If you have taken any measurements of your twins' heights or weights since we last contacted you please enter them below.

Please use the height chart and instructions we sent you to add today's heights (no shoes). If you have misplaced your instructions booklet, you can now view our online version here.

Please use the scales we sent you to weigh your children and add today's weights (indoor clothes, no shoes)


If you wish to be reminded of your GEM ID number or to request a new height chart/measuring tape, please email the Gemini team ( and we will send one out to you at the earliest convenience.

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© 2007-present, Gemini Research - Health and Development, all rights reserved. 

Proudly created by Alice Kininmonth

Gemini Research, Department of Behavioural Science and Health, University College London, London, WC1E 7HB | Tel: 020 7679 1263