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Updated: Aug 17, 2026
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Fetal size as a determinant of obstetrical outcome of post-term pregnancy
Hypothesis:
We hypothesized that there might be differences in the outcomes of post-term pregnancy according to fetal size.
Methods:
A retrospective analysis of 143 women with uncomplicated pregnancy that persisted beyond 42 weeks was conducted. Ultrasound dating was performed between 8 and 14 weeks in all cases. The obstetrical outcomes were compared between the cases in which neonatal birth weight was <3,600 g (non-large group) and >/= 3,600 g (large group).
Results:
In primiparous women, there was no significant difference between the non-large and large groups in terms of the rate of cesarean section, but the rate of cesarean section for fetal distress in the non-large group was significantly higher than that found in the large group. In addition, the non-large group showed a significantly higher incidence of low pH (<7.20) compared with the large group (14/58 vs. 0/22, p < 0.01). In contrast, the rate of prolonged labor (>24 h) and induction failure in the non-large group were significantly lower than that in the large group. In multiparous women, there was no significant difference in obstetrical outcomes between the non-large and large groups.
Conclusions:
Primiparous women who were delivered of fetuses weighing not less than 3,600 g at post-term periods were at lower risk of fetal distress on the one hand and at higher risk of induction failure associated with infavorable cervix on the other. This study suggests that post-term pregnancy should be dealt with differently based on fetal weight.
