First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography

First-trimester fetal heart rate in mothers with opioid addiction

AIM

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

DESIGN

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.

MEASUREMENT

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

FINDINGS

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.

First and early second trimester fetal heart screening

PURPOSE OF REVIEW

This review describes the recent advances in timing and effectiveness of first and early second trimester fetal echocardiography screening.

RECENT FINDINGS

Fetal echocardiography can now be reliably performed from 11 weeks' gestation owing to improvements in ultrasound transducers and processors. Three-dimensional and four-dimensional ultrasound modalities in image acquisition and postprocessing analysis, including spatio-temporal image correlation, rendering three-dimensional power Doppler and high definition power flow Doppler, and B-flow have further improved our capabilities in this area. Fetal nuchal translucency measurement screening programs create a new population of at-risk pregnancies that will be referred for early fetal echocardiography. The majority of congenital heart defects, however, still occur in low-risk patients. Improved technology has lowered the gestational age at which fetal cardiac anatomy scanning can be reliably performed by properly trained and experienced examiners.

SUMMARY

Early fetal echocardiography can be offered as a screening examination to at-risk and low-risk patients, with the proviso that it be repeated following screen-negative scans at mid-gestation to exclude later developing lesions.