Amniotic fluid index and labor length of pregnancies induced beyond 41 weeks of gestation with unfavorable cervix.

We evaluated if the response to prostaglandin E2 (PGE2) induction, in pregnancies completing 41 gestational weeks, is correlated to amniotic fluid index (AFI) values. A follow-up was performed from the time of the induction to the time of delivery of 63 pregnancies resulting in a spontaneous delivery showing unfavorable cervical examination at 41 weeks of gestation. This was induced by means of intracervical administration of PGE2 gel (Dinoprostone 0.5 mg). If the cervix was still unfavorable after 12 h, another gel administration followed. The number of PGE2 administration and AFI were both used as variables to correlate the time remaining before the delivery and the probability of delivery (Kaplan-Meier and Cox algorithms). Gestational age, parity, neonatal weight, and APGAR 5' were used as covariates. A cut-off of AFI > 6 better discriminates two groups regarding the probability of delivery at paired hours from the beginning of the induction. A statistically significant difference was demonstrated in only those patients which did not deliver within 12 h (44 cases). Multivariate analysis (Cox regression) yielded an adjusted odds ratio associated to the probability of delivery of 0.47 (0.23-0.95, 95% CI, p value = 0.0354) for AFI < or = 6 vs. AFI > 6.

Amniotic fluid volume and onset of labor in physiological pregnancy.

We measure, by means of ultrasound, the amniotic fluid volume (expressed as maximal vertical pocket or MVP) in 646 normal pregnancies at the 39th gestational week. Our aim is to evaluate the possible correlation between MVP and onset of the labor. In a 2-week follow-up, the onset of the labor is considered the "event" variable in a time-dependent statistical analysis. Univariate analysis (Kaplan-Meier algorithm) describes a different trend in predicting the onset of labor when a stratification of MVP < 50 and > or = 50 mm was performed (chi2 = 7.91 p < 0.0049 with 1 df, Breslow-Gehan test). The first category was comprised of 496 fetuses with a median (min-max) MVP of 39 mm (25-49), the second category of 150 fetuses with a MVP of 57 mm (50-100). The results suggest that lower levels of MVP are associated to a higher percentage of the onset of labor. Furthermore, in our measurement, performed at the 39th gestational week, the correlation with the events is higher within the 40th gestational week. In fact, at 7 days from the amniotic fluid measurement, the onset of labor and the subsequent delivery is observed in 80.65 and 73.00% of the cases when they are stratified according to MVP < 50 and > or = 50 mm. At the end of the follow-up, instead, the percentage of "events" is similar, 88.10 and 86.67%, respectively. Adjustment for covariates (Cox analysis), as well as maternal age, neonatal weight, and obstetrics history, show an odds ratio (95% C.I.) of 2.08 (1.61-2.69) for MVP, using the above cutoff level. In physiological pregnancy, lower levels of amniotic fluid at term correlated to a higher probability of the onset of labor.

First trimester umbilical venous Doppler sonography in chromosomally normal and abnormal fetuses.

In 342 singleton pregnancies in which the patients were undergoing chorionic villus sampling at 11 to 14 weeks of gestation, color Doppler sonography was used to obtain waveforms from the umbilical cord. The prevalence of pulsatile flow in the umbilical vein was higher in the 18 fetuses with trisomy 18 or 13 (16 of 18; 88.9%) than in the 18 fetuses with trisomy 21 (6 of 18; 33.3%) or the 302 chromosomally normal fetuses (73 of 302; 24.2%).

Pattern analysis for ultrasound anomalies in fetuses with normal karyotype.

Two hundred cases of double or multiple anomalies (up to five in the same fetus) out of 828 karyotypically normal fetuses with at least one ultrasound finding were enrolled in the present study. One hundred and sixty patterns belonging to 200 fetuses were found. Then, we included in the final analysis only those double or triple patterns of anomalies with frequency more then 1. Thus, 123 cases and 83 patterns were analyzed. A double pattern was intended as any combination of ultrasound findings present in the same fetus. Exact Chi-square test was used to evaluate the specificity of the association of the most frequent patterns. The association of patterns was expressed as ratio between observed and expected frequency (O/E) ratio. Pattern analysis was used as statistical tool to calculate the number of possible associations of ultrasound finding. Anomalies of fluid distribution, as well as Central Nervous System malformations, and facial malformations were among the most significant associations. Among the triple patterns, Cleft Lip + Cleft Palate + Holoprosencephaly showed the highest degree of association. Antenatal diagnosis of ultrasound finding can benefits by considering the present results.

The umbilical artery pulsatility index in the first trimester: is there an association with increased nuchal translucency or chromosomal abnormality?

OBJECTIVE: The aim of this study was to examine the possible association between umbilical artery pulsatility index (PI) at 10-14 weeks of gestation and either increased fetal nuchal translucency (NT) or fetal chromosomal abnormality. DESIGN: This was a prospective study of women undergoing chorionic villus sampling (CVS). SUBJECTS: A total of 458 women undergoing CVS were studied; in 418 cases the karyotype was normal and in 19 cases fetal trisomy 21 was identified. METHODS: Data from the women with a normal fetal karyotype and in whom the NT was also normal were used to calculate reference anges for the umbilical artery PI. Associations were sought between umbilical artery PI and increased NT and between the PI and fetal trisomy 21. RESULTS: We found no association between umbilical artery PI and NT, nor was there a difference in the PI between chromosomally normal pregnancies and those with fetal trisomy 21. CONCLUSION: The results suggest that fetoplacental vascular resistance per se does not contribute to increased NT and that measurement of the umbilical artery PI does not contribute to the first-trimester detection of fetal trisomy 21.