Sonographic evaluation of uterine cervical dimension within 4-24 weeks of pregnancy

To determine the normal range of uterine cervix within 4-24 weeks of pregnancy and also assess whether variations are related to some selected extraneous human conditions.

This was a prospective study conducted in University of Benin Teaching Hospital, Benin, Nigeria, and Nigerian National Petroleum Cooperation Health Centre, Warri, Nigeria.

A prospective ultrasonographic (USS) study of uterine cervical dimension of 150 pregnant women within 4-24 weeks gestational age in two sonographic centers in Nigeria between January 2007 and October 2007 was conducted. The patients were examined by the authors. The uterine cervical dimensions (length, upper lip diameter, and lower lip diameter) were taken by means of ultrasonography. In addition, vital history, height and weight of patients were documented. The vital history included the age, number of childbirths, number of induced abortion, miscarriages and family history of miscarriages. Using Statistical program of social science (SPSS), the data were analyzed. Informed consent was obtained from all the patients and the study was done in line with the ethical guidelines of the centers.

The following uterine cervical dimensions were obtained: mean cervical length of 6.14 cm and standard deviation of 2.0, and the upper and lower lips' uterine cervical diameters of 1.81 and 1.76 cm, respectively, with standard deviations of 0.86 and 0.71, respectively. There was no significant correlation of dimensions of uterine cervix to the aforementioned extraneous human condition. However, the increasing number of miscarriages correlated with decreasing length or shortness of the cervix.

Uterine cervical dimension in pregnancy between 4 and 24 weeks is reproducible with sonographic documentation and the following normal ranges were deduced: cervical length (6.14 ± 2.0 cm), upper lip (1.81 ± 0.86 cm) and lower lip (1.76 ± 0.71 cm). The study revealed that increasing number of miscarriages was associated with effacement or reduction in the cervical length.