Monochorionic Twins and the Early Mother-Infant Relationship: An Exploratory Observational Study of Mother-Infant Interaction in the Post-Partum Period

Round 1

Reviewer 1 Report

Dear Colleagues, Thank you for the chance to read this very interesting study.  There is one area in the discussion that seems curiously short and lacking real consideration.  As this is in the section on implications it should be expanded properly.

Regarding lines 340-341: The poorer quality of maternal behaviour during interactions suggests that mothers of twins may benefit from interventions to promote effective interactions with their infants [25].  

Comment: Please expand this section of the discussion.

1. Why is the mother cast as inadequate?
2. What intervention do you suggest?
3. Is this a medical or social issue?
4. Who would be responsible for providing the intervention? 
5. Where is the consideration of the partner's role as support for the mother? 
6. Could the mother be encouraged to take advantage of other potential support, for example aunts, uncles, grandparents to share time with one of the infants while the mother can focus on the other infant more fully - or even get some rest to regain her energy? 

Author Response

Dear Editor,

We revised the manuscript entitled Monochorionic twins and the early mother-infant relationship: An exploratory observational study of mother-infant interaction in the post-partum period submitted to the International Journal of Environmental Research and Public Health.

We thank the editor and the reviewers for taking the time for reviewing our article. 

We are grateful for the meaningful suggestion they gave us.

We have followed the reviewers’ suggestions, trying to answer all comments.

You can find our response for each point highlight below.

Reviewer #1

 

Comment#1: Dear Colleagues, thank you for the chance to read this very interesting study. 

Reply#1: We thank the reviewer for the positive comment.

 

Comment#2: There is one area in the discussion that seems curiously short and lacking real consideration. As this is in the section on implications it should be expanded properly. Regarding lines 340-341: The poorer quality of maternal behavior during interactions suggests that mothers of twins may benefit from interventions to promote effective interactions with their infants [25].

Why is the mother cast as inadequate? What intervention do you suggest? Is this a medical or social issue? Who would be responsible for providing the intervention? Where is the consideration of the partner's role as support for the mother?  Could the mother be encouraged to take advantage of other potential support, for example aunts, uncles, grandparents to share time with one of the infants while the mother can focus on the other infant more fully - or even get some rest to regain her energy?

Reply#2: We have added some strategies following the advice

Reviewer 2 Report

The current manuscript present an interesting study investigating the differences in mother-child interactions between singletones and monozygotic twins. Authors hypothesized that mothers interactions would be less appropiate in the case of monozigotic twins. They confirmed their hypothesis, although they could not determine based on their results the factors explaining these differences. Althought it is a valuable contribution in the field of developmental psychology and parenting, there are some aspects to review before the manuscript is ready for publication.

Regarding the introduction section, authors justify why they specifically investigated mother-child interactions in monozygotic twins to continue the following paragraphs explaining the consequences that prematurity may have for infants and mothers that may affect the quality of mother-child interaction. As far as it seems, prematurity it is not a central variable in the study, they just keep prematurity comparable between groups. Authors should make a bigger effort to focus their introduction in the charachteristics that could hinder mother-child interactions in the case of monozygotic twins.

In relation to the design of the study, it is surprising that authors did not include a group of dizygotic twins as well. Authors state that they are studying the effect of zygosity. Thus, it would be relevant to compare mother-child interactions between dizygotic and monozygotic infants. Comparing monozygotic twins and singletones have the problem that these two groups not only varies in zygosity, but also in the dimension twin-singleton. Consequently, authors should be more cautios in the interpretation of their results regarding this limitation. It is advisable to include a sample of dizygotic twins if possible as it would improve considerable the relevance and quality of the study.

Finally, it is not clear enough whether all children selected from the initial sample were required to be premature or not. Althoguh the information about gestation weeks is provided, I recommend authors to clearly indicate this information.

 

Author Response

Dear Editor,

We revised the manuscript entitled Monochorionic twins and the early mother-infant relationship: An exploratory observational study of mother-infant interaction in the post-partum period submitted to the International Journal of Environmental Research and Public Health.

We thank the editor and the reviewers for taking the time for reviewing our article. 

We are grateful for the meaningful suggestion they gave us.

We have followed the reviewers’ suggestions, trying to answer all comments.

You can find our response for each point highlight below.

Reviewer #2

 

Comment#1: The current manuscript presents an interesting study investigating the differences in mother-child interactions between singletons and monozygotic twins. Authors hypothesized that mothers’ interactions would be less appropriate in the case of monozygotic twins. They confirmed their hypothesis, although they could not determine based on their results the factors explaining these differences. Although it is a valuable contribution in the field of developmental psychology and parenting, there are some aspects to review before the manuscript is ready for publication.

Reply#1: We thank the reviewer for the positive comment. 

Comment#2: Regarding the introduction section, authors justify why they specifically investigated mother-child interactions in monozygotic twins to continue the following paragraphs explaining the consequences that prematurity may have for infants and mothers that may affect the quality of mother-child interaction. As far as it seems, prematurity it is not a central variable in the study, they just keep prematurity comparable between groups. Authors should make a bigger effort to focus their introduction in the characteristics that could hinder mother-child interactions in the case of monozygotic twins.

Reply#2: We have re-arranged the introduction focusing more on the topic of zygosity and early interaction

Comment#3:  In relation to the design of the study, it is surprising that authors did not include a group of dizygotic twins as well. Authors state that they are studying the effect of zygosity. Thus, it would be relevant to compare mother-child interactions between dizygotic and monozygotic infants. Comparing monozygotic twins and singletones have the problem that these two groups not only varies in zygosity, but also in the dimension twin-singleton. Consequently, authors should be more cautios in the interpretation of their results regarding this limitation. It is advisable to include a sample of dizygotic twins if possible as it would improve considerable the relevance and quality of the study.

 

Reply#3: We are aware of this limit of our study and we have inserted in the limitations at the end of the paper

 

Comment#4:  Finally, it is not clear enough whether all children selected from the initial sample were required to be premature or not. Although the information about gestation weeks is provided, I recommend authors to clearly indicate this information

 

Reply#3: This is a larger study examining differences between preterm and term infants and focused only on the sample of preterm infants, as our primary focus was on monozygotic twins.
As indicated in the article, the sample was controlled by the variable gestational age.

Reviewer 3 Report

The authors performed an interesting study. The topic is timely.

Abstract: “Comparisons between mothers of MC twins and mothers of singletons showed that the quality of maternal sensitive behaviour during the interactions were poorer in mothers of twin.” This sentence sounds dramatic; accordingly, please report effect sizes and replace “poorer” with “lower” or similar.

“Mothers of twins were also more remote during the interaction with their babies and showed higher level of signs of depression than mothers of singletons.”; as above, please, report the effect sizes, and “de-dramatize” the wording.

Introduction: this was well-performed. It appears that two factors confound; pre-term condition and twin-pregnancies; please modify and explain. For infants, children, adolescents, and adults born preterm, please consider (Robinson et al., 2020; Robinson et al., 2021; Urfer-Maurer et al., 2017)

Methods: this part was well performed. Statistics: please report effect sizes.

Table 3; please report effect sizes.

Table 4; please report effect sizes.

Discussion and Conclusion: This is often a question of taste and judgement, though, I suggest to trimming these parts.

 

References

Brylka, A., Wolke, D., Ludyga, S., Bilgin, A., Spiegler, J., Trower, H., Gkiouleka, A., Gerber, M., Brand, S., Grob, A., Weber, P., Heinonen, K., Kajantie, E., Räikkönen, K., Lemola, S., 2021. Physical Activity, Mental Health, and Well-Being in Very Pre-Term and Term Born Adolescents: An Individual Participant Data Meta-Analysis of Two Accelerometry Studies. International journal of environmental research and public health 18(4).

Robinson, R., Lahti-Pulkkinen, M., Schnitzlein, D., Voit, F., Girchenko, P., Wolke, D., Lemola, S., Kajantie, E., Heinonen, K., Räikkönen, K., 2020. Mental health outcomes of adults born very preterm or with very low birth weight: A systematic review. Semin Fetal Neonatal Med 25(3), 101113.

Robinson, R.K., Heinonen, K., Girchenko, P., Lahti-Pulkkinen, M., Kajantie, E., Hovi, P., Lano, A., Andersson, S., Eriksson, J.G., Wolke, D., Lemola, S., Räikkönen, K., 2021. Optimism in adults born preterm: Systematic review and individual-participant-data meta-analysis. PLoS One 16(11), e0259463.

Urfer-Maurer, N., Weidmann, R., Brand, S., Holsboer-Trachsler, E., Grob, A., Weber, P., Lemola, S., 2017. The association of mothers' and fathers' insomnia symptoms with school-aged children's sleep assessed by parent report and in-home sleep-electroencephalography. Sleep Med 38, 64-70.

 

Maurer, N., Perkinson-Gloor, N., Stalder, T., Hagmann-von Arx, P., Brand, S., Holsboer-Trachsler, E., Wellmann, S., Grob, A., Weber, P., Lemola, S., 2016. Salivary and hair glucocorticoids and sleep in very preterm children during school age. Psychoneuroendocrinology 72, 166-174.

Möhring, W., Urfer-Maurer, N., Brand, S., Holsboer-Trachsler, E., Weber, P., Grob, A., Lemola, S., 2019. The association between sleep and dual-task performance in preterm and full-term children: an exploratory study. Sleep Med 55, 100-108.

Perkinson-Gloor, N., Hagmann-von Arx, P., Brand, S., Holsboer-Trachsler, E., Grob, A., Weber, P., Lemola, S., 2015. The role of sleep and the hypothalamic-pituitary-adrenal axis for behavioral and emotional problems in very preterm children during middle childhood. Journal of psychiatric research 60, 141-147.

Robinson, R., Lahti-Pulkkinen, M., Schnitzlein, D., Voit, F., Girchenko, P., Wolke, D., Lemola, S., Kajantie, E., Heinonen, K., Räikkönen, K., 2020. Mental health outcomes of adults born very preterm or with very low birth weight: A systematic review. Semin Fetal Neonatal Med 25(3), 101113.

Robinson, R.K., Heinonen, K., Girchenko, P., Lahti-Pulkkinen, M., Kajantie, E., Hovi, P., Lano, A., Andersson, S., Eriksson, J.G., Wolke, D., Lemola, S., Räikkönen, K., 2021. Optimism in adults born preterm: Systematic review and individual-participant-data meta-analysis. PLoS One 16(11), e0259463.

Urfer-Maurer, N., Brand, S., Holsboer-Trachsler, E., Grob, A., Weber, P., Lemola, S., 2018a. Correspondence of maternal and paternal perception of school-aged children's sleep with in-home sleep-electroencephalography and diary-reports of children's sleep. Sleep Med 48, 180-186.

Urfer-Maurer, N., Ludyga, S., Stalder, T., Brand, S., Holsboer-Trachsler, E., Gerber, M., Grob, A., Weber, P., Lemola, S., 2018b. Heart rate variability and salivary cortisol in very preterm children during school age. Psychoneuroendocrinology 87, 27-34.

Urfer-Maurer, N., Weidmann, R., Brand, S., Holsboer-Trachsler, E., Grob, A., Weber, P., Lemola, S., 2017. The association of mothers' and fathers' insomnia symptoms with school-aged children's sleep assessed by parent report and in-home sleep-electroencephalography. Sleep Med 38, 64-70.

 

Author Response

Dear Editor,

We revised the manuscript entitled Monochorionic twins and the early mother-infant relationship: An exploratory observational study of mother-infant interaction in the post-partum period submitted to the International Journal of Environmental Research and Public Health.

We thank the editor and the reviewers for taking the time for reviewing our article. 

We are grateful for the meaningful suggestion they gave us.

We have followed the reviewers’ suggestions, trying to answer all comments.

You can find our response for each point highlight below.

Reviewer #3

Comment#1: The authors performed an interesting study. The topic is timely.

Reply#1: We thank the reviewer for the positive comment. 

 

Comment#2: Abstract: “Comparisons between mothers of MC twins and mothers of singletons showed that the quality of maternal sensitive behaviour during the interactions were poorer in mothers of twin.” This sentence sounds dramatic; accordingly, please report effect sizes and replace “poorer” with “lower” or similar.

 

Reply#2: We changed the statement according to the advice

 

Comment#3:  Mothers of twins were also more remote during the interaction with their babies and showed higher level of signs of depression than mothers of singletons.”; as above, please, report the effect sizes, and “de-dramatize” the wording.

 

Reply#3:  We changed the statement according to the advice

 

Comment#4:  Introduction: this was well-performed. It appears that two factors confound; pre-term condition and twin-pregnancies; please modify and explain. For infants, children, adolescents, and adults born preterm, please consider (Robinson et al., 2020; Robinson et al., 2021; Urfer-Maurer et al., 2017)

 

Reply#4:  We have re-arranged the introduction

 

Comment#5:  Methods: this part was well performed. Statistics: please report effect sizes.Table 3; please report effect sizes.Table 4; please report effect sizes.

 

Reply#5: We have provided the effect sizes

 

Comment#6:  Discussion and Conclusion: This is often a question of taste and judgement, though, I suggest to trimming these parts.

 

Reply#6: We have taken your advice and shortened the superfluous information and kept the most important information.

Round 2

Reviewer 2 Report

Authors have addressed all the reviewers comments satisfactorily. To my view, the paper it is ready for publicable in its present form. I thank authors for the job.