Fetal heart scanning in the first trimester

The detailed study of the fetal cardiac anatomy in the first trimester of pregnancy by means of ultrasound, transvaginally or transabdominally, is feasible and remains a safe procedure provided thermal and mechanical indices are taken into account. Optimal time for successful imaging of the four chambers and great arteries in early gestation appears to be between 13 to 14 weeks. In experienced hands, first-trimester fetal echocardiography is accurate in detecting major structural cardiac abnormalities and yields a high negative predictive value. Thus, in a clinical setting, it can be offered to families considered to be ‘at risk’ of cardiac defects (e.g. those with previous family history or when fetal nuchal translucency is increased) and can be a powerful tool to reassure families regarding normality of major cardiac structures and connections. However, the early detection of an important structural abnormality (chromosomally normal or not) may be associated with a high termination rate if this is an acceptable option. The high prevalence of associated chromosomal and extracardiac abnormalities for many of the high-risk families, who may benefit from this approach, cannot be ignored. Therefore, fetal heart scanning in the first trimester should be performed in conjunction with detailed first-trimester obstetric scanning. Copyright © 2004 John Wiley & Sons, Ltd.     

High resolution chromosomes from first trimester trophoblast cultures

A simple method for obtaining prometaphase chromosomes from cultured first trimester cells involves the addition of BrdU and FdU 11 h before harvest and ethidium bromide 1.5 h before harvest. High resolution R-banding is obtained by acridine orange staining.     

Performance of comprehensive first trimester fetal anatomy assessment

Objective

Ultrasound assessment of the fetal anatomy and fetal echocardiography are feasible in the first trimester of pregnancy. This study was designed to assess the performance of a comprehensive fetal anatomy assessment in a high-risk population at a tertiary fetal medicine unit.

Methods

A retrospective review of high-risk patients undergoing comprehensive fetal anatomy ultrasound assessment between 11 weeks and 13 + 6 weeks of gestation was conducted. Findings of the early anatomy ultrasound scan were compared with those of the second trimester anatomy scan, and birth outcomes or post-mortem results.

Results

Early anatomy ultrasounds were performed in 765 patients. The sensitivity of the scan for detecting fetal anomalies compared to the birth outcome was 80.5% (95% CI 73.5–86.3) and specificity was 93.1% (95%CI 90.6–95.2). Positive and negative predictive values were 78.5% (95% CI 71.4–84.6) and 93.9% (95% CI 91.4–95.8), respectively. The most missed and overdiagnosed abnormalities were ventricular septal defects. The second trimester ultrasound had sensitivity of 69.0% (95% CI 55.5–80.5) and specificity of 87.5% (95% CI 84.3–90.2).

Conclusions

In a high-risk population, early assessments had similar performance metrics as the second trimester anatomy ultrasound. We advocate for a comprehensive fetal assessment in the care of high-risk pregnancies.     

Ultrasound diagnosis of structural abnormalities in the first trimester

The advances in ultrasound technology have made it possible to identify fetal structural abnormalities and genetic syndromes in the first trimester. First trimester prenatal diagnosis of fetal central nervous system, renal, gastrointestinal, cardiac, and skeletal abnormalities is reviewed. Copyright © 2002 John Wiley & Sons, Ltd.     

Experience with first trimester prenatal diagnosis of Menkes disease

We have performed 28 first trimester diagnoses for Menkes disease in 27 high risk pregnancies by direct copper measurement on chorionic villi (c.v.) Two male fetuses were found to be affected because of significantly increased copper content. In one male fetus a slightly increased copper content was observed indicating an exogenous copper contamination of the sample. This view was supported by normal results observed after abortion. Three out of 15 diagnostic c.v. samples with a female karyotype showed increased copper levels. In two of these cases, part of the copper content might have been released from the cannulae used for these particular biopsies. Histochemical visualization of copper accumulation in fixed chorionic villi of two affected fetuses and one female fetus was observed. [⁶⁴Cu]-uptake studies have been performed on 11 diagnostic and 10 control c.v. samples. As the control samples in some cases were found to incorporate more [⁶⁴Cu] than the corresponding diagnostic sample, this method cannot at present be used for diagnosis. Compiled results on newborn females gave evidence that two carriers expressed the paternal X-chromosome, and two carriers expressed the maternal X-chromosome in chorionic villi.     

Amnion rupture sequence in a first trimester missed abortion

We report the diagnosis of amnion rupture sequence made by sonography and fetoscopy during the first trimester of gestation in a case of missed abortion. The investigation revealed a demised fetus with the characteristics of 9 weeks of development. The early fetus had an amnion adhesion at the tip of the nose and strands of amnion wrapped around the terminal phalanges of both feet. No defects in addition to the face and limb involvement were identified. The karyotype was normal: 46,XX. In the reported case, fetoscopy allowed confirmation of the sonographic diagnosis of an amnion rupture sequence in the first trimester of gestation and consequently helped to clarify the cause of abortion in this case of early fetal demise. Copyright © 2001 John Wiley & Sons, Ltd.     

Activities of alkaline phosphatase in first trimester chorion biopsy tissue

We have determined the activity of alkaline phosphatase in chorionic villous tissue obtained in the first trimester of pregnancy, in order to obtain the normal range of values as a prerequisite for application to the prenatal diagnosis of the rare bone disease hypophosphatasia. The activities found were a combination of intestinal and liver/bone/kidney types; traces of placental type were present in only one sample.     

Gender impact on first trimester markers in Down syndrome screening

The influence of fetal gender on the level in the first trimester of the serological markers alpha-fetoprotein (AFP), pregnancy-associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotropin (βhCG) and on nuchal translucency is described for 2637 singleton pregnancies with normal outcome. Mean log MoM values for pregnancies with female and male fetuses were calculated using regression of log marker values on gestational age expressed as crown rump length and on maternal weight. A pronounced gender impact was found for free βhCG, being 16% higher for female than for male fetuses. Copyright © 2002 John Wiley & Sons, Ltd.