Contribution of fetal weight estimation in twin pregnancies: a prospective study. Perinatal Journal 2014;22(3):SE39
- Department of Obstetrics and Gynecology, Mongi Slim Hospital- La Marsa TN
Karoui Abir, Department of Obstetrics and Gynecology, Mongi Slim Hospital- La Marsa TN,
Conflicts of Interest
No conflicts declared.
Ultrasonography is an essential tool in the management of twin pregnancies. Fetal weight estimation is useful to anticipate neonatal care in case of prematurity, growth restriction or growth discordance.
The aim of this study was to evaluate the accuracy of ultrasound fetal weight prediction in twin pregnancies.
Fifty patients with an ultrasonography within 4 days before birth were studied. Estimated fetal weight (EFW) was compared with birth weight (BW). Fetal hypotrophyand growthdiscordance superior or equal to 25 % between the first and the second twin were recorded.
Absolute differences between EFW and BW were similar for both twins (155 g [72–337.5] for T1 and 150g [100–266.5] for T2).
Mean absolute percentage error was 7.7% (2.5-14.76gr) for T1 and7.55% (3.37-11.85gr) for T2.
Mean absolute percentage error was superior to 10% for 20% of T1 and 18% of T2with no significant difference.
Chorionicity, gestational age as well as fetal presentation did not influence fetal weight estimation
T1 correlation coefficient is 0.87; T2 correlation coefficient is 0.89.
PN de J1 = 415,57+ 0,846*PFE de J1
PN de J2 = 65,68+0,963*PFE de J2
Ultrasonography in the diagnosis of hypotrophy had a sensitivity of 90.32%, a specificity of 78.94%, a positive predictive value (PPV) of 83.5% and a negative predictive value (NPV) of 87.5%. For the prediction of growth discordance, sensitivity was 76.9%, specificity 81.8%, PPV 50% and NPV 93.5%.
Fetal weight can be accurately predicted in twin pregnancies.
The contribution of ultrasonography in the diagnosis of hypotrophyand growth discordance is mainly due to a high NPV.
Twin pregnancies; weight estimation