As technology advances, smartphones are now widely available and can provide a convenient and effective means to improve drug compliance by sending an electronic reminder on a regular basis. In a meta-analysis of 16 RCTs in assessing of drug compliance in chronic diseases, text message significantly improves medication compliance (OR, 2.11; 95% CI, 1.52-2.93; P < 0.001). The drug compliance improves from 50% to 67.8%, or an absolute increase of 17.8%. Further evaluation is required as most of these RCTs relies on self-reported compliance. This data may be not applicable to pregnant women and trial of using this approach to improve drug compliance during pregnancy is lacking.

The investigators hypothesize that the use of smartphone message will improve the drug compliance in pregnant women requiring long term medications. The investigators propose a randomized controlled trial to evaluate the effect of smartphone message.

Inclusion Criteria:

• All women age ≥ 18 years old
• Able to receive electronic reminder through smartphohne
• Gestational age less than 16 completed weeks as defined by pelvic ultrasound
• Part 1: Need to take aspirin or progesterone for prevention of pre-eclampsia or preterm birth respectively
• Part 2: Given multivitamin as health supplementation

Exclusion Criteria:

For Part 1:

• History of adverse reaction to aspirin
• History of adverse reaction to progesterone
• History of breast or genital tract malignancy
• History of suspected thromboembolic disease
• Congenital uterine anomaly
• Unwillingness or inability to comply with study procedures
• Known paternal or maternal abnormal karyotype

Female