Sex ratio at birth is associated with type 1 diabetes characteristics.
OBJECTIVE
To assess the association between maternal diabetes characteristics and sex ratio at birth (SRB) in women with type 1 diabetes mellitus.


METHODS
We performed a case-control study. The study subjects were infants born alive to women with type 1 diabetes and singleton pregnancies. Cases and controls were defined as male and female newborns, respectively. SRB was analysed according to diabetes-related characteristics adjusting in a logistic regression analysis for maternal characteristics known to affect SRB in the general population.


RESULTS
The observed SRB (238 males/468 live births = 0.509) did not differ from the expected. In the logistic regression analysis, SRB was significantly associated with three diabetes characteristics: (1) diabetes duration, with odds ratios (ORs) for a live male newborn = 1.22 (95 % confidence interval (CI), 0.66-2.24 for ≤5 years, OR 2.79 (95 % CI 1.36-5.74) for >20 years; (2) mean first-trimester glycated haemoglobin, with OR 1.98 (95 % CI 1.09-3.62) for ≤6.7 % (50 mmol/mol) and OR 2.61 (95 % CI 1.16-5.85) for >8.2 % (66 mmol/mol) and (3) mean first-trimester insulin dose, with OR 0.70 (95 % CI 0.36-1.38) for ≤0.5 IU/kg/day and OR 0.18 (95 % CI 0.05-0.59) for >1.0 IU/kg/day.


CONCLUSIONS
We conclude that SRB in this cohort is independently associated with three diabetes characteristics. These associations are to be confirmed.
Department of Endocrinology and Nutrition, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.
Apolonia
A
García-Patterson
Department of Endocrinology and Nutrition, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.
Inka
I
Miñambres
Department of Gynecology and Obstetrics, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.|Department of Pediatrics, Obstetrics and Gynecology and Preventive Medicine, Universitat Autònoma de Barcelona, Plaça Cívica, Campus de la UAB, 08193, Cerdanyola, Spain.
Juan María
JM
Adelantado
Department of Clinic Epidemiology and Public Health, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.|Department of Clinical Pharmacology and Therapeutics, Universitat Autònoma de Barcelona, Plaça Cívica, Campus de la UAB, 08193, Cerdanyola, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Av. de Monforte de Lemos, 5, 28029, Madrid, Spain.|Institute of Biomedical Research (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.
Ignasi
I
Gich
Department of Pediatrics, Obstetrics and Gynecology and Preventive Medicine, Universitat Autònoma de Barcelona, Plaça Cívica, Campus de la UAB, 08193, Cerdanyola, Spain.|Department of Clinic Epidemiology and Public Health, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.|Institute of Biomedical Research (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.
Teresa
T
Puig
Department of Endocrinology and Nutrition, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.|Institute of Biomedical Research (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain.|Department of Medicine, Universitat Autònoma de Barcelona, Plaça Cívica, Campus de la UAB, 08193, Cerdanyola, Spain.|CIBER Bioengineering, Biomaterials and Nanotechnology (CIBER-BBN), Instituto de Salud Carlos III, c/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain.
Alberto
A
de Leiva
Department of Endocrinology and Nutrition, Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain. rcorcoy@santpau.cat.|Institute of Biomedical Research (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Avgda. Sant Antoni Mª Claret 167, 08025, Barcelona, Spain. rcorcoy@santpau.cat.|Department of Medicine, Universitat Autònoma de Barcelona, Plaça Cívica, Campus de la UAB, 08193, Cerdanyola, Spain. rcorcoy@santpau.cat.|CIBER Bioengineering, Biomaterials and Nanotechnology (CIBER-BBN), Instituto de Salud Carlos III, c/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain. rcorcoy@santpau.cat.
Rosa
http://orcid.org/0000-0001-5055-6814
R
Corcoy
D000328:Adult; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology*; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000175:diagnosis / Q000453:epidemiology; D012744:Sex Ratio; D013030:Spain / Q000453:epidemiology
D006442:Glycated Hemoglobin
Glycated haemoglobin; Insulin; Sex ratio at birth; Type 1 diabetes