Volume 86 Number 3
Brief clinical and laboratory observations
"discordant" twin pairs. There was a highly significant (p (0.01) negative Correlation between fontanel size and epiphyseal ossification. Severe i n t r a u t e r i n e growth retardation ( d e m o n strated by the lighter twin) may result in retardation of membranous as well as enchondral ossification. My thanks are due to Linda Kapuniai, M.A. for assistance with the statistical analyses. REFERENCES 1. Philip AGS: Fontanel size and epiphyseal ossification in neonates with intra-uterine growth retardation, J PEDIATR 84:204, 1974. 2. ScottKE, and Usher R: Epiphyseal development in foetal malnutrition syndrome, N Engl J Med 270:822, 1964. 3. Lubchenco LO: Assessment of gestational age and development at birth, Pediatr Clin North Am 17:125, 1970.
Breech presentation as an indicator of feral abnormality Frederic H.T. Braun, M.D., C.M., Kenneth L.
4 19
4. Dubowitz LMS, Dubowitz V, and Goldberg C: Clinical assessment of gestational age in the newborn infant, J PEDIATR77:1, 1970. 5. Dobbing J, and Sands J: Vulnerability of developing brain; IX: The effect of nutritional growth retardation on the timing of the brain growth spurt, Biol Neonate 19:363, 1971. 6. Dobbing J: The later growth of the brain and its vulnerability, Pediatrics 53:2, 1974. 7. Babson SG, Kangas J, Young N, and Bramhall JL: Growth and development of twins of dissimilar size at birth, Pediatrics 33:327, 1964. 8. Gruenwald P: Environmental influences on twins apparent at birth: A preliminary study, Biol Neona,/~ 15:79, 1970. 9. Cope I, and Murdoch JD: The estimation of foetal maturity, J Obstet Gynaecol Br Commonw 65:56, 1958. 10. Adams PH: Intra-uterine growth retardation in the pig: 11: Development of the skeleton, Biol Neonate 19:341, 1971.
Table L K n o w n fetal disorders associated with an increased incidence of breech presentation Congenital dislocation of the hip 9 Hydrocephalus 5 Anencephaly5 Meningomyelocele5 Familial dysautonomial
Jones, M.D., and David W. Smith, M.D.,* Seattle, Wash.
A XELROD recently noted the increased frequency of breech presentation in infants with familial dysautonomia. 1 The purpose of this report is to emphasize the more general principle that breech presentation is a frequent occurrence in a n u m b e r of disorders which adversely affect the form and/or function of the fetus. BACKGROUND
AND RESULTS
Beyond those disorders in which an increased frequency of breech presentation has already been reported (Table I), 11 disorders were selected for study because it was hypothesized that the fetal problems of From the Dysmorphology Unit, Dept. of Pediatrics University of Washington School of Medicine. Supported by Maternal and Child Health Services Health Services and Mental Administration Department of Health, Education & Welfare Project 913; National Institutes of Health Grant No. HD 05961; Public Health Service Grant No. GM 15253; and The National Foundation-March of Dimes. *Reprint address: RR234 Health Sciences, RD-20, University03" WashingtonSchool of Medicine, Seattle, Wash. 98195,
form and/or function in these conditions might lessen the likelihood of such babies assuming the vertex birth positions. The p e r t i n e n t patient data were o b t a i n e d from the records of the Dysmorphology Unit of the University of Washington, The University Hospitals, the Children's Orthopedic Hospital, and supplemented by cases from the literature. None of the infants were twins. The actual percentage of breech presentations, the anticipated frequency of breech delivery based on the birth weight of the patients with each disorder,2and the factorial difference between the actual frequency of breech presentation and that expected on the basis of birth weight alone are listed in Table II. The frequency of prematurity, polyhydramnios, and congenital hip dislocation were also noted for each disorder and these factors did not explain the increased frequencies of breech deliveries in any o f the disorders studied. DISCUSSION Throughout the second trimester of pregnancy the fetus is highly m o b i l e within his relatively m o r a y aquatic environment. During the mid-to-late third trimester the amount of amniotic fluid decreases 3 and
420
Brief clinical and laboratory observations
The Journal of Pediat'rics March 1975
Table 1I. Frequency of breech presentation in disorders in this study
Disorder Prader-Willi syndrome 18 trisomy syndrome Smith-Lemli-Opitz syndrome Fetal alcohol syndrome Potter anomaly Zellweger syndrome Myotonic dystrophy 13 trisomy syndrome Werdnig-Hoffman syndrome de Lange syndrome 21 trisomy syndrome
No. of eases
Percentage of breech presentation
Expected percentagefor birth weight
Relative d(lyerence
22 14 20 10 87 15 14 8 10 52 39
50 43 40 40 36 27 21 12 10 10 5
3.9 7.1 3.2 8.2 7.7 3.7 3.7 6 2.6 5.6 2.7
12.8 6.1 12.5 4.9 4.7 7.2 5.7 2.0 3.8 1.7 2.0
Table III. Known factors associated with breech presentation and potential reasons for failure in assuming the vertex presentation Factors Uterine and placental Bicornuate to double uterus Placenta praevia or placenta in cornua of uterus Fetal Twins Prematurity Low birth weight Polyhydramnios Oligohydramnios Abnormalities in form or function of the fetus
there is relatively more uterine constraint to the movement of the rapidly growing fetus. About 1/4 to 1/3 of fetuses may be in the breech presentation at a givefi time during the second trimester; the great majority of these are in the vertex presentation by 34 weeks of gestation.4 Factors which may contribute to a failure of the fetus to assume the vertex position by the time of birth are s u m m a r i z e d in Table III. T h e general f r e q u e n c y of breech delivery at term is 3.1%, 3.5% are female and 2.7% are male. Prior to 37 weeks of gestation the frequency is twice as great as in full-term pregnancies and three times as great for infants with a birth weight under 2.5 kg. 2 The major message of this report is that breech presentation may constitute an important indication of a problem in fetal morphogenesis and/or function. The frequency of major malformations is three times as high in infants born by breech presentation as in those born in the vertex position, s, 6a difference which was not accounted for on the basis of associated prematurity. The neonatal mortality rate for infants born by breech pre-
Potential reasons Aberrant shape of pregnant uterine cavity Aberrant shape of pregnant uterine cavity Aberrant crowding Less uterine constraint to fetal positioning Less uterine constraint to fetal positioning Less uterine constraint to fetal positioning Undue uterine constraint to fetal movement Limitation in the capacity of the fetus to assume the vertex position
sentation is 25 to 35%, 2, 5, 6about 12 times the mortality rate in n o n b r e e c h deliveries. Although the cause of the majority of these deaths is related to prematurity, the mortality rate is still 10% for full-term infants born by breech presentation. Much of this latter mortality relates to problems of malformation rather than to problems of birth trauma. For example, Nielson 7 reported a 50% incidence of major malformations in term infants who died after breech delivery. The types of fetal problems which may enhance the likelihood of breech presentation are indicated within the disorders set forth in Tables I and II. These include s t r u c t u r a l anomalies such as h y d r o c e p h a l u s , which would b e less compatible with the vertex position because of the large head, and joint dislocations, which may limit the capacity for the fetus to alter its position. The babies with multiple joint dislocations, as in the Larsen syndrome, were more than four times as likely to be in breech presentation than those with dislocation of the hip alone. Neuromuscular dysfunction may also limit the ability of the fetus to assume the vertex position. Examples include hypertonia in the 18 trisomy
Volume 86 Number 3
Brief clinical and laboratory observations
421
syndrome and the Smith-Lemli-Opitz syndrome, severe hypotonia in the Prader-Willi syndrome.and the Zellweger syndrome, and presumed aberrant fetal function in some cases of myotonic dystrophy and the fetal alcohol s y n d r o m e . The o l i g o h y d r a m n i o s of the Potter anomaly due to lack of urine flow into the amniotic space, or less commonly to chronic leakage ofamniotic fluid,Smay limit the m o v e m e n t of the fetus and thereby increase the likelihood of breech presentation. It is of interest to note that infants with the Down syndrome, whose hypotonia is usually less severe than that found in the Prader-Willi or Zellweger syndromes, do not have an appreciable increase in the frequency of breech presentation. Surviving infants born by breech presentation had a 3.1% frequency of neurotogic abnormality and a 10.6% i n c i d e n c e of m o t o r r e t a r d a t i o n at one year of age. 2 These frequencies are 63% higher than those found in infants born by vertex presentation. Although such an increased incidence of deficient developmental performance might be attributed to birth trauma in those infants born by breech presentation, it is also possible that the deficient function was of prenatal onset and thereby enhanced the likelihood of breech delivery. In conclusion, when an infant is born by breech presentation the question should be asked, why the fetus failed to assume the vertex position. One reason can be a problem in the morphogenesis and/or function of the fetus. Appreciation of this fact may be of value in the earlier recognition of such problems.
The authors wish to thank Dr. M. Michael Cohen for general assistance, Mrs. Lyle Harrah for library research studies, and Mrs. Mary Ann Harvey and Mrs. Christine Hansen for secretarial assistance.
Luteinizing hormone deficiency in hereditary congenital adrenal hypoplasia
herited as an autosomal recessive trait, and is characterized by small adrenal glands and small but relatively normal cells. The pathologic anatomy of these two types is well known because until some years ago, nearly all patients died in early infancy. I n recent years, an in-
Andrea Prader, M.D., Milo Zachmann, M.D., and Ruth Illig, M.D., Zurich, Switzerland
THERE ARE TWO FORMS of hereditary c o n g e n i t a l adrenal hypoplasia~,2: The cytomegalic type affects only boys, is inherited as an X-chromosomal recessive trait, and is characterized by an abnormal adrenal architecture and the presence of cytomegalic vacuolated cells. The miniature type affects both sexes, is possibly in-
From the Department of Pediatrics, University of Zurich, K inderspitaL
REFERENCES 1. Axelrod FB, Leistner HL, and Porges RF: Breech presentation among infants with familial dysautonomia, J PEDtATR84:107, 1974. 2. Berencles HW, Weiss W, Deutschberger J, and Jackson E: Factors associated with breech delivery, Am J Public Health 55:708, !965. 3. Hellman LM, and Pritchard JA, editors: Williams' obstetrics, NewYork, 1971, Appleton-Century-Crofts, Inc., p 226. 4. Vartan CK: The behaviour of the foetus in utero with special reference to the incidence of breech presentation at term, J Obstet Gynaecol Br Commonw 52:418, 1945. 5. Brenner WE, Bruce RC, and Hendricks CH: The characteristics and perils of breech presentation, Am J Obstet Gynecol 118:700, 1974. 6. Shull WJ: Congenital malformations: Current knowledge of etiology, Clin Obstet Gynecol 4:365, 1961. 7~ Neilson DR: Management of the large breech infant; a survey of 203 cases from Emanuel Hospital, Am J Obstet Gynecol 107:345, 1970. 8. Thomas IT, and Smith DW: Oligohydramnios, cause of the non-renal features of Potter's syndrome, including pulmonary hypoplasia, J PEDIATR84:811, 1974. 9. Robinson GW: Birth characteristics of children with congenital dislocation of the hip, Am J Epidemiol 87:275, 1968.
Abbreviations used LH: luteinizing hormone TSH: thyroid-stimulating hormone TRH: thyrotropin-releasing hormone FSH: follicle-stimulating hormone HCG: human chorionic gonadotropin LHRF: luteinizing hormone releasing factor creasing n u m b e r of patients has survived because the diagnosis has been made during the first week of life and was followed by successful adrenocortical replacem e n t therapy. 35 In boys who have no affected siblings or only surviving affected brothers, it is not possible to distinguish the two types in vivo.
Brief clinical and laboratory observations
"discordant" twin pairs. There was a highly significant (p (0.01) negative Correlation between fontanel size and epiphyseal ossification. Severe i n t r a u t e r i n e growth retardation ( d e m o n strated by the lighter twin) may result in retardation of membranous as well as enchondral ossification. My thanks are due to Linda Kapuniai, M.A. for assistance with the statistical analyses. REFERENCES 1. Philip AGS: Fontanel size and epiphyseal ossification in neonates with intra-uterine growth retardation, J PEDIATR 84:204, 1974. 2. ScottKE, and Usher R: Epiphyseal development in foetal malnutrition syndrome, N Engl J Med 270:822, 1964. 3. Lubchenco LO: Assessment of gestational age and development at birth, Pediatr Clin North Am 17:125, 1970.
Breech presentation as an indicator of feral abnormality Frederic H.T. Braun, M.D., C.M., Kenneth L.
4 19
4. Dubowitz LMS, Dubowitz V, and Goldberg C: Clinical assessment of gestational age in the newborn infant, J PEDIATR77:1, 1970. 5. Dobbing J, and Sands J: Vulnerability of developing brain; IX: The effect of nutritional growth retardation on the timing of the brain growth spurt, Biol Neonate 19:363, 1971. 6. Dobbing J: The later growth of the brain and its vulnerability, Pediatrics 53:2, 1974. 7. Babson SG, Kangas J, Young N, and Bramhall JL: Growth and development of twins of dissimilar size at birth, Pediatrics 33:327, 1964. 8. Gruenwald P: Environmental influences on twins apparent at birth: A preliminary study, Biol Neona,/~ 15:79, 1970. 9. Cope I, and Murdoch JD: The estimation of foetal maturity, J Obstet Gynaecol Br Commonw 65:56, 1958. 10. Adams PH: Intra-uterine growth retardation in the pig: 11: Development of the skeleton, Biol Neonate 19:341, 1971.
Table L K n o w n fetal disorders associated with an increased incidence of breech presentation Congenital dislocation of the hip 9 Hydrocephalus 5 Anencephaly5 Meningomyelocele5 Familial dysautonomial
Jones, M.D., and David W. Smith, M.D.,* Seattle, Wash.
A XELROD recently noted the increased frequency of breech presentation in infants with familial dysautonomia. 1 The purpose of this report is to emphasize the more general principle that breech presentation is a frequent occurrence in a n u m b e r of disorders which adversely affect the form and/or function of the fetus. BACKGROUND
AND RESULTS
Beyond those disorders in which an increased frequency of breech presentation has already been reported (Table I), 11 disorders were selected for study because it was hypothesized that the fetal problems of From the Dysmorphology Unit, Dept. of Pediatrics University of Washington School of Medicine. Supported by Maternal and Child Health Services Health Services and Mental Administration Department of Health, Education & Welfare Project 913; National Institutes of Health Grant No. HD 05961; Public Health Service Grant No. GM 15253; and The National Foundation-March of Dimes. *Reprint address: RR234 Health Sciences, RD-20, University03" WashingtonSchool of Medicine, Seattle, Wash. 98195,
form and/or function in these conditions might lessen the likelihood of such babies assuming the vertex birth positions. The p e r t i n e n t patient data were o b t a i n e d from the records of the Dysmorphology Unit of the University of Washington, The University Hospitals, the Children's Orthopedic Hospital, and supplemented by cases from the literature. None of the infants were twins. The actual percentage of breech presentations, the anticipated frequency of breech delivery based on the birth weight of the patients with each disorder,2and the factorial difference between the actual frequency of breech presentation and that expected on the basis of birth weight alone are listed in Table II. The frequency of prematurity, polyhydramnios, and congenital hip dislocation were also noted for each disorder and these factors did not explain the increased frequencies of breech deliveries in any o f the disorders studied. DISCUSSION Throughout the second trimester of pregnancy the fetus is highly m o b i l e within his relatively m o r a y aquatic environment. During the mid-to-late third trimester the amount of amniotic fluid decreases 3 and
420
Brief clinical and laboratory observations
The Journal of Pediat'rics March 1975
Table 1I. Frequency of breech presentation in disorders in this study
Disorder Prader-Willi syndrome 18 trisomy syndrome Smith-Lemli-Opitz syndrome Fetal alcohol syndrome Potter anomaly Zellweger syndrome Myotonic dystrophy 13 trisomy syndrome Werdnig-Hoffman syndrome de Lange syndrome 21 trisomy syndrome
No. of eases
Percentage of breech presentation
Expected percentagefor birth weight
Relative d(lyerence
22 14 20 10 87 15 14 8 10 52 39
50 43 40 40 36 27 21 12 10 10 5
3.9 7.1 3.2 8.2 7.7 3.7 3.7 6 2.6 5.6 2.7
12.8 6.1 12.5 4.9 4.7 7.2 5.7 2.0 3.8 1.7 2.0
Table III. Known factors associated with breech presentation and potential reasons for failure in assuming the vertex presentation Factors Uterine and placental Bicornuate to double uterus Placenta praevia or placenta in cornua of uterus Fetal Twins Prematurity Low birth weight Polyhydramnios Oligohydramnios Abnormalities in form or function of the fetus
there is relatively more uterine constraint to the movement of the rapidly growing fetus. About 1/4 to 1/3 of fetuses may be in the breech presentation at a givefi time during the second trimester; the great majority of these are in the vertex presentation by 34 weeks of gestation.4 Factors which may contribute to a failure of the fetus to assume the vertex position by the time of birth are s u m m a r i z e d in Table III. T h e general f r e q u e n c y of breech delivery at term is 3.1%, 3.5% are female and 2.7% are male. Prior to 37 weeks of gestation the frequency is twice as great as in full-term pregnancies and three times as great for infants with a birth weight under 2.5 kg. 2 The major message of this report is that breech presentation may constitute an important indication of a problem in fetal morphogenesis and/or function. The frequency of major malformations is three times as high in infants born by breech presentation as in those born in the vertex position, s, 6a difference which was not accounted for on the basis of associated prematurity. The neonatal mortality rate for infants born by breech pre-
Potential reasons Aberrant shape of pregnant uterine cavity Aberrant shape of pregnant uterine cavity Aberrant crowding Less uterine constraint to fetal positioning Less uterine constraint to fetal positioning Less uterine constraint to fetal positioning Undue uterine constraint to fetal movement Limitation in the capacity of the fetus to assume the vertex position
sentation is 25 to 35%, 2, 5, 6about 12 times the mortality rate in n o n b r e e c h deliveries. Although the cause of the majority of these deaths is related to prematurity, the mortality rate is still 10% for full-term infants born by breech presentation. Much of this latter mortality relates to problems of malformation rather than to problems of birth trauma. For example, Nielson 7 reported a 50% incidence of major malformations in term infants who died after breech delivery. The types of fetal problems which may enhance the likelihood of breech presentation are indicated within the disorders set forth in Tables I and II. These include s t r u c t u r a l anomalies such as h y d r o c e p h a l u s , which would b e less compatible with the vertex position because of the large head, and joint dislocations, which may limit the capacity for the fetus to alter its position. The babies with multiple joint dislocations, as in the Larsen syndrome, were more than four times as likely to be in breech presentation than those with dislocation of the hip alone. Neuromuscular dysfunction may also limit the ability of the fetus to assume the vertex position. Examples include hypertonia in the 18 trisomy
Volume 86 Number 3
Brief clinical and laboratory observations
421
syndrome and the Smith-Lemli-Opitz syndrome, severe hypotonia in the Prader-Willi syndrome.and the Zellweger syndrome, and presumed aberrant fetal function in some cases of myotonic dystrophy and the fetal alcohol s y n d r o m e . The o l i g o h y d r a m n i o s of the Potter anomaly due to lack of urine flow into the amniotic space, or less commonly to chronic leakage ofamniotic fluid,Smay limit the m o v e m e n t of the fetus and thereby increase the likelihood of breech presentation. It is of interest to note that infants with the Down syndrome, whose hypotonia is usually less severe than that found in the Prader-Willi or Zellweger syndromes, do not have an appreciable increase in the frequency of breech presentation. Surviving infants born by breech presentation had a 3.1% frequency of neurotogic abnormality and a 10.6% i n c i d e n c e of m o t o r r e t a r d a t i o n at one year of age. 2 These frequencies are 63% higher than those found in infants born by vertex presentation. Although such an increased incidence of deficient developmental performance might be attributed to birth trauma in those infants born by breech presentation, it is also possible that the deficient function was of prenatal onset and thereby enhanced the likelihood of breech delivery. In conclusion, when an infant is born by breech presentation the question should be asked, why the fetus failed to assume the vertex position. One reason can be a problem in the morphogenesis and/or function of the fetus. Appreciation of this fact may be of value in the earlier recognition of such problems.
The authors wish to thank Dr. M. Michael Cohen for general assistance, Mrs. Lyle Harrah for library research studies, and Mrs. Mary Ann Harvey and Mrs. Christine Hansen for secretarial assistance.
Luteinizing hormone deficiency in hereditary congenital adrenal hypoplasia
herited as an autosomal recessive trait, and is characterized by small adrenal glands and small but relatively normal cells. The pathologic anatomy of these two types is well known because until some years ago, nearly all patients died in early infancy. I n recent years, an in-
Andrea Prader, M.D., Milo Zachmann, M.D., and Ruth Illig, M.D., Zurich, Switzerland
THERE ARE TWO FORMS of hereditary c o n g e n i t a l adrenal hypoplasia~,2: The cytomegalic type affects only boys, is inherited as an X-chromosomal recessive trait, and is characterized by an abnormal adrenal architecture and the presence of cytomegalic vacuolated cells. The miniature type affects both sexes, is possibly in-
From the Department of Pediatrics, University of Zurich, K inderspitaL
REFERENCES 1. Axelrod FB, Leistner HL, and Porges RF: Breech presentation among infants with familial dysautonomia, J PEDtATR84:107, 1974. 2. Berencles HW, Weiss W, Deutschberger J, and Jackson E: Factors associated with breech delivery, Am J Public Health 55:708, !965. 3. Hellman LM, and Pritchard JA, editors: Williams' obstetrics, NewYork, 1971, Appleton-Century-Crofts, Inc., p 226. 4. Vartan CK: The behaviour of the foetus in utero with special reference to the incidence of breech presentation at term, J Obstet Gynaecol Br Commonw 52:418, 1945. 5. Brenner WE, Bruce RC, and Hendricks CH: The characteristics and perils of breech presentation, Am J Obstet Gynecol 118:700, 1974. 6. Shull WJ: Congenital malformations: Current knowledge of etiology, Clin Obstet Gynecol 4:365, 1961. 7~ Neilson DR: Management of the large breech infant; a survey of 203 cases from Emanuel Hospital, Am J Obstet Gynecol 107:345, 1970. 8. Thomas IT, and Smith DW: Oligohydramnios, cause of the non-renal features of Potter's syndrome, including pulmonary hypoplasia, J PEDIATR84:811, 1974. 9. Robinson GW: Birth characteristics of children with congenital dislocation of the hip, Am J Epidemiol 87:275, 1968.
Abbreviations used LH: luteinizing hormone TSH: thyroid-stimulating hormone TRH: thyrotropin-releasing hormone FSH: follicle-stimulating hormone HCG: human chorionic gonadotropin LHRF: luteinizing hormone releasing factor creasing n u m b e r of patients has survived because the diagnosis has been made during the first week of life and was followed by successful adrenocortical replacem e n t therapy. 35 In boys who have no affected siblings or only surviving affected brothers, it is not possible to distinguish the two types in vivo.
