Biomaterial Database

Myotonic muscular dystrophy associated with ritodrine tocolysis. 1985

J S Sholl, and M J Hughey, and R A Hirschmann

A patient thought to be normal was admitted with premature labor at 29+ weeks' gestation. Treatment with the beta-mimetic ritodrine hydrochloride appeared to provoke symptoms of myotonic muscular dystrophy. Neurological history and examination confirmed the presence of previously unsuspected myotonic dystrophy in the patient, her father, and paternal grandfather. Discontinuation of the drug led to improvement in myotonia symptoms but worsening premature labor. Magnesium sulfate did not provoke the same symptoms but was unsuccessful in controlling premature contractions. Long-term management with bed rest, phenytoin, and isoxsuprine hydrochloride resulted in term delivery. Subsequently, maternal symptoms of myotonia disappeared. Congenital myotonia was suspected in the fetus because of the ultrasonic demonstration of polyhydramnios and reduced fetal movements. This was confirmed at delivery. The mechanism by which ritodrine unmasked the myotonia is unclear but may be related to changes in the cell membrane (chloride conductance, the sodium-potassium pump, or membrane polarization).

UI	MeSH Term	Description	Entries
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D007556	Isoxsuprine	A beta-adrenergic agonist that causes direct relaxation of uterine and vascular smooth muscle. Its vasodilating actions are greater on the arteries supplying skeletal muscle than on those supplying skin. It is used in the treatment of peripheral vascular disease and in premature labor.	Duvadilan,Isoxsuprine Hydrochloride,Hydrochloride, Isoxsuprine
D007752	Obstetric Labor, Premature	Onset of OBSTETRIC LABOR before term (TERM BIRTH) but usually after the FETUS has become viable. In humans, it occurs sometime during the 29th through 38th week of PREGNANCY. TOCOLYSIS inhibits premature labor and can prevent the BIRTH of premature infants (INFANT, PREMATURE).	Preterm Labor,Labor, Premature,Premature Labor,Premature Obstetric Labor,Labor, Premature Obstetric,Labor, Preterm
D008431	Maternal-Fetal Exchange	Exchange of substances between the maternal blood and the fetal blood at the PLACENTA via PLACENTAL CIRCULATION. The placental barrier excludes microbial or viral transmission.	Transplacental Exposure,Exchange, Maternal-Fetal,Exposure, Transplacental,Maternal Fetal Exchange
D009136	Muscular Dystrophies	A heterogeneous group of inherited MYOPATHIES, characterized by wasting and weakness of the SKELETAL MUSCLE. They are categorized by the sites of MUSCLE WEAKNESS; AGE OF ONSET; and INHERITANCE PATTERNS.	Muscular Dystrophy,Myodystrophica,Myodystrophy,Dystrophies, Muscular,Dystrophy, Muscular,Myodystrophicas,Myodystrophies
D009223	Myotonic Dystrophy	Neuromuscular disorder characterized by PROGRESSIVE MUSCULAR ATROPHY; MYOTONIA, and various multisystem atrophies. Mild INTELLECTUAL DISABILITY may also occur. Abnormal TRINUCLEOTIDE REPEAT EXPANSION in the 3' UNTRANSLATED REGIONS of DMPK PROTEIN gene is associated with Myotonic Dystrophy 1. DNA REPEAT EXPANSION of zinc finger protein-9 gene intron is associated with Myotonic Dystrophy 2.	Dystrophia Myotonica,Myotonic Dystrophy, Congenital,Myotonic Myopathy, Proximal,Steinert Disease,Congenital Myotonic Dystrophy,Dystrophia Myotonica 1,Dystrophia Myotonica 2,Myotonia Atrophica,Myotonia Dystrophica,Myotonic Dystrophy 1,Myotonic Dystrophy 2,PROMM (Proximal Myotonic Myopathy),Proximal Myotonic Myopathy,Ricker Syndrome,Steinert Myotonic Dystrophy,Steinert's Disease,Atrophica, Myotonia,Atrophicas, Myotonia,Congenital Myotonic Dystrophies,Disease, Steinert,Disease, Steinert's,Dystrophia Myotonica 2s,Dystrophia Myotonicas,Dystrophica, Myotonia,Dystrophicas, Myotonia,Dystrophies, Congenital Myotonic,Dystrophies, Myotonic,Dystrophy, Congenital Myotonic,Dystrophy, Myotonic,Dystrophy, Steinert Myotonic,Myopathies, Proximal Myotonic,Myopathy, Proximal Myotonic,Myotonia Atrophicas,Myotonia Dystrophicas,Myotonic Dystrophies,Myotonic Dystrophies, Congenital,Myotonic Dystrophy, Steinert,Myotonic Myopathies, Proximal,Myotonica, Dystrophia,Myotonicas, Dystrophia,PROMMs (Proximal Myotonic Myopathy),Proximal Myotonic Myopathies,Steinerts Disease,Syndrome, Ricker
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011412	Propanolamines	AMINO ALCOHOLS containing the propanolamine (NH2CH2CHOHCH2) group and its derivatives.	Aminopropanols
D002585	Cesarean Section	Extraction of the FETUS by means of abdominal HYSTEROTOMY.	Abdominal Delivery,Delivery, Abdominal,C-Section (OB),Caesarean Section,Postcesarean Section,Abdominal Deliveries,C Section (OB),C-Sections (OB),Caesarean Sections,Cesarean Sections,Deliveries, Abdominal
D005260	Female		Females