368 SPO Abstracts January 1995 Am J Obstet Gynecol 395 TWIN DISCORDANCE AS A PREDICTOR OF NEONATAL OUTCOME: A HISTORICAL COHORT OF 414 SETS OF TWINS AJ. C~dieux x, G. Bender x, J.E. Tolesa, M.C Leiva x, G. Macenes x, J. Gerdesx, V. B hutanix. Dept of OINGynand Neonstology, Pennsylvania Ho~p., Pldla., PA. OBJECTIVE:Determine how specific twin blrthweight discordance affects outcomes in the newborn (biB). STUDY DESIGN: A historical cohen of 414 sets of twins born between 1989-1994 was studied with a computerized neonatal database and chart review. Percentage of discordance by birthweighi: 0-10, 10-15%, 15-25%, >25% and association with neonatal outcomes: morality, intraventricular hemorrhage (IVH), necrotizing enterouolitis (NEC), persistent doctas astedosas (PDA), respiratory distress syndrome (RDS), use of antibiotics >=-7 days(ABX) and Apgar scores were analyzed. A Cht square for trend explored the probability of incremental risk by discordant strata, controlling for. GA, race and gender. RESULTS: % of Discordance: <10%: 198 (48%), 10-15%: 78 (19%), 15-25%: 79 (19%), >25%: 53(13%). GA at delivery <34 wks: 34%. Race (%):White 57, Black 37, Other 6; by gender (%): both males: 31, both females: 33, female/male: 36. Small forGA (SGA) <10%: 22%/small, and 4%/large twins; 4% were bo~h SGA. Mortality rates: 7.5% small, 6.2% large. Mortality was associated with discordance >25%; the small twin: R.R., 95% CJ. 5 (2, 12) p<0.01, large twin 4.2 (1.6, 11) p<O.001. The trend was significant for increasing levels of discordance, p<O.001. There is interaction between GA and mortality, but GA does not explain the increased risk. SGA was not associated with increased mmlality or other poor outcomes for either twin, at any strata of discordance. After adjusting for gender and race, mortality was higher for white NB: R.R.95% C.I.10 (3.0, 33) p<0.01, black: 2.1 (0.5, 19) p=0.35. In the small twin, discordance > 25% was associated with ABX: 1.9(1.2, 2.9) p=0.002; PDA: 2.7 (1, 7.4) p---O.02; RDS: 2.6 (1.6, 4.0) p<0.01. In the large twin with: ABX: 1.9 (I.2, 3) p=O.03; PDA:3.7 (1.7, 8) p<0.01; RDS: 3 (2, 4.6) p<0.01. When adjusted, the risk was increased in the white, male, NB for all variables in both twins. CONCLUSIONS: Birthweight discordance >25% is associated with poor neonatal outcome. The NB twin,white, male, appears to be at increased risk for mortality, ABX use, PDA and RDS. 397 MATERNAL ZINC SUPPLEMENTATION INCREASES BIRTHWEIGHT AND HEAD CIRCUMFERENCE. R. Qoideabem, T. Tamura," Y. Ncggers," R. Copper, x K. Johmton, ~ M. Dul~'d," J. Hauth. Dept. Ob-Gyn, University of Alabama, Birmingham, AL. OBJECTIVE: To study the effect of maternal zinc .uppkmentatlon (ZS) on birthweight (BWT) and other pregnancy outcomes. STUDY DESIGN: At a mean of 19 weekJ' gestational age (GA), 580 indigent African-American pregnant wonum with phumm ~ levela below the median for our population, who were receiving non-zinc containing multivitamin and mineral tablets, were randomized to receive either a daily oral dose of 25 rng zinc or a plazebo. Plume zinc levels were monitored throughout pregnam~y and anthtopometrie m e u ~ of infants including BWT we~ obtained at delivery. For atmlysis, the mothers were subgroup¢d by body ma~ index (BMI) either <26 (non- obey) or _>26 (obese). RESULTS: Women assigned to the zine-anpplemeatad group (Nffi286) had a significant incrcsan in meaa BWT (126 g, p=0.03) and mean head cix~umference (HC) (0.4era, pffiO.02) u compared to the plaeebo group (N ffi294). ~ inoreu¢ in BWT was Msueiatod with a longer GA 08.8 vs 38.3 Pffi.06) and an inereu© in size independent of GA. In women with a BMI .~.26, Z$ wu not esm¢iated with a signlfu=at change in any pregnancy outcome. In those with a BMI <26, ZS was esmeinted with a 248 g increase in Bwr (p=0.005) and a 0.7 ¢m inereu¢ in HC (pffi0.007). Regrmsion eaalysea, adjusting for GA, demongtatad that half the increu¢ in BWT was aunointed with a longe~" GA and half wag associated with increased growth. The increase in HC was due predominantly to inc~ growth. Poat treatmeat plasma zinc concentrations (in 3 time periods) were . ~ y higher in the ZS group than the pisgebo group, although both were in the normal hinge. CONCLUSIONS: Daily ZS in wnmea with relatively low plamna zinc was associated with inoreases in infant BWT and HC, These inoreues occurred only in women with a BMI of <26. 396 ANTHROPOMETRIC ESTIMATION OF NEONATAL BODY COMPOSITION. A. Thomas~, D. AvallonO, S. AminP, P. Catalano. Dept. Reproductive Biology, Case Western Reserve Univ. at MetroHealth Medical Center, Cleveland, OH. OBJECTIVE: Estimation of neonatal body composition [fat (F) and fat free mass (FFM)] hall been previously shown (SPO 1994,//83 &//84) to improve our understanding of various factors affecting fetal growth. However, body composition methods such as stable isotopes to measure total body water and Total Body Electrical Conductivity (TOBEC) are expensive and not readily available. Hence, the primary purpose of this project was to develop an anthropometric model to estimate neonatal body composition and prospectively test the model against TOBEC and a previously published anthrepometric formula (Dauncey). STUDY DESIGN: At bblh 194 nemnates had estimates of body composition using TOBEC (GROUP 1). Parental morphometries, gestational age, race, sex, parity, and neonatal measurements including birthweight, length, head circumference and skinfolds (triceps, subscapolar, flank and thigh) were correlated with F using stepwise regression analysis. The anthropometric model was tested in a second group of 65 neonates (GROUP 2) and compared with TOBEC and Dauncey. Statistical analyses were made using linear regression analysis, Chi Square, paired t and Wileoxon signed-rank tests. RESULTS: There were no significant differences in any of the parental or neonatal measurements between GROUPS 1 and 2. In GROUP 1 subjects, 78% of the variance in F using TOBEC was explained by neonatal birth- weight, length and flank skinfolds (r2=0.78, p=0.0001). When prospective- ly tested in GROUP 2, the model had significant and stronger correlation (r2=0.84, p=0.0001) with TOBEC estimated F as compared with the Dauncey model (r2=0.54, p=0001). There were no significant (p=0.11) differences beXween our anthropometric estimates of F and TOBEC. CONCLUSIONS: The anthropometric model developed and prospectively tested can be used to reasonably predict neonatal F mass at birth. NIH 22965 and Weight Watchers Foundation. 398 ASYMMETRIC GROWTH RESTRICTION IS ASSOCIATED WITH PERSISTENT PULMONARY ItYPERTENSION OF TIlE NEONATE. M.C. Williams, L.E." Wyblex, W.F. O'Brlcn, R.M. Nelson', C.D. CuanovaL The Depts. of Ob/Gyn and Pads., Univ. of So. Fla., Tampa, F1 OBJECTIVE: Persistent pulmonary hypertension of the neonate (PPHN) is associated with fetal distress, but may also result from antepartum developmental events. IUGR (low birthweight for gestational age) and asymmetric growth restriction (low bhthweight for length (ASYM)) are risk factors for perinatal morbidity. Possible associations between IUGR and ASYM (measured by low poedend index (Pl)) were sought in infants with PPHN and in matched controls. STUDY DESIGNt 80 infants with PPHN delivered over the years 1991 to 1994 at our hospital and 400 contemporaneous normal control neonates (CTRL) were matched for gestetional age, race, and gender (5 CTRL: PPHN). Pl was calculated (100 x biRhweight / lengthS). IUGR and ASYM were defined as BW and Pl less than the 5th centile for gastetionsl age and race by institutional norms, respectively. The relationship between ASYM and PPHN was sought, and additionally sought in non-IUGR infants, and in non-lUGR infants with normal 1 and 5 minute Apgar (APG) scores (APGI >7 and APG5 >.8). Chi-squared tests, Odds-ratios (O.R.), and 95% Confidence intervals (95% CI) were calculated, and McNemar's test were performed as appropriate. 95%C1's excluding 1.0 and P<0.05 were eonsidered significant. RESULTS: Pl was lower (2.54 vs 2.79, P<0.001) and bhth length was longer (50.9 am. vs 49.0 era., P <0.001) in PPHN infants. ASYM (27.5% vs 4.3%, P<0.0001) and IUGR (15.0% vs 5.5%, P <0.003) occurred more often in PPHN infants. ASYM was a better predictor of PPHN then IUGR (P<0.05, McNemsr's test). In non-lUGR infants (O.R. 9.4, 95%CI 4.1- 22), and in non-IUGR's with normal APG ~ores (O.R. 6.8, 95%C1 2.1- 22), ASYM occurred disproportionately in PPHN's. CONCLUSIONS: ASYM occurs more often in PPHN than does IUGR. ASYM is associated with PPHN, even in non-lUGR infants with normal Apgar scores. Antenatal developmental events can affect neonatal pulmonary status.