OBJECTIVE

To describe the labor curve and the dilation-time ratio of the first stage of labor in a group of patients of the Hospital de Ginecoobstetricia Luis Castelazo Ayala.

MATERIALS AND METHODS

A retrospective and descriptive study with 370 healthy pregnancy primiparous patients between 37 and 41 gestation weeks admitted in the Obstetrics & Gynecology Hospital "Luis Castelazo Ayala" of the Mexican Social Security Institute. All patients were attended of eutocic delivery without any complication. We reviewed the partogram and the progression of cervical dilation on the first stage of labor. By observing the relationship between time and cervical dilation we described we elaborate a labor curve.

RESULTS

Labor in its entirety lasted on average 862 minutes (14 hours and 12 minutes). The delivery labor curve graphed was a slope upward curve, with an acceleration phase from 4 centimeters dilated, from that moment the duration of labor average was 234 minutes (3 hours and 54 minutes), with a dilating pattern of 0.4-0.7 cm / h.

CONCLUSION

The curve of the first stage of labor we studied has an upslope pattern, with an increased acceleration from 4 centimeters of dilation. Our curve differs from the classical sigmoid curve care delivery Dr. Friedman in their basic morphology, however both curves agree that labor enters its active phase in the 4 centimeters of dilation.