Clinical Study
Intrapartum Ultrasound Assessment of Fetal Spine Position
Salvatore Gizzo,
1,2
Alessandra Andrisani,
1
Marco Noventa,
1
Giorgia Burul,
1
Stefania Di Gangi,
1
Omar Anis,
1
Emanuele Ancona,
1
Donato D’Antona,
1
Giovanni Battista Nardelli,
1
and Guido Ambrosini
1
1
Department of Woman and Child Health, University of Padua, Via Giustiniani 3, 35128 Padova, Italy
2
Dipartimento di Salute della Donna e del Bambino, U.O.C. di Ginecologia e Ostetricia, Via Giustiniani 3, 35128 Padova, Italy
Correspondence should be addressed to Salvatore Gizzo; salvatoregizzo@libero.it
Received 15 April 2014; Revised 4 July 2014; Accepted 10 July 2014; Published 4 August 2014
Academic Editor: Jose Guilherme Cecatti
Copyright © 2014 Salvatore Gizzo et al. his is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
We investigated the role of foetal spine position in the irst and second labour stages to determine the probability of OPP detection at
birth and the related obstetrical implications. We conducted an observational-longitudinal cohort study on uncomplicated cephalic
single foetus pregnant women at term. We evaluated the accuracy of ultrasound in predicting occiput position at birth, inluence
of fetal spine in occiput position during labour, labour trend, analgesia request, type of delivery, and indication to CS. he accuracy
of the foetal spinal position to predict the occiput position at birth was high at the irst labour stage. At the second labour stage,
CS (40.3%) and operative vaginal deliveries (23.9%) occurred more frequently in OPP than in occiput anterior position (7% and
15.2%, resp.), especially in cases of the posterior spine. In concordant posterior positions labour length was greater than other ones,
and analgesia request rate was 64.1% versus 14.7% for all the others. he assessment of spinal position could be useful in obstetrical
management and counselling, both before and during labour. he detection of spinal position, more than OPP, is predictive of
successful delivery. In concordant posterior positions, the labour length, analgesia request, operative delivery, and caesarean section
rate are higher than in the other combination.
1. Introduction
he foetal head typically engages in the transverse diameter
late in the third trimester and usually rotates to an occipi-
toanterior (OAP) or occipitoposterior (OPP) position. OPP
occurs in 15–20% of women before labour at term [1].
Approximately 90–95% of these foetuses rotate during
labour once the head reaches the pelvic loor [1, 2]. hus,
most of the OPP deliveries seem to arise as a consequence
of a malrotation from the initial OAP or transverse position
(OTP), rather than a persistent OPP. OPP incidence at birth
ranges between 1 and 5% [2, 3].
Intrapartum ultrasound may improve the detection of
fetal head position [4]. Although the identiication of OPP
before or during labour is not predictive of the same position
at delivery, its early detection argues for a greater monitoring
of the labour evolution [4, 5].
Blasi et al. [6] showed that the diagnostic sonographic
accuracy of the foetal occiput position assessment at the
second stage of labour had a sensitivity of 100%, speciicity
of 78%, positive predictive value (PPV) of 26%, and negative
predictive value (NPV) of 100% to predict the same position
at birth. Considering the foetal spinal position, ultrasound
showed a sensitivity of 100%, speciicity of 98%, PPV of 85%,
and NPV of 100% [6].
Peregrine et al. [1] demonstrated that the foetal spine
and occiput were oten not concordant, but the posterior
positioned spine was detected in nearly 14.5% of deliveries
frequently associated with OPP [1]. Recent literature conirms
that OPP represents an obstetric challenge because it is
associated with an increased maternal foetal and neonatal
morbidity, and its management is still debated [6].
In obstetrical practice, pregnant women with OPP foe-
tuses present prolonged second stages of labour, higher rates
of episiotomy, and severe perineal lacerations, mainly owing
to the higher rates of instrumental delivery and increased
risks of Caesarean section (CS) by nearly 4-fold [7].
Hindawi Publishing Corporation
BioMed Research International
Volume 2014, Article ID 783598, 8 pages
http://dx.doi.org/10.1155/2014/783598