NEWBORN

Immediate Information Expected by the Neonatologist from the Placenta Raili Peltonen, M.D., Tuomas Peltonen, M.D.

As the obstetrician attends to the mother and the pediatrician to the child, the placenta often tends to be ignored. Nevertheless, essential anamnestic information about the condition of a newborn infant, and especially of a premature, can be gained from careful scrutiny of the placenta and fetal membranes. This paper emphasizes the importance of gross examination of the placenta and membranes as a source of immediate information to the pediatrician within the delivery room.

ONE-THIRD (37%) marginal

of all instances of insertion and over half (54% )14 of those of velamentous insertion are found in premature births. Hence, investigative studies on the etiology of prematurity should always take the placental status into account. 12

is called pedicular insertion; the latter, cordal insertion. Their pathophysiologic significance is unknown. The eccentric umbilical cord is also of significance in pediatric malformations. Krone’s data are summarized in Table 1.

Umbilical Cord Attachments to the Placenta

Placental Size

According insertions

to

are

Krone, 68 per

central

or

cent

of cord

nearly central,

21

cent are markedly eccentric, 10 per cent marginal, and membranous attachments comprise 1 per cent. Associated with the latter two types may be a circulatory de-

per

are

fect, which in as

turn

the fetus moves,

may lead or even

to

fetal death

during delivery

(Figs. 1, 2). With central insertions, the umbilical vessels may divide before reaching the placental surface, or the placental tissue may rise conically into the umbilical cord. The former The Department of Obstetrics and Gynecology and the Department of Pediatrics, University of Turku, Turku, Finland.

The placental weight increases, of course, the fetus grows, but as a rule is not evaluated clinically.5.11 Of itself, the placental weight is not clinically useful until after it is incorporated into the ratio of the placental weight to the child’s weight (Ratio Placental Weight-RPW). The correlation between RPW and RAW (Relative Afterbirth Weight) was clarified by our team6 from studies on 707 normal neonates. The RAW was 16.9 ± 2.5; the RPW, 13.9 ~- 2.2. In normal pregnancies, the value of the RPW can be approximated by multiplying the RAW by 0.8. This positive correlation between the child’s birth weight and the weight of the placenta supports the concept that the growth of the as

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marginal

FIG.

Placenta with attachment of

umbilical

cord

I.

(insertio

marginalz’s).

fetus and of its

organ

are

nourishing and protecting governed by the same factors.

Large RPW. It has been known for decades that an overlarge placenta tends to be a sign of a fetal infection. Classic examples are congenital syphilis and congenital tuberculosis. More recent additions to the list include toxoplasmosis, listeriosis, and cytomegalovirus infection. Disorders of immunity may be related to a large placenta. Best recognized is the large placenta associated with Rh blood group incompatibility, as in hemolytic disease of the newborn. Other forms of blood group in-

compatibility between the mother and father, recognized but not as yet specifically defined, may lead to difficulties in perinatal adaptation, fetal death, abortions, and perhaps even to sterility. Small RPW. Small placental size may be reflected in defective functioning, but information here is limited. It is difficult to say how often intrauterine death is the result of insufficiency of fetomaternal metabolism and oxygenation caused by small placental size, although the placenta of a live-born child is very rarely less than 10 per cent of birth weight. There is no clear evidence that

FIG.

2.

Placenta with

primary attachment of the cord to the fetal membranes (insertio velamen-

tosa).

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TABLE 1. Umbilical Cord Attachment

Among Healthy

primary small placenta leads to a low birth weight child, but this may be possible.&dquo; Dystrophic children may have a small placenta.16 Placenta Extrachoroidalis This formation has been described as the of early primary placental insuf-

outcome

ficiency.3.4 Every placental surface has a hyalinized yellow ring, coinciding with the margin. Of 3,000 placentas studied by Fox,’ one-fourth

were represented of this type and from multiparous women. In the case of complete ci.rcu.mvallate placenta, the risk&dquo;.is great of threatened abortion, premature delivery, or small fetal growth .3 As many as 30 per cent of nontoxemic separations are a result of this came

placental anomaly.1,9 Hemorrhage

and

Signs

of

Degeneration

Marginal sinus rupture causes about half of the intrauterine hemorrhages during pregnancy. Should this occur during the first six months, the risk of premature delivery is about doubled.

FIG. 3. Placenta with

fibrotic

scar

on one

and

Malformed

Children

According to Krone7

Placental abruption, ablatio placentae, is much rarer, found in about 0.5 per cent of such hemorrhages. The cause is usually toxemia, and sometimes abdominal trauma. If the abruptive surface is less than onethird of the total placental surface, necrotic organization may occur. Later, the remnant of the separation appears as a white area thinner than the surrounding tissue.~ 2 When the separation is large, the infant’s prognosis is poor, the perinatal mortality being 40 to 50 per cent. Fibrotic degeneration of the placenta ensues as it ages or its function deteriorates. Calcium and magnesium salts deposit in the nonfunctioning areas, giving rise to white hardened specks on the surface (Fig. 3). Umbilical Cord A short umbilical cord may cause abruption of the placenta. Abdominal anomalies may be found in association with a short cord. A long acmbilical co-rd may wrap around and compress the fetal limbs or neck and cause fetal death. Knot formation has also been described.&dquo;

Single

umbilical artery. This is encountered

a

side;

tisin the center, and a fresh hemorrhage on the

functioning placental

sue

other side.

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FIG. 4. Amnion nodosum. Note the irregular white deposits of varying size in the fetal membranes.

in about 0.5 per cent of single births.’ It is an important warning sign, since in 25 to 30 per cent of such births the child may have anomalies of the internal organs. Absence of an umbilical artery is more frequent in multiple pregnancies (7%) than in

single pregnancies.* Fetal Membrane

Changes

Deposits measuring 0.5 to 3 cm across and composed of vernix, desquamated epidermis * Elsewhere it has been maintained that the umbilical artery is without any clinical value

single

mononuclear cells-arnnion nodosum, often found in the fetal mem4)-are (Fig.

and

branes in association with decreased amniotic fluid. Oligohydramnion. The usual cause of oligohydramnion is renal agenesis.5 Other possibilities of severe cardiac malformation or of fetofetal transfusion syndrome also make this

finding significant. Signs of Infection.

With rare exceptions, placenta and membranes by entering through the membranes.13 As supporting evidence, in a twin pregnancy the fetus presenting first may be the only

infections reach the

FiG. 5. A fibrotic and calcified placenta, from a toxic pregnancy. Note the insertio marginalis in the lower margin {arrow).

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FIG. 6. A set of fused

from dizygotic twins. Note the marginal insertion of one umbilical cord.

placentas

infected. In choriónamnionitis, the membranes and umbilical cord appear cloudy, and often have a green color. The amniotic fluid does not become. cloudy until later. Such infections do not always lead to untimely rupture of the membranes, but often do so. Signs of Asphyxia. A greenish tint to the membranes and umbilical cord, caused by meconium staining, may be seen in association with asphyxia.’ In chronic asphyxia, as a result of toxemia, the placenta is often fibrotic and calcified (Fig. 5). one

Findings

in Twin

Pregnancies

chorionic cases, the monoamniotic mortality rate is 38 per cent; the diamniotic, 25 per cent. In dichorionic and diamniotic cases, the mortality rate is only 8 to 10 per cent. References Altshuler, G., Tsang, R. C., and Ermocilla, R.: Single umbilical artery. Am. J. Dis. Child. 129: 697, 1975. 2. Benirschke, K., and Driscoll, S. G.: The pathology of the human placenta. New York, Springer1.

1967. Placenta extrachorialis as a cause of perinatal morbidity. III European Congress of Perinatal Medicine, Lausanne, 1972, p. 292. 4. Goodall, J. R.: Circumcrescent and circum vallate placentas. Am. J. Obst. Gynecol. 28: 707, 1934.

Verlag,

3. Fox, H.:

Ivemark, B.: Stockholm, Barnpatologi, Almqvist & Wicksell, 1971. 6. Kouvalainen, K., Pynnönen, A-L., Mäkäräinen, M., and Peltonen, T.: Istukan, sikiökalvojen ja napanuoran paino. Duodecim 87: 1210, 1971. 7. Krone, H. A.: Pathologische fruchtentwicklung bei placenta-anomalien. Arch. Gynäk. 198: 224, 5.

In multifetal pregnancies, the anatomy of the placental mass and membranes helps in the zygotic determination. Sometimes the

placenta and membranes may suggest monozygotism, but the children are of a different sex (Fig. 6). Hence, in the delivery room, it is significant to mark which umbilical cord belongs to which. ,

One of the twins may be healthy and the other may be malformed because of chromosomal anomaly occurring after the division of the egg. Thus, not all monozygotic twins need be identical. In the macroscopic examination, the clarification of vessel anastomosis may call for studies by dye and angiographic techniques. Examination of the blood vessels is essential to the confirmation of the diagnosis

of transfusion syndrome or chimerism. The structure of the membranes has an essential prognostic significance. In mono-

1963. 8. Lauslahti, K.: On intrauterine death. Acta Obstet. Gynecol. Scand. 50: 356, 1971. 9. —: Istukan ja muiden jälkeisten patologisanatominen tutkimus. Duodecim 88: 1057, 1972. 10. Lilien, A. A.: Term intrapartum fetal death. Am. J. Obst. Gynecol. 107: 595, 1970. 11. Little, W. A.: Significance of placental fetal weight rations. Am. J. Obst. Gynecol. 79: 134, 1960. 12. Peltonen, T., Peltonen, R.: Mitä välitöntä informaatiota neonatalogi odottaa istukasta. Lääkeuu23 : 11, 1974. tiset 13. Potter, E.: Facial characteristics of infants with bilateral renal agenesis. Am. J. Obst. Gynecol. 51: 885, 1946. 14. Shanklin, D. R.: The influence of placental lesions on the newborn infant. Pediatr. Clin. North Am. 17: 25, 1970. 15. Sjöstedt, S., Engleson, G., and Rooth, G.: Dysmaturity. Arch. Dis. Childh. 33: 123, 1958. 16. Thalhammer, O.: Pränatale Dystrophie. Zschr. Kinderh. 91: 193, 1964.

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Immediate information expected by the neonatologist from the placenta.

NEWBORN Immediate Information Expected by the Neonatologist from the Placenta Raili Peltonen, M.D., Tuomas Peltonen, M.D. As the obstetrician attend...
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