The Effect of Chorionic Villus Sampling on Fetal Heart Rate

Chorionic villus sampling significantly affects fetal cardiovascular function

OBJECTIVE

To assess the effects of chorionic villus sampling (CVS) on fetal heart rate (FHR).

METHODS

A prospective longitudinal study was conducted among 300 patients undergoing transabdominal CVS between 8 and 13 weeks of gestation. Duration of the procedure, number of needle passes, sample weight, maternal age, fetal gender, and FHR response to CVS were recorded.

RESULTS

The FHR before but not after CVS was inversely correlated with gestational age (r = -0.406, p < 0.001). Conversely, following CVS, no correlation was observed between FHR and gestational age (r = -0.06, p = 0.27). The difference between FHR after CVS and that obtained before CVS (delta FHR) increased with increasing gestational age at sampling (r = 0.372, p < 0.0001), decreased with increasing specimen weight (r = -0.16, p = 0.01) and increased with increasing maternal age (r = 0.22, p < 0.0001). Duration of the procedure, fetal gender and number of needle passes did not affect delta FHR. Multiple logistic regression indicated that gestational age at CVS and maternal age but not the other variables significantly affected delta FHR and together they accounted for over 22% of the variance (R(2) = 0.224, p < 0.0001).

CONCLUSIONS

In summary, our results suggest that acute fetal hemodynamic changes accompany CVS and that these changes vary with gestational age.

Chorionic villus sampling for beta-thalassemia: the first report of experience in Iran

OBJECTIVES

Beta-thalassemia is one of the most common hereditary disorders in Iran. The prenatal diagnosis of beta-thalassemia is part of a control program in our country and it began 13 years ago. During the past 8 years the number of procedures has increased significantly as also the legal abortions. This is the first report made on the CVS program in Iran.

MATERIALS AND METHODS

One thousand six hundred and sixty-one cases of transabdominal Chorionic Villus Sampling (CVS) have been retrospectively evaluated. Among them 1381 cases had inclusion criteria. CVS results, complications and fetal loss rate were evaluated. The distributions of the population at risk were divided between eight regions that have been proposed for beta-thalassemia mapping previously.

RESULTS

The mean age of the patients was 26.2 +/- 5.2 years with mean gestational age of 11.4 +/- 1.4 weeks. CVS was successful in all the patients (100%) although 1% required a second procedure. Post CVS fetal loss was 1.45%. Other minor complications were bleeding or spotting (1.81%), amniotic fluid leak (0.5%), small sub-chorionic hematoma (0.58%), severe abdominal pain (0.6%) and severe vasovagal reaction (0.14%). Late complications were seen in 0.21% (oligohydraminos). Approximately 2/3 of the patients were referred from three regions of the country, North (26.8%), South West (22.4%), Central (19.5%) and the remainder (31.3%) were from the other five regions.

CONCLUSION

CVS is a safe and effective method for prenatal diagnosis of beta-thalassemia in countries with a high prevalence as in Iran. The overall complication rate is quite low and acceptable. Fortunately the recent acceptance of legal abortion with respect to Muslim rules has increased the effectiveness of the procedure and made great advances in its application in Iran. Correspondingly, social knowledge has also improved but still there is a gap between the population at risk and the required prenatal diagnosis laboratories and sampling centers.