Iyenni Yosita, M. Lutfi Alkaff, Risanto Siswosudarmo
Department of Obstetrics and Gynecology
Faculty of Medicine Universitas Gadjah Mada/Sardjito Hospital
Yogyakarta
ABSTRACT
Background: Estimated fetal weight (EFW) is one of the most important thing to determine the mode of delivery, especially in breech fetus. Ultrasonography (USG) has been used widely to estimate fetal birth weight because of its high accuracy. Many of health workers, however, are not familiar with such instrument, and it requires training and skills for people whooperate. In addition to this, USG is a tool that was relatively expensive and may not be available in all health centers, especially in rural areas. For that reason, another method which is simple, easy to do, inexpensive and accurate for determining EFW in breech fetus is needed.
Objective: To determine whether Risanto’s formula is accurate and can be used as an alternative method to estimate fetal weight in breech fetus.
Methods: This was an observational study comparing the estimated fetal weight using Risanto’s formula (R_EFW) and the actual birth weight (ABW). A total of 400 pregnant women with singelton breech presentation, fullterm pregnancy, were recruited. Abdominal pregnancy, poly or oligohydramnios, major congenital anomalies, pregnancy with intraabdominal mass were excluded. Symphysis fundal height (SFH) was measured from the upper edge of the pubic symphysis to the uterine fundus. The measurement was performed using a non-elastic measuring tape in a reversed position. R_EFW was calculated based on the Risanto’s formula, i.e. birth weight (in gram) = 125 x fundal height (cm) – 880. Statistical analysis was done using paired T-test.
Result: The mean age of the women was 29.75 ± 5.88 years. Multiparity was 63.2%, 97% of subjects had their gestational age ranged from 37-41 weeks. Mean SFH was 30.41 ± 2.69 cm (varies from 24-40 cm). The mean R_EFW was 2920.78 ± 335.73 grams (varies from 2120-4120 grams), while the mean ABW was 2929.92 ± 397.00 grams (varies from 1900-4550grams). The difference between the mean R_EFW and ABW was 9.15 grams (95% CI: -8.49, 26.78 and P=0.31) meaning that the R_EFW and ABW was not statistically different. It was also shown that 91.7% of the R_EFW lies between 100 ± 10% (90 to 110%) of the ABW.
Conclusion: Risanto’s formula is accurate and can be used to estimate the fetal weight in breech fetus.
Keywords: Risanto’s formula – breech presentation – symphysis fundal height – estimated fetal weight.