Data from: Association between total dose of ritodrine hydrochloride and pulmonary edema in twin pregnancy: a retrospective cohort study in Japan

Objective Pulmonary edema is recognized as a severe side effect of
ritodrine hydrochloride. Recently, the number of twin pregnancies has been
increasing. Few studies have reported the association between total dose
of ritodrine hydrochloride prior to delivery and pulmonary edema in twin
pregnancy. We aimed to examine this association and determine the optimal
cutoff threshold of total ritodrine hydrochloride dose to predict the
incidence of pulmonary edema in twin pregnancy, based on obstetric
records. Design Retrospective cohort study. Setting Yamanashi Prefectural
Central Hospital, Japan Participants Two hundred twenty-six women with
twin pregnancy who delivered at Yamanashi Prefectural Central Hospital
between September 2009 and November 2016 Methods The obstetric records of
the participants were analyzed. We defined one unit of ritodrine
hydrochloride as 72 mg per 24 h continuous transfusion at 50 µg/min to
calculate the dose of ritodrine used for tocolysis. Outcome measures
Multivariable logistic regression analysis was performed to examine the
association between total dose of ritodrine hydrochloride used for
threatened preterm labor and pulmonary edema, while controlling for
potential confounding factors. Then, a receiver-operating characteristic
curve was used to determine the optimal cutoff of total ritodrine dose to
predict pulmonary edema incidence. Results Mean maternal age was 32
(range, 18-46) years; 143 participants were nulliparous (63.3%), 109 had
(48.2%) term deliveries, and 194 (85.8%) had cesarean deliveries. The
overall incidence of pulmonary edema was 13.7% (31/226). Multivariable
analysis showed that the total dose of ritodrine was significantly
associated with pulmonary edema (adjusted odds ratio 1.02; 95% confidence
interval, 1.004-1.03). The best cut-off point to predict the incidence of
pulmonary edema was 26 units (1872 mg) (sensitivity, 61.3%; specificity,
87.8%). Conclusion Our results suggest that consideration of the total
dose of ritodrine hydrochloride is helpful in the management of patients
with threatened preterm labor in twin pregnancy.