[Introduction]
Abdominal trachelectomy (AT) has been used as a fertility-sparing
surgery for early-stage cervical cancer in women of reproductive age
since the first report (Smith JR, 1997) on the same was
published,1 and is defined as surgical removal of the
uterine cervix with preservation of the uterine body. The incidence of
cervical cancer in reproductive-aged women is
increasing,2-4 and the number of women desiring
pregnancy after AT is also increasing accordingly. Many reports on
obstetric outcomes in pregnant women after AT in the past have described
the high risk of miscarriage, preterm birth, and preterm premature
rupture of membranes (pPROM).5-9 The reported
incidence of preterm birth and miscarriage ranges from 53% to
89%,6-10 and the high rate of complications in
pregnant women after AT can be attributed to the loss of the supporting
tissue of the cervical canal that maintains pregnancy and ascending
infection due to the loss of the cervical mucus plug. Although the high
risk of miscarriage has recently been well recognized, a preventive
approach for pregnancies after AT has not been discussed.
The efficacy of progesterone administration in preventing preterm birth
in high-risk pregnant women such as those with a history of preterm
birth11,12 or women with a shortened
cervix13,14 has recently been established, and the use
of this drug for managing such high-risk pregnancies has become common
in Western countries.15,16 The mechanism of action of
progesterone responsible
for preventing preterm birth has not been fully determined, but the
preventive effect is speculated to be caused by its anti-inflammatory
effect, decreased cervical stromal degradation, and a decreased
frequency of contractions of the myometrium.17 The
efficacy of progesterone in preventing preterm birth in high-risk
pregnancies is unquestioned; however, to the best of our knowledge, the
use of progesterone for reducing the risk of preterm birth in pregnant
women after AT has not been reported to date.
Against this background, we designed an interventional study to
determine whether vaginal progesterone (VP) reduces the rate of preterm
birth in pregnant women after AT.