The primary outcome of this study was the IUD expulsion rate, which was monitored for a duration of three months. We recorded the time period between device insertion and expulsion. If the women were unaware of the exact date of expulsion, it was recorded as the last day of follow-up, indicating the last known presence of the device.

Displacement rate, which was followed up for three months. This was measured using transvaginal ultrasounds, done at one month and three months.

Infection and bleeding, were followed up for three months. Uterine bleeding symptoms (including spotting, light bleeding, and heavy or longer menstrual period) were recorded. In addition, symptoms suggestive of PID, such as lower abdominal pain, or vaginal discharge were recorded.

Perforation rate was calculated over a three month period. It was diagnosed using transvaginal ultrasound and confirmed by an abdominal radiograph, showing IUD within the abdominal cavity.

The sample size calculation was based on the following equation: n = Z${}^2$$\times$ p(q)/d${}^2$ [7]. Here, n represents the sample size, Z is the standardized degree of 95% which is equal to 1.96, p is the proportion of target women estimated to be expelled one month after IUCD insertion (0.045), q is the complement of p, and d is the degree of accuracy required, usually 0.05. The result of the calculation was 66 patients, but we increased the sample size to 96 patients to improve the study’s strength and to account for expected dropouts.

One consultant applied the IUD postpartum (group II), while the other performed a post-placental application in the first group (group I). Grouping of the patients was done according to the patient’s choice of device application.

The private hospital’s ethical committee approved the study, and patients provided informed consent. Patients were subjected to full history (personal, menstrual, detailed obstetric, and past surgical history) and physical (general, obstetric and local pelvic examination) examination process.

Surgical procedure: at the time of induction of anesthesia, pre-operative antibiotics were given to all women of both groups according to the hospital protocol.

Group I (post-placental): this group included 48 women in whom IUCD was inserted during the cesarean application after delivery of the baby (Fig. 1). The placenta was removed, then the Mirena IUD was placed at the fundus of the uterus using the regular applicator, the strings were then placed in the lower uterine segment downward through the cervix. If the cervix was closed, manual opening of the cervix by surgeon’s fingers, then the strings were passed through the cervix with ring forceps, and the uterus was closed. In the first follow-up visit, trimming of long threads was done.

Fig. 1.

Patient flow diagram. CS, cesarean section.

Group II (postpartum): this group included 48 women who had elective lower-segment CS where the Mirena IUD was inserted in the traditional steps after a six-week postpartum visit (Fig. 1).

All the women were instructed about side effects, possible complications, and warning signs about using the Mirena IUD. They were taught how to recognize IUCD expulsion and how to feel strings.

The first follow-up visit was in the first week, then one month, and three months after the Mirena IUD was inserted. Follow-up of women was done by vaginal examination, including speculum examination to visualize the threads of the Mirena IUD. An extra trans vaginal sonography (TVS) and abdominal X-ray were done in cases of missed IUD.

The data collected was reviewed, organized, tabulated, and analyzed using the Statistical Package for Social Science (SPSS20.0, IBM, Armonk, NY, USA). The Student’s t-test was used to determine the statistical significance of the difference between the means of the two groups. The Chi-square test was applied to qualitative variables, while Fisher’s exact test was used for qualitative variables. A p-value greater than 0.05 was considered non-significant, and a value less than 0.05 was considered significant.

The present study found no significant differences between groups, regarding IUD displacement, or expulsion rates. There were no statistically significant differences in the expulsion rate and previous number of CSs, which supports the application of an IUD during a CS.

The Mirena device has a wider diameter and is inert, making it less likely to be expelled than the copper (Cu) IUD. However, obstetricians are concerned about the larger size of the uterus after delivery, which increases the risk of expulsion during the postpartum period [11].

In a cohort study of 90 patients who received an IUD during cesarean delivery, Levi et al. [11] reported very low expulsion rates. Additionally, 80% of the women reported high satisfaction with this method. In Levi et al.’s study conducted in 2015 [12], 112 women were randomly assigned to receive an IUD, either immediately after giving birth, or six weeks later. The researchers reported only 4 cases of IUD expulsion in the post-placental group, which is comparable to the findings of the present study [12]. However, their study used a different methodology, in which they inserted another IUD for the four women who presented the device expulsion, explaining the cases of IUD permanence at six months for the remaining patients.

The prospective cohort study by Zaconeta et al. [13] supports our findings. The study involved 48 women who had IUDs inserted during CS. According to their findings, the expulsion rate during the first six weeks was not significantly different from that between the period of six weeks and six months (9% and 9.1%, respectively). This, however, differs from our study where the expulsion rate was found to be 4.2% within the first month and 7.1% after the third month.

In the present study, in the puerperal group, the expulsion rate was about 6.3% (3 patients) during the first month follow-up and 4 patient (9.8%) in the three-month follow-up. There was no statistically significant difference between both groups in regards to the expulsion of IUCD. These results are in line with the randomized control trial (RCT) of Lester et al. [14], where there was no statistically significant differences between 34 post-placental women versus 18 women in the postpartum period [14].

Contrary to the present study is the study of Mohamed et al. [15], in which immediate postpartum IUCD insertion had a higher expulsion rate, of 6.2% compared to 1.2% postpartum, which was statistically significant. These results were similar to the study of Gupta et al. [16], where the expulsion rate was significantly higher in the post-placental group compared to the postpartum insertion group.

In the current study, there were no instances of perforation in the post-placental group. However, only one perforation was observed in the puerperal group (2.4%), which occurred three months after insertion and was managed conservatively. This can be attributed to the fact that Mirena is inserted under vision, and the myometrium is thicker immediately after the delivery of the placenta in comparison to the myometrium after six weeks. Accordingly, Gutgutia et al. [17] (2015) reported no cases of Cu IUD perforation in the post-placental insertion of IUCD. Moreover, in a study of IUD insertion in CS in six different countries, 17,000 women were observed, and there was not a single case of perforation [18].

In our study, we found no statistically significant differences between both groups in terms of excessive bleeding. This finding is in line with Gupta et al.’s research [16] in 2013, where only 5.3% of women complained of bleeding, and all of them had to remove the IUCD due to this issue. There are several factors that can explain this result, such as Mirena’s ability to imitate the normal involution of the uterus during the postpartum period. This may help reduce dysfunctional bleeding and lochia [19].

In the group of women with IUDs inserted postpartum, there was no statistically significant differences in the rate of displacement between those who received the IUD immediately after delivery, and those who received it later. In both the first- and third-month follow-ups, the rate of displacement was similar in both groups. However, in cases where the IUD was displaced, it was removed, and the women were offered an alternative form of contraception. This result was consistent with the findings of a study conducted by Lester et al. [14], which also found no statistically significant differences in the displacement rates between post-placental and postpartum women [14]. Another study by Puzey [20] found that 6% of patients experienced malposition of the IUD, conducted among 33 patients who had Mirena inserted intra-cesarean [20]. In a randomized controlled trial by Zaconeta et al. [13], 8 out of 91 women (8.8%) exhibited IUD rotation to a transversal situation inside the endometrial cavity during sonographic follow-up [13].

Our study found no statistically significant differences between groups in regard to pelvic infection. This may be due to the Mirena’s inert nature, which reduces the local inflammatory response, that is common with the Cu device. Additionally, participants who had an immediate post-placental insertion, recently completed a course of antibiotics, which lowered their risk of developing a pelvic infection. Our results are consistent with Zaconeta et al. (2019) and Gupta et al. (2013) [13, 16].

The advantage of the current study is that it was conducted in a private hospital and the consultants applied Mirena at the same level of experience, which reduced statistical bias. However, there are some weaknesses in the study. Firstly, there was no long-term follow-up due to the fact that most patients being non-Saudi, i.e., non-residents who only visited Saudi Arabia for three to six months before returning to their countries. Secondly, there was a lack of randomization, as most private patients refused the idea of randomization and preferred to make their own decisions.

We highly recommend that obstetricians insert the IUD immediately after delivery for an easier application, safety, early contraception, and patient convenience.

There have not been any large or long-term randomized controlled trials on the insertion of the levonorgestrel intrauterine system (LNG-IUS) during a CS. Further studies are necessary to evaluate patient satisfaction with post-placental IUD insertion and the reduction of psychological fear related to pain during IUD insertion, with a long-term follow-up.