Prenatal genetic counseling and consanguinity.

OBJECTIVES: To evaluate the prevalence of consanguineous patients at a Western European prenatal genetic counseling clinic and to describe demographic as well as health-related characteristics of this patient group. METHOD: Retrospective analysis of 1964 primary consultations at the Prenatal Genetic Counseling Outpatient Clinic at the Medical University of Vienna General Hospital in Austria. Characteristics of consanguineous patients were compared with those of a control group of not-related unions. RESULTS: A total of 8.9% (174/1964) of all patients lived in a consanguineous union, meaning they were related as second cousin or closer [78.7% (137/174) first cousin, 14.4% (25/174) second cousin, 6.3% (11/174) first cousin once removed or 0.6% (1/174) uncle/niece]. Consanguineous patients were significantly younger (26.6 ± 5.4 vs 30.4 ± 6.5, p < 0.01) and of non-Austrian background [92.5% (161/174) vs 32.8% (57/174), p < 0.01] than not-related controls. Forty-six per cent (80/174) were referred during an ongoing pregnancy. The main counseling issue was family history of consanguinity (ICD Z84.3) in 31.6% (55/174) of cases. CONCLUSIONS: Estimations of the prevalence of consanguinity among the general population in Western Europe likely highly underestimate the evaluated prevalence among patients referred for prenatal genetic counseling. Counseling strategies need to take into consideration that consanguineous patients are more likely to be young and have an immigrant background.

Maternal smoking and fetal lung volume-an in utero MRI investigation.

OBJECTIVE: To investigate whether fetal lung volume and fetal lung volume growth over gestation are different in mothers who reported smoking during pregnancy compared to non-smoking controls. METHOD: Cross-sectional retrospective study of the data of 200 consecutive singleton pregnancies that underwent magnetic resonance imaging (MRI). Fetal lung volumes of 32 fetuses of mothers who reported smoking during pregnancy were compared to 168 fetuses of non-smoking controls. RESULTS: Cases reported smoking between 2 and 30 cigarettes per day. The mean number of cigarettes per day for cases was 10.2 ± 6.1. After logarithmic transformation, lung volumes showed a linear increase with gestational age (r(2) = 0.7). Multiple regression analysis revealed a significant influence of gestational age (p < 0.0001) but not maternal smoking status (p = 1.0) on fetal lung volumes. Comparison of the relative difference between observed and predicted lung volumes for both groups by means of unpaired t-test revealed no significant influence of maternal smoking status on this variable (p = 0.9). CONCLUSIONS: Fetuses of mothers who reported smoking during pregnancy show similar lung volumes and lung volume growth in MRI compared to non-smoking controls. Our data suggest that a reduced lung volume is not responsible for the increase in respiratory symptoms associated with prenatal smoking.