Purpose or Case Report: To determine the accuracy and significance of a fetal diagnosis of midface hypoplasia.
Methods & Materials: This is a retrospective single center review of all fetuses referred to a tertiary fetal care center for, or subsequently diagnosed with, midface hypoplasia on same day sonography (US) and 3T MR imaging between 2014 and 2019. During this period, 38 pregnant women carrying fetuses with concern for midface hypoplasia were identified. Evaluated variables included: gestational age at referral and delivery, demise or termination, gender, singleton versus multiple, US based classification of degree of midface hypoplasia using the maxilla-mandible-nasion (MMN) angle and the prefrontal space ratio (PFSR), associated anomalies on referral, upon assessment in our fetal care center, and respiratory outcomes in the delivery room. Survival outcomes were known for 30 fetuses.
Results: Gestational age at referral ranged from 18.4 to 34.1 weeks, mean GA 23.3 weeks. 27% (8/30) fetuses underwent pregnancy termination (TOP), 13% (4/30) had intrauterine fetal demise, 13% (4/30) had neonatal demise, and 47% (14/30) were live born at gestational ages ranging from 20 to 40 weeks. There were equal numbers of males and females. All but one were singletons. Only 13% (4/30) had MMN angles in the normal range. 40% (12/30) had PFSR measurements in the normal range. Consequential associated anomalies were present in 80% (24/30), and included genetic and syndromic etiologies. 2 fetuses had cleft lip/palate, a diagnosis known to be associated with deformity of the nasal contour and profile. Of the 12 live born infants with delivery room follow up, 67% required respiratory support.
Conclusions: Fetal midface hypoplasia is strongly associated with additional anomalies and can be accurately diagnosed in the fetus by the combination of fetal US and MRI. Many fetuses with midface hypoplasia have serious underlying diagnoses. A third of fetuses who did not undergo TOP died in utero or in the neonatal period and for those born live, respiratory support may be required in the delivery room.