Placental immaturity and hyperinsulinaemia in full-term newborns.
BACKGROUND
Evidence from large studies suggests that low birthweight is a risk factor for cardiovascular disease and glucose metabolism disorders in adulthood, but the physiological mechanisms involved in intrauterine growth conditioning low birthweight are not completely understood. The objectives of this study were to determine whether placental immaturity (PI), defined as the lower quartile of placental maturity index (PMI), is associated to hyperinsulinaemia at birth and to identify the risk factors associated with PI.


METHODS
Cross-sectional study conducted at medical research units of two Mexican general hospitals. A total of 272 full-term newborns with gestational age >/= 38 and < 41 weeks were allocated into the corresponding group according to the quartile distribution of PMI. Data from the lower (PMI < 13.3) and higher quartile (PMI >/= 24.3) were compared. The PMI was estimated by dividing the number of epithelial plates by the average thickness of the epithelial plate. Serum measures included cord glucose and insulin levels of the newborns at birth.


RESULTS
A total of 74 (27.2%) children had hyperinsulinaemia at birth, of them 47 (63.5%) with PI. The adjusted multiple regression analysis showed a strong association between PI and hyperinsulinaemia at birth [odds ratio (OR) 2.6; CI 95% 1.3-4.3). Additional adjusted analysis showed that both mother's age </= 16 years (OR 1.75; CI95% 1.2-9.1) and maternal cigarette smoking (OR 2.7; CI95% 1.3-8.9) are associated to PI.


CONCLUSIONS
The PI is independently associated with hyperinsulinaemia at birth: smoking and mother's age lower than 16 years are risk factors for development of PI.
Rodríguez-Morán
M
M
Biomedical Research Unit of the Mexican Social Security Institute, Durango, México.
Levario-Carrillo
M
M
González
J L
JL
Sánchez-Ramírez
B
B
Martínez-Aguilar
G
G
Guerrero-Romero
F
F
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001724:Birth Weight; D005260:Female; D005317:Fetal Growth Retardation; D006801:Humans; D006946:Hyperinsulinism / Q000453:epidemiology*; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D008800:Mexico / Q000453:epidemiology; D009035:Mothers / Q000706:statistics & numerical data*; D010922:Placenta Diseases; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*
D007328:Insulin