Prenatal diagnosis of haemoglobin Bart's disease by cordocentesis at 12-14 weeks--experience with the first 59 cases.
We have shown that fetuses affected by haemoglobin (Hb) Bart's disease can be reliably identified by their sonographic manifestation of cardiac enlargement at 12-14 weeks. Between 1995 and 1999, 282 couples were seen before 15 weeks. They were offered the options of chorionic villus sampling, or amniocentesis and DNA study, or ultrasound examination at 12-14 weeks, followed by cordocentesis and Hb study only when the ultrasound findings were abnormal. Two hundred and thirty-four at-risk pregnancies had ultrasound assessment at 12-14 weeks, 62 fetuses showed enlarged cardiothoracic ratio [mean (SD) 0.54 (0.02)] and four of them also had hydropic changes. Fifty-nine women agreed to undergo cordocentesis at 12-14 weeks and the procedure was successful in 57 cases (97%). Cordocentesis were performed by a freehand technique using a 26- or 24-gauge spinal needle with a 20-gauge introducer. Fifteen fetuses (25%) had bleeding from the cord and 12 fetuses (20%) had bradycardia following cordocentesis. The fetal loss rate was 8% (5/59). Hb Bart's disease was confirmed in all the 62 fetuses with cardiac enlargement. Their Hb concentration ranged between 3.1 to 8.4 g/dl. One hundred and seventy-two fetuses had normal ultrasound assessment and 148 of them were confirmed to be unaffected by Hb Bart's disease. Twenty-three pregnancies were ongoing and one miscarried at 15 weeks. We believe that sonographic assessment followed by selective cordocentesis at 12-14 weeks is a feasible prenatal diagnostic option for Hb Bart's disease.
Lam
Y H
YH
Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong, China. yhlam@hkucc.hku.hk
Tang
M H
MH
D000328:Adult; D001919:Bradycardia / Q000209:etiology; D006332:Cardiomegaly / Q000151:congenital / Q000000981:diagnostic imaging; D017218:Cordocentesis / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006455:Hemoglobins, Abnormal / Q000032:analysis*; D006579:Heterozygote; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D018566:Pregnancy, High-Risk / Q000097:blood*; D011296:Prenatal Diagnosis / Q000379:methods*; D014463:Ultrasonography; D017085:alpha-Thalassemia / Q000097:blood* / Q000000981:diagnostic imaging / Q000235:genetics
D006455:Hemoglobins, Abnormal