First-trimester fetal heart rate in mothers with opioid addiction.
OBJECTIVE
To investigate the difference in fetal heart rate of opioid-dependent mothers compared to non-dependent mothers in the first trimester of pregnancy.


METHODS
The data of 74 consecutive singleton pregnancies of mothers enrolled in a maintenance programme for opioid-dependent women was matched to 74 non-exposed singleton pregnancies by maternal age, crown-rump length, smoking status, ethnic background and mode of conception.


METHODS
Fetal heart rate measured as part of first-trimester screening by Doppler ultrasound between 11+0 and 13+6 gestational weeks was compared retrospectively.


RESULTS
The mean fetal heart rate in opioid-dependent mothers was 156.0 beats per minute (standard deviation 7.3) compared to 159.6 (6.5) in controls. The difference in fetal heart rate was significant (P = 0.02). There was a significant difference in mean maternal body mass index (P = 0.01) but not in mean nuchal translucency (P = 0.3), gestational age (0.5), fetal gender (P = 0.3) and parity (P = 0.3) between both groups. Fifty-five per cent (41 of 74) of cases were taking methadone, 30% (22 of 74) buprenorphine and 15% (11 of 74) were taking slow-release morphines throughout the pregnancy.


CONCLUSIONS
In fetuses of opioid-dependent mothers a decreased fetal heart rate can already be observed between 11+0 and 13+6 gestational weeks. The effect of opioid intake needs to be taken into consideration when interpreting fetal heart rate in opioid-dependent mothers at first-trimester screening.
Schmid
Maximilian
M
Department of Obstetrics and Feto-maternal Medicine, Medical University of Vienna, A-1090 Vienna, Austria. maximilian.schmid@meduniwien.ac.at
Kuessel
Lorenz
L
Klein
Katharina
K
Metz
Verena
V
Fischer
Gabriele
G
Krampl-Bettelheim
Elisabeth
E
D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000187:drug effects*; D006801:Humans; D009035:Mothers; D048208:Nuchal Translucency Measurement; D009293:Opioid-Related Disorders / Q000534:rehabilitation*; D011247:Pregnancy; D011248:Pregnancy Complications; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal
D000701:Analgesics, Opioid