Reviewer’s report
Title: 
RISK FACTORS FOR NATURAL MENOPAUSE BEFORE THE AGE
OF 45: EVIDENCE FROM TWO BRITISH POPULATION-BASED BIRTH
COHORT STUDIES
Version: 
0 
Date: 
10 Dec 2021
Reviewer's report:
This cohort study uses data from two national cohorts of women from a 1958
and a 1970 birth cohort study to look at factors linked with early (< age 45 years)
natural menopause. 
These women (N=6,805) were studied at the individual level
looking at risk factors in three phases of life: 
birth, childhood, early adulthood
(each examined independently). Thank you to the authors for undertaking this
ambitious and complicated analysis. 
I have only minor comments. 
Background
line 82: instead "when menarche begins" change to at menarche. 
Menarche
means when periods begin. 
Under literature review line 132: what do you mean
by the effect of prenatal exposure to cigarette smoke may act via adult smoking?
I may have missed this, but what is included in "gynecological problems" under
Methods (and throughout) line 232? 
I don't see this defined anywhere. 
Lines 247
and 255: change HRT to HT. 
We no longer use the term replacement-but call it
hormone therapy. For readability, add "having" before undergone line 246.
Results line 344-not sure what is meant by "economically active." 
Does this
mean employed? 
Please clarify. Finally, in the Conclusion, you imply that you
cannot infer causality in this study, but it needs to be stated in limitations. 
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