Cord blood leptin levels in normal pregnancies, pregnancy induced hypertension and gestational diabetes mellitus.

OBJECTIVE: To compare cord blood leptin concentrations between normal pregnancy, pregnancy induced hypertension (PIH), and gestational diabetes mellitus (GDM). DESIGN: Cross-sectional study. SETTING: Academic institutes and a tertiary care maternal hospital. METHOD: 48 newborns of normal pregnancies (N=18), pregnancy induced hypertension (N=16), and gestational diabetes mellitus (N=14) were studied. Cord blood samples were collected and newborn anthropometric indices recorded at delivery. Leptin concentrations were measured using an enzyme immunoassay. RESULTS: Cord blood leptin levels were significantly different between the 3 groups (Kruskal-Wallis ANOVA; P=0.0064), and the difference resulted mainly from higher levels in GDM than in PIH [geometric mean (95% CI) for GDM: 10.89 (6.30, 18.84) vs PIH: 3.49 (2.14, 5.69) ng/ml (Dunn's multiple comparison: P<0.01). This pattern persisted even when leptin levels were normalized to the ponderal index (Kruskal-Wallis ANOVA P=0.0035; Dunn's multiple comparison: P<0.01). Leptin levels significantly and positively correlated with the ponderal index in normal pregnancy (Spearman r=0.506, p<0.05) and with birth weight in PIH (r=0.5463, p<0.05). CONCLUSION: In GDM cord blood leptin levels are significantly higher, and a source other than fetal adipocytes appears to contribute to this.

Maternal and cord blood levels of insulin-like growth factors--I and--II and insulin-like growth factor binding protein-1: correlation with birth weight and maternal anthropometric indices.

OBJECTIVES: To study the correlation of maternal and cord blood insulin like growth factor (IGF)-I and -II and IGF binding protein (IGFBP)-1 levels with birth weight and maternal anthropometric indices. DESIGN: Longitudinal prospective study. SETTING: Academic Institutions and a Tertiary Care Maternity Hospital. PARTICIPANTS: Women with uncomplicated singleton pregnancy (N = 35) and their newborns. MEASUREMENTS: Maternal weight, height, symphysiofundal height and serum levels of IGF-I, IGF-II, IGFBP-1 were measured thrice during the antenatal period, within 24 h of delivery and at 6 weeks and 6 months postpartum. Newborn anthropometric indices were recorded at birth, and at 6 weeks and 6 months of age. Cord blood levels of IGF-1, IGF-II, IGFBP-1, paternal height and weight, and placental weight measured. RESULTS: Maternal and cord blood IGF-I levels were lower than values reported for Caucasians. All newborns showed adequate growth at birth, and up to 6 months of age. Cord blood IGF-1 positively correlated with chest circumference (r = 0.4532, P = 0.0262), IGFBP-1, negatively with birth weight (r = -0.4024, P = 0.0461) and IGF-II had no effect. Cord blood IGF-I positively correlated with maternal levels at 28 +/- 2 (r = 0.4571, P = 0.0247) and 36 +/- 2 (r = 0.4291, P = 0.0364) weeks of amenorrhoea, whereas IGF-II and IGFBP-1 did not correlate with maternal values. Maternal IGF-I, IGF-II and IGFBP-1 did not correlate with newborn or maternal anthropometric indices. Placental weight correlated significantly with birth weight (r = 0.5299, P = 0.0348) and head circumference (r = 0.5031, P = 0.0470). CONCLUSIONS: Cord blood IGFBP-1 and placental weight appear to be determinants of birth weight variation even among appropriately grown for gestational age newborns.

Insulin-like growth factors-I and -II and insulin-like growth factor binding protein-1 during normal pregnancy: pattern of secretion and correlation with other placental hormones.

OBJECTIVES: To describe pattern of secretion of insulin-like growth factor (IGF)-I, IGF-II, IGF binding protein (IGFBP)-1 and their correlation with each other and major placental hormones during normal pregnancy. DESIGN: Longitudinal study. SETTING: Academic Institutions and a Tertiary Care Maternity Hospital. PARTICIPANTS: Healthy women with singleton uncomplicated pregnancies (N = 35). MEASUREMENTS: Serum levels of IGF-I, IGF-II, IGFBP-1, chorionic gonadotrophin (HCG), placental lactogen (HPL), prolactin, oestradiol and progesterone were studied thrice during the antenatal period and within 24 h of delivery. RESULTS: IGF-I, IGFBP-1, HPL, prolactin, oestradiol and progesterone increased and HCG decreased significantly with advancing gestation (Repeated measures ANOVA: P < 0.01 to 0.0001). IGF-II levels were not significantly affected by period of gestation. Significant negative correlations (multiple regression analysis) were seen between IGFBP-1 and prolactin at 28 +/- 2 (P = 0.0226) and 36 +/- 2 (P = 0.0417) weeks of amenorrhoea (WOA) and between oestradiol and IGF-II at 36 +/- 2 WOA (P = 0.037). Prolactin and IGF-I at 14 +/- 2 WOA (P = 0.0225) and progesterone and IGFBP-1 at 28 +/- 2 WOA (P = 0.0216) correlated positively. CONCLUSIONS: Maternal IGF-I and IGFBP-1 but not IGF-II significantly increase as pregnancy advances. Components of the IGF system regulate or are affected by some of the placental hormones and the effects vary with the period of gestation.

Maternal prolactin concentrations and lactational behaviour in the early postpartum period in women with lactational amenorrhoea.

OBJECTIVE: To compare early postpartum differences in maternal prolactin concentrations and lactational behaviour between women who have short and long periods of lactational amenorrhoea. METHODS: Healthy lactating women resuming regular menstruation before 24 weeks [short amenorrhoea (SA) group; n = 15], and at or after 24 weeks [long amenorrhoea (LA) group; n = 15] postpartum were studied from 4 to 12 weeks postpartum. Infant feeding pattern and maternal plasma prolactin concentrations were compared between the two groups using repeated measures ANOVA. RESULTS: Breastfeeds/24 h were significantly higher and other feeds/24 h were significantly lower (p < 0.01) at 12 weeks postpartum in the LA group when expressed as a percentage of all feeds. Number of breastfeeds (total/24 h and night) significantly decreased and the number of other feeds significantly increased (p < 0.05 to 0 < 0.001) with time in both groups. Prolactin concentrations (basal, suckling stimulated and increment) were higher in the LA group, but consistent significant differences were observed mainly in the increment (p < 0.05 to p < 0.001). Prolactin concentrations significantly (p < 0.01 to < 0.001) decreased with time postpartum in the SA group, but not in the LA group. CONCLUSIONS: Women with longer periods of lactational amenorrhoea maintain higher prolactin concentrations than those with shorter periods of lactational amenorrhoea during the early postpartum period, even when the breastfeeding frequency is reduced. This could be explained by a greater sensitivity of the pituitary lactotrophe to the suckling stimulus in women who have longer periods of lactational amenorrhoea.

Effect of age on serum prolactin concentration in presumably fertile men in Sri Lanka.

OBJECTIVE: To examine possible age related variation in serum prolactin in men. DESIGN: A cross sectional study. SUBJECTS: Healthy married men aged 21 to 85 years with one or more children. MEASUREMENTS: Serum prolactin concentrations measured by immunoradiometric assay. RESULTS: Prolactin concentrations were significantly higher (p < 0.001) from 61 years of age onwards when compared with 31 to 60 years. Prolactin concentrations between 21 to 30 years were significantly higher than between 31 to 50 years (p < 0.05), but lower than between 61 to 70 (p < 0.05) and 75 to 85 (p < 0.01) years. CONCLUSIONS: Serum prolactin concentrations show age related variations in presumably fertile men.

Prolactin concentrations during the normal menstrual cycle: rhythms within rhythms.

Prolactin concentrations were measured in frequent blood samples collected over a 2 h period randomly distributed during day and night, during the follicular and the luteal phases of the normal menstrual cycle in women. Episodic fluctuations in prolactin concentrations were observed throughout the 24 h period and the pattern of these fluctuations appeared to vary depending on the time, and sleep wake state. Thus a changing pattern of the 'primary pulse' of prolactin may be responsible for the time related and sleep related changes in prolactin during the 24 h period.