Obstetrics & Gynecology · Medical Literature
A Web-Based Intervention for Reducing Sexually Transmitted Infections and Substance Use During Pregnancy: Randomized Controlled Trial.
Abstract
Sexually transmitted infections (STIs) are at a record high in the United States and are a significant health problem for childbearing women. Rates of substance use, particularly cannabis and opioid use, have increased in recent years and are linked to negative health consequences for pregnant women and their infants. Addressing these health concerns together during this vulnerable time is a priority. This study aims to test whether the Health Check-Up for Expectant Moms (HCEM), an innovative, theory-driven, technology-delivered, and fully automated brief intervention, reduced condomless sex and STI risk, alcohol, or drug use, compared to a control condition in pregnant women seeking prenatal care. We recruited a sample of 176 pregnant women (all were at risk for alcohol or drug use or STIs during pregnancy) from clinics and using social media campaigns (Facebook and Instagram) in the state of Michigan and randomized them to the motivational interviewing-consistent HCEM intervention or to an attention-, time-, and information-matched control condition delivered using the same technology platform. We followed these women at 2 and 6 months after the initial intervention visit. Primary outcomes included self-report assessment of alcohol, drug, or cannabis use and unprotected sexual occasions during pregnancy. A total of 88 women were randomized to the intervention, and 88 to the control condition. Cannabis use was the most prevalent substance reported during pregnancy; a total of 35.2% (62/176) reported recent use (within the last 90 days) at baseline, with 10.2% (18/176) reporting use in the month prior to baseline. There were significant reductions in alcohol and cannabis use over time during pregnancy (at 2 and 6 months compared to baseline) in both HCEM and control groups; however, these reductions were not significantly different between conditions (time-by-arm interaction), and most were sustained from spontaneous reductions reported in the month before study enrollment. Moreover, there were no statistically significant differences in the change pattern of condomless sex across the groups at either follow-up. There are many potential benefits of a technology-delivered approach to support the behavioral health of pregnant women in a private and convenient way. Our sample was largely low-risk, and as such, an intervention effect may have been impossible to observe given substantial self-change. Future trials are needed to examine efficacy in other samples of pregnant women with a higher risk of current alcohol or drug use. ClinicalTrials.gov NCT03826342; https://clinicaltrials.gov/study/NCT03826342. RR2-10.2196/30367.
Clinical relevance
In pregnant women at risk for alcohol or drug use or sexually transmitted infections (STIs), does the Health Check-Up for Expectant Moms (HCEM) — a fully automated, web-based, motivational interviewing–consistent brief intervention — reduce condomless sex, STI risk, alcohol use, or drug use compared with an attention-, time-, and information-matched control condition at 2 and 6 months? __SNAPSHOT__ {"studyDesign":"Randomized controlled trial (RCT)","setting":"Prenatal care clinics and social media (Facebook and Instagram) in Michigan, USA; University of Michigan–affiliated research team","sampleSize":"n=176 (intervention [HCEM]: n=88; control: n=88)","population":"Pregnant cisgender women ≥18 years (mean age 30.2 years, SD 5.02; 25.6% Black) who reported at least one behavioral risk factor: recent alcohol or drug use, condomless sex, multiple sexual partners, or a nonmonogamous partner. Recruited April 2019 – September 2023.","intervention":"Health Check-Up for Expectant Moms (HCEM): a theory-driven (Information-Motivation-Behavior model), fully automated, web-based brief intervention consisting of one main session plus two booster sessions within one month of enrollment, delivered via a motivational interviewing (MI)–consistent approach targeting simultaneous reduction of substance use and STI risk behaviors during pregnancy.","comparator":"Attention-, time-, and information-matched web-based control condition delivered on the same technology platform as HCEM.","primaryOutcome":"Self-reported alcohol use, drug/cannabis use, and number of unprotected (condomless) sexual occasions during pregnancy at 2-month and 6-month follow-up.","followUp":"2 months and 6 months post-initial intervention visit (up to approximately 11 months total per participant)","fundingSource":"Not reported in available abstract; no competing financial interests declared by authors per pilot study publication. Funding source for the 2026 trial not reported in available sources."}
Key findings
Both the HCEM intervention group and the control group demonstrated statistically significant reductions in alcohol and cannabis use over time (at 2- and 6-month follow-up compared with baseline); however, the between-group difference in the trajectory of change (time-by-arm interaction) was not statistically significant for any substance use outcome. The authors noted that most reductions observed appeared to be sustained from spontaneous decreases participants had already initiated in the month prior to study enrollment, rather than attributable to the intervention. Similarly, there were no statistically significant differences between arms in the change pattern of condomless sexual occasions at either follow-up timepoint. Cannabis was the most prevalent substance reported: 35.2% (62/176) reported use in the prior 90 days at baseline, and 10.2% (18/176) reported use in the prior month at baseline. No between-group effect sizes, confidence intervals, or p-values for the primary time-by-arm interaction analyses are reported in the available abstract or indexed sources. Clinically important adverse events related to the intervention were not reported. NNT and NNH are not calculable from available data.
Practice implications
This fully powered RCT did not establish that HCEM is superior to an active control condition for reducing substance use or condomless sex during pregnancy. What the study established: both groups improved on substance use outcomes over the course of pregnancy, a finding consistent with well-documented spontaneous reductions in substance use that commonly occur upon recognition of pregnancy. What the study did not establish: that the HCEM intervention itself — beyond the effect of attention, time, and information provided to controls — produces incremental reductions in cannabis use, alcohol use, or risky sexual behavior. A critical interpretive challenge is that the enrolled sample appears to have been largely low-risk at the time of randomization: the majority of cannabis users had already spontaneously reduced use before enrollment, raising a floor-effect concern that likely limited the ability to detect intervention effects. Findings apply to pregnant women in outpatient prenatal care in a midwestern U.S. state who meet at least one behavioral risk criterion, but who may not represent women with active, high-level substance use disorders or persistent high-risk sexual behavior at time of enrollment. Women with more severe or ongoing risk at enrollment, those outside Michigan, and non-English-speaking populations were not adequately represented. IMPORTANT NOTE: This summary is based on abstract-level data and indexed secondary sources only; the full published article was not available for review. Exact effect sizes, confidence intervals, and p-values for primary outcomes may be available in the full-text publication. __LIMITATIONS__ Sample size (n=176) was below the originally planned enrollment of 250, potentially reducing statistical power to detect modest but clinically meaningful intervention effects.,The enrolled sample demonstrated predominantly spontaneous reductions in substance use prior to randomization, resulting in a 'low-risk at enrollment' population that severely limits the ability to detect a treatment signal (floor effect / regression to the mean).,All primary outcomes relied on self-report, introducing social desirability bias for stigmatized behaviors (substance use, condomless sex); biological verification (hair/urine sampling) was suspended during the COVID-19 pandemic protocol adaptation, removing objective corroboration.,Recruitment spanned April 2019 to September 2023, crossing the COVID-19 pandemic period, which necessitated major protocol changes including transition from in-person to fully remote recruitment and elimination of in-person STI testing, potentially introducing heterogeneity across enrollment cohorts.,The active control condition was matched for attention, time, and information, which is methodologically rigorous but also means the control itself may have provided therapeutic benefit, reducing the detectable between-group difference.,Generalizability is limited to pregnant women in Michigan meeting specific enrollment risk criteria; the sample may not reflect populations with severe substance use disorders, those in rural settings with limited technology access, or non-English-speaking patients.,The single-state, clinic-and-social-media recruitment strategy may have introduced selection bias toward more health-engaged individuals.,Funding source for this trial was not reported in available indexed sources, limiting assessment of potential sponsorship bias.,No long-term postnatal follow-up for infant outcomes was reported in the primary outcome set, limiting assessment of downstream clinical consequences.,The abstract does not report confidence intervals or exact p-values for the primary time-by-arm interaction outcomes, preventing full appraisal of precision and the magnitude of null findings. __BOTTOM_LINE_CATEGORY__ not_ready_for_clinical_application __BOTTOM_LINE__ In this RCT, the HCEM web-based brief intervention did not produce statistically significant improvements in substance use or condomless sex outcomes over and above an active matched control condition in pregnant women at behavioral risk. The null result appears substantially driven by spontaneous pre-enrollment reductions in substance use, suggesting future trials should target pregnant women with confirmed, active higher-level risk at the time of randomization. Clinicians should not alter current practice based on these findings; technology-delivered behavioral interventions during pregnancy remain promising in concept but require further evidence in higher-risk populations.