An audit of patients seen by genetic counsellors for a history of recurrent miscarriages

Abstract

Introduction: Recurrent miscarriage is traditionally defined as three or more early (≤24 weeks’ gestation) consecutive pregnancy losses. There are several common causes of recurrent miscarriages, however, 40-60% of cases remain unexplained. Unbalanced translocations resulting from balanced translocations in one of the parents, account for only 2-5% of recurrent miscarriage cases. Therefore, parental karyotyping should not be the first-line investigation for recurrent miscarriages and patients should be thoroughly worked-up prior to being referred for genetic counselling. The recommended investigations for recurrent miscarriage include screening for antiphospholipid antibodies, thyroid screening and the assessment of uterine anatomy.

Aim: The overarching aim of this study was to perform an audit of patients referred for genetic counselling for recurrent miscarriage through the Genetic Clinics of the Division of Human Genetics, National Health Laboratory Service and the University of the Witwatersrand.

Methods: The study was a retrospective file review that used quantitative research methods. A total of 101 files of patients who were referred for genetic counselling for ‘recurrent miscarriages’ and/or ‘poor obstetric history’ from the years 2011 to 2021, were assessed. A data collection sheet was designed to collect specific patient details. These details included: maternal age at miscarriage, gravidity and parity, number of miscarriages, trimester in which miscarriages occurred and investigations performed. Data were captured and analysed on Microsoft Excel.

Results: The mean (standard deviation) age of the patients at the time of the consultation was 34.4 ± 5.9 years. The median (interquartile range) number of miscarriages per individual was 4 (3-5) per person. The majority of miscarriages occurred within the first trimester (72.7%, 308/430) of pregnancy. Only 14.0% (14/101) of the patients had all the required investigations performed prior to being referred for genetic counselling. Of the 101 patients that were seen, 43.6% (44/101) of the adult females and 26.7% (27/101) of their male partners with a history of recurrent miscarriages underwent karyotyping. Out of the patients that underwent karyotyping, only 1.4% (1/71) of the results indicated the presence of a chromosomal abnormality. In 20 of the individuals with a history of recurrent pregnancy losses, their products of conception (POC) were tested and in 50% (10/20) of those cases, an abnormal genetic result was found.

Conclusion: The purpose of this study was to determine what investigations patients with recurrent miscarriages undergo in academic State Hospitals in Johannesburg, South Africa. This study highlighted that very few women were fully worked up prior to their referral for genetic counselling. Furthermore, this study revealed that parental chromosomal abnormalities accounted for a small percentage (44.6%, 1/44) of recurrent miscarriages, therefore, genetic testing should not be a priority the first-line investigation for recurrent miscarriages, and it would be worth prioritising the other recommended investigations over this.