Clinical characteristics of pregnancies complicated by congenital myotonic dystrophy

Abstract

ObjectiveAlthough the conventional prevalence of myotonic dystrophy is 1:8,000, the prevalence in Korean population was recently reported as 1:1,245. With higher domestic result than expected, we aimed to investigate the clinical characteristics of pregnancies complicated by congenital myotonic dystrophy in our institution.MethodsWe have reviewed 11 paired cases of neonates diagnosed with congenital myotonic dystrophy and their mothers between July 2004 and May 2014, with clinical features including maternal history of infertility, prenatal ultrasonographic findings, and neonatal outcomes. Cytosine-thymine-guanine (CTG) repeat expansion in the myotonic dystrophy protein kinase gene of both neonates and their mothers was also examined.ResultsNone of mother was aware of their myotonic dystrophy traits before pregnancy. History of infertility followed by assisted reproductive technology accounted for 57.1% (4/7). Distinctive prenatal ultrasonographic finding was severe idiopathic polyhydramnios (66.7%, 4/6) with median amniotic fluid index of 43 (range, 37 to 66). In 37.5% (3/8) cases, decreased fetal movement was evident during prenatal ultrasound examination. For neonatal outcomes, more than half (6/11) were complicated with preterm birth and the proportion of 1-minute Apgar score <4 and 5-minute Apgar score <7 was 44.4% (4/9) and 66.7% (6/9), respectively. Most of neonates were admitted to the neonatal intensive care unit (9/10) because of hypotonia with respiratory problems and there was one infant death. Median number of cytosine-thymine-guanine repeats in mothers and neonates was 400 (range, 166 to 1,000) and 1,300 (range, 700 to 2,000), respectively.ConclusionOur data suggest that severe idiopathic polyhydramnios with decreased fetal movement in pregnant women, especially with a history of infertility, requires differential diagnosis of congenital myotonic dystrophy.

Genetic diagnosis and clinical evaluation of severe fetal akinesia syndrome

“…Prenatally affected fetuses could present as asymptomatic ranging to severe fetal akinesia like in case 15. The majority of prenatally described DM1 cases in the literature, presented with severe polyhydramnios and club feet, comparable to case 15 of this cohort 20,21 . However, without positive family history of DM1, it is not possible to distinguish between DM1 and other disease entities of FADS.…”

Impact of prematurity and the CTG repeat length on outcomes in congenital myotonic dystrophy

“…We analyzed data on 22 CDM infants from our hospitals and 31 patients from previous studies [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”

Impact of prematurity and the CTG repeat length on outcomes in congenital myotonic dystrophy

“…We analyzed data on 22 CDM infants from our hospitals and 32 patients from previous studies [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. We summarized the clinical characteristics of all 54 CDM infants in Table 1.…”