Second-trimester sonographic comparison of the lower uterine segment in pregnant women with and without a previous cesarean delivery

OBJECTIVE

To compare measurements of the lower uterine segment during a second-trimester sonographic examination in women with and without a previous cesarean delivery.

METHODS

Women undergoing second-trimester sonographic examination, 24 with a history of cesarean delivery and 30 control subjects with no history of cesarean delivery, were recruited for transvaginal sonographic evaluation of the lower uterine segment with a high-frequency probe. The uterine niche or previous cesarean scar site was defined as a small triangular anechoic defect in the anterior wall of the uterus. The uterine wall thickness was measured successively at the level where the bladder dome meets the lower uterine segment. Measurements were obtained with cursors at the interface of the urine-bladder and the amniotic fluid-decidua. The study was approved by the Institutional Review Board, and P < .05 was considered significant.

RESULTS

The uterine niche was identified in 14 (58%) of 24 women with a previous cesarean delivery. The lower uterine segment was significantly thinner in women with a previous cesarean delivery compared with control subjects (mean +/- SD, 4.7 +/- 1.1 versus 6.6 +/- 2.0 mm; P < .001). In the previous cesarean group, the mean lower uterine segment thickness was similar in the 5 women with 2 cesarean deliveries when compared with those with 1 cesarean delivery (4.6 +/- 1.0 versus 4.7 +/- 1.4 mm; P = .91). In a linear regression model, the only variable retaining significance in the prediction of uterine wall thickness was previous cesarean delivery (P= .002). Maternal age, parity, number of previous cesarean deliveries, and gestational age did not attain significance in the model.

CONCLUSIONS

The lower uterine segment during a second-trimester sonographic examination is significantly thinner in women with a previous cesarean delivery. Identification of the scar niche is possible in most of these women.

Doppler ultrasound of the uterine artery in the prediction of severe complications during low-risk pregnancies

AIM

The aim of this prospective study was to assess the role of uterine artery colour Doppler waveform analysis in the prediction of adverse pregnancy outcome such as preeclampsia, intrauterine growth retardation, placental abruption or a combination of outcome parameters.

METHODS

Various uterine artery Doppler ultrasound parameters (RI>0.58, RI>0.7 and unilateral or bilateral notching) were tested. A second objective was to compare the predictive power of uterine artery Doppler ultrasound at 19-22 gestational weeks and 23-26 weeks' gestation for an adverse pregnancy outcome.

RESULTS

The mean time of delivery was 39+0 weeks of gestation. Eight newborns (2%) were delivered before 34 weeks of gestation. The mean birth weight was 3,240 g. Dystrophic fetuses (<10% percentile) were registered in 35 cases (10%). In 31 of the 346 women (9%) a cesarean section was performed because of abnormal fetal heart recording. Preeclampsia was diagnosed in 17 cases (5%). In 5 cases (1.4%) a placental abruption and 2 (0.6%) intrauterine fetal deaths were diagnosed. The sensitivity of notching for the prediction of preeclampsia was 88% and for the prediction of a severe pregnancy complication (preeclampsia and/or intrauterine growth retardation and/or intrauterine fetal death and/or placental abruption) at any gestational age was 62% with relative risks of 9.7 and 2.2, respectively. The sensitivity of notching for severe pregnancy complications requiring delivery before 34 weeks was 64% with a relative risk of 2.4. The sensitivity of notching in the uterine arteries for developing an IUGR was 56% with a relative risk of 1.7.

CONCLUSION

The predictive value of uterine artery Doppler for adverse pregnancy outcome in a low-risk population is of limited diagnostic value. Performing uterine artery Doppler studies at 23-26 weeks' gestation instead of 19-22 weeks' gestation increases the predictive value for adverse pregnancy outcomes.

Second trimester Doppler ultrasound screening of the uterine arteries differentiates between subsequent normal and poor outcomes of hypertensive pregnancy: two different pathophysiological entities?

The 'classical' concept that pregnancy-induced hypertension (PIH) and pre-eclampsia (PE) primarily originate from defective placentation in early pregnancy has been challenged recently. There is growing evidence that other factors, including maternal predisposing conditions, also play a significant role in the pathophysiology of PIH and PE. The aim of the present study was to test the hypothesis that PIH and PE with an early onset and poor pregnancy outcome is associated with defective placentation, e.g. inadequate spiral artery dilatation and subsequent reduced uteroplacental perfusion, whereas PIH and PE with normal pregnancy outcome is not. Using Doppler ultrasound, we measured the uterine artery pulsatility index (PI) in a population of 531 nulliparous women in the 22nd week of gestation. Uterine artery PI was used as an index of resistance to blood flow in the uteroplacental circulation. Outcome measures were PIH/PE with or without poor pregnancy outcome, preterm birth and intra-uterine growth restriction (IUGR). The results revealed a striking difference between PI values for PIH/PE with and without poor pregnancy outcome. Uterine artery PI in the 22nd week was increased significantly in pregnancies which developed early-onset (before 35 weeks) PIH/PE with a poor pregnancy outcome. In contrast, uterine artery PI values were normal in women who developed PIH/PE, but had a good pregnancy outcome. There was a significant correlation between 22nd week uterine artery PI and subsequent preterm birth or IUGR. Our results indicate that only PIH/PE with poor pregnancy outcome is associated with defective placentation, whereas PIH/PE with good outcome is not. These findings support the concept of heterogeneous causes of hypertensive disorders of pregnancy.

The value of uterine artery Doppler ultrasound in the prediction of severe complications in a risk population

AIM

The aim of this prospective study was to assess the role of uterine artery color Doppler waveform analysis in the prediction of adverse pregnancy outcome such as preeclampsia, intrauterine growth retardation, placental abruption or a combination of outcome parameters in risk pregnancies (n=52).

METHODS

Various uterine artery Doppler ultrasound parameters (resistance index (RI)>0.58, RI>0.7 and uni/bilateral or bilateral notching) were tested. The mean time of delivery was 37+1 weeks' gestation. Six newborns (12%) were delivered before 34 weeks of gestation. The mean birth weight was 2,910 g. Dystrophic fetuses (<10% percentile) were registered in 7 cases (13%). In 11 of the 52 women (21%) a cesarean section was performed because of abnormal fetal heart recording.

RESULTS

Preeclampsia was diagnosed in 4 cases (8%). In 4 cases (8%) an intrauterine fetal death was diagnosed. Placental abruption did not occur. The sensitivity of notching for the prediction of preeclampsia and for the prediction of a severe pregnancy complication was 75 and 69% with relative risks of 2.7 and 2.0. The sensitivity of notching in the uterine arteries for developing an intrauterine growth retardation (IUGR) was 71% with a relative risk of 2.2. The sensitivity of RI>0.58 in the uterine arteries for developing an IUGR was 67% with a relative risk of 5.4. The sensitivity of RI>0.58 for the prediction of preeclampsia, of intrauterine death and for the prediction of a severe pregnancy complication was 50, 75 and 80% with relative risks of 2.7, 8.1 and 10.9 respectively.

CONCLUSION

The results of this study suggest that Doppler ultrasound of the uterine artery in the second trimester of gestation is a useful method to predict abnormal outcomes in risk pregnancies, with high negative predictive values.

Accuracy of diagnosis of retained products of conception after dilation and evacuation

OBJECTIVE

Uterine re-evacuation samples taken in cases of suspected residua after curettage are occasionally negative for gestational tissue. We aimed at evaluating the occurrence of such postcurettage re-evacuation-negative samples and at exploring factors that may influence their occurrence.

METHODS

This was a cross-sectional comparative retrospective study of 69 consecutive women who underwent uterine re-evacuation for suspected postcurettage gestational remnants. Pathologic reports of samples drawn during re-evacuations were reviewed to determine whether the extracted tissue contained gestational tissue. The presence of factors that may influence the rate of a positive or negative sample (eg, sonographic findings, gestational age at initial procedure, and presenting symptom) was noted and compared between women with and without histologically verified remnants.

RESULTS

Twenty-eight (41%) of the re-evacuation samples were histopathologically positive for gestational remnants. Residual tissue was more commonly found when the initial evacuation was performed at a more advanced gestational age (> 15 weeks). Women referred by emergency department attendants had significantly fewer positive samples. Normal expert sonographic examination practically excluded yielding samples. Conversely, no negative samples were preceded by sonographic reports mentioning residua.

CONCLUSIONS

Most re-evacuation samples taken during a re-evacuation procedure for suspected residua are negative for gestational tissue. Parameters that are likely related to histologically confirmed gestational residual tissue are advanced gestational age at initial evacuation, level of the sonographer's skill, persistent bleeding as the presenting symptom, and a sonographic report specifically mentioning retained gestational tissue.

Infertility due to intrauterine residual fetal bone fragments

A case of intrauterine retention of fetal bone diagnosed 8 years after termination of a pregnancy is presented. The patient had a history of hypermenorrhea infertility, and persistent vaginal discharge beginning after the abortion. Transvaginal sonography demonstrated an intrauterine foreign body. Curettage was performed, and fetal bone fragments were found within the removed materials.

Reduced antioxidant capacity in second-trimester pregnancies with pathological uterine perfusion

OBJECTIVES

To examine whether pathological perfusion in the second trimester is characterized by an altered plasma antioxidant capacity and to investigate whether the total antioxidant capacity in maternal plasma is related to the clinical outcome of these high-risk pregnancies.

METHODS

This was a prospective cohort study that included 25 pregnancies with normal and 25 pregnancies with pathological uterine perfusion. Doppler ultrasound measurement of uterine perfusion was performed between 18 and 23 weeks of gestation. Total antioxidant capacity in maternal plasma was measured using a specific photometric assay.

RESULTS

Plasma antioxidant capacity of pregnant women with pathological uterine perfusion (227.3 +/- 4.0 micro mol/L) was significantly lower compared with the group with normal uterine perfusion (275.2 +/- 10.5 micro mol/L; P < 0.05). There was a significant negative correlation between antioxidant capacity and mean pulsatility index of the uterine arteries (r = -0.363; P < 0.05). Patients with pathological perfusion and a normal course of pregnancy did not show significantly changed values compared with those patients with later pre-eclampsia or intrauterine growth restriction (235.0 +/- 4.9 micro mol/L vs. 218.6 +/- 6.7 micro mol/L).

CONCLUSIONS

Second-trimester pregnancies with pathological uterine perfusion are characterized by a decreased antioxidant capacity in maternal plasma. This reduction is related to the impaired uteroplacental blood flow, but does not reflect the changes characteristic of the oxidative status for diseases like pre-eclampsia since the reduction of the plasma antioxidant capacity is not related to the clinical outcome of these high-risk pregnancies.

Sonographic imaging of cervical scars after Cesarean section

OBJECTIVE

To investigate whether uterine contractions at the time of a Cesarean section have an impact on future presence and location of a cervical Cesarean scar.

METHODS

A targeted transvaginal ultrasound examination of the fetus, uterus and cervix was done in 2973 consecutive women at 14-16 weeks' gestation. The sonographer was blinded to the women's previous obstetric histories. The presence and location of a sonographic cervical hypoechogenic line, which probably represented a Cesarean scar, was recorded.

RESULTS

There were 180 women with a previous Cesarean section performed before the start of uterine contractions and 173 with a Cesarean section performed during contractions in labor. The cervical hypoechogenic line was more common in sections performed during contractions (75.7% vs. 52.7%; P < 0.001) and was more distally located from the internal os (17.9 +/- 9.4 vs. 14.6 +/- 9.1 mm; P = 0.01). A hypoechogenic line was observed in 21/2620 women without a previous Cesarean section, representing a false-positive rate of 0.8%.

CONCLUSION

Cesarean sections, especially those done during uterine contractions, are actually performed through cervical tissue. This finding is in agreement with the physiological process of cervical effacement during contractions.

Hormone therapy and ophthalmic artery blood flow changes in women with primary open-angle glaucoma

OBJECTIVE

To compare the effects of hormone therapy (HT) on plasma viscosity and Doppler flow parameters in normal, healthy, postmenopausal women and in women with normal-tension and chronic, open-angle glaucoma.

DESIGN

Eight postmenopausal women with glaucoma (group I) and 15 controls (group II) were given HT. The duration of the study was 6 months, and the women were examined in basal condition and at the end of the treatment. All women underwent ultrasonographic evaluation of pelvic organs and color Doppler analysis of uterine, internal carotid, and ophthalmic arteries. Also, plasma viscosity was assayed.

RESULTS

The ultrasonographic analysis showed that none of the women presented with irregular endometrial echoes, polyps, or intracavitary fluid. In addition, endometrial thickness never exceeded the normal range (5 mm). Plasma viscosity and Doppler parameters significantly improved during therapy. However, the ophthalmic artery mean improvements of pulsatility index (-43% v -28%; P = 0.001), peak systolic blood flow velocity (+35% v +24%; P = 0.026), and time-averaged maximum velocity (+44% v +32%; P = 0.031) were significantly more evident in the control group than in the glaucoma group.

CONCLUSIONS

Although, in people with glaucoma, vasospasm can increase the risk of visual loss by inducing a retrobulbar blood flow reduction, HT seems to beneficially affect the ocular vascularization.

The longitudinal variation in uterine artery blood flow pattern in relation to birth weight

OBJECTIVE

To investigate the relationship between the timing of disappearance of high-resistance uterine artery waveforms between the first and second trimester of pregnancy and birth weight.

METHODS

Uterine artery Doppler recordings were obtained in a cohort of singleton pregnancies at 11-14 weeks of gestation and subsequently at 18-23 weeks. At each examination, the presence or absence of an early diastolic notch was recorded for each side. An abnormal pattern of blood flow was defined as the presence of bilateral notches. Cases complicated by preeclampsia or preterm delivery were excluded.

RESULTS

Four hundred eleven pregnancies showed absent or unilateral uterine artery notches at the 11-14-week scan (group 1). All these cases maintained a low-resistance uterine blood flow pattern at the second-trimester scan. Of the 251 pregnancies with bilateral notches at the 11-14-week scan, 222 subsequently displayed a low-resistance blood flow at 18-23 weeks (group 2) whereas only 29 maintained bilateral notches (group 3). The mean birth weight was higher in group 1 (3452 g) than in groups 2 (3310 g) and 3 (3224 g). This difference was confirmed after adjusting for confounding variables. Small-for-gestational-age fetuses were more common in groups 2 (14.9%) and 3 (14%) compared with group 1 (6.8%, P <.001). During the study period, severe preterm preeclampsia was observed in 6 cases only.

CONCLUSION

The longitudinal variation in uterine artery blood flow pattern has a statistically significant correlation with birth weight, likely reflecting the timing and degree of trophoblastic invasion of the maternal vessels.

LEVEL OF EVIDENCE

II-2

[Pregnancy in rudimentary uterine horn: diagnostic and therapeutic difficulties]

Ectopic pregnancy in a rudimentary uterine horn is extremely uncommon. Implantation of one embryo in the uterine cavity and of another in a rudimentary uterine horn is an extremely uncommon form of twin pregnancy. The authors report three cases of pregnancies in a rudimentary uterine horn. One was associated to a heterotopic pregnancy in the other eutrophic horn. Through these three cases, they report the risks incurred and the difficulties of the assumption of responsibility of this type of pathology, on the diagnostic as well as therapeutic level. But generally underline the interest of echography especially endovaginale and the coelioscopy in the early diagnosis of this type of uterine malformation.

Ectopic pregnancy diagnosis and the pseudo-sac

OBJECTIVE

To evaluate the impact of an ultrasound finding of a pseudo-sac (PS), a uterine sac without a double decidual ring or a yolk sac, on the management of cases with possible ectopic pregnancy.

DESIGN

A retrospective review of a series of cases.

SETTING

A general hospital.

PATIENT(S)

Seventy-seven patients who had a diagnostic laparoscopy over a period of 3 years for suspected ectopic pregnancy.

MAIN OUTCOME MEASURE(S)

A logistic regression analysis was conducted to evaluate the effect of the ultrasound finding of a PS on predicting a negative finding at laparoscopy.

RESULT(S)

The report of a PS is significantly associated with a false-positive diagnosis of ectopic pregnancy.

CONCLUSION(S)

A diagnosis of PS should not be interpreted as indicative of an ectopic pregnancy because radiological differentiation between an early intrauterine pregnancy failure and an ectopic pregnancy is not possible.

Assessment of changes in utero-ovarian arterial impedance during the peri-implantation period by Doppler sonography in women undergoing assisted reproduction

OBJECTIVE

To investigate changes in utero-ovarian blood flow during the peri-implantation period and their significance in successful embryo implantation.

METHODS

A prospective longitudinal study was conducted in 317 women undergoing in-vitro fertilization-embryo transfer (IVF-ET) treatment. All of them had at least one good-quality embryo for transfer on the second or third day after oocyte retrieval. Measurement of endometrial thickness and color flow imaging with pulsed waveform analysis of uterine and ovarian arteries were performed before ET and 5-6 days after ET.

RESULTS

There were no significant differences in the age of patients, duration of infertility or number of embryos transferred between women who became pregnant (n = 91) and those who did not (n = 226). There was no difference in mean endometrial thickness between the two groups before ET, while a thicker endometrium was found in women who had conceived compared with those who had not 5-6 days after ET (P = 0.02). Mean uterine arterial resistance index (RI) and pulsatility index (PI) values were significantly lower in the pregnant than in the non-pregnant group before ET (P = 0.04 and P = 0.003, respectively), but no significant differences were found between the two groups 5-6 days after ET. In contrast, the mean ovarian arterial RI and PI values were similar between the two groups before ET, yet the pregnant group showed significantly lower RI and PI values compared with the non-pregnant group 5-6 days after ET (P = 0.002 and P = 0.01, respectively). A significantly higher peak systolic velocity (PSV) of intraovarian vessels was also noted in the pregnant group 5-6 days after ET.

CONCLUSION

Different utero-ovarian blood flow changes during the peri-implantation period occur in conception and non-conception cycles in women following IVF. Doppler assessment of uterine arterial resistance can help to determine a time interval within the menstrual cycle that is of optimal endometrial status for embryo implantation in assisted conception programs. Delay in achieving adequate uterine perfusion during the temporal window of embryo implantation may have an impact on endometrial receptivity.

Early prenatal diagnosis by celocentesis

BACKGROUND

Celocentesis is the ultrasound-guided aspiration of fluid from the extra-amniotic cavity at 7-8 weeks of gestation. This paper reports on the clinical application of celocentesis for early prenatal diagnosis.

METHODS

Celocentesis was successfully performed in nine pregnancies and 1-2 mL of fluid were obtained after one needle insertion. The indications were prenatal diagnosis of beta-thalassemia or sickle cell disease (n = 6), Marfan syndrome (n = 1) and paternity testing (n = 2). Molecular biological techniques were used to analyze the celomic fluid and this was successfully carried out in all cases.

RESULTS

In two cases pregnancy termination was performed at the request of the mother because in one case the fetus was found to have sickle cell anemia and in the second case paternity testing demonstrated that the father was not the woman's husband. In both cases the results were confirmed using the placental samples collected after pregnancy termination. In six of the seven pregnancies with desirable results, amniocentesis was performed at 16 weeks and the results were concordant with those obtained from celocentesis. All pregnancies were uneventful and resulted in the delivery of healthy and appropriately grown babies.

CONCLUSION

Celocentesis may be a viable alternative to the currently used tests of chorionic villus sampling and amniocentesis.

Ultrasound diagnosis of severe thrombotic placental damage in the second trimester: an observational study

OBJECTIVES

To screen women with uteroplacental insufficiency between 18 and 26 weeks' gestation for sonographic evidence of destructive placental lesions, to observe the effect of low molecular-weight heparin (LMWH) in these cases, and to compare the outcome with similar but untreated controls.

METHODS

We screened 180 women at high risk for placental damage using 16-week maternal serum screening (alpha-fetoprotein and human chorionic gonadotropin), placental shape and texture, and uterine artery Doppler waveforms at the 18-20-week level II examination. Serial gray-scale examinations of placental texture were performed at 22, 24 and 26 weeks. LMWH was offered to women with ultrasound evidence of destructive placental lesions in the absence of intrauterine growth restriction and/or pre-eclampsia.

RESULTS

We prospectively identified six women (3.3%) with abnormal maternal serum screening and uterine artery Doppler in whom abnormal placental texture (echogenic cystic lesions) suggestive of destructive lesions in the placental parenchyma was found either at the 18-20-week ultrasound examination (n = 4), or by 26 weeks of gestation (n = 2). All six received LMWH and had live births (gestational age at delivery, 33-37 weeks; birth weight, 1000-3200 g). A further 14 women were referred with similar multiparameter evidence of placental damage at or after 26 weeks, outside the screening study. All had significant fetal growth restriction and were therefore not offered heparin. In 9/14 cases there was a perinatal death. Ischemic and/or thrombotic placental pathology was confirmed in each case, but no maternal thrombophilia disorders were identified in the 20 women.

CONCLUSIONS

Integrated biochemical and ultrasound testing of placental function at 16-20 weeks of gestation, followed by serial placental gray-scale ultrasound, may be an effective method of identifying a subset of pregnancies at high risk of adverse pregnancy outcome due to destructive lesions in the placental parenchyma. This strategy of identifying thrombo-occlusive placental lesions before the development of pregnancy complications may prove useful in the design of trials to study the effectiveness of LMWH in the prevention of clinical complications resulting from thrombo-occlusive placental disease.

Normal uterine size in women of reproductive age in northern Islamic Republic of Iran

To determine the efficacy of ultrasonographic assessment of uterus size in women of reproductive age, we conducted a cross-sectional analytic study of 231 women aged 15-45 years in Babol, northern Islamic Republic of Iran. Mean uterus size was 86.6 mm x 49.6 mm x 40.6 mm overall, 72.8 mm x 42.8 mm x 32.4 mm for nulliparous women and 90.8 mm x 51.7 mm x 43.0 mm for multiparous women. Mean age was 31.7 +/- 9.6 years and mean body mass index (BMI) was 24.7 +/- 4.0 kg/m2. Uterus size was significantly associated with parity and age; but not with BMI. Our findings show a greater mean uterus size than reported by others. Ultrasonographic measurement of uterus size is valuable for predicting pathologies associated with abnormal uterine size.

Prospective evaluation of blood flow in the myometrium and uterine arteries in the puerperium

OBJECTIVE

Heavy bleeding in the late postpartum has, in some cases, been attributed to subinvolution of the placental bed and enhanced myometrial vascularity (EMV) as seen on color Doppler imaging. The aim of this study was to investigate the incidence and spontaneous evolution of areas of enhanced vascularization over the whole thickness of the myometrium in asymptomatic women after uncomplicated term pregnancy.

METHODS

This was a prospective descriptive study involving 93 consecutive women who were examined on day 3 (mean 2.6 +/- 1.5) and at 6 weeks (mean 6.5 +/- 1.3) after delivery following an uncomplicated term pregnancy. EMV was defined as the presence of marked flow over the full thickness of the myometrium reaching the uterine cavity. Doppler flow examination within the area of EMV and of both uterine arteries was performed.

RESULTS

The mean patient age was 29.1 years and average parity was 1.7. The mean gestational age at delivery was 39.1 weeks. Areas of EMV were visualized in 50.5% of patients on day 3 vs. 3.9% at 6 weeks. None of the patients required therapy for bleeding problems. The mean pulsatility index and peak systolic velocity in the area of EMV on day 3 were 0.45 +/- 0.30 and 0.37 +/- 0.20 m/s, respectively. A consistent increase in vascular resistance and decrease in blood flow velocity was observed in both uterine arteries between day 3 and week 6.

CONCLUSIONS

Most areas of EMV reflect intermediate stages in the involution of the placental bed and do not cause abnormal postpartum bleeding. EVM is common in the puerperium, disappears spontaneously in the vast majority of cases, and does not warrant treatment if asymptomatic. Further research is needed to predict the rare cases in which subinvolution of the placental bed leads to heavy bleeding in the late postpartum.

[Obstetrics and gynecology]

Three-dimensional(3D) ultrasound is getting popular rapidly in obstetrics and gynecology, especially for fetal diagnosis. Three-dimensional ultrasound provide with not only various kinds of 3D images but also any arbitrary sections that cannot be obtained by conventional two-dimensional ultrasound. Fetal biometry can be performed easily and accurately on a 3-orthogonal-plane image by 3D ultrasound. Morphological abnormalities of the fetus and their severities, especially on the face, ears, extremities and skeleton, can be depicted clearly by 3D images. Realistic surface images of a normal fetus may work well on the parents-fetus bonding. Congenital uterine abnormalities are depicted easily and clearly on coronal sections of the uterus by transvaginal 3D ultrasound.