Introduction

Placenta praevia (PP) is an obstetric complication characterised by the presence of the placenta that is covering the internal cervical os in the third trimester. The cause of PP is unknown but there are many known risk factors such as previous PP, previous uterine surgery, multiparity etc. AS Anzaku et al. (1) found prior history of CD as the most common risk factor (40.7%). A recent WHO publication reported that between 1990 and 2014 the global average CD rate increased from 12.4 to 18.6% with rates ranging, depending on region, (2) and South African Saving Mothers reported a CD rate of 28% in 2019, 2020 and 2021. There is a well-known exponential increase in the risk of PP with number of prior CD. (3)

The morbidity and mortality of PP is increased when PP is associated with PAS. Prior uterine surgery causes PAS with prior CD as the most common predisposing factor, (4-5) the decidua basalis abnormally thin due to failed reconstruction following disruption so the placenta can attach and invade the myometrium. IM Usta et al. (6) found that caesarean hysterectomy was performed only in women with PAS who had a longer hospital stay, a higher estimated blood loss, and need for blood transfusion.

Queen Nandi Regional Hospital (QNRH) in northern KwaZulu Natal has a high prevalence of PP probably because of the wide referral base. No studies on PP have been done here. Hopefully this study will highlight the clinical profile, complications and the shortcomings in the management of PP.

Methods

The study was a retrospective observational cross-sectional study to review women’s medical records. The study was conducted at QNRH which is a rural and regional referral health facility for 16 district hospitals. The study population comprised women diagnosed during antenatal care with PP and managed at the hospital from 1^st January 2018 to 31^st December 2020. A hospital register was used to identify women diagnosed with PP. The hospital numbers were used to retrieve women’s medical records. Through a pre-designed structure data sheet, demographic details and clinical information were obtained including risk factors, medical and obstetric history, ultrasound findings, gestational age at diagnosis and delivery, management and complications (antepartum, intrapartum and post-partum). Only women with PP found on ultrasound with a gestational age of ≥ 26 weeks were included in the study.

Statistical analyses were performed by using descriptive statistics. Frequencies and percentages were used for categorical data. Chi-Square-Test, Mann–Whitney-Test, Fisher’s exact were used to determine categorical factors associated with outcome, applying a significance level α < 0.05, P values, odds ratios and 95 confidence intervals were given.

The research was approved by the Biomedical Research Ethics Committee of the University of KwaZulu Natal (BREC/00003226/2021), the KwaZulu Natal department of Health (KZ _202111_002) and the ethic committee of Queen Nandi Regional Hospital.

Results

Our study population were women diagnosed with PP during the study period, a sample size of 114 was required which was calculated using Stata V15. Single women were 99 (86.8%), married women were 15 (13.2%), employed were 25 (21.9%), unemployed were 76 (66.7%), students were 10 (8.8%), unknown occupation were 3 (2.6%). Women with PP who presented with complaint of per vagina bleeding were 67 (58.8%). Women who booked before 14 weeks gestational age were 46 (40.4%), 14- 22 weeks were 38 (33.3%), more than 22 weeks were 27 (23.7%) and only 3 (2.6%) were unbooked. HIV negative were 63 (55.3%) and HIV positive were 51 (44.7%). Normal BMI were 28 (24.6%), overweight were 28 (24.6%), high BMI were 42 (36.8%) and 16 (14.0%) were unknown. After diagnosis of PP was made, 87(76.3%) were managed inside the hospital (asymptomatic or symptomatic) and 27 (23.7%) were managed as outpatient (asymptomatic). Emergency CD were 64 (56.1%). Regarding haemostasis management, 20 (17.2%) had uterine artery ligation, 1 (0.9%) had internal iliac artery ligation, 17 (14.7%) had compressive sutures, 9 (7.8%) had uterine tamponade, 2 (1.7%) had stepwise devascularisation, 4 (3.4%) had abdominal swabs packed post TAH. All women with PAS (n=14) had a prior CD and all had a total abdominal hysterectomy, other cause of TAH was post-partum haemorrhage (PPH) (n=3). No cell saver machine was used for blood transfusion. General anaesthesia was administered in 82 (71.9%) women with PP.

Fig. 1: Risk factors of women with PP

Fig. 2: Maternal age distributions for women with PP

Fig. 3: Complications of women with PP

Discussion

This study showed that most of participants (73.7%) first presented at health facility before 22 weeks, high number could be due to health initiative which aims to support maternal health through the use of cell phone based technologies integrated into maternal and child health services. Most women in South Africa (56%) do not attend health facility before 20 weeks due to numerous barriers such as transportation, under-resourced clinics with excessive waiting lines. (7)

The participants in the study presented with different risk factors, the most common including: multipara, prior CD and increasing in maternal age (Fig. 1). The Increasing in parity, documented to be 50% (table 1) as compared to 57% in study by M. Kollman et al. (4) may be due to many unsettled relationships, with single women found to be 86.8%, poor contraception uptake could also be the reason.

The high prevalence of prior CD (32.5%) could be the result of increased CD rate worldwide, (2) and a wide referral base at QNRH, AS Anzaku et al. (1) and E. Jaiswal et al. (8) found respectively a prior CD rate of 40.7% and 35.4%. Surgical disruption of the uterine cavity is known to cause lasting damage to the myometrium and endometrium and the risk of PP is increased with the increased number of prior CD. (3)

Advanced maternal age was 28.9% (Fig. 1 and 2), same number (29.3%) was found by M. Kollman et al. (4) According to the study conducted by Choi et al. (9) prevalence of PP increases as the maternal age advances. This is thought to be due to atherosclerotic changes in the uterus resulting in under perfusion and infraction of the placenta, thereby increasing the size of the placenta.

A low lying placenta may be found as soon as 18-20 weeks gestational age when an ultrasound is done for an anomaly ultrasound but the diagnosis of PP will needs to be confirmed at around 32 weeks as 90% of PP will resolve before delivery at term. (10) Early access to ultrasound seemed to be limited or delayed in the participants as only 37.7% had their first ultrasound before 28 weeks gestational age (Table 2). For women who didn’t have an ultrasound done early in pregnancy, the diagnosis may be suspected and confirmed when they present with per vagina bleeding, this study found 58.8% of participants presented with per vagina bleeding.

Per vagina bleeding is the main reason for early delivery with 56.1% of participants who required emergency CD. E. Jaiswal et al. (8) found 81.5% with per vagina bleeding, with 70.8% who had emergency CD. The bleeding can be very massive, putting the life of the woman and her pregnancy in danger, emphasizing the importance of early access to ultrasound and early diagnosis.

The detection rate of PAS was low as only 5 out 14 (35.7%) (Table 3) were diagnosed by ultrasound with the remainder diagnosis made intra operatively after failed separation of the placenta. G Pagani et al. (11) found a sensitivity of 88% on sonographic identification of PAS. The combination of grey-scale and colour Doppler imaging ultrasound markers is reported to have increased the sensitivity of ultrasound imaging to around 90% with negative predictive values ranging between 95% and 98%. (12)

Most of participants were managed as inpatients (76.3%), many of them came from far with limited access to transportation or were at high risk of bleeding and needed to be managed inside the hospital. Comparison of outcome between inpatient and outpatient management was not done, due to insufficient medical notes but Wing et al. (13) found no difference in outcomes between inpatient and outpatient management in his randomized control trial.

Intra operatively, the main concern is excessive bleeding. The most common fertility sparing technique used to achieve haemostasis in the study was uterine artery ligation (17.2%) while in study by E. Jaiswal et al. (8) placenta bed compressive sutures were mostly used (39.2%). A combination of techniques can be used to achieve haemostasis if one isn’t successful and because bleeding comes from the placenta bed, compressive sutures and uterine tamponade may be among the first to be done.

Most of participants received general anaesthesia (71.9%), probably due to the perception that it is safer especially for major degree PP or PP associated with PAS. JY Hong et al. (14) compared general and regional anaesthesia (RA) found the latter was more superior in elective caesarean section for major degree PP with regard to maternal haemodynamic and blood loss but there was no difference in the incidence of intraoperative or anaesthesia complications between the 2 types of anaesthesia.

The study found different complications associated with PP. (Fig. 3) The study found 25.4% of participants had PPH (table 4), same number (24.6%) found by E. Jaiswal et al. (8) Lower segment of the uterus contracts poorly leading to excessive bleeding in women with major degree PP. In this study, the risk of PPH increased with the number of prior CD (5 fold Odds increase with Prior CDx3) (Table 5), J. Hasegawa et al. (15) had the same observation. This may be due to prior CD that is associated with PAS due to an absence or deficiency of spongiosus layer of the decidua and the main risk associated with any form of PAS disorder is massive obstetric haemorrhage, (16) with result found to be statistically significant in this study. (Table 5)

The study found that the risk of TAH increased with the number of prior CD, probably due to the association of prior CD and PAS. All participants diagnosed with PAS had a TAH. (Table 6) IM Usta et al. (6) and DA Miller et al. (17) found also an increased risk of PAS with number of prior CD. There is a place for a conservative management (leaving the placenta in situ for spontaneous resorption) when fertility is still desired, (18) no participant with PAS in this study was managed conservatively as all had completed family and were agreeable for TAH after counselling.

Majority of participants (72.8%) in the study received blood transfusion. (Fig. 3) The risk of blood transfusion increased with prior CD (5 fold Odds increase with prior CDx2) (Table 7), WA Grobman et al. (19) had the same observation but A Oya et al. (20) found increased risk of blood transfusion only in major degree PP and not in prior CD, difference could be due to small number of prior CD in his study. Our study showed that no cell saver machine was used even though it was available. S Malik et al. (21) found the usage of cell salvage practice was not very effective due to non-availability of trained staff and unfamiliarity of techniques, explanation may be similar in this study, but S Malik concluded that if it is used efficiently it has a role in decreasing the need for homologous blood transfusion and saving cost.

Placenta praevia is associated with a high risk of preterm delivery, mainly due to antepartum haemorrhage. (22) This study found 26.3% of participants delivered before 34 weeks gestational age (Table 3) as compared to 41.5% by E. Jaiswal et al. (8) Participants who delivered before 37 weeks were 55.3% as compared to 45.6% by JM Crane et al. (23) Prematurity may explain other neonate adverse outcomes found in the study such as, respiratory problems, low APGAR and perinatal death (Table 8 and 9). Respiratory problems were more likely in smaller babies as compared to bigger babies (Table 10), steroid for lung maturity was not included in the study due to insufficient notes, if not given can explain the respiratory problems in small babies.

This study being the first done at QNRH, add to the body of evidence the morbidity associated with PP. Future researchers may use this study as a reference for further studies. Clinicians may also refer to this study to better understand the condition.

Limitations and strengths

This was a retrospective study with recordkeeping not optimal in some cases. There were no maternal deaths. This study is the first in this rural health institution, identified maternal risk factors associated with bad outcome and findings could be used to improve management of women with PP.

Conclusion

Prior history of CD is a common risk factor for PP, when associated with PAS, there is an increased risk of complications such as TAH, PPH and blood transfusion. Prematurity is a major concern in women with PP. Limiting the number of caesarean section in future will decrease the incidence of PP and its complications. Further research may involve outcome of women with PP associated with PAS and manage conservatively by leaving the placenta in situ.

Acknowledgements: The authors thank all those who support this study, Dr N. Mayat, Dr P. Makinga, Dr Motsema, Sister Tshangase, and Catherine Conneli.

References

1. Anzaku A, Musa J. Placenta praevia: incidence, risk factors, maternal and foetal outcomes in a Nigerian teaching hospital. Jos Journal of Medicine. 2012;6(1): p. 42-46. https://doi.org/10.3109/14767058.2015.1049152
2. Harrison MS, Goldenberg RL. Caesarean section in sub-Saharan Africa. Maternal Health, Neonatology and Perinatology. 2016;2(1):1-10. https://doi.org/10.1186/s40748-016-0033-x
3. Ananth CV, Smulian JC, Vintzileos AM. The association of placenta praevia with history of caesarean delivery and abortion: a meta-analysis. American Journal of Obstetrics and Gynaecology. 1997;177(5):1071-1078. https://doi.org/10.1016/s0002-9378 (97)70017-6
4. Kollmann M, Gaulhofer J, Lang U et al. Placenta praevia: incidence, risk factors and outcome. The Journal of Maternal-Foetal and Neonatal Medicine. 2016;29(9):1395-1398. https://doi.org/10.3109/14767058.2015.1049152
5. Matsuzaki S, Mandelbaum RS, Sangara RN, et al. Trends, characteristics, and outcomes of placenta accreta spectrum: a national study in the United States. American Journal of Obstetrics and Gynaecology. 2021;225(5):534. e1-534. e38. https://doi.org/10.1016/j.ajog.2021.04.233
6. Usta IM, Hobeika EM, Musa AA et al. Placenta praevia-accreta: risk factors and complications. American Journal of Obstetrics and Gynaecology. 2005;193(3):1045-1049. https://doi.org/10.1016/j.ajog.2005.06.037
7. Haddad DN, Makin JD, Pattinson RC et al. Barriers to early prenatal care in South Africa. International Journal of Gynaecology and Obstetrics. 2016;132(1):64-67. https://doi.org/10.1016/j.ijgo.2015.06.041
8. Jaiswal E, Aggarwal N, Suri V et al. Clinical profile and outcome of patients with placenta praevia: a study at a tertiary care referral institute in Northern India. International Journal of Reproduction, Contraception, Obstetrics and Gynaecology. 2018;7(7):2560. https://doi.org/10.18203/2320-1770.ijrcog20182861
9. Choi SJ, Song SE, Jung KL et al. Antepartum risk factors associated with peripartum caesarean hysterectomy in women with placenta praevia. American Journal of Perinatology. 2007;37-41. https://doi.org/10.1055/s-2007-1004834
10. Oyelese Y, Smulian JC. Placenta praevia, placenta accreta, and vasa praevia. Obstetrics and Gynaecology. 2006;107(4):927-941. https://doi.org/10.1097/01.aog.0000252288.13209.40
11. Pagani G, Cali G, Acharya G, et al. Diagnostic accuracy of ultrasound in detecting the severity of abnormally invasive placentation: a systematic review and meta‐analysis. Acta Obstetricia et Gynecologica Scandinavica. 2018;97(1):25-37. https://doi.org/10.1111/aogs.13238
12. D'Antonio F, Iacovella C, Bhide A. Prenatal identification of invasive placentation using ultrasound: systematic review and meta‐analysis. Ultrasound in Obstetrics and Gynaecology. 2013;42(5):509-517. https://doi.org/10.1002/uog.13194
13. Wing DA, Paul RH, Millar LK. Management of the symptomatic placenta praevia: a randomized, controlled trial of inpatient versus outpatient expectant management. American Journal of Obstetrics and Gynaecology. 1996;175(4):806-811. https://doi.org/10.1016/s0002-9378 (96)80003-2
14. Hong JY, Jee YS, Yoon HJ et al. Comparison of general and epidural anaesthesia in elective caesarean section for placenta praevia totalis: maternal hemodynamic, blood loss and neonatal outcome. International Journal of Obstetric Anaesthesia. 2003;12(1):12-16. https://doi.org/10.1016/s0959-289x (02)00183-8
15. Hasegawa J, Matsuoka R, Ichizuka K, et al. Predisposing factors for massive haemorrhage during caesarean section in patients with placenta praevia. Ultrasound in Obstetrics and Gynaecology. 2009;34(1):80-84. https://doi.org/10.1002/uog.6426
16. Allen L, Jauniaux E, Hobson S et al. FIGO consensus guidelines on placenta accreta spectrum disorders: nonconservative surgical management. International Journal of Gynaecology and Obstetrics. 2018. https://doi.org/10.1002/ijgo.12409
17. Miller DA, Chollet JA, Goodwin TM. Clinical risk factors for placenta praevia–placenta accreta. American Journal of Obstetrics and Gynaecology. 1997;177(1):210-214. https://doi.org/10.1016/s0002-9378 (97)70463-0
18. Sentilhes L, Ambroselli C, Kayem G, et al. Maternal outcome after conservative treatment of placenta accreta. Obstetrics and Gynaecology. 2010;115(3):526-534. https://doi.org/10.1097/aog.0b013e3181f738d8
19. Grobman WA, Gersnoviez R, Landon MB, et al. Pregnancy outcomes for women with placenta praevia in relation to the number of prior caesarean deliveries. Obstetrics and Gynecology. 2007;110(6):1249-1255. https://doi.org/10.1016/j.ajog.2006.10.415
20. Oya A, Nakai A, Miyake H et al. Risk factors for peripartum blood transfusion in women with placenta praevia: a retrospective analysis. Journal of Nippon Medical School. 2008;75(3):146-151. https://doi.org/10.1272/jnms.75.146
21. Malik S, Brooks H, Singhal T. Cell saver use in obstetrics. Journal of Obstetrics and Gynaecology. 2010;30(8):826-828. https://doi.org/10.3109/01443615.2010.511727
22. Long SY, Yang Q, Chi R et al. Maternal and neonatal outcomes resulting from antepartum haemorrhage in women with placenta praevia and its associated risk factors: A single-centre retrospective study. Therapeutics and Clinical Risk Management. 2021;31-38. https://doi.org/10.2147/tcrm.s288461
23.  Crane JM, Van den Hof MC, Dodds L et al. Neonatal outcomes with placenta praevia. Obstetrics and Gynecology. 1999;93(4):541-544. https://doi.org/10.1016/s0029-7844 (98)00480-3