[The importance of betamimetics and magnesium for the outcome of pregnancy: I. Reduction of intrauterine growth retardation, premature rupture of membranes and premature birth after supplemental magnesium therapy].

Of 4 905 single pregnancies recorded within a 4 year period (1979-1982) 882 (18%) were risk pregnancies managed with Betamimetics (B); of these 348 (7,1%) had tocolysis (T) and 534 (10,9%) tocolysis and cerclage (T/C). Since the end of 1979 the patients received in addition to the Betamimetic a K-Mg-Vitamin drug (Feto-Longoral) aimed at "Cardioprotection", and since the beginning of 1981 30-40 mval oral Mg daily in the form of Magnesium aspartate (Mg 5-Longoral) to "support tocolysis". The mean age, parity, percentage with Magnesium therapy, the pregnancy outcome using a gestational age limit less than or equal to 36 weeks, the frequency of premature ruptured membranes (PROM) in premature and mature infants as well as the number of intrauterine growth retarded infants (IUR) (less than 10th percentile BPE) were yearly evaluated and compared for both risk collectives T and T/C as well as for the normal collectives (N). While only 2% of the normal collectives had a pregnancy duration of less than or equal to 36 weeks (completed) the figure was five fold in both T and T/C groups, and however was yearly reduced in the T/C group from 11,0% (1979) to 4,9% (1982). The frequency of PROM with premature infants in the T and T/C groups is about 6% (N-collectives about 1%). It is however reduced in the T/C group in 1981 to 2,2% and in 1982 to 1,6%. For mature infants it is N: 17-12% (fluctuating) and B (T + T/C): 22-11% (yearly decreasing). The rate of IUR (less than 10th percentile BPE) in the T and T/C groups in 1979 was 22,2 and 20,5% respectively and in 1980 12,6 and 17,5% respectively. It is further reduced in 1981 to 11,6 and 8,8% respectively and in 1982 to 9,7 and 10,6% respectively (N-collectives between 8,3 and 11,5%). The "weight gain" exceeds the 25th percentile (Hohenauer): 1979 and 1980 for B: 33,1 and 30,2% respectively, and 1981 and 1982 for B: 25,4 and 24,2% respectively (N between 26,5 and 19,5%). The results show that patients with tocolysis--with or without cerclage--have more premature and growth-retarded infants than normal collectives (a sign of more placenta insufficiencies). In the two years where Magnesium was supplemented at 30-40 mval daily, short term pregnancies, the PROM frequency and the IUR rate decreased (statistically evaluated). It could thus be concluded that a relative Magnesium deficiency might have been responsible for a certain percentage of premature births and hypotrophic infants and that better results were obtained after Magnesium substitution.