Practical Placental Examination for Obstetricians

Thai Journal of Obstetrics and Gynaecology April 2017, Vol. 25, pp.70-74

SPECIAL ARTICLE

Practical placental examination for obstetricians

Patou Tantbirojn, M.D.*

* Placental Research Unit and Division of Gynecologic Pathology, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand

Abstract

Placental examination can simply be performed immediately in delivery room by obstetricians in which takes only few minutes. The evaluation should be done step by step, starting from umbilical cord, membranes, and disk. Indications for placental examination are divided into maternal, fetal, and placental indications. The submitted placenta for further evaluation by pathologist can be kept in refrigerator or fixed in buffered formalin.

Keywords: gross placental examination, umbilical cord, membranes, placental disk

Correspondence to: Patou Tantbirojn, M.D., Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand, Email: [email protected]

Placenta is a special and unique organ that Steps for placental examination in delivery composed of both maternal and fetal components. room Theoretically, every placenta should be examined The gross examination can be done immediately whether in delivery room or pathology unit. The after delivery. It is not necessary to be serious of making examination can be performed by any trained personnel precise diagnosis. The most important issue is to detect such as nurse or assistant; not necessary to be the “abnormal thing” and submit the specimen to pathologist or obstetrician. However, such personnel pathologist for further evaluation. Therefore, the may not be available in most hospital and there are also examination should be followed each step as all features small numbers of specialized pathologists in this field. are properly evaluated. In this article, the guideline is In general circumstances, obstetrician has to be the only for singleton type placenta. one who examine the placenta in delivery room and 1. Observe the “usual things” besides of the makes the decision to submit the placenta for full gross placenta. and microscopic examination by pathologist. The initial The unusual odor as feces may indicate E.coli examination is quite simple and takes only a few infection. The separated fresh blood clots can be seen minutes, but it is very useful especially in cases that do in cases with early placental abruption. not have significant clinical signs and symptoms 2. Umbilical cord examination immediately after delivery. 2.1. Evaluate the number of vessels at cut

70 Thai J Obstet Gynaecol VOL. 25, NO. 2, APRIL 2017 VOL. 25, NO. 2, APRIL 2017 end of cord 2.3. Diameter Normal cord contains two arteries and one Similar to cord length, it is quite hard to vein. Single umbilical artery occurs in 1% of deliveries immediately measure the diameter after delivery. and more frequently seen in twins other gross cord Umbilical cords of preterm fetuses tend to be thicker abnormalities(1). Approximately 20% of fetus with single than those of term fetuses. The thin umbilical cord may umbilical artery will have other major malformations, reflect the uteroplacental insufficiency. Another serious but it is non-specific to any anomaly or syndrome. condition that should be identified is cord stricture which 2.2. Length is more frequently seen with hypercoiling. It is quite hard to evaluate the definite cord 2.4. Count the number of twists length in delivery room due to lacking of measuring Twists in cord play an important role in prevent tools. The main factor that determine cord length is compression of the umbilical vessels. The twist can be stretch on the cord which is related to fetal activity. Both in left or right direction without significantly difference abnormally long and short cords have related adverse of clinical outcome between both types. However, the fetal outcomes(2, 3). Long cord is associated with true most important factor is number of twists. In general, knots and cord entanglement, while short cord may the twist should be less than 3 coils in 10 cm length(4) cause traction and subsequently results in cord tearing, Excessive twisting or hypercoiling is associated with hematoma, and prone to placental abruption. The adverse perinatal outcome, including an increase in diagnosis of excessively long cord or short cord is based perinatal mortality, intrauterine growth restriction, and on the measurement of the entire cord length and fetal distress(5). With excessive coiling, stricture may be comparing to the reference chart of each gestational formed and compromise the umbilical blood flow to the age which can be ideally done in delivery room. fetus, leading to fetal hypoxia. However, most placentas are later sent for weighing 2.5. Identify type of cord insertion and cord length measuring by assistants, not the There are five types of cord insertion into the obstetricians who delivered the case; and the reference placental disk: central, eccentric, marginal, membranous chart may be too complicated for the assistants. So if or velamentous, and furcate (Fig. 1 and 2). Central and the abnormal cord length is suspected, then the eccentric insertions are considered to be normal, while placenta should be sent to fully gross examination by the later three types of insertion are abnormal and pathologist. associated with adverse outcome(6).

Fig. 1. Diagram of umbilical cord insertion type.

VOL. 25, NO. 2, APRIL 2017 VOL. 25, NO. 2, APRIL 2017 Tantbirojn P. Practical placental examination for obstetricians 71 Fig. 2. Furcate insertion.

Fig. 3. True knot.

Fig. 4. Extrachorial placentation.

72 Thai J Obstet Gynaecol VOL. 25, NO. 2, APRIL 2017 VOL. 25, NO. 2, APRIL 2017 2.6. Knots as hemorrhage, cyst, or nodules True knot is developed in early gestation as Normal membranes are translucent and white the whole body of fetus has to pass into the loop of in color. The opaque membranes are frequently seen umbilical cord, but the outcome depends on the in cases with ascending infection which may be tightening of the knot(7). With chronic loose knot, the associated with yellow green discoloration. Meconium finding may be only groove in Wharton’s jelly without stained amniotic fluid may display green brown obvious adverse outcome. In acute tightening, there will discoloration. Red brown discoloration is seen in cases be congestion and thrombosis in cord vessels on the with old hemorrhage. placental side and collapsed vessels on fetal side of 4. Placental disk knot (Fig. 3). 4.1. Assess the shape and extra lobes 2.7. Discoloration In general, placenta displays round to oval shape. The Infection may cause opacity and calcification abnormal shape of placenta may be more frequently surrounding the vessels seen as a white stripe. seen in cases with placenta previa or localized impaired Meconium stain will be seen as green brown vascular supply. Succenturiate placenta is associated discoloration, while red brown discoloration may be with postpartum hemorrhage as it is commonly retained present in cases with chronic hemorrhage. in the uterine cavity after delivery(10). 3. Membranes 4.2. Evaluate the fetal surface 3.1. Type of insertion into the disk The fetal surface or chorionic plate is The membranes normally insert at the edge of placental examined for color, vascular pattern and thrombosis, disk and can be called as marginal insertion. If there hemorrhage, abnormal nodules, and cysts. The normal is villous tissue remaining beyond the chorionic plate, fetal surface is generally glistening white and smooth. then it will be classified as extrachorial placentation The artery should be paired by vein and the vessels which can be divided into two types: circummarginate are tapering from the cord insertion to the edge of and circumvallate (Fig. 4). Circummarginate membranes placental disk. The thrombosed vessels can be seen are flat with small deposit of fibrin at the junction, seeing as opaque white and hard in consistency. White as a thin ridge, and are not associated with adverse nodules or amnion nodosum can be seen in cases with clinical outcome. In contrast, circumvallate membrane oligohydramnios. insertion is associated with high incidences of preterm 4.3. Evaluate the maternal surface delivery, placental abruption, intrauterine growth The maternal surface or basal plate is restriction, and adverse neonatal outcomes, including observed for color, completeness, discoloration, and neonatal death(8, 9). The circumvallate placenta has a adherent blood clot. The normal maternal surface will double-back membrane fold, often containing old be seen of rough cobble stone appearance and beefy hemorrhage and necrotic deciduas in that fold. It can red in color. Pale discoloration may be infarct or be seen as a very thick ridge on the chorionic plate. excessive fibrin deposits. Adherent blood clot can be 3.2. Completeness seen in cases with placental abruption. The distance of rupture point to the edge of placenta may reflect the location of placenta. The closer Indications and how to submit the placenta for distance to the edge indicates the lower location of examination by pathologist placental implantation. The opening in complete In general, obstetrician has to be the person who delivery of membranes is usually small, while the makes the decision for sending the placenta to incomplete one is frequently fragmented or has pathology unit. Indications for placental examination extensive opening. can be divided into three categories as follows:(11) 3.3. Color, opacity and other lesions such 1. Maternal indications: vascular disorders (e.g.

VOL. 25, NO. 2, APRIL 2017 VOL. 25, NO. 2, APRIL 2017 Tantbirojn P. Practical placental examination for obstetricians 73 diabetes mellitus, hypertension, connective tissue References disease), poor reproductive history, repetitive bleeding, 1. Sun L, Wang Y. Demographic and perinatal outcome data of fetuses with SUA/PRUV. J Matern Fetal Neonatal oligohydramnios, polyhydramnios, fever or suspected Med 2017;3:1-6. infection 2. Baergen RN, Malicki D, Behling C, Benirschke K. Morbidity, mortality, and placental pathology in 2. Fetal indications: stillbirth or perinatal death, excessively long umbilical cords: retrospective study. hydrops, multiple gestation, premature labor, postterm, Pediatr Dev Pathol 2001;4:144-53. intrauterine growth restriction, major congenital 3. Tantbirojn P, Saleemuddin A, Sirois K, Crum CP, Boyd TK, Tworoger S, et al. Gross abnormalities of the anomalies, suspected infection, low Apgar scores, umbilical cord: related placental histology and clinical nonreassuring fetal heart tracing significance. Placenta 2009;30:1083-8. 4. de Laat MW1, Franx A, van Alderen ED, Nikkels PG, 3. Placental indications: any cord, membranes, Visser GH. The umbilical coiling index, a review of the or placental disk abnormalities literature. J Matern Fetal Neonatal Med 2005;17:93-100. The placenta can be refrigerated at 4oc for at 5. Dutman AC, Nikkels PG. Umbilical hypercoiling in 2nd- and 3rd-trimester intrauterine fetal death. Pediatr Dev least three days before handling to pathologist. Pathol 2015;18:10-6. Another method is fixation in buffered formalin which 6. Pinar H, Carpenter M. Placenta and umbilical cord is more convenient to transportation and less abnormalities seen with stillbirth. Clin Obstet Gynecol 2010;53:656-72. infectious. The request form for placental examination 7. Räisänen S, Georgiadis L, Harju M, Keski-Nisula L, should be completed and detailed the clinical Heinonen S. True umbilical cord knot and obstetric outcome. Int J Gynaecol Obstet 2013;122:18-21. indication, including the suspected condition. 8. Taniguchi H, Aoki S, Sakamaki K, Kurasawa K, Okuda Gestational age is also a critical item to be stated in M, Takahashi T, et al. Circumvallate placenta: associated every submitted case. clinical manifestations and complications-a retrospective study. Obstet Gynecol Int 2014;2014:986230. 9. Suzuki S. Clinical significance of pregnancies with Conclusion circumvallate placenta. J Obstet Gynaecol Res Placental examination can simply be performed 2008;34:51-4. 10. Ma JS, Mei X, Niu YX, Li QG, Jiang XF. Risk Factors in delivery room and takes only few minutes. The and Adverse Pregnancy Outcomes of Succenturiate evaluation should be done step by step, starting from Placenta: A Case-Control Study. J Reprod Med 2016;61:139-44. umbilical cord, membranes, and disk. Indications for 11. Langston C, Kaplan C, Macpherson T, Manci E, Peevy placental examination are divided into maternal, fetal, K, Clark B, et al. Practice guideline for examination of and placental indications. The submitted placenta for the placenta: developed by the Placental Pathology Practice Guideline Development Task Force of the further evaluation by pathologist can be kept in College of American Pathologists. Arch Pathol Lab Med refrigerator or fixed in buffered formalin. 1997;121:449-76.

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