Drugs To Delay Preterm Labor Linked With Adverse Reactions

The use of certain drugs to delay preterm labor is associated with a high rate of serious adverse reactions, finds a study published on bmj.com today.

Preterm labor is the main cause of perinatal illness and death (the period just before, during or shortly after birth) in the developed world.

Labor-Introduction
Childbirth is one of the most marvelous and memorable segment in a woman's life that calls for celebration. Knowledge about labor and delivery can ease unnecessary fear, ensuring a unique experience.

Tocolytic drugs are used to delay delivery for up to 48 hours. This allows time for doctors to give steroids to speed up the baby’s lung development and to enable the mother to be transferred to a centre with a neonatal intensive care unit.

Drugs most often used include beta agonists and nifedipine (to relax smooth muscles including the uterus) and atosiban and indometacin (to inhibit hormones involved in labor). But it is still unclear whether tocolysis is safe for both mother and baby, so the use of these drugs to stop labor remains controversial.

So researchers assessed the incidence of serious maternal complications in 1,920 women treated with tocolytic drugs for preterm labor at 28 hospitals in the Netherlands and Belgium. The most commonly used drug was atosiban (42%), followed by nifedipine (34%), beta agonists (14%), and indometacin (8%).

Learn About Pregnancy
Pregnancy Labor is caused by series of progressive expulsive contractions by the uterus and results in delivery of the baby from the mothers womb to the outside world.

Over an 18 month period, all adverse reactions were recorded and classified as either serious or mild and according to how the drugs were given (singly, combined, or sequentially).

The overall incidence of adverse effects was low (0.7%) but combined treatment or a single treatment with a beta agonist led to a higher incidence of serious adverse drug reactions. No serious reactions were reported for atosiban or indometacin.

Pregnancy and Complications - Serious Complications
serious complications of pregnancy require monitoring of the mother and baby periodically, some situations may require a C-section to save the mother and baby.

Atosiban had the best safety profile but is considerably more expensive than nifedipine.

Based on their findings, the authors suggest that combined treatment and treatment with beta agonists should be discouraged. They also call for further trials to test the effectiveness and safety of nifedipine and atosiban.

Muscle Relaxant Not Effective in Preventing Premature Birth
Nifedipine, the muscle relaxant generally used to prevent premature birth, is not effective.

In an accompanying editorial, researchers say that this study serves as a timely reminder that the decision to use tocolysis should not be taken lightly. “After 30 years of research we still do not know whether tocolysis benefits the fetus, so the choice of which drug to use remains a secondary question. The real dilemma is whether or not we should treat at all,” they write.

The old assumption that “keeping the baby inside longer must be a good thing” can no longer go unchallenged, they conclude.

Source-BMJ
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