Breastfeeding initiation among women with preeclampsia with and without severe features

1 Background

Hypertensive disorders affect up to 10 percent of pregnancies and constitute one of the leading causes of maternal and perinatal mortality across the world [1–4]. Preeclampsia is a complication of pregnancy characterized by new onset hypertension and proteinuria occurring after 20 weeks gestation [1–4]. Early-onset preeclampsia, albeit less common, carries the most severe maternal and perinatal mortality whereas late onset PWSF may also lead to intrauterine growth restriction, uteroplacental insufficiency and prematurity [5, 6].

The only definitive treatment for preeclampsia is delivery which often precipitates indicated preterm birth [1–4]. Another mainstay in the treatment of PWSF is 24-hour postpartum administration of MgSO₄ for seizure prophylaxis [1–4]. While serious maternal and neonatal side effects of MgSO₄ are rare, this therapy in addition to the condition of the mother and her often premature infant may lead to mother-infant separation during the critical first postpartum day [7–9].

Breastfeeding (BF) is key to the short- and long-term health and wellbeing of mothers and their infants [10, 11]. In addition to traditionally recognized barriers to BF among healthy women, maternal and neonatal morbidities that complicate preeclampsia with severe features (PWSF) and without severe features (WOSF) may also interfere with or delay BF initiation and/or BF duration. Unfortunately, literature on the impact of preeclampsia on BF remains scarce [8, 12].

2 Subjects and methods

This retrospective cohort investigation was approved by the Institutional Review Board at The Ohio State University Wexner Medical Center. Electronic maternal and neonatal records (2013–18) were reviewed. Women were diagnosed with late-onset preeclampsia with PWSF or WOSF according to established clinical and laboratory criteria [1–4]. Women with late-onset preeclampsia superimposed on diabetes mellitus or on chronic hypertension were not included in this study. Women were categorized as obese (BMI 29–34 kg/m²), very obese (35–39 kg/m²) or extremely obese (≥40 kg/m²).

The study population consisted of women with late-onset preeclampsia and their infants if delivered at ≥34 weeks gestation. Pregnancies affected by major or fatal malformations were excluded. Upon arrival to labor and delivery, each woman indicated her past BF experience and her intended infant feeding choice. Our family-centered care system has rooming-in available and full-time lactation consultants whose services are offered to all women regardless of their infant feeding preference.

Per our hospital practice, any symptomatic infants were directly transferred from the delivery room to the neonatal intensive care unit (NICU) for further care. If the condition of the mother and her infant following delivery allowed, maternal-infant interactions such as holding, skin-to-skin contact, and BF were encouraged. Asymptomatic infants able to feed were transferred to the newborn nursery for routine care and glucose monitoring if applicable. Delivery room and postpartum maternal-infant interactions were observed and documented by the obstetrical, newborn nursery and NICU nursing staffs and lactation consultants.

Screening for hypoglycemia (blood glucose <40 mg/dl) was done via serial point of care testing (Accu-Chek^®) or by plasma glucose measurement in the laboratory (Beckman Coulter AU5800, Beckman Coulter Inc., Brea, CA, U.S.A.) starting within the first hour of life after the first feeding and every 2–4 hours thereafter as needed. Asymptomatic infants in the newborn nursery with hypoglycemia were promptly BF or FF and those with recurrent hypoglycemia were treated with intravenous (IV) dextrose. On admission to the NICU, most infants were started on IV dextrose and those who were able to feed were BF or FF.

BF was considered initiated if, during the 24 hours preceding hospital discharge, infants were BF exclusively or partially. Exclusive BF was defined by direct feedings from the breast, by expressed breast milk (EBM) alone or in combination with direct BF or by donor human milk (DHM). Partial BF was defined by direct BF or by EBM in combination with formula. Due to the retrospective study design, no follow-up information was available on infant feeding practices after hospital discharge.

3 Results

The study population consisted of 262 women with preeclampsia (158 women with PWSF treated with MgSO₄ and 104 women with WOSF who did not receive MgSO₄).

The incidence of preeclampsia complicating pregnancies continues to increase worldwide and its successful management based on early delivery leads to a high rate of premature births [1–4]. Thus, it may be anticipated that NICU admissions will remain high especially for infants born to women with PWSF alone or PWSF superimposed on other morbidities [8, 9]. Prematurely born infants are challenged by a myriad of developmental obstacles and illnesses that could affect initiation and continuation of BF [8, 14]. Additionally, admission to an NICU, even if temporary, diminishes opportunities for critical physiological mother-infant interactions, while creating anxiety and negative emotions in the mother [8, 12–16]. When preeclampsia develops, a formerly healthy pregnancy becomes high risk requiring the woman to cope with a serious illness that threatens not only herself but also her unborn baby [15].

Intention to BF is one of the strongest predictors of BF initiation in healthy as well as in high risk obstetrical populations [8, 17]. Despite the heterogeneity of morbidities and co-morbidities associated with high risk obstetrical pregnancies, intention to BF is similar to that of the general population [17]. However, there exists a discordance among women with complex pregnancies who intend to BF and the rate of exclusive or partial BF at discharge [8, 17]. In women with severe preeclampsia, we observed an increase in intention to BF from 2007–2011 to the present and a decline in intention to FF or to feed a combination of both [8, 17].

Among women with PWSF or WOSF, prior BF experience leads to higher intention to BF and to better BF initiation rates while the lack of prior BF experience is an additional risk factor for lower intention to BF and higher BF initiation failure. Women who declare no prior BF experience represent a group that attempted BF and failed or who did not intend to BF [17, 18]. A more detailed BF history could identify obstacles to BF intention and initiation and may help to define strategies to improve the next BF experience.

In normal as well as in high risk pregnancies certain hospital practices may delay infant feeding (i.e., cesarean delivery, eye prophylaxis, vitamin K administration, blood glucose monitoring). While some of these practices may be postponed, others may be unavoidable especially in late preterm infants born to women with preeclampsia [8, 9]. Information about early BF and BF initiation among healthy women is abundant, however, similar data among women with preeclampsia remains scarce [8, 9].

Cesarean delivery, a traditionally recognized obstacle to early mother infant interactions remain consistently high among women with PWSF and WOSF [8, 19]. Cesarean birth is known to prevent or delay skin-to-skin contact, postpone the onset of lactation, reduce the incidence of exclusive BF and increase the likelihood of formula supplementation [19–22]. The rate of BF during the first hour after birth among women in the WOSF group who delivered vaginally (46%) was similar to that reported for late preterm infants in the US [23]. The lower rates observed among infants in the PWSF group as compared to those in the WOSF group highlight the severity of the mother’s illness or their infants morbidities and present a challenge for BF initiation.

The efficacy of magnesium sulfate given postpartum to prevent seizures in women with PWSF has been well established [1–4]. Unfortunately, effects on the mothers’ sensorium during the infusion make mother-infant separation almost unavoidable [8, 9]. The number of women who had skin-to-skin contact and/or BF during the first postpartum day especially those in the PWSF group attest to hospital practices that include close monitoring of mothers and infants at the delivery room and adjacencies [16, 24].

Both the American Academy of Pediatrics and the Academy of Breastfeeding Medicine strongly recommend exclusive BF for all healthy infants during birth hospitalization and beyond [14, 26]. However, these organizations wisely acknowledge that other nutritional options may be needed to temporarily replace or supplement BF under well-defined circumstances (i.e., late preterm infants). Healthcare providers must be aware that delays associated with some morbidities will further the need for alternatives to direct BF [14, 26]. Due to their clinical condition or to the separation from their prematurely born infants, not all women with PWSF or WOSF are able to BF shortly after birth. In that case, our practice is to provide mother’s milk if obtained antenatally, EBM if tolerated, donor human milk if feasible or infant formula if prescribed by a physician [14, 27].

It has been known for many years that milk expression by hand or with an electrical pump may help mothers overcome obstacles to successful BF and therefore increase BF duration [28]. The finding that women with PWSF or WOSF who intended to BF had a BF initiation rate of 80% (exclusive or partial BF) is significant because it compares well with that of the general healthy population [29]. However, this success is tempered by the fact that less than half of women from either preeclampsia group were able to exclusively BF their infants at the time of discharge [27]. In line with current literature, we hoped that women with direct BF with or without EBM at discharge would continue to provide exclusive or partial BF [28, 30–33]. Women with PWSF who BF exclusively but only by EBM without any direct BF is concerning because available reports are pessimistic about BF duration [13, 34]. Several investigators cautioned that exclusive EBM feeding should be recommended for full-term and premature infants only when medically necessary and not as a substitute for feeding directly from the breast [32, 33].

The data on partial BF (direct BF or EBM with formula) raises similar concerns about BF duration following discharge, but it is possible that with support and guidance, this feeding modality could evolve into exclusive BF. More recently, other authors reported that pumping without feeding at the breast is associated with shorter milk feeding duration and early introduction of formula as compared to feedings at the breast with or without pumping [34, 35]. In cases of infants who cannot BF initially, an eventual transition to direct BF is possible and should be encouraged [34].

Limitations to this investigation are those inherent to the retrospective design and the lack of follow-information regarding infant feeding after discharge. Also, the definition of BF initiation at discharge may be applicable only to women with high risk obstetrical conditions for whom early mother-infant contact may be delayed. The strength of this investigation rests on the size of the obstetrical and neonatal population and the fact that the data were obtained directly from medical records, and not via post-delivery maternal questionnaires.

In conclusion, infants born to women with PWSF are at a higher risk for premature birth and concurrent morbidities that often require admission to the NICU leading to temporary mother-infant separation. Intention to BF predicts better BF initiation rates, however, exclusive BF at discharge in women with PWSF and WOSF fell short of the expected goal, raising concerns about long term BF duration. Due to severity of illness, treatment side effects and infants’ morbidities, dyads affected by PWSF who are seldom ready for early direct BF, can be helped by temporary alternatives such as EBM and DHM. Additionally, the high rate of partial BF during their hospital stay may identify women who are still striving toward exclusive BF at discharge and who, with specific support and guidance, could achieve their intended goal.