英国西中部伯明翰妇产科医院和东伯明翰医院的两个实验室检查了1,000例“危险”妊娠。其中57％属于染色体指征,43％可能是神经管缺损。在孕妇中,最大的危险群(占37％)是那些曾出生过一例神经管缺损子女(21％脊柱裂和16％无脑儿),以及那些年龄在35岁以上被认为有增加先天愚型妊娠危险的妇女。6％是已经出生过一例先天愚型。共测定了985(98.5％)例孕妇羊水内甲 Two laboratories at Birmingham Obstetrics and Gynecology Hospital in West Central England and East Birmingham Hospital examined 1,000 “dangerous” pregnancies. 57% of them are chromosomal indications and 43% may be neural tube defects. Among pregnant women, the largest group (37%) were those who had had a child born with a neural tube defect (21% of the spina bifida and 16% of the brainless) and those who were over 35 years old were considered to have a Women at risk of pregnancy. 6% is already born a Down’s syndrome. A total of 985 (98.5%) pregnant women were determined amniotic fluid