Objective: To investigate the hypothesis that maternal haemoglobin (Hb) levels in twin pregnancy fall between the first and second trimesters, and that the size of the fall is associated with gestational age at birth and birthweight (BW). Design: Retrospective study. Setting: Inner London Maternity Unit. Population: Pregnant women with twin pregnancies delivering two live, phenotypically normal neonates, after 24 +0 weeks of gestation, between October 2009 and September 2021. Methods: Measurement of Hb, at ≤14 +0 weeks of gestation, (Hb1) and again at 20 +0-30 +0 weeks gestation (Hb2). Hb drop was defined as Hb1-Hb2. Small for gestational age was defined as BW <10th percentile for gestation. The association of Hb drop with gestational age at birth, BW, SGA and intertwin BW discrepancy of ˃25%, was evaluated. Main outcome Measures: Gestational age at birth , incidence of SGA neonates and/or intertwin BW discrepancy >25%. Results: 925 women with twin pregnancies. Maternal Hb1 did not correlate with gestational age or SGA or twins with BW discrepancy >25%. However, a larger Hb drop was associated with a higher gestational age at birth (p<0.001), a larger BW of both twin 1 and 2 (p<0.001) and a trend towards reduction in the incidence of delivering one or two SGA neonates (p=0.005 and p=0.003, respectively) or twins with BW discrepancy of >25% (p=0.005). Conclusions: The study has shown that a larger maternal Hb drop from the first to the second trimester is associated with a higher gestational age at birth, a larger BW and smaller BW discrepancy in twin pregnancies.

Objective Obesity is known to be associated with cardiovascular compromise and is a major risk factor for the development of hypertensive disorders in pregnancy. The aim of this study was to investigate the effect of obesity on the maternal cardiovascular system. Design This was a prospective, observational, longitudinal study. Setting A tertiary centre in London Population Pregnant women with booking body mass index (BMI) ≥ 30kg/m2 (n=64) were compared to pregnant women with normal booking BMI (20-24.9kg/m2) (n=14). Methods Two-dimensional trans-thoracic echocardiography. Main outcomes Longitudinal difference in blood pressure, cardiac geometry and cardiac function between the groups. Results In women with obesity, the blood pressure, heart rate and cardiac output were higher and peripheral vascular resistance was lower (p<0.01 for all) compared to normal BMI women. Women with obesity had altered cardiac geometry with higher left ventricular end diastolic diameter, relative wall thickness and left ventricular mass (p<0.001 for all comparisons). There was also evidence of impaired diastolic indices in the obese group with lower E/A ratio, TDI E’ lateral and medial and higher left atrial volume (p<0.01 for all). Finally, women with obesity had reduced longitudinal function between the second and third trimester of pregnancy indicating possible early cardiac dysfunction in this group. Conclusions Obesity is associated with maternal hyperdynamic circulation, altered cardiac geometry and suboptimal diastolic function compared to normal BMI pregnant women; this may contribute to the increased risk of complications in obese pregnant women. Funding UK charities: Borne and CW+

Objective To assess if delivery mode and duration of labour in a first labour of spontaneous onset is associated with gestational length, delivery mode 3and neonatal outcome in the subsequent pregnancy. Study Design Retrospective analysis of prospectively collected data. Setting 15 Maternity units in North West London (1988 to 2000). Population 30,840 women with spontaneous onset of labour in pregnancy 1 and a subsequent birth reported in the same database. Methods Assessment of outcomes by mode of delivery in pregnancy 1, restricting the analysis to the difference in the gestational length between pregnancy 1 and 2. Main Outcome Measures Gestational length, mode of delivery and neonatal unit admission in pregnancy 2. Results Caesarean section (CS) in the first or second stage of labour in pregnancy 1 was associated with pregnancy 2 being a median of 5 and 8 days shorter and a preterm birth rate of 6.0% and 10.1% respectively, whereas following a spontaneous or instrumental birth in pregnancy 1 the median duration was similar, with preterm delivery rates of 4.5% and 3.9%. 56.2% of women with a CS in pregnancy 1 had a repeat CS and 12.5% of their babies were admitted to neonatal unit, compared with 5.3% of women with vaginal birth. Longer labours were associated with shorter gestations in pregnancy 2. Conclusions Compared to vaginal birth, an emergency CS in the first term pregnancy is associated with a shorter gestational length, increased rate of repeat CS and increased risk of NNU admission in the next pregnancy.