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 evaluate the frequency of such abnormalities and the clinical background of both mothers and neonates.


METHODS
We reviewed maternal (114 cases) and neonatal (139 cases) charts from all pregnant women who received intravenous MgSO4 administration for preterm labor and preeclampsia between June 1, 1992, and May 31, 1994. All chest X-ray films 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 subjects were divided into affected (group 1 and 1a) 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 amounted to 13 (11.4%). Group 1 consisted of 13 cases and group 2 of 101 cases. In the control group bone abnormalities were not observed (p < 0.05). Significant differences were found between groups 1 and 2 in the gestational ages at the start of MgSO4 administration and at delivery, and in the total duration of administration and doses of MgSO4. Also, cases of multiple pregnancy and pregnancy complicated with impaired glucose tolerance were more prevalent in group 1. According to the results obtained from 139 neonates, cases showing low Apgar and high magnesium 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 possible bearing on the condition. In addition, the cases with onset of bone abnormality seemed to be associated with symptoms attributable to hypermagnesemia of neonates.
Matsuda
Y
Y
Department of Obstetrics and Gynecology, Kagoshima City Hospital, Japan.
Maeda
Y
Y
Ito
M
M
Sakamoto
H
H
Masaoka
N
N
Takada
M
M
Sato
K
K
D001846:Bone Development / Q000187:drug effects*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D006811:Humerus / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000187:drug effects; D007231:Infant, Newborn; D007275:Injections, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D008499:Medical Records; D007752:Obstetric Labor, Premature / Q000188:drug therapy*; D011225:Pre-Eclampsia / Q000188:drug therapy*; D011247:Pregnancy; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013997:Time Factors; D015149:Tocolytic Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use
D015149:Tocolytic Agents; D008278:Magnesium Sulfate