Abstract
BACKGROUND:
Timely delivery and magnesium sulfate (MgSO4) are mainstay in the treatment of preeclampsia with severe features (PWSF). Premature delivery, severity of illness and mother-infant separation may increase the risk for breastfeeding (BF) initiation failure.
OBJECTIVE:
To compare BF initiation among women with late-onset PWSF treated with MgSO4 to women with late-onset preeclampsia without severe features (WOSF) who did not receive MgSO4.
METHODS:
Retrospective study of 158 women with PWSF and 104 with WOSF who delivered at ≥34 weeks. Intention to BF, formula feed (FF) or partially BF was declared prenatally. At discharge, exclusive BF included direct BF or direct BF with expressed breast milk (EBM).
RESULTS:
PWSF and WOSF groups were similar in age, race, and obstetric history. PWSF and WSOF differed in primiparity (65 & 51%), late preterm births (73 vs 15%), admission to NICU (44 &17%) and mother (5 & 4d) and infant (6 & 3d) hospital stay. Both groups were similar in intention to BF (80 & 84%), to FF (16 & 13%) and to partially BF (5 & 5%). At discharge, exclusive BF (37 & 39%), partial BF (33 & 31%) and FF (30 & 30%) were similar. Exclusive BF in the PWSF group was 43% direct BF, 28% direct BF and EBM and 29% EBM alone whereas in the WOSF group exclusive BF was 93% direct BF and 7% direct BF and EBM.
CONCLUSION:
BF initiation rates for women with PWSF and WOSF were similar. EBM alone or with direct BF enabled infants in the PWSF group to exclusively BF at discharge.
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].
Objective
To compare BF initiation among women with late-onset PWSF treated with MgSO4 to women with late-onset preeclampsia WOSF who did not receive MgSO4.
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.
Statistical analysis
Comparisons between women with PWSF and WOSF were made with two-sample t-tests for continuous variables and Chi square tests for categorical variables. Non-normally distributed variables were compared using the Wilcoxon rank sum test. Significance was established at a p value <0.05. A secondary analysis was designed to ascertain the different feeding outcomes by prior infant BF feeding experience.
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).
Comparison of women with preeclampsia with and without severe features
Clinical and demographic characteristics of women with PWSF and those with WOSF are shown in Table 1. Most variables were similar between the groups although the incidence of primiparity and mothers’ length of stay were greater in the PWSF group. Rate of cesarean delivery as well as indications for primary cesarean (failed induction of labor 20%, non-reassuring fetal well-being 30%, worsening hypertension 23%, malpresentations 16% and miscellaneous 11%) were similar among the groups. Consistent with the diagnosis and treatment of PWSF, all women in this group received 24-hour postpartum MgSO4 while 62% of them also received additional antihypertensive medications. In contrast, none of the women in the WOSF group received magnesium sulfate and only 11% received antihypertensive medications during their hospital stay.
Comparison of women with preeclampsia with and without severe features
Comparison of women with preeclampsia with and without severe features
Neonatal outcomes of infants born to women with PWSF and WOSF are shown in Table 2. The most relevant differences in neonatal outcomes between PWSF and WOSF groups were the incidence of late prematurity (73 vs 15%), admission to the NICU (44 vs 17%) and length of hospital stay (6 vs 3d). Considering their similarities in diagnoses, 70 infants from the PWSF and 18 from the WOSF groups admitted to the NICU were combined for analysis. Of the 88 infants admitted to the NICU, 16 (18%) were full-term and 72 (82%) were late preterm. NICU admission diagnoses were as follows: respiratory distress (38%), temperature instability-hypotonia-poor feeding (26%), apnea-bradycardia-cyanosis (23%) and hypoglycemia (24%). Although the incidence of small for gestational age (SGA) infants was similar, 24 of the 35 (69%) in the PWSF group and 5 of the 16 (31%) SGA from the WOSF group required admission to the NICU.
Neonatal outcomes of infants born to women with preeclampsia with and without severe features
Neonatal outcomes of infants born to women with preeclampsia with and without severe features
There was a small although significant predominance of primiparous women in the PWSF group while prior BF experience was reported by less than half of the multiparous women in each of the preeclampsia groups (Table 3). Among 50 multiparous women from both groups combined who reported prior BF experience, 88% intended to BF compared to 24% of 56 women without prior BF experience.
Prior BF experience and early breastfeeding among women with preeclampsia with and without severe features
Prior BF experience and early breastfeeding among women with preeclampsia with and without severe features
All women in the PWSF group remained in labor and delivery for the first 24-hours postpartum. The major disruption in mother-infant contact following birth arose from the need for immediate transfer of symptomatic prematurely born infants to the NICU (43% of the PWSF and 14% of the WOSF group). During the first 2 postpartum hours among the PWSF and WOSF groups the following mother-infant interactions were recorded: BF (25 & 42%) and skin-to-skin (9 & 18%). Thereafter the differences in BF rate and skin-to-skin contact during the first day between the groups declined steadily.
Further analysis of the influence of mode of delivery on BF showed that among women in the PWSF group, 29 of 91 (32%) who delivered vaginally and 11 of 67 (16%) who delivered by section BF their infants during the first two postpartum hours (p < 0.02). However, within 6 hours from birth the influence of mode of delivery on BF rate was no longer significant (vaginal 46% vs cesarean 36%). Among women in the WOSF group, 29 of 60 (48%) who delivered vaginally and 15 of 44 (34%) who delivered by section BF their infants during the first two postpartum hours.
Intention to BF was similar between the PWSF and WOSF groups (80 vs 84%, respectively). At the time of discharge the rates of exclusive BF, partial BF and FF were similar between the two groups (Table 4). However, a significant difference between the groups was the lower rate of direct BF in the PWSF than in the WOSF group (43 vs 93%, respectively). The lower rate of direct BF was offset by the addition of infants who received exclusive EBM at discharge.
Intention to BF and BF at discharge for women with preeclampsia with and without severe features
Intention to BF and BF at discharge for women with preeclampsia with and without severe features
There were 127 women from the PWSF and 87 from the WOSF group who intended to BF. At the time of discharge, the rates of exclusive BF (43 vs 46%), partial BF (40 vs 37%) and FF (17 vs 17%) were similar. The only difference between PWSF and WOSF groups was the contribution of direct BF (44 vs 93%) and EBM only (26 vs 0%) to the exclusive BF subgroup.
There were 25 women from the PWSF and 14 from the WOSF group who did not intend to BF all of whom FF exclusively at discharge. Thirty-seven women who intended to BF (22 PWSF and 15 WOSF) FF at discharge. This latter subgroup of women was similar demographically and clinically to those who intended to BF and exclusively or partially BF at discharge.
Twenty-nine of 58 (50%) infants in the PWSF group and 12 of 41 (29%) in the WOSF group that BF exclusively at discharge received some formula supplementation during their hospital stay. Sixteen infants (28%) in the PWSF group that BF exclusively at discharge received DHM during their hospital stay. None of the infants in the WOSF group received DHM.
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.