The objective was to determine the strength of relationship between maternal free beta human chorionic gonadotropin (β-hCG) concentrations and rates of adverse pregnancy outcomes. Consecutive records of the database of our Down screening project were assessed for free β-hCG levels and pregnancy outcomes. Pregnancies with foetal chromosomal or structural anomalies and those with underlying disease were excluded. Free β-hCG levels of < 0.5, > 0.5 and < 2.0, and ≥ 2.0 MoM were categorised as low, normal and high, respectively. Of 17,082 screened women, 13,620 were available for analysis. In the first trimester (n = 8150), low β-hCG levels significantly increased risk for intrauterine growth restriction (IUGR), preterm birth, low birth weight (LBW) and low Apgar score with relative risk of 1.66, 1.43, 1.83 and 2.89; whereas high β-hCG group had a significant decreased risk of preterm birth and GDM with relative risk of 0.73 and 0.62. In the second trimester (n = 5470), both low and high β-hCG groups had significant increased risks of the most common adverse outcomes, i.e. spontaneous abortion, IUGR and preterm birth. In conclusion, abnormally low (< 0.5MoM) or high (> 2.0 MoM) free β-hCG levels are generally associated with an increased risk of adverse pregnancy outcomes. Nevertheless, high free β-hCG levels in the first trimester may possibly decrease risk of preterm delivery and GDM.

Objective: To determine the association between maternal serum unconjugated estriol (uE3) levels in the second trimester and adverse pregnancy outcomes. Patients and methods: The prospective database of our fetal Down screening program was assessed and reviewed for maternal serum uE3 levels. Pregnancies with medical diseases, abnormal levels of beta-human chorionic gonadotropin, alpha-fetoprotein and fetal chromosomal or structural abnormalities were excluded. The recruited women were categorized into three groups: high (>95th percentile), normal (5–95th percentile) and low (<5th percentile) uE3 levels. Results: Of 14 212 screened women, 9183 (high; 455, normal; 8271 and low; 457) levels group, were available for outcome analysis. The rates of most adverse outcomes, including preterm birth, low Apgar scores, fetal death, placental abruption, preeclampsia and gestational diabetes mellitus, of the high and normal groups were comparable. Nevertheless, low uE3 levels increased risk of fetal growth restriction (FGR) (RR: 2.36, 95% CI: 1.79–3.10) and low birth weight (LBW) (RR: 1.87, 95% CI: 1.45–2.39), but not preterm birth. Logistic regression analysis indicated that low uE3 level was an independent risk factor for FGR and LBW. Conclusions: High uE3 levels in the second trimester are not associated with poor outcomes, whereas low levels significantly increase risk of FGR and LBW but not other adverse outcomes.