EUFO~. J. Obstet. Gynec. reprod. Biol., 11 (1980) 43-48 0 Elsevier/North-Holland Biomedical Press

43

COAGULATION CHANGES DURING MANAGEMENT OF FETAL DEATH WITH 15(S)-15-METHYLPROSTAGLANDIN Fz,

M.J.N.C. KEIRSE i, J. BENNEBROEK GRAVENHORST ‘, M.J. BOEKHOUT-MUSSERT 2, J. DUBBELDAM ’ and J.J. VELTKAMP 2

’ Department of Obstetrics and Gynecology and 2 Department of Hematology, University of Leiden Medical Cenke, Rijnsburgerweg 10, 2333 AA Leiden, The Netherlands

Accepted for publication 18 April 1980

KEIRSE, M.J.N.C., BENNEBROEK GRAVENHORST, J., BOEKHOUT-MUSSERT, M.J., DUBBELDAM, J. and VELTKAMP, J.J. (1980): Coagulation changes during management of fetal death with 15(S)-15-methylprostaglandin Fz~. Europ. J. Obstet. Gynec. reprod. Biol., 1 l/l, 43-48.

Changes in the coagulation mechanism were studied during and after 15(S)-15-methyl- prostaglandin F?, (1 5-me-PGFza) administration for termination of pregnancy because of intrauterine fetal death after 20 wk pregnancy. 12 patients, of whom 6 were under and 6 over 28 wk, were studied. 2-Hourly intramuscular administration of 250 lug 15-me- PGF2, resulted in expulsion in a median time of 9 h (range: 2-24.3 h). Although the drug may have some inhibitory effect on platelet aggregation, its influence on coagulation and the hemostatic mechanism was negligible.

hemostasis; platelet aggregation; missed abortion; missed labor; prostaglandins

INTRODUCTION

Prostanoids, including prostaglandins, have profound effects on the coagu- lation mechanism and platelet function (Samuelsson et al., 1978). Yet natu- ral prostaglandins used for termination of pregnancy or induction of labor were found to have only minimal effects on the coagulation mechanism (Badraoui et al., 1973; Brenner et al., 1973; Dillon et al., 1974; Myatt and Elder, 1975). It is not clear to what extent these findings also apply in cases of intrauterine fetal death (Brie1 et al., 1978), a condition which is known to labilize hemostatic mechanisms (Bonnar, 1975), or to the use of prostaglan- din analogues with a far longer half-life than the natural prostaglandins.

We therefore studied the coagulation mechanism during termination of pregnancy with 15(S)-15-methylprostaglandin F,, (15-me-PGF,, ) in patients with intrauterine fetal death after the 20th wk of pregnancy.

44

MATERIAL AND METHODS

A series of 12 patients with intrauterine fetal death between 20 and 36 wk of pregnancy were studied. Of these half were under (missed abortion) and half were over 28 wk (missed labor) when termination of pregnancy was per- formed. Pregnancy was terminated by intramuscular (i.m.) injection of 250 l.(g 15-me-PGFz,, repeated at 2-h intervals until expulsion occurred. Charac- teristics of the patients and data on the method of induction are given in Ta- ble I.

Blood collection, plasma and serum preparation Blood samples were obtained by flawless venipuncture from an antecubi-

tal vein before, during and after therapy. Samples during therapy were ob- tained after 1 mg of 15-me-PGF zcy had been administered (n = 10) or within 1 h of delivery if this occurred before a total dose of 1 mg was reached (n = 2). In patients who required 8 doses (2 mg) or more (n = 4) a second sample during therapy was obtained at precisely 24 h after the onset of the therapy irrespective of whether delivery had occurred (n = 3) or not (n = 1). Samples after therapy were obtained between 16 and 24 h after expulsion of the uterine contents.

After discarding the first few drops, venous blood was allowed to run freely into tubes containing either 0.1 mM sodium citrate (0.5 ml for 4.5 ml blood), fibrinolytic inhibitors (0.1 ml of a solution of 2.5 g aminocaproic acid, 25,000 units Trasylol and 1 ml human brain thromboplastin in 99 ml

TABLE I

CHARACTERISTICS OF THE PATIENTS AND OF INDUCED DELIVERY AFTER INTRAUTERINE DEATH

Age (years) (mean & SD) No. of nulliparae vs. multiparae Duration of pregnancy (weeks)

median range

Duration of fetal death (days) median range

Total dose of 1 5-me-PGFz, (mg) median range

Induction-delivery interval (hours) median range

Total blood-loss (ml) median range

Bleeding time at orrset of therapy (set) (mean ? SD)

26 + 4.4 4 vs. 8

28 20-36

4 l-10

1 0.25-3.0

9 2-24.3

60 20-450

138+24

45

barbital buffer, pH 7.42, for 4.9 ml blood), or ethylenediaminetetraacetic acid (EDTA tripotassium salt, IO mg for 5 ml blood).

Low-spun titrated plasma for prothrombin time, fibrinogen assay, partial thromboplastin time, thrombin time and ethanol gelation test was prepared by centrifugation at 1250 X g for 10 min at room temperature. Platelet-rich plasma (PRP) for aggregation studies was prepared by spinning at 164 X g

and platelet-poor plasma (PPP) by spinning at 4000 X g for 10 min at room temperature. Serum for assay of fibrin-fibrinogen degradation products (FDP) was prepared from the tube containing fibrinolytic inhibitors after clotting for 2 h at 37°C.

Coagulation assays The prothrombin time was carried out with a home-made human brain

thromboplastin (Owren,. 1949). Two consecutive batches of thromboplastin were used throughout this study (normal control times: 12.5 and 14 set) and results are therefore expressed as a percentage of the initial value (arbitrarily 100%) in each patient.

Partial thromboplastin time was carried out with the Cephotest reagent (Nyegaard, Oslo; normal value ?SD: 40 + 4). For the thrombin time, 0.2 ml thrombin solution (Roche, Basel) containing 10 NIH units/ml was added to 0.2 ml low-spun plasma (normal value: <13 set). The Normotest (Nye- gaard, Oslo) was carried out with titrated blood and time converted into per- cent with the manufacturers graph. Fibrinogen was assayed according to Clauss (1957).

The ethanol gelation test was carried out by adding 0.15 ml ethanol 50% (v/v) to 0.5 ml low-spun plasma and observation of gel-formation after stand- ing for 10 min at 20-21°C (Godal and Abildgaard, 1966). FDP concentration was assayed by rocket-immunoelectrophoresis according to Laurel1 (1972), using an antifibrinogen-antiserum (Behringwerke, Frankfurt) in 1% agarose, 12.5 V/cm for 15 h, in a thermostated (15°C) electrophoresis unit. Normal pooled titrated plasma (30 donors) served as reference material.

Platelets were counted from EDTA blood with the Autocounter (Techni- con, USA).

Platelet aggregation studies Spontaneous platelet aggregation was looked for in PRP using a Payton

aggregometer (Payton, Ontario, Canada) with siliconized disposable cuvettes and stirrers, for at least 15 min (stirring frequency: 900 rpm). Collagen- induced platelet aggregation was carried out by adding 0.05 ml collagen sus- pension (Biodata, Willowgrove, PA, USA) to 4.5 ml PRP and observing changes in optical density in the aggregometer; PPP served as a control for optimal light transmission.

RESULTS

Results of the various analyses are shown in Tables II and III. There were no statistically (paired t-test) significant changes in any of the tests shown in

TA

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2)

Th

rom

bopl

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of

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3 +

8.

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Low

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(109

/1)

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le

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(mg/

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un

tere

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ith

pos

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tion

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st

No.

of

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wit

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fibr

in-f

ibri

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ion

pr

odu

cts

> 1

4 pg

/ml

No.

of

pati

ents

wit

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pon

tan

eou

s pl

atel

et a

ggre

gati

on

No.

of

pati

ents

wit

h c

olla

gen

-in

duce

d ag

greg

atio

n

* n

orm

al

redu

ced

abse

nt

150

140

150

130

430

460

410

340

0 1

2 4

3 0 8 7

2 10

1

1 1

0 0

1 1

1

5 0 2 0

7 0

Table II. The second measurements during therapy in patients who required 2 mg 15-me-PGF?, or more may appear to deviate from both initial values and first measurements during therapy (Table II). These means f SD how- ever relate to only 4 of the 12 patients included in the other categories and none of the differences approached statistical significance. For all parameters shown, values during and after therapy were on occasions higher and on occasions lower than the initial values.

The only noteworthy changes occurred in the ethanol gelation test and in fibrin-fibrinogen degradation products (Table III). The former was always negative before induction but became positive at some stage either during or after therapy in 6 patients. Fibrin-fibrinogen degradation products exceeded the 14 E.cg/ml level in only 2 patients before induction but in 8 patients at some stage during or after therapy (Table III). Spontaneous platelet aggrega- tion was not encountered. When tested, collagen-induced aggregation was always normal before therapy (Table III). In 3 of the 10 patients it became abnormal or absent during therapy but this applied to only 1 of 11 patients in the puerperium (Table III).

DISCUSSION

There are various ways in which administration of 15-me-PGF,, may con- ceivably influence coagulation mechanisms after intrauterine fetal death. In normal pregnancy already placental separation induces consumption of platelets and fibrinogen at the placental site which may continue in the puer- perium (Bonnar, 1975). Retention of a dead fetus itself is known to induce changes in the coagulation system, though this will rarely become clinically apparent unless retention is prolonged for several weeks (Pritchard, 1959). Apart from accentuating or interfering with the above mechanisms, 15-me- PGF,, could have a direct effect on the clotting system particularly since 15-me-PGF,, can be demonstrated in the circulation for more than 2 h after i.m. administration (Green and Bygdeman, 1977).

Nevertheless, the present investigation shows that administration of 15- me-PGFz, has only minimal effects on the coagulation system. In this respect it should be noted that the dose schedule used in this study may be excessive. Indeed a large multicenter trial demonstrated no difference in efficacy between 2-h doses of 125 Erg and 250 pg (Wallenburg et al., 1980), whereas others advocate a longer interval between injections (Karim et al., 1979).

Although fibrin-fibrinogen degradation products exceeded the 14 pg/ml level in two-thirds of the patients studied, there was no evidence to suggest that 15-me-PGF,, may contribute to the development of intravascular coag- ulation. Indeed there were no significant changes in either fibrinogen level or platelet count. The observed changes in collagen-induced platelet aggregation suggest that 15-me-PGFz, may have some inhibitory effect on platelet aggre- gation, but a temporal relationship with drug administration and peak doses, which are known to occur within 30 min of i.m. injection (Green and Bygde-

48

man, 1977), could not be established. The significance of this finding for the hemostatic mechanism may be questioned, since both patients with absence of collagen-induced platelet aggregation had a total blood-loss of no more than 20 ml.

ACKNOWLEDGEMENTS

The assistance of Miss J. Hoefkens, Miss A. van Til and Miss H. Wittenberg is gratefully acknowledged. 15-me-PGF za was obtained from Upjohn-Neder- land by courtesy of Mr. H.J. Gonlag.

REFERENCES

Badraoui, M.H.H., Bonnar, J., Hillier, K. and Embrey, M.P. (1973): Coagulation changes during termination of pregnancy by prostaglandins and by vacuum aspiration. Brit. med. J., 1, 19-21.

Bonnar, J. (1975): The blood coagulation and fibrinolytic systems during pregnancy. Clin. Obstet. Gynaec., 2, 321-344.

Brenner, W.E., Fishburne, J.I., McMillan, C.W., Johnson, A.M. and Hendricks, C.H. (1973): Coagulation changes during abortion induced by prostaglandin F2e. Amer. J. Obstet. Gynec., 117, 1080-1087.

Briel, R.C., Kunz, S. and Kidess, E. (1978): Beeinfliissung der Hlmostase bei Missed abor- tion durch Prostaglandin Fzor. Geburtsh. Frauenheilkd., 38, 862-867.

Clauss, A. (1957): Gerinnungsphysiologische Schnellmethode zur Bestimmung des Fibrin- ogens. Acta haemat., 17, 237-246.

Dillon, T.F., Phillips, L.L., Risk, A., Horiquchi, T., Mohajer-Shojai, E. and Mootabar, H. (1974): The efficacy of prostaglandin Fzo, in second-trimester abortion. Coagulation and hormonal aspects. Amer. J. Obstet. Gynec., 118, 688-698.

Godal, H.C. and Abildgaard, U. (1966): Gelation of soluble fibrin in plasma. Stand. J. Haemat., 3, 342-350.

Green, K. and Bygdeman, M. (1977): Plasma levels of 15(S)-15-methyl-PGFzc following administration via various routes for induction of abortion. Prostaglandins, 14, 1013- 1023.

Karim, S.M.M., Ng, S.C. and Ratnam, S.S. (1979): Termination of abnormal intrauterine pregnancy with prostaglandins. In: Advances in Prostaglandin Research: Practical Applications of Prostaglandins and their Synsthesis Inhibitors. Editor: S.M.M. Karim. MTP, Lancaster.

Laurell, C.B. (1972): Electroimmunoassay. Stand. J. clin. Lab. Invest., 29, 21-37. Myatt, L. and Elder, M.G. (1975): The effects on platelet aggregation of oral prostaglan-

din Ez used for the induction of labour. Brit. J. Obstet. Gynaec., 82, 449-452. Owren, P.A. (1949): A quantitative one-stage method for the assay of prothrombin.

Stand. J. clin. Lab. Invest., 1, 81-83. Pritchard, J.A. (1959): Fetal death in utero. Obstet. Gynec., .14, 573-580. Samuelsson, B., Folco, G., Granstriim, E., Kindahl, H. and Malmsten, C. (1978): Prosta-

glandins and thromboxanes: biochemical and physiological considerations, pp. l-25. In: Prostaglandins and Perinatal Medicine. Advances in Prostaglandin and Thromb- oxane Research, Vol. 4. Editors: F. Coceani and P.M. Olley. Raven Press, New York.

Wallenburg, H.C.S., Keirse, M.J.N.C., Freie, H.M.P. and Blacquikre, J.F. (1989): Intra- muscular administration of 15(S)-15-methyl-prostaglandin Faor for induction of labour in patients with fetal death. Brit. J. Obstet. Gynaec., in press.