TRANSVAGINAL SONOGRAPHY OF THE FOREWATERS IN THE ASSESSMENT OF AMNIOTIC-FLUID VOLUME IN PATIENTS WITH OLIGOHYDRAMNIOS

Objective: To determine whether the forewaters should be considered in the assessment of amniotic fluid (AF) volume in patients beyond 37 we eks' gestation. Methods: Sixty patients were prospectively studied and designated as having oligohydramnios or normal AF volume based upon o n the standard four-quadrant AF index (AFI) of less than or equal to 5 cm or >5 cm, respectively. The distance between the internal os and t he fetal head was measured transvaginally. This measurement was first added to the standard AFI and subsequently interchanged with the lowes t of the two lower abdominal quadrant measurements. Statistical analys is included Student's t-test with p < 0.05 considered significant. Res ults: Thirty patients were classified as oligohydramnios and 30 normal AF volume. The two subgroups did not differ as to maternal age, parit y, gestational age at sonographic examination, incidence of meconium-s tained amniotic fluid or 5-min Apgar scores <7, or birth weight. No si gnificant difference was noted between the mean forewaters measurement of patients with oligohydramnios and controls (0.2 +/- 0.1 and 0.4 +/ - 0.1 cm, respectively). In patients with oligohydramnios, there was n o significant difference between the standard AFI and the AF volume wi th the forewaters in each of the methods assessed (2.7 +/- 0.3, 2.9 +/ - 0.3, and 2.7 +/- 0.3 cm, respectively). Conclusion: We conclude that various permutations of the AFI, which include sonographic assessment of the forewaters, do not impact on the diagnosis of oligohydramnios.