Diagnosis of placenta previa during the third trimester: role of transperineal sonography.

Department of Radiology, Duke University Medical Center, Durham, NC 27710.
American Journal of Roentgenology (Impact Factor: 2.9). 08/1992; 159(1):83-7.
Source: PubMed

ABSTRACT Placenta previa can be difficult to diagnose with transabdominal sonography during the third trimester of pregnancy, because of difficulties in imaging the cervix late in pregnancy. Although transperineal sonography offers an additional view of the cervix, its value in the diagnosis of placenta previa has not been studied. Accordingly, we performed transperineal sonography on 164 patients who had had transabdominal scans that had shown placenta previa or had been inconclusive during the third trimester of pregnancy. Transabdominal sonograms had been inconclusive for placenta previa in 157 of these patients because the cervix was not visualized. The remaining seven patients had transabdominal scans that showed placenta previa. Transperineal sonography successfully visualized the internal surface of the cervix in all 164 patients, allowing determination of the presence or absence of placenta previa in all cases. Transperineal sonograms showed absence of placenta previa in 154 patients. At delivery, none of these patients had evidence of placenta previa. Transperineal sonography showed placenta previa in 10 patients. In nine of these patients, placenta previa was confirmed at delivery. The 10th patient did not have clinically significant placenta previa at delivery. Our study shows that transperineal sonography is a valuable technique to complement transabdominal sonography for detection of placenta previa during the third trimester of pregnancy. Use of transperineal sonography should be strongly considered when a definitive diagnosis regarding placenta previa is not possible by transabdominal sonography because the cervix is not visualized. In such cases, transperineal sonography will usually show the internal surface of the cervix without overlying placental tissue, allowing confident exclusion of placenta previa. Occasionally, however, transperineal sonography will show a placenta previa that was not seen with transabdominal sonography.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Most complications of pregnancy allow time for transfer to specialized obstetric ultrasound units, but many women present to the emergency room or the labor and delivery unit with signs and symptoms suggesting genuine acute medical emergencies, where successful outcome depends on prompt diagnosis of the disorder and rapid appropriate medical management. The use of ultrasound technology in obstetric emergencies is well established. Ultrasonography plays a major role in such cases as the most important tool clinicians are using to identify the correct etiology and diagnosis, whereas in other cases it helps limit the differential diagnosis. One of the goals of any advanced training program in obstetrics and gynecology and radiology is to allow the skilled physician to perform the proper ultrasound study in case of an obstetric emergency to facilitate the proper diagnosis, enabling the medical team to provide the best possible care.
    Radiologic Clinics of North America 04/2004; 42(2):315-27. · 1.95 Impact Factor
  • Ultrasound Clinics. 01/2006; 1(2):303-319.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Antepartum haemorrhage is defined as bleeding from the genital tract from 24weeks of gestation onwards. The incidence is around 2–5% of all pregnancies progressing beyond 24weeks. Placenta praevia and placental abruption are of great clinical importance as causes of antepartum haemorrhage. Placenta praevia occurs when the placenta is totally or partly inserted in the lower uterine segment. The aetiology of placenta praevia may merely represent an accident of nature but is associated with advanced maternal age, multiparity and previous uterine damage such as in a previous caesarean section. Usually, the initial bleed is painless and mild, but it may be severe. Screening and diagnosis are normally by ultrasound. A dilemma exists as to whether hospitalisation should be offered to women with an asymptomatic placenta praevia. Caesarean section is the recommended mode of delivery for major placenta praevia. Haemorrhage arising from premature separation of a normally situated placenta is known as abruptio placentae. Risk factors include placental abruption in a previous pregnancy, pre-eclampsia, cigarette smoking, and trauma. The patient typically develops pain over the uterus, and this may not be associated with apparent bleeding at first. The diagnosis is mainly clinical and confirmed by the demonstration of a retroplacental clot after delivery. In the obvious case of abruption, early delivery is of crucial importance. If the baby is still alive and the gestation compatible with survival upon delivery, it is recommended that urgent caesarean section should be performed. However, if the fetus is dead, one should expedite vaginal delivery. Complications of antepartum haemorrhage include maternal shock, especially due to the increased risk of postpartum bleeding. There is a greater risk of premature delivery, fetal hypoxia and sudden fetal death.
    European Clinics in Obstetrics and Gynaecology 01/2006; 2(3):121-127.


Available from