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CME Credit Offered
CME Credit Offered
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Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
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Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 3

Category: Ultrasound/Imaging

Poster Session 3

(843) Misdated or Just Small: Study of Fetal Growth Restriction Outcomes in Pregnancies with Suboptimal Dating

Thursday, February 12, 2026
10:30 AM - 12:00 PM  
Objective:
To assess abnormal umbilical artery Doppler (UAD) and neonatal outcomes in fetal growth restriction (FGR) when pregnancy dating is suboptimal.

Study Design:
This was a retrospective cohort study of patients with FGR by ultrasound who delivered between January 2020 and March 2025 after 20 weeks. The cohorts were divided into optimally dated (Group 1: dating by first trimester ultrasound (1TU) or second trimester ultrasound (2TU) congruent with LMP) and suboptimally dated (Group 2: dating by third trimester ultrasound (3TU) or 2TU incongruent with LMP). The primary outcome, abnormal UAD was defined as elevated systolic to diastolic ratio (S/D), pulsatility index (PI), or resistance index (RI) greater than 95%, or absence or reversal in diastolic flow. Secondary outcomes included FGR resolution, neonatal weight, non-congruent Ballard score, small for gestational age (SGA) neonates, NICU admission, and an adverse composite neonatal outcome (CNO). Fisher’s exact, chi-squared, and Mann-Whitney U tests were used.

Results:
Among 282 patients, 226 (80.1%) were optimally dated (Group 1) and 56 (19.9%) were suboptimally dated (Group 2). Within Group 1, 123 (54.4%) were dated by 1TU and 103 (45.6%)  by 2TU congruent with LMP. In Group 2, 36 (64.3%) were dated by 2TU incongruent with LMP, and 20 (35.7%) by 3TU. The rate of abnormal UAD was significantly lower in Group 1 (27 [11.9%] vs 16 [28.6%], p=0.002). However, Group 1 was less likely to have resolution of FGR, (45 [19.9%] vs 44 [78.6%], p=< 0.0001). Neonatal weight (2600g [2295-2843] vs 2540g [2181-2871], p=0.66) and Ballard scores (38 [38-39] vs 38 [38-38], p=0.46) were similar. There were no significant differences in the rates of SGA neonates (112 [49.6%] vs 33 [58.9%], p=0.21), NICU admission (62 [27.4%] vs 19 [33.9%], p=0.49), or adverse CNO (62 [27.4%] vs 14 [25%], p=0.49).

Conclusion:
Given that the rate of abnormal UAD was significantly higher in pregnancies with suboptimal dating and that neonatal outcomes did not differ from well dated pregnancies, a diagnosis of FGR should be managed and surveilled similarly regardless of pregnancy dating.