Volume 16~ l\umber 1. Pdrt 2

19 PATHOLOGIC FETAl ACIDEMIA. K. Goldaber! L. Gllstrap, K. Leveno, J. Dax! Dept. Ob/Gyn, Un iv Texas Southwestern Med. etr., Dallas, Texas

The umbilIcal artery pH of < 7.20 has been arbItrarIly assIgned as the pH whIch classIfIes the fetus as beIng aCldemlc, and by ImpllcatlOn, more lIkely to be asphyxIated. Unfortunately, the pH that constItutes SIgnifIcant aCIdemia rema lnS undef i ned. The purpose of the present study was to define the pH cut-off for clInIcally signIfIcant or pathologIC aCIdemIa. A total of 1268 newborns (total of 32,835 dellVeries) .! 2500 grams wIth a pH .:: 7.14 were dlVlded Into four pH groups as llsted below.

Selzure

Neonata I deaths

Intens lYe care nursery

Intubated

Apga r scores .:: 3 1 mInute

5 mInutes

Umb] ] H;a] Arter;t Qti 7 00 7. 05- 7.10-

<7. 00 7.04 7. 09 7.14 n=85(%) n=95(%) n=290(%) n=798(%) 9 (10.6) 3 (3 2) a 2 (0.3)

p=.04 p=.Ol p=NS (8.2) 2 (2.1) a 3 (0.4)

p=.06 p=.06 p=NS 17 (20.5) 5 (5.3) 4 (1. 4) 7 (0.9)

p= 001 p= 04 p=NS 32 (37 6) 3 (3 2) 9 (3 1) 10 (1. 3)

p=. 0001 p=NS p=NS

23 (27.1 ) 6 (6.3) 12 (4.1) 19 (2.4) p=. 0003 p=NS p=NS

(10 6) 0 (17) a p= 0009 p=NS p=NS

In concluslOn, the cut-off for cllnlcally SIgnIfIcant aCIdemIa would appear to be < 7 05 (although the pH cut-off associated WIth hIghest neonatal morbIdIty/mortalIty was < 7.00). Remarkably, the majorlty of these Infants had no demonstrable neonatal complIcatIons.

20 SHOULD THE FETUS WITH AN ESTIMATED WEIGHT >4000G BE DELIVERED BY CESAREAN SECTION (CIS)? 0 Langer, xM. Berkus, R Huff, Dept OB/GYN, Unlv TX HSC at San AntoniO, TX.

Most authOrities recommend that an elective CIS be performed when estimated fetal weight IS >4500g. Controversy eXists on the optimum method of dehvery of the 4000-4500g fetus. 75,363 women delivered vaginally in the 1970-85 period were stratified Into diabetiC (OM) and non-diabetic (NOM) groups Overall, the inCidence of macrosomia (>4000g) in the non-diabetiC group was 8% (5,668/68,115) while 26% (327/1,253) was found In the diabetiC group They were further subdiVided by weight categories (250g Interval) The log odds ratio for shoulder dystocia for all groups IS shown

1~00~---------------------------------

100000 _ NON-OM rza OM

1~ LOGRR

1000

100

10

3999 4250 The study demonstrated that the for Increased risk for shoulder dystOCia for the NOM was reached at weight category 2:4500 and for the OM at2:4250 Additionally: 1) the 4000-4500g fetal weight category predicted shoulder dystOCia in 9 9% of the OM and 7 7% in the NOM; 2) In the >4501 weight category, the rate of shoulder dystocia for OM and NOM was 32% and 95%, respectively; and 3) vaginal delivery In the birth weight category 2: 4500g IS associated With significantly higher inCidence of neonatal morbidity and mortality In the OM, 65-75% had adverse outcome (trauma, APGAR and PNM) and the NOM 15-30% Trial of vaginal delivery should be allowed in all NOMs with estimated fetal weight (EFW) of 2:4750 Elective CIS of the OM mothers should be conSidered strongly when the EFW is > 4250

spa Abstracts 251

21 LONG TERM CHILD DEVELOPMENT AFTER PROLONGED PREGNANCY ~,C. LibrachX, 1. Andrews\ D. Garex, and C. Cookx

Department of Obstetncs and Gynecology, Womens College Hospital, UniverSity of Toronto, Canada

Management of postterm pregnancy remains controversial and should be based on both short and long term outcome. We have examined the long term outcome of a previously described cohort of newborns (Shime et ai, 1984: Shime et ai, 1986) from prolonged pregnancies (greater than 294 days) (PP) and term controls (T). The subjects were SUb-classified as normal or dysmature (mild or advanced) at birth by physical characteristics. Two separate developmental assessments were performed 6 and 7 years of age using the Griffiths Mental Developmental Scale (by a single blmded tester) and the Myklebust Pupil Rating Scale (by multiple testers). Test scores were obtamed in 43.8% of the origmal study entrants and there was no significant difference in the number lost to fallaw-up between the groups. A total of 137 children were tested; 76 from T and 61 from PP. Student's t test was used to compare overall and subscale scores for each test between T and PP, and analysis of vanance was used to compare scores for subgroups. No sigmflcant difference m mean score was found between T and PP for all developmental tests performed. No significant difference was found for subgroup comparisons. By power analyses, it is unhkely there were any clinically significant differences not detected by the study. These results are reassunng to the parent of a child from a prolonged pregnancy and lend support to the use of expectant management With appropriate monitoring for PP. Supported by the P.S.1. Foundation.

22 ADVERSE FETAL WELFARE & OUTCOME AT 2 YRS Todd AU, Trudinger BJ, Cole MJx & Cooney GHx University of Sydney, Westmead Hospital 2145 Australia

In a prospective study of early childhood development we investigated whether adverse placental and fetal welfare results were associated with poorer outcome at 2 years. Forty fetuses from high risk pregnancies delivered elec­tively prior to 34 weeks were assessed antenatally using Doppler umbilical artery flow velocity wavefonns (FVW) and fetal heart rate (FHR) monitoring. Children were seen at 2 yrs for physical, neurological, auditory and visual testing, and administration of the Bayley Scales of Infant Development and SICD language test. In analysing results children were stratified by a) placental FVW result into those with a systolic diastolic (SD) ratio below (n"'17) or above (n",23) the 99,95th percentile; and b) FHR perfor­mance into those with a nonnal (n=23) or non-reactive (n= 13) trace. For comparison we also carried out devel­opmental studies on babies delivered spontaneously before 34 weeks (n=33) and at tenn (n=55). Results within the elective group indicated fetuses with high SD ratios had lower weight at 2 yrs than those with lower SD ratios (p=0.05). Fetuses with non-reactive FHR tracings had lower Bayley MDI scores (85.73 ± 5.22 vs 99.87± 4.01, p=0.05 (Mean±SE» and lower PDI scores (82.95±4.30 vs 95,99±3.30, p<0.05) than the normal FHR group. No other differences were evident within the elective group. Fetal compromise defined by a non-reactive FHR trace, and not SD ratio, was associated with cognitive delay.