Prospective audit of vitamin D levels of women presenting for their first antenatal visit at a tertiary centre.

BACKGROUND

Vitamin D deficiency in pregnancy is associated with adverse events such as pre-eclampsia, primary caesarean section and vitamin D deficiency of the newborn. Vitamin D screening in pregnancy is not universal.

AIMS

To evaluate the vitamin D status of pregnant women at our institution and assess the sensitivity of the current risk-based screening guideline.

METHODS

A prospective audit of vitamin D levels of all women presenting for their first antenatal booking visit during 3 four-week periods (in 2009-2010) was conducted at the Women's and Children's Hospital, South Australia. The main outcome measure was 25-hydroxyvitamin D3 levels. Information was also collected on body mass index, self-reported ethnicity and whether or not vitamin D testing was indicated based on the hospital guidelines.

RESULTS

Four hundred and seventy-two women consented to inclusion in the audit. 67.4% (318/472) were 'low-risk' according to the hospital guidelines for vitamin D screening. 46.2% of these women and 78.6% of 'high-risk' women were vitamin D deficient (<60 nmol/L). Mean vitamin D levels were 62.7 ± 22.0 and 43.4 ± 26.3 nmol/L for low- and high-risk women, respectively. 54.9% (147/268) of women who were found to be vitamin D deficient were classified as 'low-risk' giving a sensitivity of 45% for the current risk-based screening guideline.

CONCLUSIONS

Based on current normal ranges for vitamin D, risk-based screening criteria for vitamin D deficiency in pregnancy fails to detect over half of vitamin D deficient women at our institution. Current South Australian guidelines should be amended in favour of universal screening of vitamin D for all pregnant patients at their booking visit.