Prenatal diagnosis of fetal omphalocele by ultrasound: A comparison of two centuries

Limited Role of MSAFP Screening for Prenatal Omphalocele Detection

OBJECTIVES

Although serum screening for aneuploidies has become less prevalent, maternal-serum alpha-fetoprotein (MSAFP) screening for body-wall defects remains widespread. We explored whether MSAFP screening is associated with earlier omphalocele detection than ultrasound alone.

METHODS

This is a retrospective cohort study of prenatally detected omphalocele cases at our center from 2007 to 2023. We explored the association between MSAFP screening, gestational age at omphalocele detection, and clinical outcomes.

RESULTS

Among 101 pregnancies with prenatally diagnosed omphalocele, 27 (26.7%) had MSAFP screening. The median gestational age at MSAFP screening was 17 weeks 4 days. Of those who received MSAFP screening, 11 (41%) had values ≥2.5 multiples of the median (MoM) and 16 (59%) were not elevated. MSAFP results did not correlate with omphalocele size and were not associated with prenatal or postnatal outcomes. MSAFP screening did not result in earlier suspicion for or confirmation of omphalocele (P = .97 and P = .87, respectively). In contrast, first-trimester ultrasound screening was associated with earlier suspicion for and confirmation of omphalocele (P < .01 and P = .01, respectively). There were no clinical or demographic differences between those who received MSAFP screening and those who did not (including body mass index or commute distance to an urban center).

CONCLUSION

MSAFP screening is not associated with earlier omphalocele detection. Furthermore, in pregnancies with prenatally diagnosed omphalocele, the results of MSAFP screening are not predictive of clinical outcomes.

The analysis of pregnancies terminated before and after the limit of viability: A medicolegal view

PURPOSE

In the present study, the purpose was to determine the indications of pregnancy termination procedures that are performed before and after the limit of viability (between 10 and 22 weeks) in a tertiary center and to investigate the characteristics of the cases in which fetocide procedure was offered after the limit of viability (22 weeks and later). It also aimed to discuss the legal deadline for the fetocide procedure and legal aspect of pregnancy termination.

MATERIAL AND METHOD

The present study was conducted as a result of the retrospective examination of 198 cases who underwent pregnancy termination after the 10th week of pregnancy (the legal limit for voluntary termination of pregnancy in our country) in our clinic and met the study criteria. The cases were divided into two main groups as Early Termination (10-22 weeks) and Late Termination (22 weeks and later). The characteristics of these groups (i.e. reason for termination, termination week) and the characteristics of the cases in which fetocide procedure was performed and the cases that were not (i.e. termination week, reasons for termination) were compared.

RESULTS

A total of 171 (86%) cases were under 22 weeks and 27 (14%) were 22 weeks or more. In the cases terminated early, the gestational week was found to be highest [20 + 1 (12+3-21 + 1)] in those with preterm premature rupture of membranes, and lowest in those with fetal gastrointestinal abnormalities. No statistically significant differences were detected between the termination reason and the gestational week in the late-terminated group, and also, although the termination week of 5 patients for whom the fetocide procedure was offered [median = 23 + 1 (22+4-26 + 0] was higher than the week of 22 patients for whom the fetocide procedure was not offered [median = 22 + 4 (22+1-25 + 4], the difference was not found to be statistically significant.

CONCLUSION

Since the majority of pregnancy terminations are performed before the viable period, the need for the fetocide procedure in pregnancy terminations is relatively low, and we think that this rate will decrease even more because the rate of early diagnosis of fetal anomalies increases as a result of developments in ultrasonographic imaging. Families who choose the termination of pregnancy search for other countries with appropriate legislation and the loss of time and the indecision of the family might cause the application of pregnancy termination after the viable period because of the limitations in the legal regulations of countries.

Clinically Relevant Prenatal Ultrasound Diagnosis of Umbilical Cord Pathology

Umbilical cord abnormalities are not rare, and are often associated with structural or chromosomal abnormalities, fetal intrauterine growth restriction, and poor pregnancy outcomes; the latter can be a result of prematurity, placentation deficiency or, implicitly, an increased index of cesarean delivery due to the presence of fetal distress, higher admission to neonatal intensive care, and increased prenatal mortality rates. Even if the incidence of velamentous insertion, vasa praevia and umbilical knots is low, these pathologies increase the fetal morbidity and mortality prenatally and intrapartum. There is a vast heterogeneity among societies’ guidelines regarding the umbilical cord examination. We consider the mandatory introduction of placental cord insertion examination in the first and second trimester to practice guidelines for fetal ultrasound scans. Moreover, during the mid-trimester scan, we recommend a transvaginal ultrasound and color Doppler assessment of the internal cervical os for low-lying placentas, marginal or velamentous cord insertion, and the evaluation of umbilical cord entanglement between the insertion sites whenever it is incidentally found. Based on the pathological description and the neonatal outcome reported for each entity, we conclude our descriptive review by establishing a new, clinically relevant classification of these umbilical cord anomalies.

Abdominal wall defects

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

Giant Omphalocele Complicated by 9P Minus Syndrome

Omphalocele is characterized as a ventral wall defect in which there exists a midline herniation of abdominal viscera into the base of the umbilical cord. Fetuses with a diagnosis of this entity are at a significantly increased risk of having an aneuploidy, additional anomalies, or associations with other syndromes such as Beckwith Wiederman. Secondary to these interconnections, there is an elevated risk of fetal loss in affected pregnancies. Detection of concordant abnormalities, appropriate genetic counseling, and involvement of pediatric subspecialties are paramount in affording a prognosis, and providing optimal perinatal management of omphalocele.

Antenatal diagnosis of isolated omphalocele

The concern of obstetric and surgical teams is when diagnosis of omphalocele, the care of the newborn and the prognosis of the malformation, mainly linked to the existence of associated malformations or chromosomal abnormalities. In our case of isolated omphalocele, the overall prognosis was good.