Author/Authors :
Kazemnejad Anoshirvan نويسنده , Farhadi Roya Roya نويسنده Non-Communicable Pediatric Diseases Research Center, Babol University of Medical Sciences, Babol, Iran Farhadi Roya Roya , Gholami Fesharaki Mohammad نويسنده Biostatistics Department, Tarbiat Modarres University, Tehran, IR Iran , Hamta Amir نويسنده 5Department of Biostatistics, Faculty of Health, Mazanderan University of Medical Sciences, Sari, Iran Hamta Amir
Abstract :
Background The effectiveness of cervical cerclage (CC) in mothers
suffering cervical incompetence (CI) for preventing preterm birth (PTB)
in twin gestations remains controversial. Some studies show that it
plays a preventive role in the occurrence of PTB, while others suggest
it is ineffective. Objectives Our aim was to evaluate the effectiveness
of CC in preventing PTB and negative neonatal outcome (e.g., respiratory
distress syndrome (RDS) and birth weight) based on a new statistical
framework: multilevel analysis and propensity score matching (PSM) in
twin pregnancies. Methods A cross-sectional study was conducted in the
maternity wards of three general and teaching hospitals in Tehran, Iran,
during January 2014 to February 2015. Using stratified random sampling
with the proportional allocation method, twin pregnancies were randomly
selected from the medical files list. Of 431 eligible individuals, 31
patients underwent CC as a result of CI, and the others had healthy
cervixes and no CC. Next, variables that confound the relationships
between CC and PTB (e.g., assisted reproductive technology (ART),
preterm rupture of membrane (PROM), nulliparous, history of abortion,
and mother’s age) by applying 1:2 PSM were matched in both groups. The
CC group was considered the case group and, based on PSM, 61 patients,
whose characteristics were similar to the CC group, were selected from
400 healthy mothers as a control group. For considering twins
dependencies, multilevel modeling was used, and prevalence of PTB, LBW,
and RDS, as well as mean gestational age in the two groups, were
compared. Results The standardized mean difference (SMD) shows that the
distribution of confounding variables in the propensity-matched data is
the same in both groups. Results revealed that, although gestational age
in the case group was significantly less than the control group, the
prevalence of PTB in case and control was not significantly different (P
= 0.190). The prevalence of neonatal outcome of RDS and LBW in the case
and control groups was not significant (P > 0.05). Conclusions It
appears that CC has an effective role in prevention of PTB, LBW, and
RDS, because their prevalence in both groups was the same. However,
drawing a clear conclusion regarding its role requires more research
with a random clinical trial (RCT) design.
