EFFECT OF MAGNESIUM-SULFATE TREATMENT ON NEONATAL BONE ABNORMALITIES

Objective: It has been reported that neonatal bone abnormalities occur as a result of long-term intravenous magnesium administration (MgSO4) to pregnant women. The purpose of this retrospective study was to eva luate the frequency of such abnormalities and the clinical background of both mothers and neonates. Patients and Methods: We reviewed matern al (114 cases) and neonatal (139 cases) charts from all pregnant women who received intravenous MgSO4 administration for preterm labor and p reeclampsia between June 1, 1992, and May 31, 1994. All chest X-ray fi lms were obtained within 48 h after birth and reviewed by a doctor who was unaware of the clinical data. Radiolucent transverse metaphyseal bands of the proximal humerus were considered as abnormal. The subject s were divided into affected (group 1 and la) and unaffected (group 2 and 2a) groups. Neonates born to pregnant women given no MgSO4 at the same period, were considered as control. Results: The total number of bone abnormalities in the offspring of mothers receiving MgSO4 amounte d to 13 (11.4%). Group 1 consisted of 13 cases and group 2 of 101 case s. In the control group bone abnormalities were not observed (p < 0.05 ). Significant differences were found between groups 1 and 2 in the ge stational ages at the start of MgSO4 administration and at delivery, a nd in the total duration of administration and doses of MgSO4. Also, c ases of multiple pregnancy and pregnancy complicated with impaired glu cose tolerance were more prevalent in group 1. according to the result s obtained from 139 neonates, cases showing low Apgar and high magnesi um score and those receiving respiratory support were more noticeable in group 1a(15 cases). Conclusions: The gestational ages and the total doses of MgSO4 in pregnant women were the main factors related to the onset of neonatal bone abnormalities, but other factors also have a p ossible bearing on the condition. In addition, the cases with onset of bone abnormality seemed to be associated with symptoms attributable t o hypermagnesemia of neonates.