133

134

284 SPO Abstracts

MATERNAL GLYCEMIC CONTROL: WHAT CONSTITUTES THE MEAN? 'Karen Bauer Smith. 'Deanna Gonzales. Oded Langer Dept of OB/GYN. The University of Texas Health SCience Center at San Antonio. TX

It became axiomatic that metabolic control can significantly reduce adverse outcome in diabetes In pregnancy. To characterize the level of glycemic control. some centers obtain fasting and preprandial values. others collect fasting and 1 or 2-hour (h) postprandial (PP) and still others obtain a combination of these samples. Different timing of blood glucose determination in relation to meals may result In varied results of mean blood glucose. Thus. researchers' results may not be comparable. The purpose of this study was to determine if different testing schemes Will vary the results. In a prospective study. 160 diabetic women tested blood glucose at fasting. premeal. and at 1 and 2h postprandial Six mean blood glucose groups from the sample were identified: fasting alone. preprandial. postprandial at lh. postprandial at 2h. overall mean uSing 1 h PP. and overall mean using 2h PP The results revealed: 1) significant difference was found between 1 and 2h PP glucose determinations (137 ± 28 vs. 105±25. p<.OOOI); 2) a higher glucose excursion eXIsts in the lh group when compared to the 2h group (42 ± 23. vs. 8 ± 19. p< .0001); 3) the fasting plasma !:/Iucose (92 ± 19) was Significantly lower than the 1 h PP determination and no significant difference was found between 2h PP and premeal; 4) there was a higher overall mean at lh in comparison to the 2h (114±28 vs. 101 f25.

< 03 . and 5 the correlation matrix of the 6 rou s revealed: ast. Mean 1 ean 2

Fast r=.49 r=.47 r= 82 r=.86 lhPP r=.69 r= 90 r=.58 2hPP r=.58 r=.85

We conclude that there IS a clear difference In mean maternal blood glucose levels in each combination which is dependent upon sampling times and their relationship to meals. The data suggest that 1 h postprandial is more representative of glucose excursion in the pregnant diabetic.

SHOULDER DYSTOCIA AND BIRTH TRAUMA IN GESTATIONAL DIABETES: A FIVE-YEAR EXPERIENCE. JD Keller". JA Lopez­Zeno', SL Dooley, ML Socol, Dept. of OB-GYN, Northwestern Univ. Med. Sch., Chicago, IL.

Diabetes mell~us is an accepted risk factor for macrosomia, shoulder dystocia. and birth trauma. Most data have been generated from studies of diabetic patients w~hout differentiating pregestational from gestational diabetes mellitus (GDM). The resultant conclusions may not be applicable to both groups making counseling of women with GDM difficuH. We addressed this issue by examining the charts of 210 pregnancies complicated by GDM w~h birth weights ::3500 gms. Only three cesarean sections were performed for macrosomia without a trial of labor. Mode of delivery, occurrence of shoulder dystocia, and incidence of brachial plexus injury are shown below.

BIRTH WEIGHT (gms) n Cesarean section Vaginal delivery Shoulder dystocia (Total)

w/Clavicular fracture wlBrachial palsy w/Residual palsy (mild)

3500-3999 4000-4499 126 65 51(40%) 28(43%) 75(60%) 37(57%) 7(9.3%) 5(13.5%) 2(2.7%) 0 2(2.7%) 1(2.7%) o 1(2.7%)

>4500 -19--

11(58%) 8(42%) 3(37.5%) o 1(12.5%) o

Our data suggest: (1) If all fetuses ::4000 gms could be identified and delivered by cesarean section, only approximately half of shoulder dystocia and birth trauma would be obviated; (2) As permanent brachial plexus injury is uncommon and the errors in estimating fetal weight are considerable, a liberal policy towards cesarean section may increase maternal morbidity w~h minimal fetal benefit.

135

136

Jdnuaq 1991 Am J Obstet G} necol

THE DIABETIC VS. NON-DIABETIC MACROSOMIC INFANT: WHO IS AT RISK? O. Lan~r. xMichael Berkus. *Elly Xenakis. xByron Elliott Dept OB/GYN. T e University of Texas Health Science Center at San Antonio. Texas

The problem of the macrosomlC fetus has been debated for five decades The malority of studies have failed to distinguish between diabetiC (DM) and non-diabetic (NDM) gravlds or contained an inadequate sample size to permit accurate analysis Our research question was to determine the rate of morbidity and mortality of macrosomlC infants in both groups. Using the 75.363 consecutive vaginally-delivered infants from the departmental data bank (1970-85). gravids were stratified Into DM/NDM groups and by weight categories (> or < 4000g) Comparison of selected variables are shown'

Non-Diabetic Diabetic < 4kg >4kg <4kg >4kg Tota/Cases

No complications 61 6% 552% 593% 547% 610% Toxemia 6.6% 68% 127% lB 0% 68% Trauma .5% 1 5% 1 1 % 3.7% 6% Fetal distress 17.8% 241% 18.1% 33.3% 18.3% Comp delivery 23.5% 31 3% 208% 44.0% 241% Birth defects 2.4% 29% 42% 6.7% 25% Shoulder dystOCia .2% 42% .6% 190% .6% Stillbirth 12% 12% 4.2% 122% 1.2% Total Cases 68115 5668 1253 327 75363 The study revealed 1) a 4-fold fISk for macrosomia in DM vs. NDM; 2) overall. the risk for shoulder dystocia was 5 9 (95% CI 4.4-8.0) for the DM; and 3) a higher fISk for shoulder dystocia was found In both weight categories « 4000g and > 4000g) for the DM group (RR 2.60 95% Cll 3-5.3; RR 3495% CI 2 4-4 8. respectively) We conclude that the macrosomlc infant is at Increased risk for adverse outcome With an even greater risk for the diabetic macrosomic mfant

MORBID MACROSOMIA: THE RELATIVE IMPORTANCE OF GESTA nONAL DIABETES MELLITUS AS A PREDISPOSING FACTOR Nanette B Okun, MD*. Judy Campanaro, MD*. Robert Stenstrom MSc,*.PR Garner. MD*. Division of Perinatology, Ottawa General Hospital, University of Ottawa. Ottawa.

Macrosomia is potentially the most serious morbid perinatal outcome in pregnancy complicated by gestational diabetes mellitus (GDM). We hypothesized that factors other than GDM were more powerful predictors of macrosomia, and this retrospective study was conducted to determine the relative importance of the following factors: (J) gestational age over 40 weeks, (2) pre-pregnancy weight. (3) body mass index, (4) weight gain in pregnancy, (5) gravidity. (6) parity. (7) the presence of treated GDM. (8) the severity of the glucose intolerance. and (9) diet or insulin requirement. 100 treated gestational diabetics (NDDG criteria) were compared with 100 controls (negative glucose screen). There was no significant difference betweeen the groups in factors I to 6 (t-test, chi-square). Logistic regression demonstrated that gestational age over 40 weeks was the strongest predictor of birthweight over 4000 gms. (odds ratio 6.1 when the groups were combined, 5.1 in group with GDM. 26.3 in controls). Pre-pregnancy weight was second in importance. (odds ratio 1.04 per 10 kg increase). and GDM. third (odds ratio 3.4). Because these results are so dramatic with treated GDM. we are planning a randomised, controlled trial comparing standard treatment for GDM with ultrasound surveillance alone. wilh macrosomia a.~ the primary outcome variable.