstract

Worldwide, the incidence of cesarean sections has increased. Cesarean scar dehiscence, in which the scar tissue from the prior cesarean section is disrupted and separated, is one of the most significant complications of cesarean deliveries. Spontaneous cesarean scar dehiscence is among rare obstetric events. It carries catastrophic fetal and maternal complications. Timing of occurrence, screening, diagnosis, and obstetrics management in the current and subsequent pregnancies are full of controversies. Here, we present a case of spontaneous cesarean scar dehiscence in a patient who had an inter-pregnancy interval of only 4 months. We present the case of spontaneous cesarean scar dehiscence during pregnancy in a 30-year-old patient from western Ethiopia. She got pregnant after 4 months of previous cesarean delivery. Currently, she presented to the hospital with previous two cesarean scars and a term pregnancy. Intraoperative findings showed separation of the uterine wall which is covered by only fetal membranes. After delivering the fetus and placenta, the uterus was repaired in two layers. The patient had a smooth postoperative course and was discharged on the fifth day with appropriate counseling. During pregnancy, there is a chance of spontaneous cesarean scar dehiscence. Therefore, it is essential to properly assess pregnant mothers who have had a previous cesarean scar. If the cesarean scar dehiscence is diagnosed before the elective cesarean section, the obstetrician should get prepared to prevent potential complications.

Introduction

Cesarean section is the most commonly performed operative procedure of the uterus in women of reproductive age.¹ Its incidence has steadily increased worldwide.² One of its notable complications is cesarean scar dehiscence (CSD).² CSD develops from a previous cesarean section and grows during pregnancy. As the gestation progresses and the uterus expands, the scar may lose integrity, leading to the separation of uterine layers.³

In most cases, the exact etiological factor contributing to cesarean scar dehiscence is unknown.⁴ But, CSD and subsequent uterine rupture are associated with factors like type and number of uterine incisions, inter-pregnancy interval, and factors that lead to excessive uterine distension.^1,2,5,6

The natural course of cesarean scar dehiscence is uterine rupture which is more dangerous to the life of the mother and fetus.^1–3 Therefore, making an early diagnosis of cesarean scar dehiscence potentially gives better obstetrics outcomes compared to that of uterine rupture.^1,2,7 Here, we present a case of spontaneous cesarean scar dehiscence involving over two-thirds of the anterior uterine wall in a patient who had an inter-pregnancy interval of only 4 months. Interestingly, this degree of spontaneous cesarean scar dehiscence with good maternal and neonatal outcome is not reported so far.

This case report was performed following the CARE criteria (Supplementary Material 1). It is also supported by literature review. A total of 11 studies were included in this review (Figure 1).

Figure 1.

PRISMA flow diagram.

Source: Adapted from PRISMA 2020 statement.

Case report

This is a 30-year-old gravida 3 para 2 patient from western Ethiopia whose gestational age from reliable last normal menstrual period (LNMP) was 39 weeks plus 4 days presented to Wollega University Referral Hospital (WURH) for elective cesarean delivery. Here, previous two deliveries were by cesarean section. The interval between the first and the second pregnancy and between the second and the third pregnancy (current pregnancy) was 17 and 4 months, respectively. During the current pregnancy, she had five antenatal care (ANC) contacts during which time she was supplemented with iron and folic acid. She was also given two doses of tetanus toxoid. She had a history of hyperemesis gravidarum in all pregnancies.

Her past obstetric history showed unremarkable maternal complications. Her postoperative conditions during previous deliveries were smooth. Postpartum ultrasound examination showed no isthmocele. But she had early neonatal death in her second delivery. This made her get pregnant only after 4 months of delivery. She has no history of trauma to her abdomen. Her past medical and surgical history is unremarkable.

On examination, she was healthy-looking. Her vital signs were blood pressure (BP) = 110/70 mmHg, pulse rate (PR) = 80 beats per minute, respiratory rate (RR) = 18 breaths per minute, and temperature of 37.5°C. She had pink conjunctivae. Lymph glandular system, chest, and cardiovascular system were normal. On abdominal examination, there was a transverse suprapubic healed scar, 38 weeks-sized uterus, longitudinal lie, cephalic presentation, no uterine contraction, on the area of tenderness, and fetal heartbeat (FHB) = 142 beats per minute. Pelvic examination showed an unfavorable Bishop score.⁸ On the integumentary system, she had no palmar pallor. On neurologic examination, she was oriented to time, person, and place. She had normal reflexes and no neurologic deficits.

Ultrasound examination was done by radiologist four times during the current pregnancy (in first trimester, second trimester, early third trimester, and at admission). However, the uterine defect was not detected during these examinations. Uterine wall thickness was also not measured. The last ultrasound examination showed aggregate gestational age of 39 weeks plus 3 days, cephalic presentation, reassuring biophysical profile, fundal placenta, and adequate amniotic fluid.

On laboratory investigation, urinalysis, complete blood count, and serum blood glucose level were normal. Serology for syphilis, hepatitis, and human immunodeficiency virus was non-reactive (Table 1). With the final diagnosis of full-term pregnancy and previous two cesarean scars, the patient was prepared for a cesarean section. Intraoperatively, there was a transverse lower uterine segment defect including more than two-thirds of its length through which fetal parts were visible and moving. The defect was only covered by a fetal membrane (Figure 2). After rupturing the fetal membrane, a female alive neonate weighing 3200 g and placenta was delivered. The edge of the defect was trimmed and sutured in two layers with chromic catgut. The abdomen was closed in layers. The patient was transferred to the recovery room with stable vital signs. The patient was counseled for family planning, and she preferred Implanon. On the sixth postoperative day, the patient and new born were discharged in good condition.

Table 1.

Laboratory investigations of spontaneous cesarean scar dehiscence during pregnancy managed at Wollega University Referral Hospital, western Ethiopia, 2022.

Time of the investigations	Laboratory tests	Results
At admission	CBC count	WBC count = 10,000 cells/μL; RBC count = 4.5 million cells/μL; hematocrit = 37.3%; platelet count = 248,000 cells/μL
	Urinalysis	Non-revealing
	RBG	123 mg/dL
	Blood group	A+
	Obstetric ultrasound	Third trimester pregnancy plus reassuring biophysical profile
	VDRL	Non-reactive
	HBsAg	Non-reactive
After cesarean delivery	CBC count	WBC count = 19,000 cells/μL; RBC count = 4.6 million cells/μL; platelet count = 222,000 cells/μL; hematocrit = 34.9%

CBC: complete blood count; WBC: white blood cell; RBC: red blood cell; VDRL: venereal disease research laboratory; HBsAg: hepatitis B surface antigen; RBG: random blood glucose.

Figure 2.

Spontaneous uterine scar dehiscence detected during cesarean section at Wollega University Referral Hospital, western Ethiopia, 2022.

M: fetal membranes; U: uterine wall.

Discussion

Uterine scar dehiscence is a separation of the uterine musculature with intact uterine serosa.⁹ Unlike in the case of uterine rupture, it does not involve uterine serosa or fetal membranes and is not associated with intra-abdominal hemorrhage.^10,11 It can be encountered at the time of cesarean delivery or be suspected on obstetric ultrasound examination during pregnancy. In a cesarean section, the fetus may visible through the perimetrium.^9,11 In our case, the uterine layers were separated, but the defect was covered by fetal membranes. The fetus was visible through the defect.

Cesarean scar dehiscence is associated with short inter-pregnancy intervals (less than 12 months) and previous cesarean done before term.^5,6,12 When the inter-pregnancy interval is short, there is no adequate time for the myometrium to heal adequately and attain maximum strength.¹ This makes the healed myometrium to be thinner and less resistant to uterine distension.^1,3 Thus, the previous incision site is at increased risk of dehiscence during pregnancy and labor. In this particular case, the inter-pregnancy interval was only 4 months. The previous cesarean section was also done before the term. These two factors might contribute to poor uterine scar healing and subsequent scar dehiscence.

There is no appropriate screening method for the detection of uterine scar dehiscence.¹² Using ultrasound examination, measuring the thickness of the uterine wall at the previous uterine incision site could be used to predict the occurrence of uterine dehiscence during pregnancy or in labor.^1,4,13,14 Uterine wall thickness less than 2 mm is associated with an increased risk of dehiscence.^1,15 Magnetic resonance imaging (MRI) is useful in the work-up of cesarean scar dehiscence and has demonstrated superior accuracy in the evaluation of uterine wall defects. However, it is not an ideal tool for screening purposes as it is expensive and not available like ultrasound.^10,16

Antepartum diagnosis of uterine scar dehiscence is challenging.¹⁷ This is because of the absence of signs and symptoms of urinary stone disease (USD), and the yield from ultrasound is also low.^9,17 For example, in one study, USD was detected with preoperative ultrasound examination in 26.1%. MRI, although not done in this case, is the better option to make its diagnosis.^10,16 However, there is no gold standard for diagnosing cesarean scar dehiscence.⁸

It has been proposed that elective cesarean sections at 36–37 weeks gestational age, in women with a history of isthmic rupture, and at 32–33 weeks gestational age after fetal lung maturation, in women with a history of fundal uterine rupture and those who had short inter-pregnancy intervals, can reduce the likelihood of recurrent uterine ruptures or uterine scar dehiscence.^9,12,18

The other controversial issue in cesarean scar dehiscence is its management. The best surgical approach for repairing cesarean scar dehiscence during delivery has not been established.^1,2 Repairing cesarean scar dehiscence and allowing for future pregnancy are possible.³ Abdelazim et al. advised doing a two-layer repair of the uterus utilizing vicryl 0 interrupted mattress stitches for the second layer and vicryl 0 interrupted simple stitches for the first layer. In contrast to continuous stitches, which may cause further tear of the already weak anterior uterine wall, interrupted sutures permitted healing and approximation of the two margins of the uterine incision without any stress or traction on the edges of the incision.¹² Ijarotimi OA and colleagues, however, advised employing two layers of vicryl 2 in a continuous manner.¹⁷ In our case, we trimmed the dehisced edge and repaired it in two layers using chromic catgut. She was advised to have specialized ANC during a future pregnancy. This is supported by study conducted by Tinelli et al.¹⁹

This case report is not without limitations. The main limitation is that this case report is not the first of its kind. However, it has a great interest to a general audience. Poor quality of the figure and failure to include ultrasound images in the manuscript were among the other limitations.

Conclusion

During pregnancy, there is a chance of spontaneous cesarean scar dehiscence. Therefore, it is essential to properly assess pregnant mothers who have had a previous cesarean scar. The authors also recommend avoiding short inter-pregnancy intervals in these patients.