Premature mortality

PREMATURE MORTALITY A N A N A L Y S I S OF 5 1 8 CASES OF P R E M A T U R I T Y W I T H A COMPAIr

OF NERGO

AND W H I T E I~ACES

GEORGE E. BI~0CKWAY~ M.D., EDWARD T. R~:nJLY, M.D., AND MARG.4nET M. RICE, M.D. BROOKLYN,N. u H E PURPOSE of this paper is to present our mortality in 518 premature induring the months from J a n u a r y through December, 1949. We have presented a brief comparison of white and ~Negr 0 premature babies. The American Academy of Pediatrics has adopted the following definition of prematurity: " A premature infant is one who weighs 2,500 grams or less at birth (not at admission) regardless of the period of gestation. All live-born premature infants should be included, evidence of life being heart beating or breathing. ,'1 Anderson, Brown, and Lyon suggest that the gestation period for the Negro infant may actually be shorter than for the white infant. In a later study these authors presented data for lowering the upper limit of birth weight for prematurity from 2,500 to 2,350 grams for the Negro infants. ~

T fants born at Kings County tIospital

INCIDENCE

In our analysis of the incidence of prematurity among 3,872 white and Negro patients we found that under the present definition of prematurity 20 per cent Negro and 15.5 per cent white babies were premature. Chart I shows the proportion of Negro to white patients including full-term and premature babies. If, however, we accept 2,350 grams as the upper limit for Negro babies, the incidence of prematurity for that race falls to 15.2 per cent. That would equalize th e incidence of prematurity for both races. At Kings County ttospita] the patients, whether Negro or white, have similar environmental and economic backgrounds. Approximately two-thirds of the obstetric patients attend prenatal clinic. The majority of patients with positive Wassermann tests have prenatal'antisyphilitic therapy. In this brief survey we have not considered maternal illnesses and their influence on prematurity. Our findings support those of Anderson, Brown, and Lyon which justify the redefinition of prematurity for Negro babies to those weighing 2,350 grams or less at birth. We agree with their feeling that the two racial groups would be more nearly comparable under this new criterion. Their incidence of prematurity was 9 per cent f o r both races m~der tile new standards. ~ On Chart II we have divided the premature infants into four weight groups for comparison of mortality between tile two races. We have added a table with the new standard for Negro premature infants for comparison with the old. The four weight groups for the new proposed standard are: (1) those F r o m the I n t r a m u r a l Hospital, Brooklyn, 3, N. Y.

Premature

Nursery 362

of I4ings C o u n t y

Service,

Kings

County

363

BROCt(WAY ET AL. : PREMATURE MOlgTALITu CHART 1. MONTH 1949

BIRTH STATISTICS AT }~INGS COUNTY HOSPITAL, ] 9 4 9 NEGgO

TOTAL

WHITE

I,'ULL -TEI~IVl

1

FULL-TERM

1

NEGRO PI~EI~I A TU R~3

I

w~i,n'E

January February March April

342 305 350 306

183 290 191 176

104 60 108 "80

46 37 37 61

9 18 14 11

May June

317

186

80

33

]8

88 113 102 81 81 71 67 1,035

40 48 39 28 43 32 26 450

14 10 ]2 12 1,i 15 14 ]61

338 196 July 354 183 August 345 192 September 273 ] 52 October 321 183 November 308 190 December 313 206 Total 3~872 2,226 Stillbirths: Negro premature 66 White p r e m a t u r e 27 Incidence o f P r e m a t u r i t y : Negro--20% White--15,5% CHART IL

WEIGI~T (6~.)

~ORTALITY COMPAgISON

I

~1,000

I

IN

WEIGIIT

1,000-1,500

--

-

GROUPS

I 1,500-2,000

I

2,000-2,500

White Premature Deaths Mortality

infants

Negro

Premature infants Deaths Mortality WEtOHT (G~[.)

11 10 90 %

20 8 40%

29 25 86.2% ~850

25 8 32% 850-1,350

I

23 5 21.5 % 81 9 1t ,1% I 1,350-1,85(/

76 0 0%

]

254 1 0,3% 1,850-2,35(I

Negro Prematures Deaths Mortality

20 18 90%

18 1J 61.1%

57 9 15,7%

182 4 2.1%

weighing less than 850 grams, (2) 850 to 1,350 grams, (3) 1,350 to 1,850 grams, and (4) 1,850 to 2,350 grams. Our aim is toward a more accurate comparison of mortality in different weight ranges between the races. M0fgTALITY

Our neonatal m o r t a l i t y for 518 consecutive live-born p r e m a t u r e infants is 12.7 per cent. Tayler, Phalen, and D y e r of Denver reported a 16 per cent m o r t a l i t y for 480 consecutive live-born i n f a n t s ? New York City hospitals reported a m o r t a l i t y of 17.1 per cent in 1945.1 Our mortality in the different weight groups is as follows: u n d e r 1,000 grams, 87.5 per cent; 1,000 to 1,500 grams, 35.5 per cent; 1,500 to 2,000 grams, 13.5 per cent; and 2,000 to 2,500 grams, 0.3 p e r cent. This is demonstrated on Chart I I I . I n Bain and H u b b a r d ' s report on hospitals, the m o r t a l i t y was 89.6 p e r cent, 54.4 per cent, 22.8 p e r cent, and 7.3 per cent, respectively2 The Denver group reports 228 eases with a m o r t a l i t y of 91 per cent, 38 per e a t , 15 per cent, and 3 per cent, respectively, a I t i s , i n t e r e s t i n g to review the p r e m a t u r e mortality of a few years ago. I n 1937, there were 157 p r e m a t u r e births in Charity H o s p i t a l with a mortality of 85.3 p e r cent. I n 1938, the m o r t a l i t y d r o p p e d to 73.6 per cent. This was sur-

36,~

THE

CHART .[]:I. WEIGI~T (G~.)

~1,000

JOURNAL

OF

PEDIATRICS

COlV~BtNEDMORTALITY IN THE ]~)I.FI~EEENT WEIGtt~ ~ROUPS

1,0001,500P 2,000DEATHS 1,500 DEATHS 2,000 DEATHS t 2,500

DEATI~S TOTAL DEATttS

Month 1

3

3

4

1

10

2

27

1

44

7

2 3 4 5

4 3 4 4

3 3 4 4

6 6 4 2

2 3 2 0

13 11 6 8

1 1 2 0

26 20 30 32

0 0 0 0

49 40 44 46

6 7 8 4

0 0 0

48

4

47

7

41

5

31 53 40

5 4 4

35

5

6

3

3

4

0

9

1

7

6

5

3

1

11

1

8

4

3

2

0

9

2

32 27 27

9 1 1 10 3 3 11 3 2 t2 2 1 Total 40 35 Mortality 87.5%

3 2 4

3 1 1

6 6 8

1 0 1

21 42 25

0 0 0

5

2

7

2

21

0

104

14 13.5%

330

1

45

16 35.5%

0.3%

518 66 12.7%

raised to be due to the segregation of p r e m a t u r e f r o m f u l l - t e r m babies for the first time. I n 1939, g r a d u a t e nurses were assigned to p r e m a t u r e care a n d the m o r t a l i t y d r o p p e d to 59.3 p e r cent. I n 1940, the m o r t a l i t y was 42.2 p e r cent which was a t t r i b u t e d to the new h e a d q u a r t e r s and i m p r o v e d conditions f o r isolation. ~ Of our 518 p r e m a t u r e babies, 7.7 p e r cent weighed less t h a n 1,000 grams, 8.6 p e r cent weighed f r o m 1,000 to 1,500 grams, 20.1 p e r cent weighed from 1,500 to 2,000 grams, a n d 63.7 p e r cent weighed f r o m 2,000 to 2,500 grams. These p e r c e n t a g e s are v e r y s i m i l a r to those r e p o r t e d by the C h i l d r e n ' s B u r e a u in 1948. They r e p o r t e d 6.8 p e r cent, 9.9 p e r cent, 20.2 p e r cent, a n d 63.1 p e r cent, respectively. The total f a t a l i t y for p r e m a t u r e babies in 323 hospitals was 21.5 p e r cent. 4 CAUSES OF DEAT~ I n our series there were sixty-six deaths. P r e m a t u r i t y was considered as the cause of death in t h i r t y - e i g h t eases. This is a d m i t t e d l y a poor t e r m but on post-mortem e x a m i n a t i o n no other d e m o n s t r a b l e cause of death was found. F i f t e e n died of congenital atelectasis. F i v e deaths were due to i n t r a c r a n i a l hemorrhage, three to sclerema, a n d five to eongenital abnormalities. These a b n o r m a l i t i e s were a t r e s i a of the esophagus, congenital h e a r t disease, atresia of the bile ducts, p o l y e y s t i e kidneys, a n d aneneephalus. B r o n e h o p n e u m o n i a was a c o n t r i b u t a r y cause of death in two of these cases. F o r t y - f i v e deaths (68.1 p e r cent) were w i t h i n the first t w e n t y - f o u r hours. A u t o p s i e s were obtained in 67 p e r cent of the deaths. I n 1942 in the C h a r i t y ]:lospital group, p r e m a t u r i t y alone accounted for 28 p e r cent of the deaths. B r o n c h o p n e u m o n i a was the cause in 15 p e r cent. Other acute r e s p i r a t o r y diseases a n d otitis media accounted f o r 18.6 p e r cent. D i a r r h e a was responsible f o r 12.4 p e r cent of the m o r t a l i t y . C e r e b r a l i n j u r y accounted f o r 11 p e r cent a n d syphilis for 4.6 p e r cent of the d e a t h s r A c c o r d i n g to T y s o n , babies who are born dead or who die w i t h i n the first two d a y s of life, in most instances die as a result of complications of p r e g n a n c y , labor, a n d d e l i v e r y . The r e s p o n s i b i l R y f o r such d e a t h s c a n n o t a l w a y s be a t t r i b uted to one definite f a c t o r b u t is u s u a l l y a combination of one or more. I n

B R O C K W A Y E T AL. :

PREMATURE MORTALITY

365

his experience he found that heroic efforts u n d e r these conditions will save only a few babies. 6 Since 1942, chemotherapy has played a tremendous role in eliminating the mortality due to pneumonia and other respiratory infections. The incidence of infection is lower and when it does occur, fatality is rare. PREMATURE ROUTINE

All the premature infants considered in this p a p e r were born at Kings County Hospital. Babies weighing less than 1,814 grams at birth and those in poor condition are placed in incubators immediately. Oxygen is administered to all initially and for as long a period as necessary. Some very small infants are given continuous oxygen for as long as one month. Vitamin K is given intramuscularly upon admission to the n u r s e r y in doses of 2.5 rag. immediately and every twelve hours for three days. Mothers receive vitamin K routinely before delivery. Initial resuscitation is performed by the obstetrician. Nasopharyngeal suction is performed as necessary t h e r e a f t e r by the graduate nurse especially trained in p r e m a t u r e care. Only rarely is laryngoseopic examination and tracheal suction performed. I t is felt that unless there is a definite tracheal plug the procedure does little to alleviate ateleetasis in very small infants. The trauma that the procedure entails even in expert hands on tiny infants and the excessive handling is felt to be more detrimental than beneficial, in our brief survey. Nothing is given by mouth for twenty-four hours to babies weighing less than 1,361 grams, and for twelve hours to heavier babies. Then fluids are started in this manner: Glucose water Distilled water Glucose water Distilled water Glucose water Distilled water

1 1 2 2 4 4

dr. dr. dr. dr. dr. dr.

at at at at at at

the the the the the the

24 25 26 27 28 29

hour hour hour hour hour hour

The formula is s t a r t e d at 25 per cent S t a n d a r d F o r m u l a 75 per cent distilled water 5 dr. • for smallest babies. The l a r g e r ones s t a r t on 50 per cent S t a n d a r d F o r m u l a 50 per eent distilled w a t e r 6 dr. x3• This is followed by 100 per cent S t a n d a r d F o r m u l a 1 oz. x3x8; 5 per eent glucose in Ringer's lactate may be used instead of distilled water to help prevent the metabolic acidosis commonly found in p r e m a t u r e infants. A one part evaporated milk to two parts boiled water formula with two tablespoonfuls of Dextri-Maltose is used to start. The concentration is gradually increased as the child demands it. Garage feedings are given only to v e r y small, weak infants and to larger babies only when necessary, as during infections. The formula averages 120 or more calories per kilogram initially. Vitamins are started at two weeks of age. A water-miscible multivitamin preparation has been used satisfactorily. Blood transfusions are given to almost all premature infants under 1,361 grams to alleviate anemia of prematurity. These transfusions of 20 c.e. per kilogram are usually given when the babies are one month old and shortly before discharge from the nursery.

366

THE JOURNAL 0E PEDIATRICS

No drugs are used unless absolutely necessary. Caffeine sodimn benzoate is the stimulant most frequently used and it is administered in a minims 2 dosage. It is given only when the child shows signs of respiratory irregularity or failure. When penicillin is indicated, it is given orally, usually mixed with the formula in 50,000 unit doses every three or four hours. Aureomycin has been used successfully for otitis media and pustular rashes. It is administered in doses of 80 mg. per kilogram diluted with distilled water and given with 1 dram of Creamalin. No severe gastric irritation or diarrhea has been encountered as yet. The baby's future home is investigated by the social se:wiee to assist tile parents in providing' an mlvironment which is suitable for a very small infant. The visiting nurse calls on the mother and baby shortly after they arrive home. The babies are discharged to our pediatric clinic for monthly follow-up examinations. The mothers also may bring" their babies to the well-baby clinic provided by the Board of Health. This system of follow-up is being encouraged, but many mothers wait until the child is really ill before seeking aid. Education and encouragement may help to solve this problem. SU1V[~{[ARY

A survey of 518 consecutive prematnre b~ants has been made at Kings County Hospital. Since there are a great number of Negro patients in this hospital, it is possible to make a fair comparison of Negro and white premature infants with special re~erence to incidence, size, and mortality. It was found that the incidence of prematurity among 3,872 patients was 20 per cent for the Negro race anc] ]5.5 per cent for the white race. However, it is proposed that the weight standards for Negro premature infants be lowered to 2,350 grams. Under this standard the incidence of prematurity for the Negro race falls to 15.2 per cent in our series. The total premature mortality for the year 1949 (518 babies) is 12.7 per cent. This compares quite favorably with Other reports in recent publications. The mortality is shown in the different weight groups with a newly proposed grouping for premature Negro infants. The causes of death are listed and compared with the causes of death at Charity Hospital in 1942. The effect of chemotherapy is evidenced by the lowered mortality due to infection. A brief outline of the premature routine at Kings County Hospital is given. REFERENCES 1. Dunham, Ethel C.: Premature Infants, Federal Security Agency, Children's Bureau Publication 325, :1948~ p. 2. 2. Brown, Estelle W., Lyon, R. A., and Anderson, Nina A. Causes of Promaturlty: IV. Influence of Ma.ternal Illness on the Incidence of Prematurity, Employment of a New Criterion of Prernaturity for the Negro 1gaee, Am. J. Dis. Child. 70: 314, 194'5. 3. Tayler, Stewart E., Pt*alen, James R., and Dyer, Harold: Effect of Obstetric Difficulties and Maternal DiSeases on the Premature I n f a n t Mortality. J. A. M." A. 141: 904, 1949. 4. BMn, Katherine, Hubbard, g. P., and Peanell, Maryland: Hospital F a t a l i t y Rates for Prematm'e Infants, Pediatrics 4: 454, 1949. 5. Flax, Lee, Levert, Edward I~., and Strong, Robert A.: A Study of Premature Mortality, J. PEDIAT. 21: 717, 1942. 6. Tyson, R. EL: A Fifteen-Year Study of P r e m a t u r i t y , J. PEDIAT. 28: 648, 1946.