Antenatal Milk Expression in Nulliparous Pregnant People

Antenatal milk expression (AME) has emerged as a simple, inexpensive, novel method to increase maternal breastfeeding confidence, avoid early formula use, and increase proportion of mother's own milk (MOM) feeds-potentially leading to greater breastfeeding satisfaction, increased breastfeeding duration and exclusivity, and improved maternal-infant health outcomes. AME capitalizes on the production, and sometimes leaking, of milk-commencing during the second trimester of pregnancy by allowing women to collect and store milk for later use if needed and gain confidence in breastfeeding and their milk-making capabilities. AME may also "prime" the hormonal milk production process to create a larger postpartum milk supply. Pilot studies conducted with diabetic women demonstrate AME's safety, feasibility, and preliminary effectiveness in improving breastfeeding rates. AME has yet to be investigated in non-diabetic populations.

In the current study, investigators trialed our study procedures and milk collection and analysis methods, and examined the preliminary effectiveness of AME on breastfeeding outcomes among pregnant people without other biological children. Forty-five healthy, nulliparous women were enrolled and randomized to either a structured AME educational intervention or usual care/control group at Magee-Womens Hospital midwife practice at their 34-36 week prenatal appointment. The Principal Investigator (PI) or an research assistant (RA) met with all participants weekly from 37 weeks until delivery, during postpartum hospitalization, and at 1-2 weeks and 3-4 months postpartum. During visits, the PI/RA collected questionnaire data on maternal health and delivery, stress, depression, as well as outcomes of perceived milk supply and breastfeeding attitude, satisfaction, confidence, continuation and exclusivity. Those randomized to AME were taught the technique at the 37 week visit by a lactation consultant, with instructions to continue 1-2 times/day at home. AME was practiced and reinforced with the lactation consultant at each subsequent visit. Those in the control group received breastfeeding handouts at each prenatal visit. For those in the AME group, the PI/RA also collected a small milk sample at each prenatal visit, along with a written diary documenting AME at home. The PI/RA collected a milk sample from all participants at postpartum visits; samples are stored at University of Pittsburgh School of Nursing lab for subsequent analyses (TBD). The PI/RA conducted semi-structured interviews at 1-2 weeks postpartum with AME participants about their experiences with the intervention. Summary statistics were then calculated for feasibility and breastfeeding outcome data, with significance tests (ANOVA, chi-square) to determine group differences breastfeeding outcomes as applicable. Interview data were analyzed for major themes to refine the intervention for a larger trial.

Data collected in this study were used to revise our AME clinical teaching protocol, AME diaries, and establish standard operating procedures for milk collection and storage for an ongoing, larger randomized trial examining AME's effect on breastfeeding outcomes.

Inclusion criteria

• Pregnant with a single fetus
• 34-36 6/7 weeks pregnant (calculated from anticipated due date)
• No other living children and no prior breastfeeding experience
• Plan to breastfeed exclusively for at least 4 months
• At least 18 years old
• Plan to deliver baby at Magee-Womens Hospital of UPMC
• Healthy (no major medical or pregnancy condition which would constitute a high-risk pregnancy)

Exclusion criteria

• Women with contraindications to breastfeeding, as specified by American Academy of Pediatrics, including HIV+ status, human T-cell lymphotrophic virus, etc. HIV status will be assessed by history (maternal self-report of diagnosis).
• Conditions known to significantly adversely impact maternal milk supply (e.g., breast hypoplasia, history of breast reduction surgery, as assessed on screening form)
• Conditions which predispose to preterm labor or otherwise constitute a high-risk pregnancy as outlined by the National Institute of Child Health and Human Development including: breech presentation, vaginal bleeding during second or third pregnancy trimester (more than one episode, not related to possible cervical mechanical trauma from sexual intercourse or cervical exam), diagnosed or suspected developmental abnormalities in the fetus, less than 6 months between last birth and the beginning of current pregnancy, placenta previa, diabetes type I or II or gestational diabetes, preeclampsia (or hypertension with proteinuria), smoking, alcohol use, or illicit drug use during pregnancy, oligohydramnios/polyhydramnios, any previous second or third trimester pregnancy loss/miscarriage