Assisted Reproductive Technologies: A New Player in the Foetal Programming of Childhood and Adult Diseases?

Round 1

Reviewer 1 Report

This paper reviews information on the risks of ART. The authors present major risks. They also suggest that these risks be adequately conveyed to patients undergoing the procedures.

The paper presents the risks associated with ART. While major risks are presented, many of the references are not the newest ones in the field and some of them are from smaller studies rather than meta-analyses or reviews of the data. This reviewer suggests that the authors update their references to include mostly those published after 2020.

The overall point of the paper and its value to the research and clinical communities is not clearly stated by the authors. 

The Abstract does not adequately convey the substance of the information presented in the paper. The Abstract suggests that the paper will discuss that clinicians should convey the "complexity of the procedures" as well as risks of ART, however, the complexity of the procedures is not discussed in any detail and although the risks are presented the need to discuss these with patients is not the focus of the paper. The paper actually presents the risks, and the Abstract would better convey the substance of the paper if it were to list out the major risks that will be discussed. 

Some specific issues:

The first paragraph of the Introduction presents a series of issues (using a numbering system that is not sequential) that are never returned to later in the paper. Guidelines, regulations, donor gametes, and other issues introduced here are not covered in the paper and should not be part of the Introduction.

Line 96 "liver birth" should be changed to "live birth".

On lines 126-128 more information should be added as to what is meant by the statement that ART children grew differently from spontaneously conceived children.

On line 138, the sentence starting with "A French narrative..." is not a full sentence. It is also not clear what is being conveyed in this sentence.

On lines 161-162, what is meant by embryos transferred "in the same period"? The rest of this paragraph also needs extensive copy editing.

On line 166 the reference for the rate of multiples after ART (reference 23) is from 2013. This reference is much too old to be used here. Transfer of multiple embryos and thus multiple pregnancy has been declining over the years such that a more recent reference is needed on this subject.

On line 182, reference 25 on birth defects is much too old. More recent references are needed.

In the sentence on lines 246-248, what is meant by neurodevelopmental outcome of preterm infants with and without ART overlapping? More information on the meaning of this statement is needed.

The section on the Barker hypothesis and fetal programming is very speculative and no data are available to show that there are actually differences in ART children. The lack of actual data supporting this speculation needs to be made very clear.

On lines 313-314 what solutions and procedures could possibly be introduced to counteract infertility? This sentence is not explained.

The suggestion on lines 317-319 that number of embryos transferred be reduced is nothing new and should presented with the observation that there has been a worldwide effort to reduce the number transferred for many years.

The sentence on lines 321-323 concerning patient education doesn't make sense as written.

On line 330, what do the authors mean by "later in life"? Do they mean the elderly? Do they mean that too few ART children have yet reached middle age to understand the effects of the treatments?

It is not clear what is meant by lines 342-344. What is a "reproductive identity"?

As with the Abstract and the Introduction, the Conclusion does not really summarize what is in the paper. There is nothing in the paper about "cost relevant success" and little about "counselling and education of patients". It would be better for the Conclusion to summarize the actual content of the paper on the risks of ART.

Copy editing is needed. Many sentences are unclear.

Author Response

Q1) This paper reviews information on the risks of ART. The authors present major risks. They also suggest that these risks be adequately conveyed to patients undergoing the procedures. The paper presents the risks associated with ART. While major risks are presented, many of the references are not the newest ones in the field and some of them are from smaller studies rather than meta-analyses or reviews of the data. This reviewer suggests that the authors update their references to include mostly those published after 2020.

R1) We thank the reviewer for assessing our work. We have updated the references to include mainly studies published in the last 4 years.

Q2) The overall point of the paper and its value to the research and clinical communities is not clearly stated by the authors. 

R2) This has been explicitly stated in the revised version of the manuscript: “Thus, the overarching aim of this narrative review was to better delineate the long-term risks associated with ART in the offspring of mothers undergoing these procedures. To this end, we have summarized multiple aspects regarding ART procedures and the possible consequences on the mother and on the newborn. Moreover, we will provide an overview on the possible long-term consequences of ART procedures on the health of newborns, although longitudinal evidence is particularly scant. In the final part of this work, we will discussed the role of ART in foetal programming of adult diseases, according with the Barker’s theory [2].”

Q3) The Abstract does not adequately convey the substance of the information presented in the paper. The Abstract suggests that the paper will discuss that clinicians should convey the "complexity of the procedures" as well as risks of ART, however, the complexity of the procedures is not discussed in any detail and although the risks are presented the need to discuss these with patients is not the focus of the paper. The paper actually presents the risks, and the Abstract would better convey the substance of the paper if it were to list out the major risks that will be discussed. 

R3) The abstract has been revised according to the indications of the reviewer.

Q4) The first paragraph of the Introduction presents a series of issues (using a numbering system that is not sequential) that are never returned to later in the paper. Guidelines, regulations, donor gametes, and other issues introduced here are not covered in the paper and should not be part of the Introduction.

R4) This section has been extensively revised as follows: “There are several important open questions regarding ART that have been discussed in recent years in the literature. For instance, it remains unclear who maintains property of the embryos. And there is also no specific indication on how many embryos should be developed for each woman undergoing ART. Furthermore, it is still matter of debate the upper age limit for women asking to access ART procedures. Finally, there is still un-certainty on whether same-sex couples and single women could be eligible for ART.”

Q5) Line 96 "liver birth" should be changed to "live birth".

R5) Done

Q6) On lines 126-128 more information should be added as to what is meant by the statement that ART children grew differently from spontaneously conceived children.

R6) This has been specified and extended in the revised manuscript.

Q7) On line 138, the sentence starting with "A French narrative..." is not a full sentence. It is also not clear what is being conveyed in this sentence.

R7) This has been revised.

Q8) On lines 161-162, what is meant by embryos transferred "in the same period"? The rest of this paragraph also needs extensive copy editing.

R8) This sentence has been extensively revised.

Q9) On line 166 the reference for the rate of multiples after ART (reference 23) is from 2013. This reference is much too old to be used here. Transfer of multiple embryos and thus multiple pregnancy has been declining over the years such that a more recent reference is needed on this subject.

R9) We have updated the reference and the text accordingly.

Q10) On line 182, reference 25 on birth defects is much too old. More recent references are needed.

R10) The reference and the sentence has been updated and revised as follows: “A large population-based cohort studied 135051 ART children (78 362 singletons and 56 689 twins), 23 647 naturally conceived ART siblings (22 301 singletons and 1346 twins) and 9396 children born to women treated with ovulation induction (6597 singletons and 2799 twins) and 1067 922 naturally conceived children comparing rates of birth defects [26]. The results showed that, compared to naturally conceived children, ART singletons (conceived from autologous oocytes, fresh embryos without the use of ICSI) had increased risks of a major nonchromosomal birth defect, cardiovascular defects, and any birth defect [26]. Further, compared to naturally conceived children, ART singletons conceived (from autologous oocytes, fresh embryos) with the use of ICSI, the risks were increased for a major nonchromosomal birth defect, blastogenesis defects, and cardiovascular defects. In addition, the risk for musculoskeletal defects was increased as well as the risk for geni-tourinary defects in male infants [26]. In addition, another recent study aimed to defining a hierarchy of risks for pregnancy outcomes in women undergoing ART conception, showed that major birth defects including cardiac, urogenital and musculoskeletal defects are doubled after fresh intracytoplasmic sperm injection, the technique that accounts for about 70% of all fertilization techniques [24].”

Q11) In the sentence on lines 246-248, what is meant by neurodevelopmental outcome of preterm infants with and without ART overlapping? More information on the meaning of this statement is needed.

R11) We have rephrased this sentence.

Q12) The section on the Barker hypothesis and fetal programming is very speculative and no data are available to show that there are actually differences in ART children. The lack of actual data supporting this speculation needs to be made very clear.

R12) We clarified that this a speculative part of the manuscript.

Q13) On lines 313-314 what solutions and procedures could possibly be introduced to counteract infertility? This sentence is not explained.

R13) The Discussion has been rephrased and this sentence removed.

Q14) The suggestion on lines 317-319 that number of embryos transferred be reduced is nothing new and should presented with the observation that there has been a worldwide effort to reduce the number transferred for many years.

R14) Rephrased.

Q15) The sentence on lines 321-323 concerning patient education doesn't make sense as written.

R15) This has been removed.

Q16) On line 330, what do the authors mean by "later in life"? Do they mean the elderly? Do they mean that too few ART children have yet reached middle age to understand the effects of the treatments?

Q17) It is not clear what is meant by lines 342-344. What is a "reproductive identity"?

R17) Clarified.

Q18) As with the Abstract and the Introduction, the Conclusion does not really summarize what is in the paper. There is nothing in the paper about "cost relevant success" and little about "counselling and education of patients". It would be better for the Conclusion to summarize the actual content of the paper on the risks of ART.

R18) Done.

Reviewer 2 Report

It is a manuscript about a significant topic that unfortunately needs major revision.

Introduction

Line 30: “We think is important...” change to “... it is important…”. I would recommend avoiding using the word we

Lines 31–38: rewrite the questions, avoiding the numbers 1, 2, 3, etc. It is obvious that you made changes in the question presentation, make a major revision in the introduction part.

Line 40: emphasizes change to emphasize

Line 42: “... and evolving in parallel with the evolving and changing society.”. Rewrite it.

Lines 47–50: remove lines and present the study in another part of the text.

The introduction needs editing and major changes.

2. Historical notes.

Line 79: more than eight million children. In line 98, more than 10 million children. The presentation is misleading the reader. Make proper alterations.

The topic is significant; you could avoid historical notes and expand on other topics.

3. Concepts of ART

Chapters 3.1 and 3.2. Rewrite them in concise form or delete.

4. clinical outcomes of ART—some chapters are very small, rewrite them, merge some of them and produce fewer chapters

4.8 Congenital malformations; use more recent references, confirming your points

4.9 and 4.8 merge these two chapters

4.10: use recent references

4.11, delete or report it in another chapter.

4.12: Make additional comments about the paternal age (Kaltsas et al, 2023) and the impact on neuropsychiatric sequalae.

7. Discussion: I would prefer an extensive description of the chapter 6 or previous chapters rather than a repetition of already written data.

Improve some references using more recent data.

The manuscript needs extensive editing of the English language

Author Response

Q1) Line 30: “We think is important...” change to “... it is important…”. I would recommend avoiding using the word we

R1) Done

Q2) Lines 31–38: rewrite the questions, avoiding the numbers 1, 2, 3, etc. It is obvious that you made changes in the question presentation, make a major revision in the introduction part.

R2) This has been extensively revised.

Q3) Line 40: emphasizes change to emphasize.

R3) Done.

Q4) Line 42: “... and evolving in parallel with the evolving and changing society.”. Rewrite it.

R4) Done

Q5) Lines 47–50: remove lines and present the study in another part of the text.

R5) This part of the text has been extensively revised as follows: “However, psychological well-being is essential during ART procedures. For instance, a recent study showed that women with recurrent implantation failure showed high serum epinephrine level, which might result from psychological distress and high anxiety levels [1]. Importantly, epinephrine signalling was shown to regulate endometrial receptivity through the PI3K-AKT and FOXO1 pathways [1].”

Q6) Line 79: more than eight million children. In line 98, more than 10 million children. The presentation is misleading the reader. Make proper alterations.

R6) This has been corrected.

Q7) Chapters 3.1 and 3.2. Rewrite them in concise form or delete.

R7) 3.2. removed; 3.1. was extensively reduced.

Q8) Clinical outcomes of ART—some chapters are very small, rewrite them, merge some of them and produce fewer chapters.

R8) Done.

Q9) 4.8 Congenital malformations; use more recent references, confirming your points

R9) This has been done.

Q10) 4.9 and 4.8 merge these two chapters

R10) Done

Q11) 4.10: use recent references

R11) Done

Q12) 4.11, delete or report it in another chapter

R12) Done

Q13) 4.12: Make additional comments about the paternal age (Kaltsas et al, 2023) and the impact on neuropsychiatric sequalae.

R13) Done.

Q14) 7. Discussion: I would prefer an extensive description of the chapter 6 or previous chapters rather than a repetition of already written data. 

R14) We revised the discussion accordingly.

Q15) Improve some references using more recent data.

R15) We have updated the references as requested.

Round 2

Reviewer 1 Report

The authors have improved the paper. A few issues remain.

Sections 3.2 and 4.2 both concern multiples. It would be better to either combine these sections or specify what is being stated in each that makes them different.

While discussion of multiples is important, the authors should also specifically discuss what has been shown by studies that include singletons only. 

Extensive editing for English grammar is needed. Note that the word on line 98 should be "Epidemiological", not what is written.

Author Response

Q1) The authors have improved the paper. A few issues remain.

R1) Thanks for the assessment.

Q2) Sections 3.2 and 4.2 both concern multiples. It would be better to either combine these sections or specify what is being stated in each that makes them different.

R2) These have been combined in the revised version of the manuscript.

Q3) While discussion of multiples is important, the authors should also specifically discuss what has been shown by studies that include singletons only.

R3) A brief section was added at the end of 3.2.

Reviewer 2 Report

Introduction

Rephrase/rewrite the sentences, lines 43-5.

Minor editing, for example line79, we will discussed the role

Historical notes

Minor editing for example Epidemillgical  line 98

minor editing

Author Response

Q1) Rephrase/rewrite the sentences, lines 43-5.

R1) Done

Q2) Minor editing, for example line79, we will discussed the role

R2) Done

Q3) Minor editing for example Epidemillgical  line 98

R3) Done