The impact of national guidance for anomaly screening and invasive testing: unintended consequences.

Recent guidance from the UK National Screening Committee (NSC) and the Fetal Anomaly Screening Programme (FASP) has led to important changes in prenatal ultrasound diagnosis and invasive testing. These relate to prenatal ultrasound investigation of what were previously known as 'soft markers' for Down's syndrome at the time of the detailed anomaly scan and as to whether full karyotype or FISH (fluorescent in situ hybridisation)/QFPCR (quantitative fluorescence PCR) testing for trisomies should be carried out when an invasive test is performed. Neither recommendation is directly related to the other but both in combination could have profound implications for the detection of chromosomal abnormalities other than trisomy 21 (Down's syndrome). In the light of two cases recently managed in one regional fetal medicine unit, we retrospectively reviewed cases where, with correct application of the NSC and FASP recommendations, non-lethal and clinically important chromosomal abnormalities would most likely not have been detected.

A rare report of foetal lingual cyst excised with harmonic scalpel.

Diagnosis of foetal lingual cysts is extremely rare. If large enough, it can compromise the upper oropharyngeal airway. A case of a large ventral lingual thyroglossal duct cyst mimicking a ranula was identified at 20 weeks of gestation and excised 11 weeks postnatally using the harmonic scalpel. The diagnosis and the benefit of ultrasonic dissection in the treatment of glossal lesions are reviewed.

Non-invasive prenatal diagnosis: implications for antenatal diagnosis and management of high-risk pregnancies.

There has been a huge effort in the last 2-3 decades to develop non-invasive prenatal diagnosis to avoid the risks to the fetus caused by invasive procedures. Obtaining fetal nucleic material for molecular analysis without the need of invasive procedures has been a goal of prenatal diagnosis for many years; this is now been made possible by the use of non-cellular fetal nucleic acids circulating in maternal blood. The placenta is the primary source of these nucleic acids, raising the possibility that they could be a marker for pregnancy complications resulting from placental disease/dysfunction such as pre-eclampsia and fetal growth restriction. If so, these markers might be able to identify cases at risk, predict disease and/or its severity or allow early diagnosis. This has the potential to allow improvements in the management of complicated pregnancies.

Free fetal DNA in maternal plasma in anembryonic pregnancies: confirmation that the origin is the trophoblast.

OBJECTIVE: To test the hypothesis that free fetal DNA (ffDNA) circulating in maternal plasma originates mainly from the placenta we studied ffDNA levels in anembryonic pregnancies. METHODS: Maternal blood samples were collected from 15 normal first-trimester pregnancies in which fetal sex was subsequently determined and nine patients with a diagnosis of anembryonic gestation (AG). The Y chromosome DYS14 gene was quantified by real-time quantitative PCR (RT-PCR) for the determination of fetal sex in both plasma and chorionic tissue samples. Fetal sex in chorionic tissue samples was also determined using quantitative fluorescence PCR (QF-PCR). RESULTS: The correct sex result was obtained from maternal plasma in all. Four AG pregnancies were female (DYS14 negative) results. In five of the AG cases, the chorionic tissue was found to be male (by both QF-PCR and RT-PCR which agreed) and positive male signal was found in maternal plasma by RT-PCR. There was no statistical difference between median free fetal DNA concentration in plasma between the AG male cases (148.3 GE/mL) and controls (145.8 GE/mL). CONCLUSION: Since ffDNA levels are normal in pregnancies without a fetus, the data support the hypothesis that the trophoblastic cells are the major source ffDNA in maternal plasma.

Management of fetal growth restriction.

Fetal growth restriction (FGR) is challenging because of the difficulties in reaching a definitive diagnosis of the cause and planning management. FGR is associated not only with a marked increased risk in perinatal mortality and morbidity but also with long-term outcome risks. Combinations of fetal biometry, amniotic fluid volume, heart rate patterns, arterial and venous Doppler, and biophysical variables allow a comprehensive fetal evaluation of FGR. However, no evidence supports that the use of cardiotocography or the biophysical profile improves perinatal outcome. Therefore, obstetricians aim to identify fetuses with early FGR so delivery can be planned according to gestational age and severity of the condition. The balance of risks and the need for the availability of services mean that the involvement of neonatologists in FGR management is vital. In this review, the focus is on the pathophysiology and management of FGR caused by placental diseases.