Increase in incidence of gastroschisis in the south west of England in 1995.

OBJECTIVE

To describe the incidence of gastroschisis and to identify possible aetiological factors.

DESIGN

A retrospective case review study.

SETTING

The South West Region of England.

POPULATION

All known cases of gastroschisis were identified from the regional fetal medicine, ultrasound, pathology and neonatal surgery, databases. Datasets to be collected were agreed prospectively and included demographic, past medical, family and obstetric information for all pregnancies conceived between January 1987 and December 1995.

RESULTS

In the first eight years the incidence was 1.6/10,000 but in 1995 a highly statistically significant rise to 4.4/10,000 was found (P = 0.0009). The increased incidence was not associated with changes in maternal age, proportion of primigravidae, use of tobacco or illicit drugs, conception while taking the oral contraceptive pill, or an increase in the number of teenage pregnancies. The median maternal age at last menstrual period for pregnancies with gastroschisis was 20.4 years which was much younger than the national average of 28 years. Thirty-seven percent of these conceptions occurred during the first quarter of the year compared with the expected 25%.

CONCLUSIONS

The incidence of gastroschisis has risen to a higher level than previously reported which, despite a marked association with young maternal age at conception, is not due to an increase in the teenage pregnancy rate. As the average length of inpatient stay in the neonatal intensive care unit for cases with this malformation is approximately four weeks, the rise has considerable cost implications. The increasing incidence may also offer opportunities to determine the cause of gastroschisis.