This is a retrospective observational analysis from a single, tertiary care, university-affiliated fertility centre, located in Lombardy, Rozzano, Milan, Italy, including all couples who underwent Assisted Reproduction (ART) procedures (fresh and frozen transfer cycles) during two time periods used for comparison: November 1st, 2018 to February 28th, 2019 (non COVID-19 risk) and November 1st, 2019 to February 29th, 2020 (COVID-19 risk.
No exclusion criteria were considered.
Patients were from all over Italy with a prevalence (70%) from the Lombardy region. The great majority of patients spent the entire period of the ovarian stimulation/monitoring in preparation for their treatments at 1-2 hours car distance from the hospital.
Information collected included: female age, BMI and smoking habits, duration of infertility, basal Follicle Stimulating Hormone (FSH), Anti Mullerian Hormone (AMH), Antral Follicular Count (AFC), indication for ART treatment, primary or secondary infertility and previous abortions. In addition, follow up data about pregnancy, first trimester abortion, and ectopic pregnancy outcome were collected until June 15, 2020.
No data about serological or oropharyngeal swab was considered. Of note, one embryologist with very mild symptoms had a confirmed positive oropharyngeal swab for SARS-CoV-2 during the study period, but no one else among medical, embryological, nurse and staff (about 60 people) had symptoms relatable to the viral infection.
Patient follow up included first Beta-hCG’s performed 12 days after blastocyst transfer or 14 days after cleavage stage transfer and for pregnant patients repeated every 48 hours, until reaching at least 1,500 UI/ml. Transvaginal ultrasound was scheduled 4 weeks after transfer or earlier in case of abdominal pain and vaginal bleeding or abnormal rising Beta hCG levels. All non-essential ART activities were interrupted on April 16, 2020. Only emergency services, including fertility preservation for oncological patients and pregnancy follow-ups were allowed during the lockdown period.
Patients were required to email the results of ultrasounds if performed in other facilities. Every day, medical staff and assistants on duty called patients and updated the pregnancy outcome in their medical charts. Less than 5% of patients were lost at the follow-up that was considered concluded only when all known pregnant patients completed at least the 12th gestational week (as of June 15, 2020).
Statistical Analysis and variable description
Clinical pregnancy was defined as a pregnancy diagnosed by ultrasonographic visualization of one or more gestational sacs or or definitive clinical signs of pregnancy 16. It therefore included ectopic pregnancy. Pregnancies with bHCG levels reaching less than 1,000 mIU/ml, and after exclusion of ectopic localization, were considered biochemical.
Data were described as number and percentage, or mean and standard deviation, as appropriated. Associations with period (pre and during COVID) were explored with χ2 test for categorical variables, or t student test for Gaussian continuous variables, or Mann Whitney for asymmetrical continuous variables. Association with abortion rate was explored with logistic regression analysis. Independent variable with a p value under 0.2 were then submitted to a multivariable logistic regression analysis. Pre and during COVID period variables were included in the multivariable analysis being the primary endpoint of the research. A p value under 0.05 was considered as significant. All analyses were conducted using Stata Statistical Software: Release15 (College Station, TX: StataCorp LLC).
Ethical approval
Generally, all patients undergoing ART procedures consent in writing that their medical records can be used for research purposes if anonymity and confidentiality is protected. Since both conditions were met, this study had expedited review and approval by the center’s Institutional Review Board (IRB), Humanitas Clinical Institute Ethic Committee.
All methods were performed in accordance with the relevant guidelines and regulations and the present research has been performed in accordance with the Declaration of Helsinki.
An informed specific consent was obtained from all participants and/or their legal guardians.
The study was also approved by our Independent Ethical Committee on May 14th, 2020 (protocol n. 37/20).