Comparison of Fetal Behavior in Single and Twin Pregnancies with the use of KANET Test
1Department of Infertility and IVF, Clinic “Korak do Života,” Prve Inžinjerijske Brigade bb, Tuzla, Bosnia and Herzegovina
2University Clinical Center Tuzla, Tuzla, Bosnia and Herzegovina
3The University of Sarajevo School of Science and Technology (SSST), Sarajevo Medical School, Hrasnicka cesta 3a, Sarajevo Bosnia and Herzegovina
Corresponding Author: Suada Tinjić, Department of Infertility and IVF, Clinic “Korak do Života,” Prve Inžinjerijske brigade bb Tuzla, Bosnia and Herzegovina, Phone: +38762424837, e-mail: firstname.lastname@example.org
Received on: 17 December 2022; Accepted on: 12 January 2023; Published on: 14 April 2023
Aim: According to the results of the Kurjak antenatal neurodevelopmental test (KANET) in comparison of fetal behavior in single and twin pregnancies with the use of KANET test.
Materials and methods: Between May 2015 and December 2019, 66 low-risk single pregnancies were assessed with KANET, along with eight twin pregnancies between 28 and 38 weeks of gestation.
Results: Out of 66 patients with single pregnancies, 64.02 (97%) had a normal KANET score, and 1.8 (3%) of them had a borderline KANET score. Out of eight patients with twin pregnancies, 7.84 (98%) had a normal KANET score and 0.16 (2%) of them had a borderline KANET score.
Conclusion: Our data suggest that twins show different types of motility than singletons at the same gestational age. The difference in the number of normal, borderline, and abnormal KANET scores between singletons and twins was not statistically significant, although the differences were found in certain parameters of the test between singletons and twins. It could be concluded that movements in twins become more complex and occur more frequently with increasing gestational age.
How to cite this article: Tinjić S, Nevačinović E, Tinjić S. Comparison of Fetal Behavior in Single and Twin Pregnancies with the use of KANET Test. Donald School J Ultrasound Obstet Gynecol 2023;17(1):88-90.
Source of support: Nil
Conflict of interest: None
Keywords: Fetal behavior, Four-dimensional ultrasound, General movements, Growth and development, Twin pregnancies.
This paper was presented at the symposium Zagreb-New York Ethical and Perinatal Dialogue (1st International Symposium When does human life begin? Ethics, law, and professionalism in reproductive medicine; and fetal neurology—from short to the long-term follow-up—how to proceed? Multicenter results on the clinical use of KANET, held on 8–9th October 2022 in Zagreb, Croatia.
The assessment of fetal behavior using four-dimensional ultrasound (4D US) indirectly monitors the maturation and staged development of the central nervous system (CNS).1 Behavior is the attribute of a functional CNS. Fetal expressions may offer insight into the function and development of the fetal brain in the second half of pregnancy.2 These expressions reflect the maturation and development of different parts of the CNS controlling these actions.3,4
The 4D US assessment of fetal behavior and facial expressions, as well as studying the usefulness of the KANET, represent a diagnostic criterion for prenatal brain injury and may be a useful diagnostic method when predicting postnatal developmental disabilities.1,3,5
Multiple pregnancies are high-risk pregnancies due to many risk factors which can adversely affect pregnant women, fetuses, and the newborn.4,6,7 The main issues that affect neonatal outcomes of multifetal pregnancies include preterm delivery, low birth weight, and intrauterine growth retardation. In 2006 in the United States of America, 11% of singletons were premature (<37 weeks gestation), while 61% of multiples were premature, combining for a total preterm delivery rate of 12%.8 Low birth weight rate was 6% in singletons and 59% in multiples, with a total low birth rate of 8%.8 The percentage of very low birth weight neonates (birth weight below 1500 gm) was 1% in the whole population of newborns, while it was 11% in multiples.4,8 The risk for cerebral palsy (CP), the most common lifetime neurodevelopmental disability in childhood, increases with decreasing gestational age and birth weight. Twin pregnancies are associated with increased risk of CP not only because of increased prematurity rate but also due to vanishing twin phenomenon). The prevalence of CP among twins is 7.4%, while in singletons, it is estimated to be 2–3/1000 live borns.9 The prevalence of CP in triplets and quadruplets is increasing exponentially with the number of fetuses.4,9 The highest difference in the incidence of CP between singleton and twin births was at gestational age of 37 weeks and more.9 Thus, early detection of neurological impairment might be of some significance from the obstetrical point of view.4
The aim of the KANET test is to evaluate the motional activity of the fetus and thus monitor the neurological development of the fetus.
The importance of KANET in detecting twin fetuses who might be at risk for neurological problems was the study’s main objective.
To compare the results between the singleton and twin pregnancy groups.
MATERIALS AND METHODS
In the period from May 2015 to December 2019, KANET was administered to 66 pregnancies in a single pregnancy with low risk and eight twin pregnancies between 28 and 38 weeks of pregnancy. The gestational age estimated for the 1st day of the last menstruation was confirmed by US evaluation. Fetal behavior was estimated using 4D US Voluson E6 and S10 with a 5 MHz volumetric transabdominal probe. It was performed by one doctor. All pregnant women have signed informed consent to the study. The trial was conducted in the private gynecological clinic “Korak do Života” in Tuzla, Bosnia and Herzegovina.
Two requirements for inclusion were the existence of a viable twin pregnancy and the absence of a significant size difference between the twins as verified by US.
Family history: A previous child with CP.
Personal pregnancy history: Diabetes mellitus type 1 and 2, hypertension, drug abuse, thrombophilia, anemia, infection during pregnancy, and first pregnancy after 35 years.
Pregnancy disorders: Polyhydramnios, premature births, intrauterine infections, and viral diseases.
Fetal state: Intrauterine growth restriction, abnormal cardiotocography, biophysical profile, and Doppler.
After detailed two-dimensional measurements of fetal growth and examination of the placenta and amniotic fluid, mothers were offered fetal behavior estimation using the KANET scoring system using 4D US. The study was conducted while the fetuses were awake.
The maximum viewing time is 30 minutes. KANET borderline results were repeated in 2 weeks until birth. Patients with an abnormal outcome of KANET were hospitalized due to intensive monitoring of pregnancy, time planning, and termination of pregnancy by birth.
In this prospective longitudinal study, KANET was administered to 66 pregnancies in single pregnancies between 28 and 38 weeks of gestation. In the twin pregnancy group, there were eight pregnant women, all of them diamniotic and dichorionic. Five of the pairs were spontaneous, while the remaining three pregnancies were achieved by assisted reproductive techniques. Out of 66 patients with single pregnancies, 64.02 (97%) had a normal KANET score, and 1.8 (3%) of them had a borderline KANET score (Fig. 1). Out of eight patients with twin pregnancies, 7.84 (98%) had a normal KANET score and 0.16 (2%) of them had borderline KANET score (Fig. 2). The distribution of fetuses from singleton and twin pregnancies belonging to the normal, borderline, and abnormal KANET groups is presented and was not statistically significant (Table 1). KANET score between the two groups of fetuses is presented in Table 2, which suggests that the twins are showing different behavioral patterns than singletons. Scoring of the following KANET parameters between twins and singletons differed significantly for—isolated eye blinking, mouthing, grimacing, hand-to-head movement, finger movements, gestalt perception, and general movements.
|Group||Number of examinees (N)||Normal||Borderline||Abnormal|
|Singleton||66||64.02 (97%)||1.8 (2%)||0 (0%)|
|Twin||8||7.84 (98%)||0.16 (2%)||0 (0%)|
|Kanet Parameter||Group||Kanet score|
|Isolated head anteflexion||Singleton twins||0||1||2|
|Cranial sutures and head circumference||Singleton twins||0||0||66|
|Isolated eye blinking and grimacing and mouthing||Singleton twins||0||1||65|
|Isolated hand movements||Singleton twins||0||2||64|
|Hand-to-head movement||Singleton twins||0||2||64|
|Isolated leg movement||Singleton twins||0||3||63|
|Finger movements||Singleton twins||0||0||66|
Our data suggests that twins show different types of motility than singletons at the same gestational age. The difference in the number of normal, borderline, and abnormal KANET scores between singletons and twins was not statistically significant, although the differences were found in certain parameters of the test between singletons and twins. It could be concluded that movements in twins become more complex and occur more frequently with increasing gestational age.
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