Non-invasive prenatal testing for autosomal recessive disorders: A new promising approach

Background: In pregnant women at risk of autosomal recessive (AR) disorders, prenatal diagnosis of AR disorders primarily involves invasive procedures, such as chorionic villus sampling and amniocentesis.

Methods: We collected blood samples from four pregnant women in their first trimester who presented a risk of having a child with an AR disorder. Cell-free DNA (cfDNA) was extracted, amplified, and double-purified to reduce maternal DNA interference. Additionally, whole-genome amplification was performed for traces of residual purified cfDNA for utilization in subsequent applications.

Results: Based on our findings, we detected the fetal status with the family corresponding different genes, i.e., LZTR1, DVL2, HBB, RNASEH2B, and MYO7A, as homozygous affected, wild-type, and heterozygous carriers, respectively. Results were subsequently confirmed by prenatal amniocentesis. The results of AmpFLSTR™ Identifiler™ presented a distinct profile from the corresponding mother profile, thereby corroborating the result reflecting the genetic material of the fetus.

Conclusion: Herein, we detected AR disease mutations in the first trimester of pregnancy while surmounting limitations associated with maternal genetic material interference. Importantly, such detection strategies would allow the screening of pregnant women for common AR diseases, especially in highly consanguineous marriage populations. This technique would open avenues for the early detection and prevention of recessive diseases among the population.

Comparing pregnancy outcomes between symptomatic and asymptomatic COVID-19 positive unvaccinated women- Multicenter study in Saudi Arabia

Introduction

COVID-19 infection in pregnancy ranges from asymptomatic infection to severe disease. However, the maternal and pregnancy outcomes are primarily favorable. Acute Respiratory Illness (ARI) score is a Visual Triage Checklist for Acute Respiratory symptoms created by the ministry of health of Saudi Arabia ¹² to screen the patient for acute respiratory infection with MERS-CoV. It has been used during the COVID-19 pandemic to identify suspected cases and place patients in isolation precautions if the score is≥ 4.

Method

This study is a cross-sectional study of all pregnant women who tested positive for COVID-19 in four medical centers located in four different cities in Saudi Arabia. The study period was from 1/3/2020 until 31/10/2020. Outcomes investigated were the prevalence of COVID infection in pregnant women at the time of delivery. Rate of asymptomatic disease, different maternal and pregnancy outcomes. Women were divided into symptomatic and asymptomatic groups according to the ARI score. The two groups were compared in maternal, perinatal, and neonatal outcomes. Furthermore, the cohort was divided according to maternal age into two groups: women of advanced maternal age ≥ 35 years and younger. The two groups were compared in maternal, perinatal, and neonatal outcomes

Results

During the study period, 9573 women gave birth at KAMCs, and 402 pregnant women were identified as COVID positive. Out of all COVID-positive women, only 394 women gave birth at KAMCs. The screening for COVID infection differed between the centers, but the testing was the same by the Nasopharyngeal polymerase chain reaction (PCR) swab. In Riyadh, screening was based on ARI scoring at the beginning of the pandemic. Then, it became universal. In Jeddah, the screening was based on ARI scoring. Any woman who scored four or more was labeled as suspected, and she was tested. Finally, in Madinah and Dammam, the screening was universal throughout the study.

The prevalence of COVID-19 infection among women who gave birth at KAMCs was 4.2% (402/9573). (CI 3.8–4.6%). At the time of diagnosis, most women (62%) were asymptomatic. The most common symptoms were cough and shortness of breath. Twenty-two women (5.5%) had Pneumonia, and five women (1.3%) needed admission to Intensive care units (ICU). One woman died due to respiratory failure.

When pregnancy outcomes were compared between symptomatic and asymptomatic women, pregnancy in symptomatic women was more likely to be complicated by Abortion (6 versus 2% p-value 0.00), fetal death (3 versus 1.3%), and cesarean delivery (30.8 versus 22.4%, p-value 0.001). COVID-positive pregnant women of advanced maternal age (AMA) were more likely to be symptomatic, have Abortion (5 versus 1%, p-value 0.01), and have Preterm delivery (17 versus 11% p-value 0.01) than younger women. In addition, neonatal death was more common in AMA COVID-positive women than younger (4 versus 0%), regardless of COVID-related symptoms.

Conclusion

Most of the COVID-infected pregnant women are asymptomatic. Therefore, the ARI scoring system does not help to triage patients. Symptomatic women, especially those older than 35, tend to have a higher maternal and pregnancy complication rate.