Int J Gynaecol Obstet 16: 287-288, 1979

Amniotic Fluid Levels of a-Fetoprotein and Other Proteins in a Case of Turner's Syndrome of the Fetus Lars L. Cederqvist, John T. Cole, Desider J. Rothe and Richard J. Derman Department of Obstetrics and Gynecology, The New York Hospital-Cornell Medical Center, New York, New York, USA

ABSTRACT Cederqvist LL, Cole JT, Rothe DJ, Derman RJ (Dept of Obstetrics and Gynecology, The New York Hospital-Cornell Medical Center, New York, NY, USA). Amniotic fluid levels of a-fetoprotein and other proteins in a case of Turner's syndrome of the fetus. Int J Gynaecol Obstet 16: 287-288, 1979 A 34-year-old primigrávida underwent genetic amniocentesis at 20 weeks' gestation and the fetus was diagnosed as having Turner's syndrome. The concentration of a-fetoprotein in amniotic fluid was greatly elevated. Normal concentrations of amniotic fluid total protein, albumin and immunoglobulin indicated that the elevated level of a-fetoprotein was not the result of leakage through a hygroma, which has been previously suggested without supporting data in cases of Turner's syndrome of the fetus.

INTRODUCTION Determination of a-fetoprotein (AFP) concentration in amniotic fluid is useful in antenatal diagnosis of neural tube defects (1). Increased levels of AFP in amniotic fluid have also been found in other congenital malformations, multiple pregnancies and pregnancies ending in fetal death. Elevated AFP levels associated with Turner's syndrome have been explained as due to leakage through a cystic cervical hygroma (3, 5). T h e case presented here does not support this view.

CASE R E P O R T A 34-year-old primigrávida was first referred to the New York Hospital-Cornell Medical Center for ultrasonography in her 16th menstrual week of pregnancy. T h e biparietal diameter was 2.8 cm, corresponding to a gestational age of 15 to 15V2 weeks.

Fetal movements were identified; there seemed to be less movement than expected. T h e fetal heart movements were seen and were audible with the Doppler stethoscope. T h e AFP level in maternal serum, determined by AFP-Roche radioimmunoassay test kit (Roche Diagnostics, Nutley, NJ, USA), was normal, 58 n g / m l . T h e patient returned in her 19th week of gestation. T h e biparietal diameter measured 3.8 cm, corresponding to a gestational age of 18 weeks. Fetal heart motion was observed a n d auscultated. Fetal movements were again noted to be significantly diminished from what were expected. T h e patient returned at 20 weeks' gestation for genetic amniocentesis which had been postponed due to expected fetal demise. Ultrasonography done just prior to amniocentesis showed a complete absence of fetal movements. T h e heart movements, however, were still visible a n d a normal heart rate was audible with the Doppler stethoscope. T h e fetal skull was somewhat distorted in contour, although there was no gross overlap of the parts. It was impossible to obtain a true midline echo; the widest diameter of the skull was 3.8 cm, corresponding to 18-19 weeks' gestation. T h e measurement represented little significant interval growth from the previous examinations. At amniocentesis, 25 ml of clear amniotic fluid was removed. Karyotyping, including G-banding, revealed a 45X karyotype consistent with Turner's syndrome. T h e amniotic fluid AFP level was considerably elevated, 684 jug/ml, while the maternal serum AFP concentration again was normal, 58 n g / m l . As seen in T a b l e I, the amniotic fluid had a normal level of total protein as determined according to the Folin method, a normal level of albumin as determined by single radial immunodiffusion (Kallestad, Chaska, M N , USA) and normal levels of IgA, IgAi, IgA2, IgG and IgM as determined by a hemagglutination inhibition method previously reported from our laboratory (2). T h e patient was admitted in her 26th week of gestation for therapeutic abortion. Her uterus h a d

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Table I. Concentrations of a-fetoprotein (AFP), total protein, albumin, IgA, IgA,, IgAz, IgG and IgM in amniotic fluid from a fetus with Turner's syndrome and in ten normal controls. Weeks of Total Pro- AFP (/¿g/ Albumin IgA IgA, IgAz IgG (mg/ IgM (mg/ Sample Gestation tein (mg/dl) ml) (mg/dl) (mg/dl) (mg/dl) (mg/dl) dl) dl) Case 20 6ÕÕ 684 460 ÏÏ2 TT2 (M 8Ü 02 Controls (N = 10) 20.8 ± 0.9 437 ± 133 14 ± 13 389 ± 194 4.1 ± 3.4 3.0 ± 1.5 1.0 ± 0.4 45 ± 23 0.3 ± 0.2

not grown since the time of amniocentesis. An attempt to induce abortion by intraamniotic instillation of prostaglandin was unsuccessful, and the patient was given vaginal suppositories of prostaglandin E2 in accordance with an approved protocol. She aborted a macerated fetus 12 hours after the initiation of prostaglandin administration. T h e fetus measured 20 cm from crown to heel, compatible with 18 weeks' gestation. A pronounced cervical hygroma was present. Unfortunately, no amniotic fluid could be obtained, and the fetal tissues were too macerated to permit cultivation in order to confirm the diagnosis. T h e AFP level in maternal serum prior to the initiation of the abortion was much elevated (1800 n g / m l ) .

DISCUSSION This case indicates that the elevated AFP level is not the result of leakage through a hygroma, which has been suggested without supporting data in two other reports of Turner's syndrome (3, 5). As the concentration of protein in serum is approximately ten times greater than in amniotic fluid (4), and as the molecular weight of AFP and albumin is about the same (64 000 daltons for A F P and 69 000 daltons for albumin), an increased level of albumin in amniotic fluid would be expected if leakage occurred through the hygroma. T h e levels in amniotic fluid of albumin, as well as of total protein and the different immunoglobulins, were within normal limits, however, in contrast to the very high level of AFP. Ultrasonography on several occasions showed this fetus to be in distress and fetal demise finally occurred. At the time of amniocentesis, there was ultrasonographic evidence of impending fetal death, a condition which can result in increased amniotic fluid AFP levels (6). T h e fetal urine, the major source of AFP in amniotic fluid (7), was most likely the source in the case presented here. It is unknown why the AFP level in the maternal serum was normal at the time of amniocentesis and only became elevated later.

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In order to establish a cause relationship for the elevated concentration of AFP, it is important to evaluate carefully all available data, including the fetal condition, in cases of elevated AFP levels and fetal malformations.

ACKNOWLEDGMENT This study was supported by a grant from Hoffman-LaRoche, Nutley, NJ, USA.

REFERENCES 1. Brock D J H , SutclifTe R G : Alpha-fetoprotein in the antenatal diagnosis of anencephaly a n d spina bifida. Lancet 2.197, 1972. 2. Cederqvist LL, Ewool LC, Bonsnes R W , Litwin SD: Detectability and pattern of immunoglobulins in normal amniotic fluid throughout gestation. Am J Obstet Gynecol 130:220, 1978. 3. H u n t e r A, H a m m e r t o n LJ, Baskett T, Lyons E: Raised amniotic fluid alpha-fetoprotein in T u r n e r syndrome. Lancet /:598, 1976. 4. Q u e e n a n J T : Amniotic fluid proteins, amniotic fluid amino acids and their clinical significance. In Amniotic Fluid, Research a n d Clinical Application, 1st Ed (ed D V I Fairweather, T K A B Eskes), p 194. Excerpta Medica, Amsterd a m , 1973. 5. Seller M J , Creasy M R , Alberman E D : Alpha-fetoprotein levels in amniotic fluid from spontaneous abortions. Br Med J 2:524, 1974. 6. Weiss R R , Macri J N , Elligers K W : Origin of amniotic fluid alpha-fetoprotein in normal and defective pregnancies. O b stet Gynecol -¿7:697, 1976. 7. Weiss R R , Macri J N , Robins J , Elligers K L : Maternal serum and amniotic fluid alpha-fetoprotein as a marker of acute fetal distress in midtrimester abortion material. Obstet Gynecol 48:118, 1976.

Address for reprints: Lars L. Cederqvist Dept of Obstetrics and Gynecology New York Hospital-Cornell Medical Center 525 E 68th St New York, NY 10021 USA

Amniotic fluid levels of alpha-fetoprotein and other proteins in a case of Turner's syndrome of the fetus.

Int J Gynaecol Obstet 16: 287-288, 1979 Amniotic Fluid Levels of a-Fetoprotein and Other Proteins in a Case of Turner's Syndrome of the Fetus Lars L...
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