Evaluating skeletal dysplasias on prenatal ultrasound: an emphasis on predicting lethality.

Lethal skeletal dysplasias can be diagnosed by prenatal ultrasound (US) using several sonographic parameters. Degree of femoral shortening, lung volumes, femur length to abdominal circumference ratio, and chest circumference to abdominal circumference ratio are the most sensitive and specific predictors. Although there are more than 450 different skeletal dysplasias, only a few are lethal in the perinatal period. We review current fetal US literature and present an updated algorithmic approach to first establish lethality and, second, evaluate for hallmark sonographic features to help determine a specific diagnosis.

Endometrial thickness and risk of breast and endometrial carcinomas in the prostate, lung, colorectal and ovarian cancer screening trial.

Postmenopausal women with higher circulating estrogen levels are at increased risk of developing breast and endometrial carcinomas. In the endometrium, excess estrogen relative to progesterone produces a net proliferative stimulus, which may result in endometrial thickening. Therefore, the hypothesis that endometrial thickness is a biological marker of excess estrogen stimulation that is associated with risk of breast and endometrial carcinomas was tested. Endometrial thickness was measured in 1,272 postmenopausal women, aged 55-74 years, who underwent transvaginal ultrasound (TVU) screening as part of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Serial endometrial thickness measurements were available for a subset of women at 1 year (n = 1,018), 2 years (n = 869) and 3 years (n = 641) after baseline. The associations between endometrial thickness and breast (n = 91) and endometrial (n = 14) carcinoma were evaluated by estimating relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression with age as the time metric. Models incorporating baseline endometrial thickness and as a time-varying covariate using all measurements were examined. Median follow-up among study participants was 12.5 years (range: 0.3-13.8 years). Compared to baseline endometrial thickness of 1.0-2.99 mm, women with baseline endometrial thickness greater than or equal to 5.0 mm had an increased risk of breast (RR = 2.00, 95% CI = 1.15-3.48) and endometrial (RR = 5.02, 95% CI = 0.96-26.36) carcinomas in models adjusted for menopausal hormone use and BMI. These data suggest that increased endometrial thickness as assessed by TVU was associated with increased risk of breast and endometrial carcinomas.

Twin pregnancy with a chimeric androgenetic and biparental placenta in one twin displaying placental mesenchymal dysplasia phenotype.

OBJECTIVES: The aim was to report an unusual trizygotic pregnancy that resulted in live-born twins. The placenta of one twin had placental mesenchymal dysplasia (PMD), which resulted from a chimeric fusion of an androgenetic zygote and a normal biparental zygote. The literature review was summarized. METHODS: The case was first detected by prenatal ultrasound, and was then followed by a histologic and detailed genetic investigation. The literature on PMD, complete hydatidiform moles (CHMs), and placental mosaicism and chimerism was also reviewed. RESULTS: One placenta of a twin pregnancy was noted to be diffusely cystic and enlarged. The macroscopic and microscopic findings were consistent with the diagnosis of PMD; however, genetic findings confirmed confined placental chimerism involving a normal biparental 46,XY male conceptus and an androgenetic 46,XX complete hydatidiform mole. CONCLUSIONS: This case represents a rare placental abnormality, PMD, which may have a diverse etiology. Therefore, detailed histologic and genetic analysis were performed for an accurate diagnosis.

Transvaginal ultrasound measurement of endometrial thickness as a biomarker for estrogen exposure.

OBJECTIVE: In clinical settings, transvaginal ultrasound has been used to evaluate abnormal vaginal bleeding. Because the endometrium responds to estrogens, endometrial thickness may constitute a biomarker of estrogen status in postmenopausal women. This study aimed to validate the transvaginal ultrasonographic measurement of endometrial thickness as an estrogen biomarker in asymptomatic, postmenopausal women by demonstrating an association between endometrial thickness and risk factors known to be associated with estrogen exposure. METHOD: Endometrial thickness was measured in 1,271 women ages 55 to 74 years who underwent transvaginal ultrasound screening as part of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. A questionnaire, completed before screening, provided risk factor information, including reproductive and hormone use histories. RESULTS: Endometrial thickness measurements ranged from 1 to 32 mm (median 3.0 mm). The frequencies of thicker endometrium (> or =3.0 mm), according to body mass index (BMI) quartile, were 55.2%, 66.1%, 69.7%, and 76.7% (P < 0.0001). The frequencies of thicker endometrium were 57.8%, 58.3%, and 82.6% among never users, ex-users, and current users of hormone replacement therapy (HRT), respectively (P < 0.0001). Other factors associated with thicker endometrium included age, marital status, history of uterine fibroids, years since menopause, and history of hypertension. Statistically significant associations were not seen in analyses limited to current HRT users (n = 461). In multiple variable analysis (R2 = 0.08), current HRT use (P < 0.0001) and higher BMI (P < 0.0001) were independently associated with thicker endometrium. CONCLUSION: In postmenopausal women, factors reflecting exogenous (current HRT use) and endogenous (BMI) estrogen exposure were associated with increased endometrial thickness as measured during screening transvaginal ultrasound. Practical limitations related to screening transvaginal ultrasound include measurement variability, lack of information regarding type or dose of HRT, and problems of differentiating true endometrial thickening from unrecognized endometrial polyps or fluid accumulations. Constrained by these limitations, these results partially validate a transvaginal ultrasound measurement of endometrial thickness as a potential biomarker related to estrogen status.

Sonographic detection of gallbladder duplication: two cases discovered in utero.

OBJECTIVE: To report the in utero diagnosis of a duplicated gallbladder. METHODS: Obstetric sonography was performed at 2 separate referral centers. A comprehensive level 11 examination was performed at each center. RESULTS: In both cases, a duplicated gallbladder was detected in utero without the presence of other anatomic abnormalities. CONCLUSIONS: Gallbladder duplication, although uncommon, should be considered when an additional cystic structure is seen in the right upper quadrant. Recognition of the presence of a duplicated gallbladder, a relatively benign condition, prevents invoking a more serious diagnosis, such as a choledochal or duodenal duplication cyst.