Results
After excluding monochorionic or dichorionic triplets, we identified 524
trichorionic triplet pregnancies which included 213 cases in expectant
management (EM) group and 311 cases in embryo reduction (ER) group.
Table 1 shows the clinical characteristics of the study population.
There were no differences in the mean maternal age and body mass index
and the frequency of nulliparity and history of previous preterm birth
between two groups. There were more cases becoming pregnant after in
vitro fertilization (IVF) in the ER group than in the EM group.
Table 2 compares the obstetric outcomes between the two groups of cases.
In the EM group, the risk of preterm delivery (<36,
<34, <32, and <28 weeks) was higher
compared to the ER group. However, in EM group, the risk of non-viable
pregnancy loss was lower [2(0.9%) vs. 20(6.4%), p=0.008] that in
ER group. Moreover, the rate of cases with at least one alive neonate
were higher [208(97.7%) vs. 287(92.3%), p=0.013]. In terms of
obstetric complications, the risk of preeclampsia was higher in EM group
than in ER group [27 (12.8%) vs. 16 (5.5%), p<0.05],
whereas the risk of gestational diabetes and postpartum hemorrhage was
not different between the two groups. Even after adjustment for maternal
age, BMI, and method of conception, the risk of non-viable fetal loss
and the rate of no neonatal survivor were significantly lower in EM,
whereas the risk of preterm delivery and preeclampsia was higher in EM
than in ER group.
The study population included 1,261 fetuses: 639 in the EM group and 622
in the ER group (Table 3). The survival rate during 2 hours after birth
[612(95.8%) vs. 552(88.7), p=0.001] and the survival rate until
discharge of neonates were also significantly higher in the EM group
than the ER group [607(95.0%) vs. 545(87.6), p=0.001]. The rate of
neonates who admitted to NICU was higher in ER group [313(50.4%) vs.
201(36.3), p<0.001], but the risk of neonatal composite
morbidity during hospitalization was not different between the two
groups [113(19.1% vs. 105 (20.0%), p=NS). The risk of PDA and BPD
was higher in EM group, but the risk of neonatal sepsis was lower in EM
group [10(1.7%) vs. 27(5.1), p=0.017].
We evaluated the risk of developmental delay and cerebral palsy in 958
babies. The risk of developmental delay and cerebral were not
significantly different between the two groups both in the univariable
and multivariable analyses.