Which of the following statements regarding monitoring of fetal heart rate (FHR) is true? (LQ)
|A||A sinusoidal FHR pattern is almost invariably associated with an anemic, asphyxiated fetus|
|B||A saltatory FHR pattern is almost invariable seen during rather than before labor|
|C||The FHR tracing of the premature fetus should be analyzed by different criteria than tracings obtained at term|
|D||Fetuses with congenital anomalies will invariably exhibit abnormal FHR patterns|
A saltatory FHR pattern is almost invariable seen during rather than before labor
i. The sinusoidal pattern was first described in a group of severely affected Rh-isoimmunized fetuses. It has also been described, however, in normal fetuses and in association with maternal medication (e.g., alphaprodine).
ii. A saltatory pattern, which in the past was associated with depressed fetuses with low Apgar scores, is now thought to represent episodes of brief and acute hypoxia in the previously normally oxygenated fetus.
iii. This pattern is almost invariably seen during rather than before labor.
b. The same relationship between the FHR pattern and the acid-base status has been documented in preterm and term fetuses.
i. Thus, both the antepartum and the intrapartum FHR patterns of the premature fetus should be analyzed by the same criteria used at term.
ii. The vast majority of fetuses with congenital anomalies have normal FHR patterns and a response to asphyxia similar to that of the normal fetus.
iii. Although no pathognomonic abnormal FHR patterns have been described for such fetuses, the rate of cesarean sections for fetal distress is reported to be significantly increased in this group.
iv. This maybe explained by the oligo hydramnios and fetal growth retardation that commonly occur in pregnancies affected by fetal congenital anomalies.