A prospective longitudinal investigation of spontaneous cephalic version from breech presentation in the last trimester is reported. All pregnancies were assessed with ultrasound in the 32nd week of gestation, and were thereafter checked weekly. Of the 3 I0 singleton breech presentations identified at 32 weeks, spontaneous cephalic version occurred in 177 (57%) while breech presentation persisted in 133 patients (43%). Of 140 patients with a breech presentation at delivery 95%) were already presenting by the breech in the 32nd week. Spontaneous cephalic version was less likely in pregnancies with extended fetal legs. low birthweight, short umbilical cord and primiparity.
An improved technique for direct vision chorionic biopsy that gives a clear view of the amniotic sac was developed. With this technique, used in 48 women prior to vacuum aspiration and in six cases for diagnosis (karyotyping or enzyme analysis), it was possible to obtain chorionic villi free from contamination by maternal tissue. It was also possible to pick out villi (rich in blood vessels and with abundant buds on their surface) found to be most capable of growing in vitro. In the diagnostic cases, the pregnancies have continued uneventfully since the sampling; one pregnancy is now in the 32nd week.
The cytogenetic findings in 20 experimental and 80 diagnostic cases of first trimester trophoblast biopsy arc presented. All samples were obtained between the 8th and 13th week of gestation with the direct vision, trans-cervical technique. Except when fetal sexing because of X-linked disease was the issue, long-term culture with in situ preparation was the method routinely employed in processing the biopsies for cytogenetic analysis. In 78 of the 80 clinical cases and in all reported experimental cases we were successful in establishing a karyotype from the sampled tissue. Unbalanced karyotypes were found in two experimental and six clinical cases. Tetraploidy was found in one clinical case, but was not confirmed in subsequently sampled amniotic fluid cells. In another clinical case, we were unable to confirm in the aborted placenta the trisomy 18 found in the trophoblast biopsy. In the rest of the induced abortions in the clinical series, the karyotype arrived at prenatally has been confirmed, and the 27 babies so far born have bcen healthy and with phenotypic sex corresponding to the prenatal findings. Six women have miscarried after sampling; in one of these cases the fetus had the karyotype 47,XX,+ 13.
Chorionic villi were obtained by a direct vision technique. Villi without vessels (38 cases) failed to grow in vitro, irrespective of the amount of tissue. Vascular villi with an estimated weight exceeding 5 mg (71 cases) grew in vitro--with two exceptions.
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