ARCH: Australian Research Centre for Health of Women and Babies, Discipline of Obstetrics and Gynaecology, The University of Adelaide, Women's and Children's Hospital, 72 King William Road, Adelaide, South Australia, Australia, 5006.
Magnesium does not reduce preterm birth or improve the outcome for the infant when given to women after contractions of preterm labour have been stopped. Babies born preterm, before 37 weeks of pregnancy, may not survive or they may have later physical health and developmental problems if they do survive. Women whose preterm labour is stopped with tocolytic therapy (medication to reduce uterine contractions) remain at high risk of preterm birth. A variety of agents (tocolytics) are used to halt the uterine contractions. These include betamimetics, calcium channel blockers, magnesium sulphate, and oxytocin receptor antagonists. Subsequent tocolytic maintenance medication has been advocated. Oral and intravenous magnesium has been used to prevent further early contractions. We included four randomised controlled trials involving a total of 422 women in this review. The trials did not demonstrate any differences between magnesium maintenance therapy and placebo or other treatments (ritodrine or terbutaline) in the prevention of preterm birth or perinatal deaths. The trials were too small to exclude either important benefits or harms from magnesium maintenance therapy. Magnesium was less likely than the alternative tocolytics (betamimetics) to result in side effects, particularly palpitations or tachycardia, although diarrhoea was more likely. This finding is based on very few studies of low quality, and none of them looked at the infants' later development.
"Considerable debate remains as to whether maintenance tocolysis is appropriate after initial tocolysis for spontaneous preterm labor. Various drugs with different dosage schedules and routes have been used for maintenance tocolysis (β-agonists, calcium-channel blockers, magnesium, and atosiban) but no significant prolongation of pregnancy or improved perinatal outcome has been noted    . Progesterone has been widely used as a uterine sedative in the prevention of preterm labor but it has not been investigated thoroughly for maintenance tocolysis. "
[Show abstract][Hide abstract] ABSTRACT: Objective
To evaluate the efficacy of maintenance therapy with oral micronized progesterone (OMP) for prolongation of pregnancy in cases of arrested preterm labor.
Ninety women at 24–34 weeks of singleton pregnancy with intact membranes and arrested preterm labor were randomly allocated to receive OMP (n = 45) or placebo (n = 45) daily until 37 weeks or delivery, whichever was earlier. Outcome parameters were compared using Student t test, χ2 test, Fisher exact test, and log-rank χ2 test.
OMP significantly prolonged the latency period (33.29 ± 22.16 vs 23.07 ± 15.42 days; P = 0.013). Log-rank analysis revealed a significant difference in mean time to delivery between the 2 groups (P = 0.014). There were significantly fewer preterm births (33% vs 58%; P = 0.034) and low birth weight neonates (37% vs 64%; P = 0.017), and significantly higher mean birth weight (2.44 ± 0.58 vs 2.14 ± 0.47 kg; P = 0.009) in the OMP group. Perinatal outcomes and adverse effects were similar in the 2 groups.
Maintenance tocolysis with OMP significantly prolonged pregnancy and decreased the number of preterm births.
Clinical Trial Registry of India: CTRI/2011/10/002043.
International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics 07/2014; 126(1). DOI:10.1016/j.ijgo.2014.01.019 · 1.54 Impact Factor
"Secondly, MgSO 4 can be applied as a tocolytic drug. Magnesium maintenance therapy is a type of tocolytic therapy used after an episode of preterm labour in an attempt to prevent the onset of further preterm contractions . Therefore, atonia or hypotonia of the uterus could be possible when using magnesium sulfate. "
[Show abstract][Hide abstract] ABSTRACT: The incidence of Postpartum Hemorrhage (PPH) is increasing in the western world. We hypothesize that magnesium sulfate (MgSO 4) could be a contributing factor. MgSO 4 might increase the incidence of PPH by induction of vasodilation, tocolytic effects, and effects on the blood like red cell deformity, platelet activity inhibition and a prolonged bleeding time. Based on these effects of MgSO 4 a correlation with PPH is suspected. MgSO 4 is widely used in the pre-vention of eclampsia. However, the working mecha-nism of this effective drug is largely unknown. We performed a systematic search to find all Random-ized Controlled trials (RCTs) containing MgSO 4 in preeclamsia as well as all MgSO 4 studies with infor-mation on PPH. Titles, abstracts and references of publications were evaluated for appropriateness and whether they met the inclusion criteria. RCTs about MgSO 4 with original data on PPH prevalence were included in our systematic review. We calculated the relative risk of PPH in every study as well as an overall relative risk. Four relevant and valid RCTs were found, totalling 11,621 relevant patients. The relative risk of PPH in women treated with MgSO 4 is 0.964 (95% CI 0.886 -1.050) In this systematic review we found no significant increase in PPH in women treated with MgSO 4 . However, there is still room for discussion due to the heterogeneity in methods (dos-age and duration of treatment), results, and tertiary outcomes, as well as the small number of studies found with respect to this important issue.
[Show abstract][Hide abstract] ABSTRACT: Women who are undelivered after 48 hours of tocolysis remain at increased risk of preterm labour, but it is not clear whether prolonged treatment is effective.
To review the current evidence for the effectiveness of maintenance tocolysis.
The results of published systematic reviews were summarised.
Four systematic reviews and two trials published too recently for inclusion were identified. Maintenance tocolysis with beta-agonists and magnesium sulphate was ineffective in prolonging gestation or reducing any adverse fetal outcomes. One trial of maintenance tocolysis with nifedipine was underpowered to rule out an effect on prolonging gestation. One trial using the oxytocin receptor blocker, atosiban, showed that this drug used as maintenance tocolysis does prolong gestation, but the trial was too small to demonstrate any reduction in substantive fetal outcomes.
There is insufficient evidence to justify the routine use of maintenance tocolysis in preterm labour. It remains plausible that prolongation of gestation might be beneficial in selected cases of very preterm labour where fetal compromise and infection have been ruled out. The only tocolytic that has been shown to prolong gestation when used as maintenance therapy is atosiban.
BJOG An International Journal of Obstetrics & Gynaecology 04/2005; 112 Suppl 1(s1):118-21. DOI:10.1111/j.1471-0528.2005.00599.x · 3.45 Impact Factor
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