Antenatal findings and early postnatal outcomes in pregnancies with trisomy 21: a 10 year retrospective review at a tertiary centre.

OBJECTIVE

To examine the antenatal imaging features, intrapartum findings and early postpartum course of pregnancies with trisomy 21 (T21) at a tertiary hospital in the United Kingdom.

METHODS

Women with pregnancies diagnosed with T21 on antenatal or post-mortem/postnatal karyotyping, from February 2010-2020. Outcome measures included antenatal imaging findings, fetal growth restriction (FGR), birthweight, mode of delivery and early neonatal outcomes.

RESULTS

76 women were included. There were six intrauterine deaths and 70 livebirths. Thirty-eight (50%) had an antenatal diagnosis and twenty-five (33%) had a suspected diagnosis but declined further testing. The diagnosis was unanticipated in 13 (17%). Cardiac anomalies (35.5%) were the most common antenatal anomaly. Doppler abnormalities were apparent in 48/73 (68%). Eighteen (25.7%) had antenatal FGR. The majority were delivered by Caesarean section, and 21.4% of babies weighed <third percentile at delivery. Fifty-eight (82%) were admitted to the neonatal unit. Forty-three (61%) required respiratory support and fifty-five (78%) needed naso-gastric feeding or were nil by mouth. Mean PAPP-A values were significantly lower in cases with abnormal Dopplers, FGR, congenital anomalies and birthweight <10 percentile.

CONCLUSIONS

T21 fetuses have high rates of placental insufficiency, FGR and Doppler abnormalities. Postnatally, most require respiratory and feeding support. Antenatal counselling should reflect these risks.