The purpose of this pilot randomized trial is to determine the effectiveness, feasibility, and acceptability of a mobile, semi-automated text message-based intervention (MILK) to prevent perceived low or insufficient milk supply (PIM) among mothers without prior breastfeeding experience. PIM is the leading cause of premature breastfeeding cessation, and prior work shows that it is often rooted in low breastfeeding self-efficacy and misconceptions about lactation physiology and trajectory. The MILK intervention is designed to address PIM, as well as other common breastfeeding problems via semi-automated text messages of prenatal and postpartum breastfeeding education and support. Messages are time-sensitive (e.g., specific to gestational age, time since delivery) and based on the Breastfeeding Self-Efficacy (Social Cognitive) Theory; they are also modeled from pilot work that investigated how first-time mothers view, manage and describe breastfeeding problems. Messages were vetted with clinical lactation experts, as well as pregnant and postpartum women with no other children.

The MILK intervention will be trialed against a control intervention group, who will receive general perinatal education through the national Text4Baby system. The investigators will recruit approximately 186 healthy, pregnant women at 13-25 weeks gestation from Magee Women's Hospital clinics and outpatient sites. Women will be randomized via computer-generated simple randomization to the experimental or control intervention. Both groups will receive text messages 3-5 times per week from week 25 of pregnancy through week 8 postpartum. Measured outcomes of interest will include perceived breast milk supply, breastfeeding confidence, maternal anxiety, breastfeeding exclusivity, and breastfeeding duration. Data will be collected at baseline (13-25 gestational weeks), 34-36 gestational weeks, and at 1, 2, 4, and 8 weeks postpartum via online survey or telephone call. To assess the potential longer-term impact of the intervention, breastfeeding continuation and exclusivity will be reassessed via telephone at 6 months postpartum. Between group and group x time differences in outcome measures will be examined graphically and via linear mixed modeling. To inform modifications to MILK, telephone interviews will be conducted with a subset of participants in each group to assess and compare intervention use, burdens and challenges, and suggested alterations (8 weeks).

The purpose of the MILK Trial is to examine and compare the effectiveness, feasibility, and acceptability of a semi-automated, text-based, theory-driven intervention ("MILK" intervention) to prevent perceived insufficient milk and its potential inter-related sequelae, including maternal anxiety and early breastfeeding cessation, among mothers without breastfeeding experience who intend to exclusively or nearly exclusively breastfeed. Specifically, the investigators will:

1. Determine the effect of the MILK intervention on perceived insufficient milk supply (PIM) and related maternal psychological and behavioral sequelae.

   Compared to the control intervention group ("Text4Baby"), the investigators hypothesize that MILK participants will have a perception of greater breast milk volume/supply, higher self-reported breastfeeding confidence, lower anxiety scores, and longer duration of exclusive breastfeeding.

2. Assess the feasibility of a semi-automated text-based PIM intervention (MILK) for mothers.

The investigators will compare characteristics of women who are and who are not eligible for, chose to participate in, and complete this randomized pilot intervention study. The investigators will also conduct post-study individual interviews with mothers to determine how the interventions were used and perceived (e.g., burden, challenges).

Inclusion Criteria:

Pregnant women who:

1. are ≥ 18 years;
2. are between 13-25 gestational weeks;
3. have no prior breastfeeding experience or other living biological children;
4. have a personal cell phone with internet access and an unlimited text message plan; and
5. intend to exclusively, or nearly exclusively breastfeed (<2 ounces of artificial milk per day) for at least 2 months postpartum; (6) plan to deliver their infant at MWH.

Exclusion Criteria:

1. Maternal, fetal, or neonatal conditions or complications with the potential to physiologically compromise breastfeeding or milk supply (e.g., history of breast reduction surgery, infant cardiac defects, postpartum infant ventilator dependence);
2. current gestation of ≥ 1 fetus;
3. contraindications to breastfeeding as specified by the American Academy of Pediatrics (e.g., HIV+ status).

Measures with numbers analyzed less than the overall baseline numbers include all participants with data collected.

From study enrollment at 13-25 weeks of gestation until conclusion of the intervention and data collection of primary aims at 8 weeks postpartum

Only reportable adverse events were collected/recorded for the study, and here we are only including reportable adverse events for maternal participants. Infants of participants are not included in numbers. Relevant to this, all-cause mortality does not include infants. As such, we report here that there were two infant deaths during the course of the study in the control group, and it was determined that they were unrelated to the study.

Lactation consultant providing assistance has no knowledge of group assignment. Statistician completing final analysis of data will be blinded to group assignment.