title: Ventricular septal thickness and cardiac function in neonates after in utero ritodrine exposure.
abstract: Cardiac septal hypertrophy occurs after in utero ritodrine exposure. To assess the effect of septal hypertrophy on cardiac function we obtained M-mode echocardiograms on day 1 of life in 41 infants exposed to ritodrine and 22 control infants matched for gestational age. Mean duration of ritodrine exposure was 16.2 +/- 13.2 days (range 1 to 49 days). Disproportionate septal hypertrophy (DSH) was defined as an interventricular septal thickness/posterior wall thickness ratio (ST/PW) of greater than 1.3. Infants exposed to ritodrine in utero had DSH and increased right systolic time intervals compared with control values (P less than 0.05). A subgroup, those infants exposed for 2 weeks or longer, had not only DSH but also an absolute increase in septal thickness compared with control infants and infants exposed to ritodrine for less than 2 weeks. ST/PW correlated well with the duration of ritodrine exposure (r = 0.96); the longer the exposure the thicker the septum. Although all echocardiographic changes lasted for less than 3 months, we have no information regarding the effect on the fetus of maternal ritodrine exposure for longer than 7 weeks. Until such information is available, cardiac evaluation is recommended in neonates exposed to ritodrine in utero for longer than 7 weeks.
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000139:chemically induced* / Q000209:etiology; D004452:Echocardiography; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006346:Heart Septum / Q000187:drug effects*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012312:Ritodrine / Q000009:adverse effects*; D013610:Tachycardia / Q000150:complications
chemical_list: D006003:Glycogen; D012312:Ritodrine