Lower levels of placental growth hormone in early pregnancy in women with type 1 diabetes and large for gestational age infants

•Women with T1DM delivering LGA infants had lower placental GH in early pregnancy.•Thereafter placental GH was similar in women with and without LGA infants.•During pregnancy IGF-I was similar in women with and without LGA infants.•In early pregnancy placental GH correlated negatively with gestational weight gain.•Placental GH at 8 weeks independently predicted LGA adjusted for pre-pregnancy BMI.

ObjectiveTo evaluate whether levels of placental growth hormone (GH) and Insulin-like Growth Factor-I (IGF-I) are associated with development of LGA infants in pregnant women with type 1 diabetes.DesignObservational study of 103 consecutive pregnant women with long-term type 1 diabetes and median HbA1c 6.6% (range 4.9–10.5) (49 mmol/mol (30–91)) in early pregnancy. At 8, 14, 21, 27 and 33 weeks weight was recorded and blood was sampled for measurements of placental GH, IGF-I and HbA1c. LGA was defined as birth weight > 90th percentile after adjustment for gender and gestational age.ResultsThroughout pregnancy placental GH levels were similar in 51 (50%) women delivering LGA infants compared with the remaining women except at 8 weeks where placental GH levels were lower in women with LGA infants (1.1 ng/ml (0.1–4.3) vs. 1.7 (0.3–11.7), p = 0.04). IGF-I levels were similar in women with and without LGA infants (p = 0.97). Gestational age at first blood sampling was similar in women with and without LGA infants (60 days (37–89) vs. 61.5 (42–94), p = 0.42). Placental GH levels at 14 weeks correlated negatively with weight gain in early pregnancy (r = − 0.32, p = 0.002). As predictors of LGA infants, multivariate logistic regression analysis identified placental GH levels at 8 weeks (OR 0.4 (95% CI: 0.2–0.9), p = 0.02), HbA1c at 33 weeks (3.6 (1.3–9.9), p = 0.01) and parity ≥ 1 (3.1 (1.3–7.5), p = 0.01) after adjustment for pre-pregnancy BMI.ConclusionsWomen delivering LGA infants had lower placental GH levels in early pregnancy. Growth factors and maternal weight gain in early pregnancy may be important for healthy fetal growth.