Cry analysis in infants with Rh haemolytic disease
Authors: Koivisto Maila 
Published: February 2018

Koivisto, M. (Department of Paediatrics, University of Oulu, Oulu, Finland) Cry analysis in infants with Rh haemolytic disease. Acta Paediatr Scand 1987; Suppl. 335: 1–73.

The influence of hyperbilirubinaemia on the infants' cries and the feasibility of the use of cry analysis for the early identification of developing kernicterus were studied by analyzing the cries of 100 healthy one‐day‐old infants and 31 infants with Rh haemolytic disease of the newborn (Rh‐HDN) by using sound spectrographic methods. The newborn infants with RhHDN were divided into three subgroups according to the findings in a neurological examination: an evident group (10 infants), a transient group (13 infants) and an asymptomatic group (8 infants) and followed up until one year of age.

Cry recording and a neurological examination were carried out once for each of the healthy one‐day‐old infants and twice a day during the first week of life for the infants with Rh‐HDN, and thereafter once a day until discharged and at the ages of 1 and 3 months. Additional neurological examinations were performed on the Rh‐HDN infants at the ages of 6 and 12 months. Bilirubin determination was carried out in connection with the cry recordings during the first week of life. The effect of blood exchange transfusion on the cry sound was investigated in infants with a bilirubin level above 250 µmol/l (n = 12) and below this level (n = 15) before the procedure. An electroencephalography (EEG) was recorded once during the neonatal period and once during the follow‐up.

The cries of the healthy infants were used to develop a cry score comprising 16 characteristics (latency. duration of phonation, maximum and minimum pitch of fundamental frequency, occurrence and maximum pitch of shift, glide, melody form, biphonation, fureation, noise concentration, voice quality, double harmonic break, glottal plosives, vibrato and glottal roll), which was then applied to the analysis of the cries of the 31 infants with Rh‐HDN. In addition, maximum pitch of fundamental frequency, furcation and combination of biphonation and lor furcation were studied.

The cry score and maximum pitch of fundamental frequency increased most obviously in the infants in the evident group as compared with the values after birth in the various subgroups and with the values of the healthy one‐day‐old infants or the infants in the asymptomatic group day by day. Both parameters also increased in the asymptomatic group between days 2 and 3 as compared with the initial value after birth and with the healthy infants.

Neither the cry score nor maximum pitch of fundamental frequency seemed to depend on the plasma bilirubin value itself, but both increased in conjunction with neurological symptoms even at an early stage.

Furcation occurred once or more in all the infants in the evident group, in 4 out of the 13 in the transient group, but none of those in the asymptomatic group. Biphonation often occurred at the same time as furcation, although more frequently. Biphonation was observed in 9 out of the 10 infants in the evident aroup, 6 out of the 13 in the transient group and once in one infant in the asymptomatic group. Both furcation and biphonation occurred in the majority of infants on or after the appearance of neurological symptoms.

Blood exchange transfusion did not affect the cry score within the next six hours.

The EEG was normal in 11 out of 30 infants (from one infant EEG was not taken), 6 had a borderline finding and 13 were interpreted as pathological. Infants with an abnormal EEG had a higher cry score at the time than the infants with a normal EEG, but furcation and the combination of biphonation and/or furcation had no correlation with the EEG findings.

Two infants out of 30 (one infant died, probably of kernicterus) showed neurological symptoms on discharge from the neonatal ward and 10 exhibited signs of neurological abnormality during the follow‐up period of a year, but only 2 continued to do so at the age of one year. A cry score of 5 or more on discharge was associated with abnormal neurological development during the first year of life.

On the basis of the results it can be suggested that crying is labile during the first few days of life even in symptomless infants. The plasma bilirubin value itself has no influence on crying, but cry changes are noted in infants with hyperbilirubinaemia in connection with neurological symptoms. Furcation seems to be an early sign of developing kernicterus. An abnormal cry after a hyperbilirubinaemic period seems to be associated with abnormal neurological development during the first year of life.