Defining the fetal cardiac axis between 11 + 0 and 14 + 6 weeks of gestation: experience with 100 consecutive pregnancies.
OBJECTIVE
The purpose of this study was to establish normal fetal cardiac axis values during the first and early second trimesters of pregnancy.


METHODS
This was a prospective observational cohort study in which the fetal cardiac axis was assessed during ultrasound examinations in 100 consecutive fetuses between 11 + 0 and 14 + 6 weeks of gestation. Transabdominal, and, when indicated, transvaginal, approaches were used. Intraobserver and interobserver reproducibility were calculated.


RESULTS
The cardiac axis ranged from 34.5 to 56.8° (mean (SD) 47.6 ± 5.6°) in 94 fetuses with normal cardiac anatomy. The fetal cardiac axis tended to be significantly higher in fetuses at 11 + 0 to 11 + 6 weeks of gestation than in fetuses at 12 + 0 to 14 + 6 weeks of gestation. Congenital heart defects were found in six out of 100 fetuses, four of which had abnormal cardiac axis values at 11 + 0 to 14 + 6 weeks of gestation.


CONCLUSIONS
Cardiac axis measurement is possible in the first and early second trimesters of pregnancy. The assessment of cardiac axis at an early gestational age may help to identify pregnancies at high risk for congenital heart defects. Copyright
Sinkovskaya
E
E
Division of Maternal-Fetal Medicine of the Department of Obstetrics & Gynecology, Eastern Virginia Medical School, Norfolk, VA 23507, USA. sinkove@evms.edu
Horton
S
S
Berkley
E M
EM
Cooper
J K
JK
Indika
S
S
Abuhamad
A
A
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000196:embryology; D018618:Echocardiography, Doppler, Color; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005865:Gestational Age; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000196:embryology; D006801:Humans; D015588:Observer Variation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods