Amniotic Fluid Lecithin/Sphingomyelin Ratio in Pregnancy Complicated by Diabetes

Abstract

Summary The lecithin/sphingomyelin (L/S) ratio in the amniotic fluid of 57 patients attending an antenatal diabetic clinic was determined. The L/S ratio in Class A, B and C patients (White, 1965) showed a similar rise with gestation to non‐diabetic patients; 89 per cent in this group had an L/S ratio above 2:1, but of these 27 per cent developed mild or moderate respiratory distress syndrome (RDS). In Class D, F and R diabetic patients there was a little correlation of the L/S ratio with gestational age and in this group 55 per cent of the infants developed some form of RDS. The value of measuring amniotic fluid L/S ratios in the diabetic pregnancy is questioned.

Delayed fetal pulmonary maturation in a rabbit model of the diabetic pregnancy.

“…Therefore, estimation of fetal pulmonary lecithin production by measurement of the lecithin to sphingomyelin ratio in amniotic fluid is used as an index of fetal pulmonary maturity (4). Although this measure is highly predictive of lung maturation in normal pregnancies, it is peculiarly unreliable in the diabetic pregnancy (5). This finding suggests that maternal diabetes interferes with fetal pulmonary maturation without affecting total lecithin synthesis.…”

The effect of clinical characteristics on the lecithin/sphingomyelin ratio and lamellar body count: a cross-sectional study

“…Nevertheless, there is evidence in the literature that fetal lung maturation in pre-existing diabetes is altered 1,3,[22][23][24][25]42 .…”

“…Since the L/S ratio may be influenced by the presence of pre-existing diabetes 1,[22][23][24][25]42 , the construction of normal Table 1 Comparison of lecithin/sphingomyelin (L/S) ratio and lamellar body count (LBC) (× 1000/µl) in women who had received glucocorticoids for < 10 days prior to amniocentesis, and women who had not received glucocorticoids. Ranges are shown in parentheses curves for the L/S ratio was performed after exclusion of women with pre-existing diabetes.…”

“…Maternal diabetes has been shown to increase the probability of RDS 21 , but effects on fetal lung maturity test results are uncertain. Some authors have reported a lower L/S ratio 1,22 or a lower predictive value of the L/S ratio [23][24][25] , while others have found that L/S ratios in diabetic and non-diabetic women were comparable [25][26][27][28] , thereby questioning the accuracy of the test 29,30 . Few data are available on the relation between the diabetic status of the woman and the LBC 3,4,25 .…”

Maternal diabetes and neonatal respiratory distress. I. Maturation of fetal surfactant

“…Similarly the amniotic fluid lecithin/sphingomyelin (L/S) ratio seems to be less reliable in diabetic pregnancies at predicting Correspondence: D. K. James, Department of Obstetrics and Gynaecology, Southmead Hospital, Westbury-on-Trym, Bristol BSlO 5NB. 316 fetal lung maturity (Dahlenburg et al 1977;Mueller-Heubach et al 1978).…”