Etiology and perinatal outcome of periviable fetal growth restriction associated with structural or genetic anomaly.

OBJECTIVE: To investigate the etiology and perinatal outcome of periviable fetal growth restriction (FGR) associated with a structural defect or genetic anomaly. METHODS: This was a retrospective study of singleton pregnancies seen at a referral fetal medicine unit between 2005 and 2018, in which FGR (defined as fetal abdominal circumference ≤ 3rd percentile for gestational age) was diagnosed between 22 + 0 and 25 + 6 weeks of gestation. The study group included pregnancies with periviable FGR associated with a genetic or structural anomaly (anomalous FGR), while the control group consisted of structurally and genetically normal pregnancies with periviable FGR (non-anomalous FGR). Results of genetic testing, TORCH screen and postmortem examination, as well as perinatal outcome, were investigated. RESULTS: Of 255 pregnancies complicated by periviable FGR, 188 were eligible; of which 52 (28%) had anomalous FGR and 136 (72%) had non-anomalous FGR. A confirmed genetic abnormality accounted for 17/52 cases (33%) of anomalous FGR, with trisomy 18 constituting over 50% (9/17; 53%). The most common structural defects associated with FGR were central nervous system abnormalities (13/35; 37%). Overall, 12 (23%) cases of anomalous FGR survived the neonatal period. No differences were found in terms of perinatal survival between pregnancies with anomalous and those with non-anomalous FGR. CONCLUSIONS: Most pregnancies complicated by anomalous FGR were associated with a structural defect. The presence of an associated genetic defect was invariably lethal, while those with a structural defect, in the absence of a confirmed genetic abnormality, survived into infancy in over 90% of cases, with an overall one in three chance of perinatal survival. These data can be used for counseling prospective parents. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Short-term outcome of periviable small-for-gestational-age babies: is our counseling up to date?

OBJECTIVE: There are limited data for counseling on and management of periviable small-for-gestational-age (SGA) fetuses. We therefore aimed to investigate the short-term outcome of periviable SGA fetuses in relation to the likely underlying cause. METHODS: This was a retrospective study of data from three London tertiary fetal medicine centers obtained between 2000 and 2015. We included viable singleton pregnancies with a severely small fetus, defined as those with an abdominal circumference ≤ 3rd percentile, identified between 22 + 0 and 25 + 6 weeks' gestation. Data obtained included fetal biometry, presence of placental anomalies, uterine and fetal Doppler and neonatal outcome. We excluded cases with structural abnormalities, proven or suspected abnormal karyotype or genetic syndromes. Cases were classified according to the suspected underlying cause of the small fetal size into one of the following categories: uteroplacental insufficiency, evidence of placental damage with normal uterine artery Doppler, viral infection, or unclassied. RESULTS: There were 245 cases included in the study. Of these, at diagnosis of SGA, 201 (82%) were categorized as uteroplacental cause, 13 (5%) as suspected placental cause, one (0.4%) as suspected viral cause and 30 (12%) could not be assigned to any of these categories. Overall, 101 (41%) cases survived the neonatal period; 89 (36%) underwent in-utero fetal demise, 22 (9%) died neonatally and 33 (14%) pregnancies were terminated. The diagnosis-to-delivery interval was 8.1 weeks in those that survived and 4.5 weeks in those that died neonatally. CONCLUSIONS: Almost 90% of periviable SGA cases are associated with uteroplacental insufficiency or intraplacental damage. Survival is related to gestational age at delivery, with outcomes better than might be assumed at diagnosis and some pregnancies reaching term. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Dichorionic triplet pregnancies: risk of miscarriage and severe preterm delivery with fetal reduction versus expectant management. Outcomes of a cohort study and systematic review.

BACKGROUND: In trichorionic pregnancies, fetal reduction from three to two lowers the risk of severe preterm delivery, but provides no advantage in survival. Similar data for dichorionic triamniotic (DCTA) triplets is not readily available. OBJECTIVES: To document the natural history of DCTA triplets and the effect of reduction on the risk of miscarriage and severe preterm delivery, compared with expectant management. SEARCH STRATEGY: Systematic search on MEDLINE, EMBASE, and the Cochrane Library. SELECTION CRITERIA: DCTA triplets with three live fetuses at 8-14 weeks of gestation, outcome data with expectant management and/or reduction, miscarriage before 24 weeks of gestation and/or severe preterm delivery before 32-33 weeks of gestation. DATA COLLECTION AND ANALYSIS: Five studies were included. Data from these were combined with data from three centres. MAIN RESULTS: There were 331 DCTA triplets. The miscarriage rate was 8.9% (95% CI 5.8-13.3%) and the severe preterm delivery rate was 33.3% (95% CI 27.5-39.7%), with expectant management. The miscarriage rate was 14.5% (95% CI 7.6-26.2%) with a reduction of the monochorionic pair, 8.8% (95% CI 3.0-23.0%) with a reduction of one fetus of the monochorionic pair, and 23.5% (9.6-47.3%) with a reduction of the fetus with a separate placenta. Severe preterm delivery rates were 5.5% (95% CI 1.9-14-9%), 11.8% (95% CI 4.7-26.6%), and 17.6% (95% CI 6.2-41.0%), respectively. CONCLUSIONS: In DCTA triplets, expectant management is a reasonable choice when the top priority is a liveborn infant. Where the priority is to minimise severe preterm delivery, the most advisable option is fetal reduction. Further studies are needed to clarify which particular technique is advisable to optimise the outcome.