Amnioscopy: is it actual?
Amnioscopy is an invasive exam employed to visualise the forebag of the amnionic sac and to look out for meconium staining. Even though recognition of strongly stained fluid is easy, interpretation of those cases that are thinly stained is more difficult, since in these cases which are more common to find there could be an initial staining. On the other hand, visualisation of the forebag does not necessarily depict the condition of the rest of the amniotic fluid, especially in those cases where the fetal head is engaged. Moreover ascertainment that the amniotic fluid is limpid, only holds a temporary significance since it cannot predict successive release of meconium. The incidence of meconium stained fluid prior to labour has been found to range between 6-11%. Amnioscopy hence seems to hold a historical interest, and should only be employed in pregnancies at term where the cervix is sufficiently dilated to permit introduction of the amnioscope. Correlation between finding of meconium stained fluid during labour (1.5-18% reaching 44% in post-term pregnancies) with alterations at cardiotocography and above all to fetal acidosis or low Apgar scores at birth still remains controversial. Passage of meconium does not seem to express fetal compromise, at least until other parameters (CTG) do not support this suspicion. Finally it is important to remember that amnioscopy could in some cases lead to serious infections with chorioamnionites occasionally leading to fetal death. Accidental rupture of the membranes could also occur, reported in 1.4% of the cases, harmful especially when far from labour. From these considerations, and since majority of the cases especially with chronic fetal distress, release of meconium is preceded or accompanied by reduction in the amniotic fluid quantities, the last identifiable through ultrasound. We agree with those authors who advise its use only when adequate management through CTG and ultrasound is not possible, and anyhow only in pregnancies at term.
Raboni
Stefano
S
Department of Gynecology, Obstetrics and Neonatology, University of Parma, Parma, Italy. stefano.raboni@unipr.it
Kaibura
Christine T
CT
Fieni
Stefania
S
D005260:Female; D005316:Fetal Distress / Q000175:diagnosis; D005332:Fetoscopy / Q000379:methods*; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011256:Pregnancy Outcome; D014463:Ultrasonography