Molecular analysis of products of conception obtained by hysteroembryoscopy from infertile couples

Abstract

Purpose: To analyze the molecular cytogenetic data obtained from products of conception (POC) obtained by selective biopsy of first trimester miscarriages and to estimate the rate of chromosomal anomalies in miscarriages from pregnancies achieved by natural conception (NC) or by assisted reproductive technology (ART) interventions.

Methods: We used KaryoLite™ BoBs™ (PerkinElmer LAS, Wallac, Turku, Finland) technology to analyze 189 samples from ART or NC pregnancies.

Results: All POC were successfully evaluated. A higher incidence of chromosomal abnormalities was observed in POC after ART using the patient's own oocytes than from NC pregnancies (62.7% vs. 40.6%; p < 0.05). The lowest incidence of chromosomal abnormalities was observed in POCs ART using donor eggs from women younger than 35 years (12.8%). No statistical differences in the percentage of abnormal miscarriages were observed in correlation with sperm concentration: a sperm concentration less than 5 million/mL produced 75% abnormal results and a concentration higher than 5 million/mL produced 51%.

Conclusions: POC analysis is essential to determine the cause of pregnancy loss. Using culture-independent molecular biology techniques to analyze POCs avoids limitations such as growth failure and reduces the time required for analysis. Selective biopsy of fetal tissue by hysteroembryoscopy avoids the risk of misdiagnosis due to maternal cell contamination. Our results show that maternal age, sperm quality, and ART-assisted pregnancies are risk factors for abnormal gestations.

Figures

Fig. 1

KaryoLite™ BoBs™ assay flowchart

Fig. 2

Aneuploidy analysis by chromosome. Dark grey: NC. Black: ART with the patient’s own oocyte. Light grey: ART with a donated oocyte

Fig. 3

Results according female age and gestation origin. a: Natural conception. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. b: ART using the patient’s own oocyte. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. c: ART using a donated oocyte. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. The distribution of monosomies is independent of age in all three pregnancy type groups. Trisomies onset at an earlier age in the group of ART-assisted pregnancies using the patient’s own oocyte compared to the NC group (32 years and 36 years respectively). In ovum donation there is no relationship between recipient age and the occurrence of trisomies

Fig. 4

Results according to the gestational age. a: Natural conception. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. b: ART using the patient’s own oocyte. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. c: ART using a donated oocyte. Dark grey: Normal; Black: Trisomy; Light grey: Monosomy. Miscarriages with abnormal results are mainly concentrated at around weeks 7–8 and 9 weeks gestation, with the highest incidence occurring in week 8 of gestation. There are no differences in the type of gestation origin and gestational age at which spontaneous abortions with chromosomal abnormalities appear