Читать книгу Protocols for High-Risk Pregnancies - Группа авторов - Страница 86

Modified BPP is a commonly employed primary mode of fetal surveillance in many institutions. It takes into consideration the two most important predictors of fetal well‐being – fetal heart rate reactivity and amniotic fluid volume. The NST is an excellent predictor of normal fetal oxygenation when reactive. The amniotic fluid assessment is a means to evaluate the chronic uteroplacental function. The NST is performed in the usual manner and interpreted as previously defined. An amniotic fluid index is obtained as in the BPP and a value of greater than 5 is considered to represent a normal amount of amniotic fluid. The combination of the NST and ultrasonographic evaluation of amniotic fluid volume appears to be as reliable as BPP in acutely assessing fetal well‐being, with a very low incidence of false negativity. Indeed, the rate of stillbirth within one week of a normal modified BPP is the same as a normal BPP (0.8 per 1000).

Consequently, the modified BPP is reliable, easy to perform and can be utilized as a primary means of surveillance. The testing frequency should be at least once per week. In a setting of an AFI of less than 8 but greater than 5, a repeat evaluation of the amniotic fluid is recommended within 3–4 days.