High failure rate of postmortem karyotyping after termination for fetal abnormality

Induction of labor compared to dilation and evacuation for postmortem analysis

OBJECTIVE

This study aimed to evaluate the ability to obtain autopsy and cytogenetics after midtrimester termination.

METHODS

A retrospective cohort study of women undergoing termination, via induction or dilation and evacuation (D&E), at 16 0/7-23 6/7 weeks was performed. Exclusion criteria were elective termination, preterm labor, PPROM, and no autopsy or cytogenetic exam performed. The ability to obtain cytogenetics and autopsy as well as complications rates were compared between the two groups with Chi-square tests.

RESULTS

Of the 469 women who met the inclusion criteria, 158 had an induction and 312 had a D&E. The induction of labor group had higher mean gestational ages, p < 0.01. Successful autopsy was more likely in the induction group, 94.3%, versus D&E group, 34.7%, p = 0.01. There was no difference in ability to obtain cytogenetics between the two groups, 89.1% in the induction group, and 92.3% in D&E group, p = 0.4. There was a difference in the total complication rates between the groups, 9.8% (26) in the induction versus 6.4% (20) in the D&E group, p < 0.01; however, there was no difference in major complications.

CONCLUSIONS

Midtrimester terminations by induction were more likely to have successful autopsies when compared with D&E. The ability to obtain cytogenetics was similar regardless of termination mode.

Pathologic Examination of Fetal and Placental Tissue Obtained by Dilation and Evacuation

Context.—Dilation and evacuation (D&E) is an alternative method to induction of labor for pregnancy termination and intrauterine fetal demise, and it is the most common mode of second-trimester uterine evacuation in the United States. Many D&E specimens are examined in surgical pathology, and there is little information available in surgical pathology textbooks or the literature to assist pathologists in these examinations.

Objective.—To provide an overview of the D&E procedure, discuss related legal issues, provide guidelines for routine pathologic examination of D&E specimens, and demonstrate the importance of careful pathologic examination of D&E specimens.

Data Sources.—Case-derived material and literature review.

Conclusions.—Pathologic examination of D&E specimens has been understudied. However, the available literature and our experience support the fact that careful pathologic examination of D&E specimens can identify significant fetal and placental changes that can confirm clinical diagnoses or provide definitive diagnosis, assist in explaining the cause of intrauterine fetal demise, and identify unexpected anomalies that may provide further clues to a diagnostic syndrome or mechanism of anomaly formation.

Success rate for culture of fetal postmortem tissue is dependent on the method of pregnancy termination

OBJECTIVE

To determine the effect of different methods of pregnancy termination on the culture success rate of postmortem fetal tissue.

METHODS

In a randomized trial, umbilical cord specimens were collected in a standardized manner and culture success rates were compared according to the method of pregnancy termination.

RESULTS

There was a significantly higher culture success rate in the vaginal (90.0%) and oral misoprostol (83.0%) groups compared to the intra-amniotic injection of prostaglandin group (52.8%).

CONCLUSION

The results of our study and the very high success rate reported by others from specimens following dilatation and evacuation lead us to suggest that exposure to drugs used to induce abortion may be a more important factor in culture failure than either tissue type or time in transit.

A comparison of prenatal versus postnatal karyotyping for the investigation of intrauterine fetal death after the first trimester of pregnancy

INTRODUCTION

Aneuploidy is an important cause of intrauterine fetal death (IUFD) after the first trimester. Determination of the fetal karyotype of these pregnancies is commonly done in most units from solid tissues. Results from such techniques are disappointing. The aim of this audit was to compare the results of karyotyping IUFD by invasive testing (amniocentesis or chorionic villus sampling) and solid tissues (skin biopsy).

SUBJECTS AND METHODS

Women with IUFD managed in our unit between 1 January 1998 and 31 December 2002 (inclusive) were offered either invasive testing before medical induction of labour or solid tissue biopsy after delivery. The amniotic fluid, chorionic villi and biopsies were processed following standard laboratory procedures.

RESULTS

During the 60 months, 230 samples from cases of IUFD were received by the laboratory in our unit; 126 had skin biopsies and 104 underwent invasive testing (81 amniocenteses and 23 chorionic villus sampling). Successful karyotyping was possible in 90% of those who underwent amniocentesis, 100% of those who had chorionic villus sampling and 13.5% of those who had skin biopsies. 50% of skin biopsies were unsuitable for analysis compared to none in the CVS and amniocentesis group. The difference in successful karyotyping between invasive testing and solid tissue testing was statistically significant (P < 0.0001). There were 12 (10.6%) abnormal karyotypes from the 113 successful samples (11/96 in the invasive group versus 1/17 in the solid tissue group).

CONCLUSION

Invasive testing has a much higher success rate of karyotyping in cases of IUFD and should, therefore, be offered to women presenting with this complication irrespective of gestational age.

Isolated mild fetal ventriculomegaly

Ventriculomegaly is an excess of fluid in the lateral ventricles within the developing cerebrum. It is usually diagnosed at a routine fetal anomaly scan at 18-22 weeks gestation. Management of the condition and counselling of parents are difficult, as the cause, absolute risk, and degree of resulting handicap cannot be determined with confidence.

Fetal and placenta chromosome constitution in 237 pregnancy losses

The aim of the study was to carry out cytogenetic analyses in pregnancy losses. Samples of cartilage and placenta tissue were obtained prospectively from 237 pregnancy losses of more than 16 weeks of gestation (130 stillbirths, 97 induced abortions and 10 early neonatal deaths). Cartilage culture was performed in 222 samples and placental culture was initiated in 224. The overall culture success rate was 83.5%, 72.3% in stillbirths, 97% in induced abortions and 100% in early neonatal death. An abnormal karyotype was detected in 52 cases: 6.9% in stillbirths, 43.6% in induced abortions and 20% in early neonatal deaths. The rate of discrepancy between the prenatal cytogenetic results in amniotic fluid and the post-termination karyotype was 3%. The tissue of choice for cytogenetic analysis was cartilage in induced abortions and early neonatal death, and placenta in stillbirth. The majority of cases had a chromosome abnormality: multiple congenital anomalies in 74.6%, and a single major anomaly in 9.7%.

Success rate of cytogenetic analysis at the time of second-trimester dilation and evacuation

OBJECTIVE

The aim of this study was to determine the success rate of cytogenetic analysis from specimens obtained at the time of second-trimester termination of pregnancy by dilation and evacuation.

STUDY DESIGN

All second-trimester dilation and evacuations performed by a single practitioner at a single institution from 1993 through 1995 were evaluated to pick out those patients in whom biopsy specimens were submitted for cytogenetic analysis. The main outcome studied was the ability to obtain karyotype results for these specimens.

RESULTS

Cytogenetic studies were performed on 258 dilation and evacuation specimens with a median gestational age of 18 weeks (range 13-25 weeks). The indications for termination were fetal aneuploidy (n = 88, 34%), sonographically diagnosed fetal malformations (n = 82, 32%), intrauterine fetal death (n = 67, 26%), oligohydramnios or premature rupture of membranes (n = 16, 6%), and others (hematologic and metabolic disorders, n = 5, 2%). Successful karyotyping was achieved for 99% of specimens obtained at second-trimester dilation and evacuation, with 3 failures of growth (1% failure rate). The failures included a 14-week molar pregnancy, an 18-week fetus with Dandy-Walker malformation, and a 19-week intrauterine fetal death. Of the samples obtained in cases of intrauterine fetal death, 99% (66/67) provided adequate cytogenetic information.

CONCLUSIONS

Karyotyping for abnormal second-trimester pregnancies and intrauterine fetal deaths at the time of a dilation and evacuation procedure has a success rate nearing 100%. In contrast to previous reports, our data indicate that it is unnecessary to perform pretermination invasive karyotyping in patients with abnormal second-trimester pregnancies or intrauterine fetal death who elect to undergo dilation and evacuation. Chromosome analysis at the time of termination of pregnancy by dilation and evacuation reduces patient discomfort, risk of infection, and cost while still providing reliable and vital cytogenetic information for future genetic counseling.