Discussion
Main findings: The nuchal cord is considered as a physiological
finding due to its high prevalence25. The incidence of
NC is growing over a while.1, 2, 3, 4, 22, 23 and the
perinatal outcome is uncertain, leaving behind increasing apprehension.
The application of USG exhibit low sensitivity in diagnosing the nuchal
cord.20,21 Our study shows similar results (Table 1).
The factors responsible for this condition are unestablished. Few
studies deny the association of NC with maternal age and
parity.3,8,9,20 However, some studies exhibit
significant relation of NC with male sex.6,9 The other
aetiological factors like socioeconomic status and education level were
not explored.
For the first time, in this study, we attempted to search in the
maternal socioeconomic status, educational status apart from her age,
parity, fetal gender. We observed that the socioeconomic factors played
a significant role in NC (Fig.2). The lower SES patients had the highest
incidence of NCB and the lowest incidence of NNCB. As the SES advanced
to a middle and higher level, the incidence of NCB steeply decreased
(***p). It was fascinating to follow no statistically significant
difference in high school education groups (NCB versus NNCB). As the
educational status advanced to intermediate, the incidence of NCB
becomes significantly higher (Fig.3). The incidence of NCB was highest
in graduates compared to all other groups (***p). We found that the NCB
incidence is highest in the younger age group (up to 29 yrs) (***p).
However, after 30 yrs there is no significant difference in NCB and
NNCB. The result indicates that with the advancement of maternal age,
there are decreased chances of an NC (Fig.1). We also observed that the
nuchal cord was most common in the primigravidas (***p) (Fig.4). As
parity advanced, the incidence of NCB declined. However, the incidence
of NNCB was the maximum in the 2nd gravidas (**p). In
the 3rd and 4th gravida groups, the
incidence of NNCB was higher compared to NCB (*p). It was noted that NC
is directly related to the male gender of the fetus (***p) (Fig 10).
The effect of NC on perinatal morbidity and mortality is studied with
controversies. Few studies deny any perinatal morbidity associated with
the NC, but it should be considered an ominous sign if associated with
certain findings like intrauterine growth retardation and
oligohydramnios.18 Some found that NC has adverse
perinatal outcomes in their separate
studies.4,11,12,13,14,19 Further, it was found that
there was no APGAR score change due to the nuchal cord but increased
fetal distress and fetal asphyxia.2, 3 The incidence
of 1 min APGAR scores <7 was significantly higher in the NCB
group, whereas that of 1 min APGAR ≥ 7 was significantly higher in the
NNCB group (***p) (Fig.7). The need for O2 (***p) and
NICU admission rate (*p) in the NCB group were significantly higher than
those in the NNCB group (Fig.8). Interestingly, healthy babies’
incidence was higher in the NNCB group than the NCB group (**p). The
study shows that the nuchal cord affects fetal outcomes, with
significantly enhanced chances of low APGAR score (Fig.7) and the need
for external support (Fig.8). We found that NC is associated with low
fetal birth weight (***p) compared to NNCB (Fig.11).
The relationship between the amniotic fluid levels and the nuchal cord
is scarcely known. It was observed that it might have a relation to
acute onset polyhydramnios.7 We observed in our study
that in the NNCB group, a maximum number of patients had AFI 11-12 cm,
whereas those in the NCB group fell into AFI 8 – 9 cm (***p) (Fig.5).
Most of the patients in NNCB had AFI ranging from 5 – 10.5 cm with none
below AFI 4.5 cm and above 14 cm. However, many patients in the NCB
group had AFI ≤ 4.5 cm and ≥ 14 cm (***p). The widespread distribution
of the graph with a general shift towards the left in the NCB group
versus the consolidated graph in the NNCB group shows the nuchal cord’s
relationship to amniotic fluid volume (Fig.5). The nuchal cord’s
occurrence in excessive amniotic fluid indicates that the excess fluid
may be one of the etiological factors in the nuchal cord.
Similarly, its presence of lesser AFI (< 5 cm) group (***p)
indicates that the nuchal cord is responsible for reduced liquor (Maybe
due to disturbance of blood flow towards the fetus). The findings of
liquor levels at the labour time were parallel to those of the AFI
(Fig.5, Fig.6). We observed a significantly higher incidence of reduced
liquor in the NCB group than the NNCB group. Whereas, in the NNCB group,
the chances of having adequate liquor are more than having reduced
liquor (***p). As per the excess liquor group is concerned, the NCB
group incidence is significantly higher than that of the NNCB group.
Overall, amniotic fluid and nuchal cord are significantly related to
each other.
Strength and limitations: We observed 3 cases of short cord and 1
case of a true knot in the NNCB group. Simultaneously, there were no
cases of either short cord or true knots in the NCB group. All these
cord conditions and tightness of the nuchal cord could not be detected
on USG prenatally. The tightness of the nuchal cord may play a vital
role.11, 13, 14 Other cord conditions like short and
stretched cord, true knot, highly coiled cord, compressed cord do affect
the perinatal outcome. There was an important statement in a study
saying that USG diagnosis will only be useful if we can 1. Diagnose a
nuchal cord reliably, and 2. Predict which babies with nuchal cords are
likely to have a problem.20 The tightness of the cord
and other cord conditions are challenging to be detected with the
present investigating methodologies. Thus, the question of diagnosing
the problematic cord conditions persists. Hence, there is a definite
need for a better diagnostic tool to assess the exact cord conditions,
predicting perinatal morbidity if associated with them.
This study denotes that the nuchal cord incidence is high in theyoung age group, primigravida, higher educated, and low
socioeconomic status . All of these situations are very stressful. By
combining all these parameters, we could claim that the nuchal cord
incidence is higher in patients with more stress. An extensive
study needs to be conducted in this area.
Interpretation: The nuchal cord, with its aetiological factors
and pathological outcomes, is no more a physiological condition. The
proper management protocol is needed.