Monochorionicity in the absence of TTTS is not associated with an increased risk of adverse neurodevelopment at 5 years of age.Richard N Brown, MBBS, FRCOG, FACOGDirector of Obstetrics and Maternal Fetal Medicine, McGill University, McGill University Health Centre, Montreal, CanadaCorrespondence AddressRichard Brown, Division of Maternal Fetal Medicine, McGill University Health Centre, 1001 Decarie Blvd, Montreal, Canada H4A 3J1Richard.brown@mcgill.caDisclosures: noneDespite stabilising twin pregnancy rates over the last two decades, as much as one birth in 30 is a twin birth. With twin preterm birth rates being as high as 60% (Martin et al, National Vital Statistics Reports;2019:68), prematurity represents the major factor influencing overall perinatal outcomes in twins. Monochorionicity (MC), with its attendant unique complications (including twin-to-twin transfusion syndrome (TTTS) and selective fetal growth restriction (sFGR)), represents another major risk factor for adverse perinatal outcome in twinning. MC complications contribute to the increased perinatal death rate evident in MC twins compared to dichorionic (DC) twins, as well as the greater premature birth rates [often iatrogenic] amongst MC twins. The potential for neurological harm associated with TTTS is now well understood, whilst in comparison that associated with growth discordance / sFGR or monochorionicity itself, remains less well established.Existing data have suggested increased rates of long-term neurodevelopmental deficits in MC twins overall and especially in those with growth discordance. Perinatal care of twins has improved significantly since data from cases followed in the 90’s reported an 8-fold greater risk of cerebral palsy (CP) in MC twins over DC twins, with this being 19-fold higher in MC twins with discordant growth (Adegbite et al AJOG 2004,190:156-63). A 37% rate of neurological damage has been reported even in the normally grown twin of an sFGR pair, when the co-twin has abnormal Dopplers; however, this was based on neuro-imaging findings within the first month and a half of life (Gratacos et al Ultrasound Obstet Gynecol 2004;24: 15-63). More recent data has shown a difference in mild neurological morbidities only, but follow-up, at a median of 24 months, ranged broadly from 12 months to 7 years (Rustico et al Ultrasound Obstet Gynecol 2017,49, 387-93). Despite the limitations of the available outcome data, such information underpins counselling in MC gestations complicated by sFGR. The question “will my twins be OK in the end?” remains one that is not easy to answer with confidence.The EPIPAGE2 cohort has the advantage of representing a more recent large national cohort of preterm births, recruited over a single year and with long term follow-up data. The sub-analysis presented here (Horau et al BJOG 2023, TBC), addresses the association of chorionicity and neurodevelopmental outcomes of prematurely delivered twins (22-34 weeks) at early school age (5 ½ years). The comprehensive testing likely paints a more realistic picture of the neurodevelopmental and neurobehavioural status of MC twins than these prior studies.Within the described population, 24% of twins were MC. The 20% of these complicated by TTTS were excluded from the outcome analysis given the known impact of TTTS. Growth discordance of 20% or more was found in 26.2% of the MC twins compared with 11.8% of the DC twins. In the context of a population with over a quarter of MC twins displaying significant growth discordance, the results are encouraging. Although fewer (68%) of MC twins were alive at discharge compared to DC twins (78%), the severe CP rates at 5 years were equivalent at around 1%. Amongst survivors there were no differences in the neuro-developmental or neuro-behavioural assessments between the MC and DC twins; with adverse outcomes seemingly therefore being linked principally to prematurity rather than chorionicity or growth discordance itself.

An improved understanding of pregnancy in women with Turner’s syndrome may save lives!BJOG-21-1221Around 25% of maternal deaths are related to heart disease and up-to 20% of these are the consequence of aortic dissection (Lameijer et al, Neth Heart J (2020) 28:27–36). Connective tissue disorders (e.g. Marfan’s, Loeys-Dietz, Ehlers Danlos), Bicuspid aortic valve, Turner’s Syndrome (TS) and pre-existing coarctations constitute the bulk of aortopathies encountered in pregnancy. Although a true XO karyotype in pregnancy had been rarely encountered historically due to the reduced fertility in these patients, women with a mosaic TS may have normal fertility and in recent years reproductive technologies with oocyte donation have increasingly been used in the sub-fertile TS population. Although pregnancies in such women remain infrequent, the risk of death during pregnancy amongst all women with TS (inclusive of mosaicism) has been reported as high as 2%, 150-200 times greater than the general population. This increased risk has led to the establishment of guidelines for the use of reproductive technologies in these women (Karnis. Fertility Sterility (2012) 98(4),787-91).The rarity of these cases means that available data, even when drawn from multicenter registries, has been relatively sparse. A study of TS patients gathered from ten cardiovascular centres over 12 years evaluated 68 pregnancies (Grewal J, et al. Heart 2021;107:61–66). Although the majority had no structural cardiac disease and no major cardiovascular complications were observed, the adverse obstetric event rate was around 20% with a similar rate for adverse fetal outcomes. Like the present paper (BJOG-21-1221) which reports a larger population, these cases were followed within centres offering a dedicated obstetric-cardiac clinic.Standardized guidelines for preconceptual and perinatal care of these women have improved outcomes, as evidenced by a French study evaluating cohorts from before and after the establishment of such guidance in France (Cadoret et al, EJOGRB(2018) 229,20–25). Whilst these guidelines encourage the care of TS mothers in dedicated obstetric-cardiac centers, this is not always the case; either due to lack of diagnosis of the condition (esp in mosaic cases with milder phenotypes) or lack of appreciation of the risks. The present paper reports only cases followed in cardiac-obstetric centres; without an overall population pregnancy case number it will remain uncertain what proportion of women with TS were followed in an appropriate centre and whether the reported cohort therefore excludes cases with worse outcomes.Although it might be expected that mothers followed within appropriate centres receive optimal care, studies continue to show that this is not always so. In the present cohort only half of the women had a pre-pregnancy cardiac evaluation and 20% had no record of imaging during pregnancy; perhaps reflecting late referral to the tertiary centre. While this remains a high-risk population with risks for both maternal and fetal adverse outcomes with high haemorrhage rates, hypertensive disease rates (~19%) and an SGA rate exceeding 20%, the data from this cohort is reassuring with respect to severe perinatal morbidity. Particularly striking in this cohort was a caesarean rate of 67%.To provide women with TS optimal care, preconceptual evaluation and pregnancy planning with medical optimisation is vital, with subsequent close follow-up in an obstetric-cardiac centre capable of managing whatever complications this cohort might experience, even if rare.Disclosure of InterestRB has no conflicts of interestRB is supported by the CIHR and FRSQ