Maternal postpartum behaviors and mother-infant relationship during the first year of life

Maternal postpartum behaviors and mother-infant relationship during the first year of life Helen L. Britton, MD, Virginia Gronwaldt, PhD, and John R. Britton, MD, PhD Objective: To assess the hypothesis that maternal postpartum behaviors toward the newborn may predict the quality of the maternal-infant relationship during the first year. Design: Prospective, non-randomized, longitudinal cohort study of 174 maternal-infant dyads. Methods: A Postpartum Parenting Behavior Scale (PPBS) was formulated to measure clearly defined observed maternal behaviors toward the infant shortly after birth. The quality of the maternal-infant relationship was assessed at 6 months after birth with the Nursing Child Assessment Satellite Training (NCAST) Feeding Scale and at 12 months after birth with the NCAST Teaching Scale and Ainsworth Strange Situation. Results: The PPBS score correlated significantly with the Feeding Scale score (r = .27, P < .005) and with the Teaching Scale score (r = .23, P < .01). Mothers whose infants were later classified as securely attached in the Ainsworth Strange Situation had higher PPBS scores than mothers of infants classified as insecurely attached (mean ± SD: 5.18 ± 1.51 vs 4.63 ± 1.69, respectively, P < .05). In regression models adjusting for social and demographic factors, the PPBS remained a significant predictor of the Feeding Scale score, the Teaching Scale score, and security of attachment. Conclusions: Maternal behaviors in the immediate postpartum period may aid in predicting quality of the maternal-infant relationship during the subsequent 12 months, suggesting the potential for early identification of suboptimal parenting. (J Pediatr 2001;138:905-9) Early identification of maternal behaviors that reflect later parenting quality might aid in development of interventions for those at risk.1,2 The perinatal period has many advantages in this regard, because frequent interactions with health care providers offer numer-

ous opportunities for assessment.3 Although the American Academy of Pediatrics has recommended the evaluation of parenting quality during this time,4 current assessment focuses on demographic and psychosocial factors, which have only limited predictive value,5 and

From the University of Arizona, Tucson. Supported in part by grant MCJ-040523-03-0 from the Maternal and Child Health Bureau.

Submitted for publication May 19, 2000; revision received Sept 19, 2000; accepted Dec 1, 2000. Reprints not available from author. Correspondence: John R. Britton, MD, PhD, PO Box 25104, Scottsdale, AZ 85255. Copyright © 2001 by Mosby, Inc. 0022-3476/2001/$35.00 + 0 9/21/113358 doi:10.1067/mpd.2001.113358

health care providers often rely on subjective impressions in their evaluations. Several decades ago, Gray et al6,7 used information from an interview, questionnaire, and perinatal observations to identify women at risk for abnormal parenting practices. Children born to such women were later found to have greater rates of abuse and neglect than those born to low-risk mothers. The most accurate indicator of risk was the observational record of maternal behavior toward the infant in the delivery room. Although subsequent reports have explored the utility of perinatal screening for adverse family outcomes,8-12 none has re-evaluated the predictive value of direct observation. NCAST Nursing Child Assessment Satellite Training PPBS Postpartum Parenting Behavior Scale

The following study was designed to assess parenting quality in the immediate postpartum period. We hypothesized that maternal parenting quality would be reflected by a mother’s behaviors toward her newborn after birth and that these behaviors in turn would predict the quality of the maternal-infant relationship later in infancy. To evaluate this relationship, we used the Nursing Child Assessment Satellite Training Program (NCAST) Feeding and Teaching Scales and the Ainsworth Strange Situation, highly validated measures of dyadic interaction and attachment.13-15 Abnormalities detected with these instruments have been associated with a variety of subsequent adverse outcomes, including poor social and cognitive functioning and child abuse and neglect.13-16 905

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METHODS The data presented are from a prospective non-randomized longitudinal study. Approval by relevant institutional review boards and individual informed consent were obtained for all cases.

THE JOURNAL OF PEDIATRICS JUNE 2001 ing black and Native American. Educational levels completed were: did not graduate from high school, 15.7%; high school graduate, 15.1%; attended college but did not graduate, 41.3%; college graduate, 27.9%; advanced degree, 8.1%. Twenty-three percent were primiparous, and 82.1% were married.

Subject Selection Pregnant women were recruited to participate in a study of maternal-infant interaction by use of posters in waiting rooms and letters given at routine 32-week prenatal care visits. Only mothers with singleton gestations expecting uncomplicated vaginal deliveries were enrolled. Cases were excluded if complications at the time of birth required cesarean section, preterm delivery, or transfer of the newborn to a neonatal intensive care unit. The sites of recruitment included a freestanding birthing center, a large private obstetric group practice, university hospital obstetric and family practice clinics, and neighborhood family health centers. At the time of delivery, 174 dyads were enrolled: 36 mothers recruited from the birthing center delivered at that center; 59 mothers from the private obstetric group practice delivered at a large metropolitan private hospital; 68 mothers from the university hospital clinics and 11 mothers from the neighborhood health centers delivered at a university hospital. Although there was some attrition throughout the period of the study, 158 dyads continued to participate at 6 months, and 152 remained in the study at 12 months after birth.

Social and Demographic Characteristics Social and demographic characteristics were determined from medical record review and maternal questionnaires. Of the study mothers, 4.1% were less than 18 years old, 37.2% were between 18 and 25, 50% were between 26 and 35, and 8.7% were over 35 years of age. With respect to ethnicity, 75.4% were white non-Hispanic, 21.6% were Hispanic, and 2.9% were other, includ906

Maternal Behaviors After Birth All infants were given to their mothers shortly after birth, at which time a trained observer videotaped the initial maternal-infant interaction for the first 10 minutes. The tape was later scored for maternal behaviors with the use of an instrument, which we termed The Postpartum Parenting Behavior Scale (see Appendix), the components of which were chosen in part based on aspects of early maternal-infant interaction described by previous investigators.6,7,17 For this and all other instruments used, two trained observers scored all tapes, and any differences were reconciled by discussion and consensus, usually with a third impartial rater.

Maternal-Infant Interaction Maternal-infant interaction was assessed by using the NCAST Feeding Scale at 6 months after birth and the NCAST Teaching Scale at 12 months after birth.13,14 For each, individual subscales evaluate parental and infant contributions to the interaction (Parent NCAST and Child NCAST). Feeding and teaching sessions were videotaped in the home and later scored by two raters trained and certified by developers of the scales. Scales had inter-rater and internal consistency reliabilities of 0.89-0.92 and 0.80-0.82, respectively. Mean scores, SDs, and ranges were: Feeding Scale, 58.69 ± 7.52 (29-73); Teaching Scale, 55.57 ± 4.88 (40-69). All are consistent with published values.13,14

Maternal-Infant Attachment Maternal-infant attachment was assessed by using the Ainsworth Strange Situation,15 with videotaped laboratory

sessions obtained at 12 months after birth scored by two or more observers trained and certified by Michael Lamb, PhD. Dyads were categorized as securely attached (classes B1-B4), insecure-avoidant (classes A1 or A2), insecure-resistant (classes C1 or C2), or unclassified. For most analyses, dichotomization with respect to membership in the major attachment categories was used. Of the 152 dyads that completed the study and were assessed in the Ainsworth Strange Situation, 86 (56.6%) were classified as type B (secure), 36 (23.7%) as type A (avoidant), 26 (17.1%) as type C (resistant), and 4 (2.6%) as unclassified. This distribution is similar to that generally reported for populations from the United States.15,16

Analysis of Data Bivariate analyses utilized Pearson correlations, analysis of variance with Bonferroni post hoc tests, and the t test for continuous variables. Multivariate analyses included linear regression for continuous criterion variables and logistic regression for dichotomous outcomes. Potentially confounding social and demographic factors previously associated with the chosen measures of the maternal-infant relationship (maternal age, ethnicity, education, parity, and marital status13-15) were entered into all regression models on the first block by using either stepwise (linear regression) or forward conditional (logistic regression) procedures, and the potential predictor variable (the PPBS score) was entered on a subsequent block. All analyses were performed by using SPSS,18 with significance accepted at P < .05.

RESULTS The PPBS score had a mean (± SD) of 4.92 ± 1.63 and ranged from 0 to 7. The inter-rater reliability was .91, and the internal consistency reliability (α) was .64. The score did not vary significantly with respect to maternal age,

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THE JOURNAL OF PEDIATRICS VOLUME 138, NUMBER 6 educational level, ethnicity, parity, or marital status (Table I). The PPBS score correlated significantly with most of the NCAST Feeding and Teaching Scale scores (Table II). These included the total scores and the parent scores for both the Feeding and Teaching Scales. Although the PPBS score was significantly correlated with the child score on the Feeding Scale, the correlation with the child score on the Teaching Scale was not significant. All significant correlations were of moderate magnitude. Similarly, mothers of infants classified as securely attached in the Ainsworth Strange Situation at 1 year after birth had significantly higher scores on the PPBS than mothers of infants classified as insecure (5.18 ± 1.51 vs 4.63 ± 1.69, respectively, P < .05). There was no significant difference between the PPBS scores of mothers of infants in the insecurely attached categories (avoidant, 4.54 ± 1.62; resistant, 4.65 ± 1.77; P = NS). To control for potentially confounding social and demographic factors, we constructed individual regression models with the PPBS score as the predictor variable and the measures of relationship quality as outcomes. For the NCAST scales (Table III), the PPBS score significantly predicted the total and parental Feeding and Teaching Scale scores, in addition to the child Feeding Scale score. The PPBS score accounted for a greater portion of the variance in the Feeding Scale and its components than the Teaching Scale. With respect to attachment category (Table IV), the PPBS score significantly predicted dyads with secure attachment in the Strange Situation. However, it did not predict membership in the other attachment groups.

DISCUSSION Our results illustrate that maternal behaviors displayed toward the infant shortly after delivery may predict the

Table I. The PPBS and social and demographic factors

Factor Maternal age (y) <18 18-25 26-35 >35 Education Did not graduate from high school High school graduate only Attended some college College graduate only Postgraduate study Ethnicity White, non-Hispanic Other Married Yes No Primiparous Yes No

N

Mean

SD

7 63 85 15

4.57 4.70 5.20 4.60

2.30 1.61 1.43 2.06

26 26 71 34 13

4.38 4.85 5.14 4.82 5.69

1.81 1.78 1.43 1.64 1.18

127 42

4.98 4.74

1.57 1.70

138 33

5.01 4.55

1.56 1.89

40 132

4.75 4.97

2.00 1.50

Table II. Correlation of PPBS score with NCAST Feeding and Teaching Scale scores

Scale score

Feeding Scale

Parent Child Total

.26‡ .20* .27‡

Teaching Scale .27‡ –.01 .23†

*P < .05. †P < .01. ‡P < .005.

quality of the maternal-infant relationship as much as 1 year later. We have formulated a measure of these behaviors, the PPBS, whose predictive capability transcends social and demographic characteristics. Although previous investigators have described these behaviors and their predictive value,6,7,17 our study combined them as an instrument and related them to highly validated formal measures of the maternal-infant relationship later in infancy.13,14,16,19,20 The PPBS is simple, brief, and easily assigned, and it has the potential for administration to a majority of mothers on a routine basis. It is important to recognize that the PPBS evaluates only maternal behavior toward the infant, making no at-

tempt to assess the newborn’s contribution to the interaction. Although it is possible that the behavior and/or appearance of the infant may have influenced maternal behavior, these factors were not evaluated, and their potential impact on the PPBS is unknown. On the other hand, it is equally possible that some mothers might display similar parenting behaviors irrespective of the infant’s characteristics or contributions to the interaction. If this is the case, the PPBS may measure intrinsic parenting characteristics that may even predate the birth of the infant. The formal outcome measures used in our study assessed the combined parental and infant contributions to the dyadic relationship, but because of the 907

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Table III. Linear regression analyses: Prediction of NCAST Feeding and Teaching Scale scores by the PPBS score

NCAST Feeding Scale score Parent Child Total Teaching Scale score Parent Child Total

B

SE

β

R2

∆R2

F

.82 .43 1.26

.27 .15 .37

.24‡ .23‡ .27‡

.107 .053 .101

.058 .053 .070

8.91§ 8.32‡ 8.29§

.56 –.09 .50

.20 .14 .24

.20† –.05 .16*

.305 .003 .217

.040 .003 .026

14.59§ .393 9.24§

*P < .05. †P < .01. ‡P < .005. §P < .001.

Table IV. Logistic regression analyses: Prediction of attachment category by the PPBS score

Attachment category Secure Avoidant Resistant

B

SE

AOR

95% CI

.23 –.20 –.15

.11 .12 .14

1.26* .82 .86

1.02, 1.56 .64, 1.04 .66, 1.12

AOR, Adjusted odds ratio. *P < .05.

structure of the NCAST Feeding and Teaching Scales, it was possible to separate the parental and child contributions for analysis. Because the PPBS focuses on maternal behaviors, its association with the parental contributions to the NCAST scales was not unexpected. However, its ability to predict the child component of the Feeding Scale was more surprising. This observation may reflect a degree of inseparability of the individual contributions to the dyadic interaction, a phenomenon argued by van den Boom21 for maternal characteristics such as sensitivity. On the other hand, lack of correlation between the PPBS and the child component of the Teaching Scale may reflect the development of increased autonomy of the child’s behavior at this later age, rendering its contribution to the overall interaction more distinct. Although research on attachment security has focused largely on the predictive value of maternal sensitivity to infant signals,16,20,22,23 a meta-analysis 908

revealed that several other parenting dimensions may be important determinants of security.23 Among these are physical contact and positive attitude, aspects that formed the focus of our PPBS score. In older populations, these dimensions have effect sizes of .09 and .18, respectively, for secure attachment.23 Our observations are consistent with these data, and they provide the first evidence for the predictive capability of these dimensions in the immediate postpartum period. Nevertheless, it must be recognized that although the PPBS correlated significantly with later indices of the maternal-infant relationship, the magnitude of its predictive effect was modest. Clearly, other intervening factors during infancy may have an impact on the developing relationship between the mother and child, making it likely that multiple pathways to parenting competence exist, which may vary in their importance for individual dyads. Given these considerations, it is important to

caution against overemphasis of the PPBS as a predictive measure. Having a low PPBS score does not necessarily destine a mother to a suboptimal relationship with her infant, because any of a variety of other factors may contribute more favorably to the positive development of that relationship over the course of infancy. It is also important to note several potential limitations of our study. First, the cohort of mothers was almost certainly subjected to selection bias in that they enrolled electively and agreed to be subjected to delivery room observations and repeated evaluations throughout the first postpartum year. It is thus possible that they represented a group with greater parenting quality than those not choosing to participate. Conceivably, the relationship between postpartum behaviors and later outcomes could have been different in other, more diverse populations. Second, the mere awareness of being studied might have influenced maternal behaviors at all observation periods (Hawthorne effect). Third, although the outcomes evaluated were among the best formal measures of the quality of the parentchild relationship, it is conceivable that other selected outcome measures could have yielded different results. Finally, it should be noted that the internal consistency of the PPBS was modest, and the scale will require refinement, perhaps by the addition of other observable postpartum behaviors. Clearly, further studies in more diverse populations, with the use of additional maternal behaviors and outcome measures, will be required before more definitive conclusions regarding the use of the PPBS may be made. Despite these reservations, our data indicate that observation of maternal behaviors in the immediate postpartum period may help in the prediction of later quality of the maternal-infant relationship. These findings are consistent with the reports of other researchers,6,7 and they raise the possibility that observational data may be combined with

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THE JOURNAL OF PEDIATRICS VOLUME 138, NUMBER 6 other information, such as social risk factors,5 in attempting to identify those mothers best targeted for interventions to improve parenting.

7.

We thank Michael Lamb, PhD, for helpful discussions.

8.

9.

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of child abuse and neglect. Child Abuse Negl 1977;1:45-58. Gray JD, Cutler CA, Dean JG, Kempe CH. Prediction and prevention of child abuse. Semin Perinatol 1979;3: 85-90. Britton HL. Perinatal screening for child abuse and neglect. Clin Perinatol 1998;25:453-60. Altemeier WA, O’Conner SM, Vietze PM, Sandler H, Sherrod K. Prediction of child abuse: a prospective study of feasibility. Child Abuse Negl 1984;8:393-400. Brayden RM, Altemeier WA, Dietrich MS, Tucker DD, Christensen MJ, McLaughlin FJ, et al. A prospective study of secondary prevention of child maltreatment. J Pediatr 1993;122:511-6. Leventhal JM, Garber RB, Brady CA. Identification during the postpartum period of infants who are at high risk of child maltreatment. J Pediatr 1989; 114:481-7. Murphy S, Orkow B, Nicola RM. Prenatal prediction of child abuse and neglect: a prospective study. Child Abuse Negl 1985;9:225-35. Sumner G, Spietz A. NCAST Caregiver/Parent-Child Interaction Feeding Manual. Seattle (WA): NCAST Publications; 1994. Sumner G, Spietz A. NCAST caregiver/parent-child interaction teaching manual. Seattle (WA): NCAST Publications; 1994.

15. Ainsworth MDS, Blehar MC, Waters E, Wall S. Patterns of attachment: a psychological study of the strange situation. Hillsdale (NJ): Erlbaum; 1978. 16. Cassidy J, Shaver PR, editors. Handbook of attachment. New York: Guilford Press; 1999. 17. De Chateau P. The influence of early contact on maternal and infant behavior in primiparae. Birth Fam J 1976; 3:149-55. 18. SPSS. SPSS for the Macintosh. Version 6.1, 1st ed. Chicago: SPSS, Inc; 1995. 19. Thompson RA. Early attachment and later development. In: Cassidy J, Shaver PR, editors. Handbook of attachment. New York: Guilford Press; 1999. p. 265-86. 20. Lamb ME, Thompson RA, Gardner W, Charnov EL. Infant-mother attachment: the origins and developmental significance of individual differences in strange situation behavior. Hillsdale (NJ): Erlbaum; 1985. 21. van den Boom DC. Sensitivity and attachment: next steps for developmentalists. Child Dev 1997;64:592-4. 22. Goldsmith HH, Alansky JA. Maternal and infant temperamental predictors of attachment: a meta-analysis. J Consult Clin Psychol 1987;55:805-16. 23. de Wolff MS, van Ijzendoorn MH. Sensitivity and attachment: a meta-analysis on parental antecedents of infant attachment. Child Dev 1997;68:571-91.

APPENDIX The Postpartum Parenting Behavior Scale Component Close contact Eye contact Loving touch Examining infant Loving talk Positive comments

Happiness

Explanation Holding the infant closely in contact with body, clothed or unclothed, and encircling with an arm as much as possible Attempting to make eye contact with baby, even if unsuccessful, with en face positioning Touching the infant lovingly, such as gentle stroking, kissing or kissing motions, patting, caressing with cheek, etc, that is not for caretaking or inspection purposes Demonstrating definite exploratory behavior, such as lifting the blanket to look at the infant, opening the baby’s hands to inspect the fingers, examining the feet, etc Talking lovingly to baby, where “lovingly” refers to both affectionate tone and content Making positive comments about the infant, where “positive” means not negative or neutral, either descriptive (using, for example, adjectives such as pretty, good, beautiful, etc) or projective about the future (“You’re going to be very strong when you grow up, just like your father.”) Smiling and/or appearing happy >75% of the time

Scoring period: first 10 minutes after the infant is given to the mother Score: one point given for each behavior observed, irrespective of the frequency of that behavior, with total score consisting of numerical sum of points

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