Correlation of the umbilical cord coiling pattern and fetal outcome: A single-center observational analytical study

The umbilical cord (UC) anatomically embodies the feto-placental bridge with a major role in fetal development due to the vascular structures embedded in Wharthon's jelly. The helical coiling of the umbilical cord may be counterclockwise, viewed from the fetus, defined as sinistral coiling, while the opposite as dextral coiling. This study aimed to determine any associations between UC coiling patterns and medical disorders of pregnancy.

An observational analytical study was conducted at the Clinical Emergency Hospital of Targu-Mures, Romania between January 2023-December 2023. Consecutive singleton placentas with attached UC submitted to the Pathology Department for various feto-maternal conditions were considered for appropriate measurements. The coiling number and direction (sinistral or dextral) of the umbilical cord were assessed per first 10 cm measured at the placental end.

Of 187 cases this study included, 57.21 % (97) had sinistral and 42.79 % (90) had dextral UC coiling. The minimum and maximum maternal age group was 12-44 years old. Sinistral UC coiling was associated with an increased risk of spontaneous abortion and stillbirth (25.77 %, p = 0.028). Sinistral coiling was also associated with extreme prematurity (p = 0.013), smaller birth weight (p = 0.040) and lower placental weight (p = 0.029). A lower 1 min (p = 0.045) and 5 min Apgar score (p = 0.017) were associated with sinistral coiling. No relevant risk of premature rupture of membranes (PROM) was observed (p = 0.324). No significant association of sinistral coiling and metabolic or blood-related maternal diseases was observed (p = 0.385 and p = 0.725).

According to the literature approximately 25 % of all pregnancies have a dextral UC coiling direction. In contrast, in our study a significantly higher percentage was found (slightly higher than 42 %) to have dextral coiling of the UC. Data from our selected group indicated that certain neonatal pathologies (extreme prematurity, stillbirth, smaller birth weight, and lower Apgar score) were more associated with sinistral coiling as compared to dextral. More extensive studies are necessary to ascertain the clinical relevance of these data, particularly concerning high-risk pregnancies.