1. Rewrite the paragraph into your own words. Do not copy theparagraph below. The context of the original paragraph should beretained.

We did a retrospective review of medical records from ninepregnant women with COVID-19 pneumonia admitted to ZhongnanHospital of Wuhan University from Jan 20 to Jan 31, 2020. Diagnosisof COVID-19 pneumonia was based on the New Coronavirus PneumoniaPrevention and Control Program (4th edition) published by theNational Health Commission of China.4 All nine pregnant womenwith COVID-19 pneumonia tested positive for severe acuterespiratory syndrome coronavirus 2 (SARS-CoV-2) by use ofquantitative RT-PCR (qRT-PCR) on samples from the respiratorytract.

This study was reviewed and approved by the Medical EthicalCommittee of Zhongnan Hospital of Wuhan University (approval number2020004). Written informed consent was obtained from each enrolledpatient.

Data collection

We reviewed clinical records, laboratory findings, and chest CTscans for all nine pregnant women. All infor- mation was obtainedand curated with a customised data collection form. Two studyinvestigators (JG and XY) independently reviewed the datacollection forms to verify data accuracy.

Maternal throat swab samples were collected and tested forSARS-CoV-2 with the Chinese Center for Disease Control andPrevention (CDC) recommended Kit (BioGerm, Shanghai, China),following WHO guidelines for qRT-PCR.5–7 All samples wereprocessed simultaneously at the Department of Clinical Laboratoryof Zhongnan Hospital and State Key Laboratory of Virology/Instituteof

Medical Virology, School of Basic Medical Sciences, WuhanUniversity. Positive confirmatory cases of COVID-19 infec- tionwere defined as those with a positive test result from eitherlaboratory.

Amniotic fluid samples from patients with COVID-19 pneumoniawere obtained via direct syringe aspiration at the time ofdelivery. Cord blood and neonatal throat swab samples werecollected immediately after delivery in the operating room.Additionally, breastmilk samples from patients with COVID-19pneumonia were col- lected after their first lactation. Evidence ofvertical transmission was evaluated by testing for the presence ofSARS-CoV-2 in these clinical samples. Sample collection wassuccessful in six cases (patients 2, 4–6, 8, and 9). Among thethree patients from whom sample collection was not successful,patient 1 was diagnosed after caesarean section, thus no sample wasobtained. Patients 3 and 7 underwent caesarean section at night,thus immediate sample collection was not possible. All samples wereprocessed at the State Key Laboratory of Virology/Institute ofMedical Virology, School of Basic Medical Sciences, WuhanUniversity, for further testing. Sample collection, processing, andlaboratory testing complied with WHO guidance.6 All samples,as described above, were tested for SARS-CoV-2 by use of qRT-PCRwith the CDC recommended Kit. The test results were confirmed bynested RT-PCR with designed primers. For the nested RT-PCR assay,total RNA was extracted from samples by use of the TRIzol LSreagent (Invitrogen, Carlsbad, CA, USA), followed by reversetranscription by use of the one-step RT-PCR Kit (TaKaRa, Dalian,China). Primers were designed on the basis of the sequence ofWuhan-Hu-1 (MN908947). Partial S segment sequences (nt21730-22458)were amplified with primers: 5′-CTCAGGACTTGTTCTTACCTT-3′ and5′-CAAGTGCACAGTCTAC-AGC-3′.

Statistical analysis

Statistical analysis was done with SPSS, version 20.0.Continuous variables were directly expressed as a range.Categorical variables were expressed as number (%).