Fetal blood sampling and pregnancy loss in relation to indication.
OBJECTIVE
To assess the relation between the indication for fetal blood sampling and pregnancy loss following the procedure.


METHODS
Retrospective study.


METHODS
The tertiary referral Fetal Medicine Units at Guy's and University College Hospitals, London.


METHODS
Women undergoing diagnostic fetal blood sampling in four groups: (1) 94 having prenatal diagnosis with normal ultrasound findings; (2) 94 with a structural fetal abnormality; (3) 30 having fetal assessment and (4) 35 with non-immune hydrops.


METHODS
Freehand ultrasound guided fetal blood sampling from umbilical cord, intrahepatic vein or fetal heart.


METHODS
Pregnancy losses were divided into those within 2 weeks and those 2 weeks after the procedure, obstetric accidents and neonatal deaths.


RESULTS
The 253 patients had fetal blood sampled on 268 occasions. Fifty-one pregnancies were terminated. Overall, 51 of the remaining 202 desired continuing pregnancies were lost, of which 19 (9%) were lost within 2 weeks of the procedure. After exclusion of the pregnancies that were terminated, the procedure-related losses within 2 weeks of sampling were 1 in 76 (1%), 5 in 76 (7%), 4 in 29 (14%) and 9 in 36 (25%) in groups 1, 2, 3 and 4 respectively.


CONCLUSIONS
The risk of fetal blood sampling is increased in abnormal pregnancies, reflecting the underlying pathology and this must be taken into account when counselling patients before the procedure.
Maxwell
D J
DJ
Guy's Hospital, London.
Johnson
P
P
Hurley
P
P
Neales
K
K
Allan
L
L
Knott
P
P
D000022:Abortion, Spontaneous / Q000209:etiology*; D001800:Blood Specimen Collection / Q000379:methods*; D000013:Congenital Abnormalities; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005315:Fetal Diseases / Q000175:diagnosis; D006801:Humans; D015160:Hydrops Fetalis / Q000175:diagnosis; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D012306:Risk; D013997:Time Factors