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| Pfizer.com |
Sildenafil Citrate (Viagra) improves amniotic fluid index in pregnancies complicated by oligohydramnios according to a new study published ahead of print on March 6,2017 in Journal of Obstetrics and Gynecology.[1]
Viagra, a
specific phosphodiesterase-5 inhibitor, has recently been proposed as a
potential therapeutic strategy to maintain placental function and increase the
amniotic fluid index (AFI).
This was an open-label
randomized trial, carried out over a period of one year and recruited a total
of 184 women. The study included all women at 30 weeks or more in pregnancy
with oligohydramnios detected during routine sonography. No specific cause or
etiology was detected for oligohydramnios in all these women.
The women
were randomized to receive either Sildenafil Citrate 25 mg three times a day
along with intravenous infusion of 2 L isotonic solution (82 women) or just
fluids only (84 women). All women were hospitalized for initial 24 hours and received
the IV fluids.
The women
were followed up for 6 weeks on the basis of outpatient monitoring with NST,
USG and biophysical profile. Patient is readmitted if the AFI drops below 5 for
Intravenous fluid therapy. Final assessment of the amniotic fluid volume is
done at 6 weeks or before delivery if she went into labor before completing 6
weeks.
It was seen
that women who received Sildenafil have considerable good amniotic fluid at
follow up with AFI of 11.5 vs 5.4 in the control group. (P=.02).
The women in
sildenafil group also went further into pregnancy with mean gestational age of 38.3
weeks as compared to 36 weeks. (P=.001). These women had one third the rate of
Cesarean section and one fourth neonatal intensive care admission as compared
to placebo group.
The authors
concluded that “Sildenafil citrate increases amniotic fluid volume in
pregnancies complicated by oligohydramnios.”
The proposed
mechanism is vasodilatation of small myometrial vessels, thereby increasing the
placental perfusion which leads to improvement in amniotic fluid index, fetal
weight, and even uterine and umbilical artery Doppler patterns.
Currently
there is no effective therapy for early onset IUGR or oligohydramnios.
Sildenafil
citrate in the same dose has also shown promising results in improving the birth
outcomes in early and late onset IUGR.[2]
Preliminary
studies have also shown that it is effective in early onset preeclampsia to
improve fetal growth retardation, but more randomized trials are needed.[3]
The trial is
registered with Clinicaltrials.gov number NCT02372487
