Is Anti-Mullerian Hormone (amh) Associated with Preterm Birth? Results from the Effects of Aspirin on Gestation and Reproduction (eager) Trial.

Although recent studies suggest that lower AMH is associated with adverse obstetric outcomes like preeclampsia, less is known about an association with preterm birth. The objective was to assess a possible association between preconception AMH levels with preterm. Secondary analysis of a multicenter, block-randomized, double-blind, placebo-controlled clinical trial. 1228 women attempting pregnancy, aged 18–40 years, with one to two prior pregnancy losses and no history of infertility, pelvic inflammatory disease, tubal occlusion, endometriosis, anovulation, uterine abnormality, or polycystic ovarian syndrome were included. Women were randomized to preconception-initiated daily low-dose aspirin or placebo. The primary outcome for this analysis was preterm birth (defined as a living infant born before 37 weeks and 0 days gestation). AMH was assayed using the Gen II ELISA assay (Beckman-Coulter) at the baseline visit before randomization. AMH was clinically categorized and verified by data analysis into low (<1.25 ng/mL), normal (1.25 to 4.0 ng/mL), and high (>4.0 ng/mL). The Mann Whitney test was utilized to evaluate AMH levels by preterm birth status. Relative Risk (RR) and 95% confidence intervals (CIs) for preterm birth by AMH categories were estimated using generalized linear models adjusted for age. Women were followed for up to six menstrual cycles with N=776 (72%) achieving pregnancy and N=51 (9%) with a preterm birth. Women were predominately of white race (95.6%) with a mean age of 28.9 years (standard deviation (SD) 4.7) and body mass index (BMI) of 26.1 (SD 6.5). Mean AMH among women with a preterm birth were 3.4 ng/ml (SD 2.6) compared to women without a preterm birth at 3.6 (2.7) (p=0.81). There were no significant associations between AMH and preterm birth in women with low AMH (<1.25 ng/mL) (RR=0.72, 95% CI 0.30, 1.7) or high AMH (>4.0 ng/mL) (RR=0.78, 95% CI 0.43, 1.4) compared to women with normal AMH levels after adjustment for age. Although AMH has been recently associated with preeclampsia and pregnancy loss, AMH was not associated with preterm birth in women with normal fertility, suggesting that AMH may be a more of a marker of ovarian and reproductive vasculature, thus affecting vascular diseases of pregnancy.