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Fetal lung maturation in twins: a study of tracheal aspirates
EUROP. J. OBSTET. GYNEC. REPROD. BIOL., 1977,7/2,65-67 @ Elsevier/North-Holland Biomedical Press
Fetal lung maturation in twins: a study of tracheal aspirates D. Peleg, J.A. Goldman, J. Boyanover and E. Elian Department of Obstetrics and Gynecology, and Department University Medical School, Tel-Aviv, Israel
of Pediatrics, Hasharon Hospital, Petach-Tikva, and Tel-Aviv
PELEG, D., GOLDMAN, J.A., BOYANOVER, J. and ELIAN, E. (1977): Fetal lung maturation in twins: a study of tracheal aspirates. Europ. J. Obstet. Gynec. reprod. Biol., 7/2,65-67. In 10 pairs of twins born at 36-40 wk gestation lung maturity was evaluated immediately after delivery by means of an analysis of their tracheal aspirates. The foam-stability test was performed by the method of Clements in all newborns within 5 min of their birth. In 6 pairs of twins the lecithin/sphingomyelin ratio was also determined, using the Cluck method. In all pairs the foam test was positive in greater dilution in the first twin than in the second. In spite of these differences not one of those newborns with positive foam tests showed evidence of respiratory distress, even when the test was positive in the smallest dilution. In the second twins of 2 pairs the foam test was negative in all dilutions. The L/S ratios in these babies were 1.8 and 1.6, respectively. Both of them showed transient signs of respiratory distress syndrome shortly after delivery. These differences in lung maturity may possibly be attributed to earlier lung maturation due to greater stress in the firstborn of multiple pregnancies. This stress may cause increased secretion of glucocorticosteroids from fetal adrenals with an accelerating effect on fetal lung maturation. It is possible that this simple and safe procedure for evaluating lung maturity in the newborn is indicated in all such newborns who are prone to or are at special risk of respiratory distress syndrome, such as in multiple pregnancy. twin pregnancy; fetal lung maturation; RDS; tracheal aspirate; L/S ratio
Introduction
Material and method
In the past years the ratio of lecithin to sphingomyelin (L/S ratio) in amniotic fluid has been used effectively to determine lung maturity of the fetus in utero. Recently the L/S ratio has been determined postnatally in the delivery room in either tracheal or pharyngeal fluid of newborn infants. The correlation of these findings with the clinical state of the babies has been found to be fair (Blumenfeld, Driscoll, James, Weller, Jenkins, Gupta and Baum, 1974; Cowett, Unsworth, Hakanson, Williams and Oh, 1975 ; Peleg and Goldman, 1976). We have studied the L/S ratio in the tracheal aspirate postnatally as related to lung maturation in the newborn babies of multiple births.
In 10 pairs of twins born at 36-40 wk gestation lung maturity was evaluated immediately after delivery by means of an analysis of their tracheal aspirates. The tracheal aspirate was obtained by means of a disposable sterile mucus extractor made of polyethylene. The foam-stability test was performed by the method of Clements, Platzker, Tierney, Hobel, Creasy, Margolis, Thiebault, Tooley and Oh (1972) in all newborn within 5 min of their birth. In 6 pairs of twins the lecithin/sphingomyelin ratio was also determined, using the method of Gluck, Kulovich, Borer, Brener, Anderson and Spellacy (1971). The foam test was done without separating the mucus from the tracheal aspirate. All determinations were carried out 65
D. Pelag et al.: Fetal lung maturation
66
while the person doing them was unaware of the babies’ clinical condition.
Results
Table I details the results of tests on the tracheal aspirates collected after delivery from 10 pairs of twins. In all pairs a consistent difference was observed in the degree of positivity of the foam test between the first and second twin, the first twin always having a foam test positive in a greater dilution. In spite of these differences not one of those newborns with positive foam tests showed evidence of respiratory distress, even in the smallest dilution. In the second twins of two pairs (No. 5, 7) the foam test was negative in all dilutions. The L/S ratios in these babies were 1.8 and 1.6, respectively. In both transient signs of respiratory distress syndrome appeared shortly after delivery. The infants required oxygen during this period, and signs of distress disappeared within 72 h. L/S ratio done in 6 sets of twins always showed a higher ratio in the first twin.
TABLE I
NO.
1 2 3 4 5 6 I
a 9 10
Foam tests and L/S ratios in tracheal aspirates of 10 pairs of twins Degree of dilution 1:l
1 : 1.3
I II I II I
(+I
(+I (+I
;:; (+I (+I
(Y;
II I II I II I II I II I II I II I II
(+I (+I (+) (+) (-) (+I (+) (+) C-1 (+) (+I (+) (+I (+I (+)
(+I C-1 (+I (+) (+I C-1 (+I (-) (+) (-)
L/S 1:2
(+I C-1 C-1 C-1
(Y; (y
I:;
(+) C-1 (-) (-) t-1 t-1 (+) (+I
(+)
(+)
;:; (+I
(-) C-1 (+I
not done not done not done 9.0 4.0 4.0
1.8
2.2 1.75
1.80
0.79 5.3 5.1 4.3 3.7 2.7 2.1
in twins
Comment
The incidence of the respiratory distress syndrome (RDS) is increased in the second of twins. This syndrome certainly contributes to the rise in incidence of neonatal death of these infants (Rokos, Vaeusorn, Nachman and Avery, 1968). In view of this, the neonatal lung maturity in 10 pairs of twins was evaluated by means of an analysis of their tracheal aspirates close to their delivery. In all these infants a difference was observed between positive foam tests in the aspirate of the first- and secondborn twins of each pair. Moreover a positive foam test, even in the first dilution, was sufficient to ensure normal lung maturity of the neonate. Nevertheless, marked differences in L/S ratios were observed between the first and following twins. When the L/S ratio was lower than 2 in two infants, with a foam test which was negative in all dilutions, a transient, mild RDS occurred. Similar differences in L/S ratio have been reported previously by Weller, Jenkins, Gupta and Baum (1976) in the pharyngeal secretion of the subsequent babies in triplet and quadruplet deliveries, while others (Sims, Cowan and Parkinson, 1976) did not find such differences. These differences may possibly be attributed to earlier lung maturation due to greater stress in the firstborn of multiple pregnancies. This stress may cause increased secretion of glucocorticosteroids from fetal adrenals. These steroids have an accelerating effect in the production and release of surface-active lecithin. This hypothesis is supported by the fact that specific binding sites for glucocorticosteroids have been discovered in the fetal lung (Giannopoulos, Mulay and Solomon, 1973), the low cortisone levels in the umbilical cord in infants with RDS (Beverley, 1974), the acceleration of fetal lung maturation following the administration of glucocorticosteroids to the mother (Liggins and Howle, 1972), and also from animal experiments. The determination of fetal lung maturity by means of the foam test and L/S ratio in amniotic fluid carries all dangers inherent to amniocentesis (Burnett and Anderson, 1968). The determination of lung maturity by means of evaluation of the amniotic fluid reflects the lung maturity at the moment of amniocentesis, not at the time of delivery. In certain conditions, such as pregnancy complicated by diabetes mel-
D. Peleg et al.: Fetal lung maturation in twirls
litus, postponement of delivery for 48 h or more may occasionally result in an unfavorable change of lung maturity as reflected in surfactant status (Whitfield, Sproule and Brudenell, 1973). In others, such as Rh incompatibility, amniocentesis may endanger the fetus further by the bleeding inherent to the process. In other cases technical failure of procedure may occur. However, examination of the tracheal aspirate and its evaluation for lung maturity is a simple procedure, devoid of inherent dangers, demonstrating the presence or lack of lung maturity at the moment of birth. It is suggested that this procedure is indicated in all such newborns who are prone to or are at high risk of RDS, such as in multiple pregnancy, diabetes of the mother, or other conditions.
61
Creasy, R.K., Margolis, A.J., Thibcault, D.W., Tooley, W.H. and Oh, W. (1972): Assessment of the risk of the respiratorydistress syndrome by a rapid test for the surfactant in amniotic fluid. New .&rgl. J. Med., 286, 1077. Cowett, R.M., Unsworth, E.J., Hakanson, D.O., Williams, J.R. and Oh, W. (1975): Foam-stability test on gastric aspirate and the diagnosis of respiratory-distress syndrome. Nen Engl. J. Med., 293, 413. Giannopoulos, G., Mulay, S. and Solomon, S. (1973): Glucocorticoid receptors in lung: II. Specific binding of glucocorticoids in nuclear components of rabbit fetal lung. J. biol. Chem., 248,5016.
Gluck, L., Kulovich, M.V., Borer Jr, R.C., Brener. P.H., Anderson, G.G. and Spellacy, W.N. (1971): Diagnosis of the respiratory distress syndrome by amniocentesis. Amer. J. Obstet. Gynec., 109, 440.
Liggins, G.C. and Howle, R.N. (1972): A controlled trial of antepartum glucocorticoid treatment for prevention of the respiratory distress syndrome in premature infants. Pediatrics, 50, 5 15.
References Beverley, E.P.M. (1974): Cortisol and cortisone levels in the cord blood at delivery of infants with and without the respiratory distress syndrome. Amer. J. Obstet. Gynec., 119,1112.
Blumenfeld, T.A., Driscoll, J.M., James, L.S., Weller, P.H., Jenkins, P.A., Gupta, J. and Baum, J.D. (1974): Lecithin/sphingomyelin ratios in tracheal and pharyngeal aspirates in respiratory distress syndrome. J. Pediat., 8.5, 403.
Burnett, R.G. and Anderson, W.R. (1968): The hazards of amniocentesis. J. Iowa St. med. Sot., 58, 130. Clement% J.A., Platzker, A.C.G., Tierney, D.F., Hobel, C.H.,
Peleg, D. and Goldman, J. (1976): Lecithin/sphingomyelin ratio in tracheal aspirate. Lancer, I, 1188. Rokos, J., Vaeusorn, O., Nachman, R. and Avery, E.M. (1968): Hyaline membrane disease in twins. Pediatrics, 42, 204.
Sims, C.D., Cowan, D.B. and Parkinson, C.E. (1976): The lecithin/sphingomyelin (L/S) ratio in twin pregnancies. Brit. J. Obstet. Gynaec., 83, 447.
Weller, P.H., Jenkins, P.A., Gupta, J. and Baum, J.D. (1976): Pharyngeal lecithin/sphingomyelin ratios in newborn infants. Lancet, I, 12. Whitfield, C.R., Sproule, W.B. and Brudenell, M. (1973): The amniotic fluid lecithin/sphingomyelin area ratio (LSAR) in pregnancies complicated by diabetes. J. Obstet. Gynaec. Brit. Cwlth, 80, 928.
Fetal lung maturation in twins: a study of tracheal aspirates D. Peleg, J.A. Goldman, J. Boyanover and E. Elian Department of Obstetrics and Gynecology, and Department University Medical School, Tel-Aviv, Israel
of Pediatrics, Hasharon Hospital, Petach-Tikva, and Tel-Aviv
PELEG, D., GOLDMAN, J.A., BOYANOVER, J. and ELIAN, E. (1977): Fetal lung maturation in twins: a study of tracheal aspirates. Europ. J. Obstet. Gynec. reprod. Biol., 7/2,65-67. In 10 pairs of twins born at 36-40 wk gestation lung maturity was evaluated immediately after delivery by means of an analysis of their tracheal aspirates. The foam-stability test was performed by the method of Clements in all newborns within 5 min of their birth. In 6 pairs of twins the lecithin/sphingomyelin ratio was also determined, using the Cluck method. In all pairs the foam test was positive in greater dilution in the first twin than in the second. In spite of these differences not one of those newborns with positive foam tests showed evidence of respiratory distress, even when the test was positive in the smallest dilution. In the second twins of 2 pairs the foam test was negative in all dilutions. The L/S ratios in these babies were 1.8 and 1.6, respectively. Both of them showed transient signs of respiratory distress syndrome shortly after delivery. These differences in lung maturity may possibly be attributed to earlier lung maturation due to greater stress in the firstborn of multiple pregnancies. This stress may cause increased secretion of glucocorticosteroids from fetal adrenals with an accelerating effect on fetal lung maturation. It is possible that this simple and safe procedure for evaluating lung maturity in the newborn is indicated in all such newborns who are prone to or are at special risk of respiratory distress syndrome, such as in multiple pregnancy. twin pregnancy; fetal lung maturation; RDS; tracheal aspirate; L/S ratio
Introduction
Material and method
In the past years the ratio of lecithin to sphingomyelin (L/S ratio) in amniotic fluid has been used effectively to determine lung maturity of the fetus in utero. Recently the L/S ratio has been determined postnatally in the delivery room in either tracheal or pharyngeal fluid of newborn infants. The correlation of these findings with the clinical state of the babies has been found to be fair (Blumenfeld, Driscoll, James, Weller, Jenkins, Gupta and Baum, 1974; Cowett, Unsworth, Hakanson, Williams and Oh, 1975 ; Peleg and Goldman, 1976). We have studied the L/S ratio in the tracheal aspirate postnatally as related to lung maturation in the newborn babies of multiple births.
In 10 pairs of twins born at 36-40 wk gestation lung maturity was evaluated immediately after delivery by means of an analysis of their tracheal aspirates. The tracheal aspirate was obtained by means of a disposable sterile mucus extractor made of polyethylene. The foam-stability test was performed by the method of Clements, Platzker, Tierney, Hobel, Creasy, Margolis, Thiebault, Tooley and Oh (1972) in all newborn within 5 min of their birth. In 6 pairs of twins the lecithin/sphingomyelin ratio was also determined, using the method of Gluck, Kulovich, Borer, Brener, Anderson and Spellacy (1971). The foam test was done without separating the mucus from the tracheal aspirate. All determinations were carried out 65
D. Pelag et al.: Fetal lung maturation
66
while the person doing them was unaware of the babies’ clinical condition.
Results
Table I details the results of tests on the tracheal aspirates collected after delivery from 10 pairs of twins. In all pairs a consistent difference was observed in the degree of positivity of the foam test between the first and second twin, the first twin always having a foam test positive in a greater dilution. In spite of these differences not one of those newborns with positive foam tests showed evidence of respiratory distress, even in the smallest dilution. In the second twins of two pairs (No. 5, 7) the foam test was negative in all dilutions. The L/S ratios in these babies were 1.8 and 1.6, respectively. In both transient signs of respiratory distress syndrome appeared shortly after delivery. The infants required oxygen during this period, and signs of distress disappeared within 72 h. L/S ratio done in 6 sets of twins always showed a higher ratio in the first twin.
TABLE I
NO.
1 2 3 4 5 6 I
a 9 10
Foam tests and L/S ratios in tracheal aspirates of 10 pairs of twins Degree of dilution 1:l
1 : 1.3
I II I II I
(+I
(+I (+I
;:; (+I (+I
(Y;
II I II I II I II I II I II I II I II
(+I (+I (+) (+) (-) (+I (+) (+) C-1 (+) (+I (+) (+I (+I (+)
(+I C-1 (+I (+) (+I C-1 (+I (-) (+) (-)
L/S 1:2
(+I C-1 C-1 C-1
(Y; (y
I:;
(+) C-1 (-) (-) t-1 t-1 (+) (+I
(+)
(+)
;:; (+I
(-) C-1 (+I
not done not done not done 9.0 4.0 4.0
1.8
2.2 1.75
1.80
0.79 5.3 5.1 4.3 3.7 2.7 2.1
in twins
Comment
The incidence of the respiratory distress syndrome (RDS) is increased in the second of twins. This syndrome certainly contributes to the rise in incidence of neonatal death of these infants (Rokos, Vaeusorn, Nachman and Avery, 1968). In view of this, the neonatal lung maturity in 10 pairs of twins was evaluated by means of an analysis of their tracheal aspirates close to their delivery. In all these infants a difference was observed between positive foam tests in the aspirate of the first- and secondborn twins of each pair. Moreover a positive foam test, even in the first dilution, was sufficient to ensure normal lung maturity of the neonate. Nevertheless, marked differences in L/S ratios were observed between the first and following twins. When the L/S ratio was lower than 2 in two infants, with a foam test which was negative in all dilutions, a transient, mild RDS occurred. Similar differences in L/S ratio have been reported previously by Weller, Jenkins, Gupta and Baum (1976) in the pharyngeal secretion of the subsequent babies in triplet and quadruplet deliveries, while others (Sims, Cowan and Parkinson, 1976) did not find such differences. These differences may possibly be attributed to earlier lung maturation due to greater stress in the firstborn of multiple pregnancies. This stress may cause increased secretion of glucocorticosteroids from fetal adrenals. These steroids have an accelerating effect in the production and release of surface-active lecithin. This hypothesis is supported by the fact that specific binding sites for glucocorticosteroids have been discovered in the fetal lung (Giannopoulos, Mulay and Solomon, 1973), the low cortisone levels in the umbilical cord in infants with RDS (Beverley, 1974), the acceleration of fetal lung maturation following the administration of glucocorticosteroids to the mother (Liggins and Howle, 1972), and also from animal experiments. The determination of fetal lung maturity by means of the foam test and L/S ratio in amniotic fluid carries all dangers inherent to amniocentesis (Burnett and Anderson, 1968). The determination of lung maturity by means of evaluation of the amniotic fluid reflects the lung maturity at the moment of amniocentesis, not at the time of delivery. In certain conditions, such as pregnancy complicated by diabetes mel-
D. Peleg et al.: Fetal lung maturation in twirls
litus, postponement of delivery for 48 h or more may occasionally result in an unfavorable change of lung maturity as reflected in surfactant status (Whitfield, Sproule and Brudenell, 1973). In others, such as Rh incompatibility, amniocentesis may endanger the fetus further by the bleeding inherent to the process. In other cases technical failure of procedure may occur. However, examination of the tracheal aspirate and its evaluation for lung maturity is a simple procedure, devoid of inherent dangers, demonstrating the presence or lack of lung maturity at the moment of birth. It is suggested that this procedure is indicated in all such newborns who are prone to or are at high risk of RDS, such as in multiple pregnancy, diabetes of the mother, or other conditions.
61
Creasy, R.K., Margolis, A.J., Thibcault, D.W., Tooley, W.H. and Oh, W. (1972): Assessment of the risk of the respiratorydistress syndrome by a rapid test for the surfactant in amniotic fluid. New .&rgl. J. Med., 286, 1077. Cowett, R.M., Unsworth, E.J., Hakanson, D.O., Williams, J.R. and Oh, W. (1975): Foam-stability test on gastric aspirate and the diagnosis of respiratory-distress syndrome. Nen Engl. J. Med., 293, 413. Giannopoulos, G., Mulay, S. and Solomon, S. (1973): Glucocorticoid receptors in lung: II. Specific binding of glucocorticoids in nuclear components of rabbit fetal lung. J. biol. Chem., 248,5016.
Gluck, L., Kulovich, M.V., Borer Jr, R.C., Brener. P.H., Anderson, G.G. and Spellacy, W.N. (1971): Diagnosis of the respiratory distress syndrome by amniocentesis. Amer. J. Obstet. Gynec., 109, 440.
Liggins, G.C. and Howle, R.N. (1972): A controlled trial of antepartum glucocorticoid treatment for prevention of the respiratory distress syndrome in premature infants. Pediatrics, 50, 5 15.
References Beverley, E.P.M. (1974): Cortisol and cortisone levels in the cord blood at delivery of infants with and without the respiratory distress syndrome. Amer. J. Obstet. Gynec., 119,1112.
Blumenfeld, T.A., Driscoll, J.M., James, L.S., Weller, P.H., Jenkins, P.A., Gupta, J. and Baum, J.D. (1974): Lecithin/sphingomyelin ratios in tracheal and pharyngeal aspirates in respiratory distress syndrome. J. Pediat., 8.5, 403.
Burnett, R.G. and Anderson, W.R. (1968): The hazards of amniocentesis. J. Iowa St. med. Sot., 58, 130. Clement% J.A., Platzker, A.C.G., Tierney, D.F., Hobel, C.H.,
Peleg, D. and Goldman, J. (1976): Lecithin/sphingomyelin ratio in tracheal aspirate. Lancer, I, 1188. Rokos, J., Vaeusorn, O., Nachman, R. and Avery, E.M. (1968): Hyaline membrane disease in twins. Pediatrics, 42, 204.
Sims, C.D., Cowan, D.B. and Parkinson, C.E. (1976): The lecithin/sphingomyelin (L/S) ratio in twin pregnancies. Brit. J. Obstet. Gynaec., 83, 447.
Weller, P.H., Jenkins, P.A., Gupta, J. and Baum, J.D. (1976): Pharyngeal lecithin/sphingomyelin ratios in newborn infants. Lancet, I, 12. Whitfield, C.R., Sproule, W.B. and Brudenell, M. (1973): The amniotic fluid lecithin/sphingomyelin area ratio (LSAR) in pregnancies complicated by diabetes. J. Obstet. Gynaec. Brit. Cwlth, 80, 928.