Background: First-trimester miscarriage is common, with women increasingly offeredanultrasoundscanearlyinthefirsttrimestertoassessthestatusoftheir pregnancy. Ultrasound is uniquely situated to significantly impact the clinical managementofthesewomen.

The placenta is the link between mother and fetus and its function is central to a successful pregnancy. The predominant theory within the literature is that the development of placental dysfunction is a result of abnormal trophoblast invasion early in pregnancy. Knowledge of the development of the early placenta and the establishment of the fetomaternal circulation assists in understanding the origins of placental dysfunction which manifest later in pregnancy. Perinatally, chronic placental dysfunction may result in a growth-restricted fetus, maternal problems such as gestational hypertension, pre-eclampsia, eclampsia and pregnancy complications such as placental abruption, preterm labour and delivery. In addition, the growth-restricted fetus and the mother are at an increased risk of a myriad of disorders later in life. The role of ultrasound in the assessment of first trimester pregnancy is evolving with the potential for value in the prediction of placental function in later pregnancy. This review will address two aims, first to describe the development of the placenta from fertilisation to 12 weeks' gestation, correlating this with first trimester ultrasound findings. Second, to describe the link between placental development and function later in pregnancy. Understanding the link between early placental development and later placental function is essential in directing the focus of new research addressing the role of ultrasound in the first trimester in the prediction of adverse obstetric outcomes.

Objectives: The fetal adrenal gland receives rising awareness as a predictor of spontaneous preterm birth. As previous studies focused on cross-sectional assessments, the aim of the present study was to provide longitudinal assessments of the fetal adrenal gland in a low risk population with an additional focus on growth-trajectories in fetuses born preterm. Methods: Analyses were based on data from a population-based low-risk prospective pregnancy cohort situated in Hamburg, Germany. Fetal adrenal gland was assessed via transabdominal ultrasound at gestational weeks (gw) 24-26, 28-30, and 34-36. Longitudinal trajectories of the total adrenal gland and the adrenal mark (so called fetal zone) as well as ratio of fetal zone width/ total adrenal gland widths (w/W) were analysed using repeated measurements ANOVA. To compare trajectories of the ratio w/W for fetuses preterm and term as well as women with and without clinical signs of preterm labour we additionally used the propensity score method. Results: Regarding total adrenal gland, longitudinal trajectories indicated a statistically significant increase for adrenal length, width, and volume (p < 0.0001) for those women with available measures at all three timepoints (n=386). Likewise, the fetal zone width increased over the course of pregnancy (p < 0.0001), while the ratio w/W decreased (p < 0.0001) (n= 329). Comparing the trajectories of the ratio w/W in fetuses born preterm (n=11) with propensity-score matched term born fetuses (n=22), a decrease between gw 24-26 and 28-30 was observed in both groups, which continued to decrease for the term born fetuses. However, in preterm born fetuses, the ratio increased above the term born values at gw 34-36. Conclusions: Our study provides longitudinal growth data on the fetal adrenal gland and supports the hypothesis that fetal zone enlargement is associated with preterm birth which could play an important role in risk-prediction. OP08.11 Uterine artery pulsatility index assessment < 11 weeks of gestation: a prospective study

Poster discussion hub abstracts of acute abdomen, serum human chorionic gonadotropin (hCG) < 5000 IU/L, absence of fetal cardiac activity on TVS and absence of significant hemoperitoneum, defined as blood above the level of the uterine fundus and/or in Morison's pouch. Those women with severe lower abdominal pain, hemodynamic instability or significant blood in the abopelvis defined as blood above level of uterine fundus or positive blood in Morison's Pouch were excluded from the study. The correlation with type and success of management were investigated. Results: 5880 consecutive women presented to the EPU.287 (4.8%) women diagnosed with EP.246 had tubal EP. Hemoperitoneum was seen in 143/246 (58%) of cases. Significant hemoperitoneum was noted in 84/143 (59%) these cases were managed surgically and therefore excluded from the study. Of the remaining 59/143 (41%) with non-significant hemoperitoneum, 29/59 (49%) had surgery for clinical indications, 30/59 (51%) had non-surgical management. For these 30 cases mean hCG level at 0h was 1487.8±1654.7 IU/L and at 48 h 1270.7±1745. 1IU/Lumen Hemoglobin at presentation was 11.0±1.2 g/dL. 15/30 received methotrexate (MTX) (6/15 had successful management and 9/15 had failed medical management and treated surgically. 15/30 were managed expectantly (12/15 were successful, 1/15 had surgery and 2/15 had MTX). In total, 18/30 (60%) women with non-significant hemoperitoneum had successful management. Conclusions: This study suggests that the finding of hemoperitoneum on ultrasound examination may not be an absolute contraindication to conservative management of tubal EP. P23.07 Ultrasound markers prior to 8 weeks' gestational age for the prediction of fetal demise prior to 12 weeks' gestation