Dramatic physiological, psychological, and social changes during the antenatal period may significantly affect a woman's psychosocial and physical conditions, thereby resulting in stress, anxiety, and depressive symptoms. Cognitive behavior therapy (CBT) is a well-established effective psychotherapy to modify thoughts, beliefs, and perceptions, as well as change the behavioral patterns under numerous conditions. However, at-risk women that need access to CBT are challenged by many issues, such as insufficient therapists, stigmatization, long waiting times, and high costs. Preventive strategies may offer a more acceptable means of addressing the problem. Internet-based CBT can help overcome some barriers to improve psychological well-being by providing a timely and efficacious intervention that is customizable, cost-effective, and flexible in terms of time and geography.

Hypotheses Compared with the control group,

1. Women who completed an internet-based CBT (MoodUP) will have significantly lower scores for stress, anxiety, and depressive symptoms immediately post-intervention and at 12 weeks post-intervention;
2. Women who completed MoodUP will reduce the frequency of negative automatic thoughts, achieve a better sleep quality, life satisfaction, and mental health immediately post-intervention and at 12 weeks post-intervention;
3. Women who completed MoodUP will have better client satisfaction.

Approach A two-stage research design will be used for 3 years. Stage I will consist of the development and validation of MoodUP based on theoretical and empirical rationales. The development of MoodUP will be guided by a combination of the basic principles from behavioral and cognitive psychology. Essential components, teaching strategies, and technical elements of MoodUP will be established according to literature review and a meta-analysis by the principal investigator and her team. Ethical and quality standards will be assessed using the Health on the Net code of conduct and the Health-Related Website Evaluation Form, respectively.

Stage II will be used to evaluate the efficacy of MoodUP among 143 antenatal women using a randomized controlled trial, two-armed parallel group pretest, and repeated post-test following the Consolidated Standards of Report Trials guidelines for an internet-based intervention. Primary outcomes will be the presence and severity of antenatal stress, anxiety, and depressive symptoms using the 21-item Depression Anxiety Stress Scale. Secondary outcomes will be automatic thoughts, sleep disturbance, life satisfaction, mental well-being, and client satisfaction, as determined by the 30-item Automatic Thoughts Questionnaires, four-item Sleep Disturbance subscale of the Medical Outcomes Study Sleep Scale, the five-item Satisfaction with Life Scale, the WHO five-item Well-Being Index, and the seven-item Client Satisfaction Questionnaire, respectively. Multivariate analysis of variance with repeated measures will be used to compare the mean difference of scores in the three-time points through Wilks's lambda test. The data will be analyzed according to the intention-to-treat principle with baseline values imputed for missing follow-up data.

Inclusion Criteria:

• < 18 weeks of gestation (the upper limit of < 18 weeks allows time to complete six sessions and follow-up questionnaires prior to delivery)
• 21 years of age or older
• ability to speak and read English
• plan to deliver baby in Singapore
• can access the internet.

Exclusion Criteria:

• severe psychiatric illness
• severe medical complications
• severe obstetric complications
• fetal abnormality.

Pregnant women

A randomisation algorithm on the HappyMUM website automatically assigned women to either the intervention (MoodUP) group or the control (HealthyMum) group in a 1:1 allocation ratio. A computer-generated message notified women of their group assignment. We aimed to blind women to use the active nature of the control condition. Due to the computer-based randomisation, the researchers and research assistants were unaware of the group assignment before allocation and remained blinded to the participants' group allocation throughout the trial, which ensured allocation concealment. We also blinded the group assignment to data collectors and analysts.