Selections from the 26th Annual Meeting of the Society for Maternal-Fetal Medicine, January 30-February 4th, 2006, Miami, Florida
Tocolysis in women with preterm labor between 32 0/7 and 34 6/7 weeks of gestation: A randomized controlled pilot study

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Objective

The purpose of this study was to determine whether intravenous magnesium sulfate (MgSO4) followed by oral nifidepine tocolysis in women with preterm labor between 32 0/7 and 34 6/7 weeks' gestation reduces neonatal hospital stay.

Study design

Fifty-four women between 32 0/7 and 34 6/7 weeks with preterm labor were randomized to receive either MgSO4 and oral nifidepine (n = 24) or no tocolysis (n = 30). All women received betamethasone and prophylactic antibiotics. The primary outcome was total neonatal hospital stay. Data were analyzed using Chi-square and Mann Whitney U test.

Results

The 2 groups had similar mean cervical dilation and gestational age at enrollment. There were no statistically significant differences in total neonatal hospital stay (5.8 ± 7.2 days; median of 3 days in the no tocolysis vs. 7.5 ± 8.6 days; median of 3 days in the tocolysis group), rate of preterm delivery (57% vs. 75%) or need for oxygen supplementation (7% vs. 21%, p < 0.23). The neonatal complications were similar in each group.

Conclusion

Tocolysis after 32 weeks gestation does not reduce neonatal hospital stay.

Section snippets

Material and methods

This trial was performed at the University Hospital, Cincinnati, Ohio between August 2002 and July 2005. Pregnant women with singleton gestation, who were in preterm labor between gestational age of 32 0/7 and 34 6/7 weeks with intact amniotic membranes, a diagnosis of preterm labor and a cervical dilation of ≤4 cm were considered for the study. Preterm labor (PTL) was defined as progressive cervical dilation or effacement associated with regular uterine contractions (≥6/hr). At our

Results

A total of 54 women were enrolled; 30 were randomized to the control group (no tocolysis) and 24 were randomized to the treatment group (IV and oral tocolysis). There were 2 (7%) women in the no tocolysis group and 4 (17%) women in the tocolysis group who were maternal transfers from other institutions. Table I reports the baseline characteristics for the women at randomization. There were no statistically significant differences with regard to maternal demographics, mean cervical dilation and

Principal Findings of the Study

In this prospective, randomized clinical trial we evaluated the efficacy of aggressive tocolysis with IV MgSO4 followed by maintenance oral nifedipine in women determined to be in preterm labor between 32 0/7 and 34 6/7 weeks gestational age. Our results indicate that aggressive tocolysis does not improve neonatal outcome as measured by the total length of neonatal hospital stay. In addition, we found that neonatal morbidity is minimal at this gestational age following administration of

Cited by (22)

  • Tocolysis for preterm labor without premature preterm rupture of membranes

    2016, Journal de Gynecologie Obstetrique et Biologie de la Reproduction
  • Does magnesium sulfate delay the active phase of labor in women with premature rupture of membranes? A randomized controlled trial

    2014, Taiwanese Journal of Obstetrics and Gynecology
    Citation Excerpt :

    Preterm labor refers to progressive cervical dilatation or effacement associated with regular uterine contractions (≤6/hour)[1].

  • Indications for delivery and short-term neonatal outcomes in late preterm as compared with term births

    2009, American Journal of Obstetrics and Gynecology
    Citation Excerpt :

    The question arises as to whether women presenting late preterm should be managed expectantly at 34, 35, or 36 weeks, weighing the possible benefit of prolonging a late preterm pregnancy against risks such as chorioamnionitis, eclampsia, abruptio placentae, periventricular leukomalacia, pulmonary edema, and fetal demise. The research addressing expectant management of late preterm birth is scant, and studies that have been done failed to demonstrate a benefit from expectant management of PPROM9 or tocolysis10 in late preterm labor. In fact, the ACOG recommendation for PPROM after 33 completed weeks is delivery.11

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Presented at the 26th Annual Meeting of the Society for Maternal Fetal Medicine, Miami, FL, January 30-February 4, 2006.

Reprints not available from the authors.

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