Retained placenta

Retained placenta can be defined as lack of placental expulsion within 30 minutes of delivery of an infant. it is more common in preterm. Retained Placenta can lead to massive PPH and increase maternal morbidity and mortality.

1. RETAINED PLACENTA

2. Dr. Niranjan Chavan MD, FCPS, DGO, DFP, MICOG, DICOG, FICOG Professor and Unit Chief, L.T.M.M.C & L.T.M.G.H Chairperson, FOGSI Oncology and TT Committee (2012-2014) Treasurer, MOGS (2017- 2018) Chair and Convener, FOGSI Cell- Violence against Doctors (2015-2016) Chief Editor, AFG Times (2015-2017) Editorial Board, European Journal of Gynecologic Oncology Editor of FOGSI FOCUS, MOGS, AFG & IAGE Newsletters Member, Managing Committee, IAGE (2013-2017) Member , Oncology Committee, AOFOG (2013 -2015) Recipient of 6 National & International Awards Author of 15 Research Papers and 19 Scientific Chapters Course Co-Ordinator, of 11 batches, of MUHS recognized Certificate Course of Basic Infertility Management Including Endoscopy (BIMIE) at LTMGH

3. DEFINITION Retained placenta can be defined as lack of expulsion of the placenta within 30 minutes of delivery of the infant. This definition is suitable in the third trimester when the third stage of labour is actively managed because 98 percent of placentas are expelled by 30 minutes in this setting.

4. Natural history of retained placentas with active and physiological management.*   * The retained placenta. Best Pract Res Clin Obstet Gynaecol 2008; 22:1103 .

5. DEFINITION In the second trimester and with physiological management of the third stage, it takes about 60 minutes before 98 percent of placentas are expelled.   In part for these reasons, the World Health Organization (WHO) concluded that the length of time before making a diagnosis of retained placenta should be “left to the judgement of the clinician” *   * World Health Organization. WHO recommendations for the prevention and treatment of postpartum hemorrhage . 2012.  

6. Rate of retained placenta by gestational age * Dombrowski , MP, Bottoms, SF, Saleh, AA, et al. Third stage of labor : analysis of duration and clinical practice. Am J Obstet Gynecol 1995; 172:1279.

7. TYPES Trapped or incarcerated placenta:   separated placenta but not delivered spontaneously or with light cord traction because the cervix has begun to close. Placenta adherens: The placenta is adherent to the uterine wall, but easily separated manually. Placenta accreta: The placenta is pathologically invading the myometrium due to a defect in the decidua.

8. PHASES OF 3 RD STAGE OF LABOR* Latent phase – Immediately after birth, all of the myometrium contracts except for the portion beneath the placenta. Contraction phase – The retroplacental myometrium contracts. Detachment phase – Contraction of the retroplacental myometrium produces horizontal (shear) stress on the maternal surface of the placenta, causing it to detach. Expulsion phase – Myometrial contractions expel the detached placenta from the uterus. *Herman A, Weinraub Z, Bukovsky I, et al. Dynamic ultrasonographic imaging of the third stage of labor : new perspectives into third-stage mechanisms. Am J Obstet Gynecol 1993; 168:1496.

9. In 2000, Krapp et al published a paper emphasizing that: There is no major difference on sonography between the contraction and the detachment phase. Cessation of blood flow between the basal placenta and myometrium following delivery of the baby is the sonographic hallmark of normal placental separation. Persistent blood flow demonstrated by color Doppler sonography is suggestive of placenta accreta .

10. PHASES OF 3 RD STAGE OF LABOR A trapped placenta may be seen as a failure of the expulsion phase. Placenta adherens appears to result from contractile failure in the retroplacental area (i.e., a prolonged latent phase of the third stage of labour). The pathogenesis of placenta accreta   is completely different, as it is a structural rather than a functional abnormality . 

11. PREVALANCE In a systematic review of observational studies, the median prevalence of retained placenta at 30 minutes is between 2.7 - 1.5%. * The overall prevalence of retained placenta varies across settings and over time. * Cheung WM, Hawkes A, Ibish S, Weeks AD. The retained placenta: historical and geographical rate variations. J Obstet Gynaecol 2011; 31:37.

12. RISK FACTORS In a series of > 91,000 singleton vaginal deliveries ≥ 24 weeks of gestation, Following risk factors were found: Preterm gestational age was the most important risk factor Stillbirth Maternal age ≥30 years Use of ergometrine Uterine abnormalities Defective placental implantation Velamentous cord insertion Previous retained placenta Coviello EM, Grantz KL, Huang CC, et al. Risk factors for retained placenta. Am J Obstet Gynecol 2015; 213:864.e1.

13. DIAGNOSIS A diagnosis of trapped placenta is made when the classic clinical signs of placental separation are present and the edge of the placenta is palpable through a narrow cervical OS.

14. A diagnosis of placenta adherens or placenta accreta is made in the absence of signs and symptoms of placental separation. Ultrasound can differentiate between a detached trapped placenta and an adherent placenta. On USG, the myometrium will be thickened in all areas except where the placenta is attached, where it will be very thin or even invisible DIAGNOSIS

15. COMPLICATIONS POST PARTUM HAEMORRHAGE ENDOMETRITIS   Case fatality rate is around 1 %

16. WHEN TO INTERVENE? Retained placenta with post partum haemorrhage is an OBSTETRIC EMERGENCY. For stable 3 rd Trimester Deliveries: expectant management can be continued till 30 minutes. However, for 2 nd trimester deliveries, waiting time can be extended till 60 min in absence of bleeding. In a trial including 51 women with retained placenta at 60 minutes and no pharmacologic intervention, 23 women (45 percent) eventually expelled the placenta spontaneously, but 24 of the 51 women (47 percent) bled over 1000 mLs and 9 (18 percent) were transfused.* *van Stralen G, Veenhof M, Holleboom C, van Roosmalen J. No reduction of manual removal after misoprostol for retained placenta: a double-blind, randomized trial. Acta Obstet Gynecol Scand 2013; 92:398.

17. MANAGEMENT CONTROLLED CORD TRACTION MANUAL REMOVAL OF PLACENTA INSTRUMENT EXTRACTION MANAGING UNEXPECTED PLACENTA ACCRETA PPH MANAGEMENT MANAGING THE UNDERLYING CAUSE

18. PREREQUSITES Ensuring that the mother’s bladder is empty. Offering the baby the breast as it releases oxytocin causing uterus to contract. Fundal massage.

19. MANAGING THE UNDERLYING CAUSE EXCESSIVE CERVICAL/UTERINE CONTRACTION If the lower uterus/cervix is contracted, thereby preventing expulsion of the placenta, administration of nitroglycerin will result in relaxation and facilitate placental delivery . Glyceryl trinitrate two sprays (400 micrograms/spray) onto or under the tongue. IV sequential bolus : 50 micrograms, maximum cumulative dose 200 micrograms, until sufficient uterine relaxation is achieved Sublingual tablets 0.6 to 1.0 milligrams. Uterine relaxation occurs within 60 seconds after the dose and lasts for one to two minutes.

20. MANAGING THE UNDERLYING CAUSE ATONY IV infusion of oxytocin may facilitate placental delivery in dose is 10 to 40 units in 500 mL saline. Prostaglandin F2-alpha may also be of benefit if bleeding is severe and not controlled with oxytocin. Ergometrine should be avoided, if possible, as it constricts the cervix, making manual removal very difficult . 

21. UMBILICAL VEIN OXYTOCIN INJECTION WHO support that a dose of 10-20 IU of oxytocin can be administered Intraumbilically. It directly reaches the retroplacental myometrium. However, the quality of evidence is moderate.

22. CONTROLLED CORD TRACTION Gentle controlled cord traction alone may result in successful delivery of a trapped or incarcerated placenta or promote separation of placenta adherens. In a Meta analysis of 5 RCT’s in 2013 , it was found that Controlled cord traction appears to reduce the risk of any postpartum hemorrhage and manual removal of the placenta. * *Du Y, Ye M, Zheng F. Active management of the third stage of labor with and without controlled cord traction: a systematic review and meta-analysis of randomized controlled trials. Acta Obstet Gynecol Scand 2014; 93:626 .

23. BRANDT ANDREW MANEUVER   For the Brandt-Andrews maneuver , one hand is placed on the abdomen to push uterus upward and backward and prevent uterine inversion while the other hand exerts sustained downward traction on the umbilical cord.* In modified technique, cord is held with forceps instead of hand. *Brandt ML. The mechanism and management of the third stage of labor . Am J Obstet Gynecol 1936; 25:662.

24. MANUAL REMOVAL OF PLACENTA MROP is indicated after failed Drug therapy and controlled cord traction. Preparations: Consent Bladder catheterisation Anaesthesia IV access Routine surgical preparation IV Antibiotics In cases of excessive uterine contraction, Nitroglycerine can be used

25. ROLE OF UTERINE CURETTAGE AFTER MROP? There is no role for routine uterine curettage after manual extraction. It has no benefit and carries the risk of uterine perforation and Asherman syndrome. * However, if placental tissue is retained and the patient is bleeding excessively, then curettage using a large blunt placental curette is reasonable to remove the remaining placental tissue. *The Retained Placenta. In: Progress in Obstetrics and Gynaecology 16, Studd J (Ed), Churchill Livingstone Elsevier, Edinburgh 2004. ROLE OF ROUTINE USG AFTER MROP? Routine ultrasound evaluation of the uterus after manual extraction is also unnecessary . * * Weissbach T, Haikin -Herzberger E, Bacci -Hugger K, et al. Immediate postpartum ultrasound evaluation for suspected retained placental tissue in patients undergoing manual removal of placenta. Eur J Obstet Gynecol Reprod Biol 2015; 192:37.

26. INSTRUMENT EXTRACTION If digital extraction is not possible, large-headed forceps ( eg , Bierer forceps, Ring forceps) can be used to grip and extract the placenta in pieces or intact; ultrasound guidance can be helpful. * The procedure requires less analgesia than digital extraction. *Rosenstein MG, Vargas JE, Drey EA. Ultrasound-guided instrumental removal of the retained placenta after vaginal delivery. Am J Obstet Gynecol 2014; 211:180.e1.

27. INCOMPLETE EXTRACTION Even after manual extraction, some bits of placenta may be left adhered to uterine wall. This will not lead to postpartum haemorrhage as long as the uterus contracts well and there is no area of sub involution at the site of the retained placental fragments. Curettage should be done only in cases of bleeding, as the myometrium may be very thin at the point of adherence, thus increasing the risk of perforation.

28. UNEXPECTED ACCRETA Rarely, a complete placenta accreta is first recognized at the time of manual removal of the placenta. In these cases, there is no plane of dissection between the uterus and placenta and, almost invariably, attempts at manual removal lead to life-threatening haemorrhage. Administration of uterotonic drugs and preparation for Obstetric hysterectomy.

29. OBSTETRIC HYSTERECTOMY In most cases, it is a last resort lifesaving procedure, undertaken when other more conservative method to control haemorrhage have failed. It is definite treatment for placenta accreta.

30. PPH MANAGEMENT Explore the uterus and perform curettage for retained placenta or bits of placenta Examine the uterus to rule out atony Examine the vagina and cervix to rule out lacerations; repair if present To be undertaken simultaneously with management of hypovolemic shock

31. TEMPORIZING MEASURES Temporizing measures recommended for intractable atonic and non-atonic PPH include: External aortic compression Bimanual uterine compression Non-pneumatic anti-shock garment (NASG )

32. EXTERNAL AORTIC COMPRESSION External aortic compression significantly reduces blood flow to the pelvic organs while preserving blood supply to surrounding organs. It has traditionally been accomplished manually, with a provider applying pressure with a closed fist on the abdominal aorta slightly to the patient’s left and immediately above the umbilicus.

33. EXTERNAL AORTIC COMPRESSION DEVICE EACD, consists of a strong metal spring, cylindrical in shape, covered with leather. It has a height of 12 cm (5 cm when compressed), diameter of 8 cm, and a net surface area of 22.3 cm2. It is fixed in place by a leather belt wrapped around the waist Pressure of 103.5 mm Hg/cm2 (30 kg) on the abdominal wall is achieved in order to stop bleeding. EACD use was associated with significantly reduced time to cessation of uterine bleeding in one study * * Soltan MH, Sadek RR. Experience managing postpartum hemorrhage at Minia University Maternity Hospital, Egypt: no mortality using external aortic compression. J. Obstet. Gynaecol . Res. 37(11), 1557–1563 (2011)

34. NON-PNEUMATIC ANTI-SHOCK GARMENT For women suffering from uncontrollable PPH, a method to control the bleeding, reverse the shock, and stabilize the patient for safe transport to a comprehensive obstetric care facility could be lifesaving. It is a lightweight neoprene garment that is made up of five segments that close tightly with Velcro. The NASG applies pressure to the lower body and abdomen, thereby stabilizing vital signs and forcing blood to the essential organs - heart, lungs, and brain.