Routine Pregnancy Screening for Women on Opioid Substitution Therapy (PREG-O)

Women who take opioid substitution therapy have higher rates of unintended pregnancy, more pregnancies, and a higher risk of pregnancy complications than the general population. Current practice is to test for pregnancy only at patient request or if the clinician suspects pregnancy. This study will compare monthly pregnancy testing to current practice in a double blind randomized control trial. As many women of childbearing age as possible will be recruited from the Hamilton Clinic for Opioid Substitutional Therapy. Women assigned to the intervention will have monthly testing at the same time as their monthly urine drug testing at the clinic. The primary objective is to assess if there is a significant difference is early pregnancy detection and the secondary objectives are to assess differences in pregnancy disposition and gestational age at entry to prenatal or abortion care.

The Routine Pregnancy Screening in Women on Opioid Substitutional Therapy study involves screening women from the The Hamilton Clinic for OST regularly for pregnancy to determine if this results in earlier prenatal care and improved pregnancy disposition. All eligible women at the Hamilton clinic will be approached for recruitment. The study phase last for 18 months. The investigators will assess for any significant difference in the rates of early pregnancy diagnosis, pregnancy disposition, and associated outcome measurements. Study results could inform best practices in the care of child-bearing women on OST and will provide baseline information and feasibility data to inform design of a larger RCT to assess the effect on pregnancy and birth outcomes. This pilot study will serve to demonstrate whether routine pregnancy screening is effective for earlier pregnancy diagnosis and whether it has any impact on pregnancy disposition and entry into pregnancy-related care for women on OST. In addition, the investigators will also be seeking to address whether routine pregnancy testing is logistically and financially feasible for patients receiving OST at a primary care-run addiction setting. If this intervention is found to be both effective and feasible, it would be possible to apply this study methodology to larger-scale RCTs across multiple clinical sites with the power to assess maternal and fetal outcomes.

Participants will not know if they are assigned to the intervention or control group. Their weekly urine test that is collected by the opioid substitution therapy clinic will be tested monthly for pregnancy. Pregnancy will then be reported to the patient's attending physician on the day of testing, who would then communicate the result to the patient. The physician will continue with standard pregnancy care. The investigators will remain blind throughout data analysis and will not know if the pregnancy was discovered via monthly testing or standard practice.

Patients at the Hamilton Clinic present to the clinic most often on a weekly basis to provide a urine sample for urine drug screening and to meet with their MRP. This same urine sample will be tested for pregnancy in the intervention group once per month. Resulting positive test results will be reported to the patient through their attending physician on the day of testing.

Participants in the control group will not receive study-initiated urine pregnancy testing but will receive usual care, which may include pregnancy testing based on patient request or clinical judgement.

Patients at the Hamilton Clinic present to the clinic most often on a weekly basis to provide a urine sample for urine drug screening and to meet with their MRP. This same urine sample can be tested for pregnancy in the intervention group once per month. Positive pregnancy test rates will be recorded for the intervention and control groups over the 1 year study period.

Pregnancy disposition will be measured by the woman's choice to either continue with the pregnancy and enter care or enter into induced abortion care. Participants will either give the researchers access to their medical records and outcomes will be recorded from that information or participants can complete a self-report on pregnancy outcomes.

Gestational age at entry into pregnancy related care will be obtained from ultrasounds and/or dates estimated from last menstrual period if access is granted to medical records. Otherwise researchers will depend on self-report. Pregnancy related care includes prenatal care or induced abortion services.

The cost of additional pregnancy testing will be recorded by The Hamilton Clinic for OST for the length of the trial.

Inclusion Criteria: currently on methadone or buprenorphine maintenance therapy have some male sexual partners Exclusion Criteria: females who have exclusively female sexual partners a previous diagnosis of premature menopause hysterectomy, oophorectomy, and/or tubal ligation current pregnancy current intrauterine device (hormonal or non-hormonal) unable to give informed consent in English

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College of Physicians and Surgeons of Ontario: Methadone Maintenance Treatment Program Standards and Clinical Guidelines