Context

This is a single center QI study at Peking Union Medical College Hospital (PUMCH) in Beijing, China. PUMCH is a university-affiliated general hospital, with approximately 3500 annual deliveries, and a 25-bed NICU with approximately 800–900 annual admissions. Our team takes care of all the infants born in PUMCH. A neonatologist rounds in the obstetrics department and cares for neonates rooming in with their mothers. Breast pumps are available in maternity ward. A portion of late preterm infants, mostly were 34 and 35 weeks of gestation, will be transferred to NICU for further medical care and separated from their mothers. The NICU is equipped with refrigerators to store breast milk and heaters to reheat breast milk.

Study team

The QI team included neonatologists and nurses from obstetric units and NICU. In addition, social workers were invited to participate the QI project.

Study population

Late preterm infants born at PUMCH and admitted to the NICU on the first day of life during May 2017 and November 2019 were qualified for this QI study. Infants with gastrointestinal anomalies, severe infection, and congenital metabolic disease were excluded. In addition, infants were excluded if the length of hospital stay was less than 7 days, or if their mothers did not intend to breast feed the infants.

Measures

The primary outcome measure was the rate of full breast milk feeding, which we defined as the percentage of late preterm infants who reached 120ml/kg/d of enteral breast milk feeding on the 7th day (D7). This was based on previous data that the median length of hospital-stay for NICU admitted late preterm infants was 8 days (7-11days), and enteral feeding at discharge was 108.7ml/kg/d [8]. We speculated that the minimum volume of breast milk to maintain full breast milk feeding would be 120 ml/kg/d by discharge. So we defined full breast milk feeding as reaching 120ml/kg/d of breast milk on D7. On the control chart, late preterm infants were easily and clearly grouped by five to calculate full breast milk feeding rate. In addition, data were reviewed monthly for potential errors. We defined our SMART (specific, measurable, attainable, relevant, time-based) aim as 50% increase of full breast milk feeding rate for hospitalized late preterm infants by November 2019.

Interventions

Active QI efforts began in December of 2017 and completed in November of 2019. Multidisciplinary team mapped current processes based on the best evidence from the literature, experience, previous data and failure mode and effect analyses. Developed key drivers to prioritize QI interventions, including informational materials and education about breast milk feeding, consultations and support on optimal breast milk initiation, initiating breast milk expression within 1 h after birth, accurate measurement and recording of expressed breast milk, stimulating continuous and effective lactation, proper breast pump selection in and out of hospital and sending and preserving of expressed milk to NICU (Fig. 1). Specific interventions were identified and tested with Plan Do Study Action (PDSA) cycles (Table 1). Outcome and processes data were shared at monthly meetings.

Fig. 1

Key driver diagram to increase full breast milk feeding of late preterm infants. Note: LOR # = Levels of Reliability Number, e.g., LOR 1; SMART: specific, measurable, attainable, relevant, time-based; NICU neonatal intensive careunit;

Early initiation of milk expression

The timing of breast milk pumping initiation after giving birth to very low birth weight infants has been studied extensively. In a randomized study, mothers who used a hospital-grade electric breast pump within the first hour post-delivery produced significantly greater cumulative human milk output at Day 7 and Week 3 compared to mothers who used the same breast pump after the first hour post- delivery [15, 16].

The nurses in maternity ward and social workers assisted mothers separated from their late preterm infants in initiating milk expressing as soon as possible after birth, mostly within one hour, to achieve 8 to 12 times of milk expressing per day. Both manual and pump expressing are effective in establish and maintain lactation.

Table 1 Interventions and starting time for each intervention Optimal devices for milk pumping

Hospital grade breast pumps could mimic the infant’s sucking rate, rhythm and pressures to the greatest possible extent in pump-dependent women. Studies have proved the effectiveness, efficiency, comfort and convenience of breast pumps and breast pump suction patterns compared with the infant as the “gold standard” [17, 18]. New hospital grade breast pumps were obtainable in the maternity ward.

Lactation stimulation

Suckling by the newborn helps to maintain lactation by the release of oxytocin, which causes contraction of the mammary epithelium and the ejection of milk [19]. When mothers and infants are separated, there is interruption of this suckling. Kangaroo care may partially compensate for this condition. Kangaroo care is a cost-effective intervention recommended by the World Health Organization for the care of stable preterm infants. Infants may receive skin-to-skin care on the chest of their mother or another caregiver while exclusively breastfeeding (ideally) or while receiving breast milk feedings. Data showed that intermittent kangaroo care was associated with a nearly doubled increase in exclusive breast milk feeding and breastfeeding at both discharge and 42 days after discharge for late preterm infants [20,21,22].

To promote kangaroo care in NICU, we provided comfortable reclining chairs for mothers and hand-held mirrors to observe their infants while performing kangaroo care. The length of time that mothers could stay in the NICU with their infants was increased to at least two hours per day. Videos and photos of hospitalized infants were sent to the smartphone of parents to increase emotional connections and further stimulate lactation.

Sending breast milk to the NICU

Parents were encouraged to send expressed breast milk to NICU at any time. Refrigerators for storage of breast milk and milk heaters were equipped in the NICU.

Sending and storage of breast milk was standardized in the NICU as well as the key points was demonstrated to the parents.

Analysis

For the primary outcome, baseline median and control limits were calculated and displayed from May 2017 through November 2017. The baseline mean was carried forward and displayed throughout the intervention period from December 2017 to November 2019. Data values were added monthly and monitored for evidence of significant change by using standard SPC rules, including the presence of (1) 1 point outside the upper or lower control limits, (2) 2 of 3 successive points in the outer third of the control limit, (3) 8 successive points above or below the center line, or (4) 6 consecutive points increasing or decreasing [10].