Abstract
Objective: To explore the relationship between small fetal second-trimester head circumference (HC) and pregnancy outcome and identify a cutoff point for offering genetic testing. Method: Data from second-trimester scans in Denmark were linked to national registers. Fetuses with anomalies diagnosed before this scan were excluded. Fetuses were grouped according to HC z-score. Results: We included 352 515 singleton fetuses. The mean HC was significantly larger among males than among females with z-scores averaging 0.52 more in males. Small HC was associated with chromosomal anomaly, malformations of the CNS and heart, miscarriage/perinatal death, termination, preterm delivery, and intrauterine growth restriction (test for trend: P <.001 for all outcomes). Fetuses in the group with z-score less than –3 had the highest incidence of adverse outcome, irrespective of fetal sex. In the groups with z-scores between –3 and –2.5, and between –2.5 and –2, risk of adverse outcome was lower for females than males for all outcome categories. Conclusion: Small HC in second trimester is a prognostic marker for adverse outcome. The smaller the HC, the higher the risk of adverse outcome. We suggest an HC cutoff point of –2 SD for males and –2.5 SD for females for offering genetic testing.
Original language | English |
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Journal | Prenatal Diagnosis |
Volume | 39 |
Issue | 10 |
Pages (from-to) | 910-920 |
Number of pages | 11 |
ISSN | 0197-3851 |
DOIs | |
Publication status | Published - Sept 2019 |
Keywords
- BIPARIETAL DIAMETER
- BIRTH
- CHARTS
- DISCREPANCY
- FETUSES
- GESTATIONAL-AGE
- GROWTH
- INCREASED RISK
- LAST MENSTRUAL PERIOD
- PREDICTORS