Inl J Gynaecol Obstei 17: 284-289, 1979

Breech Presentations in a Sample of Colombian Hospitals G. López-Escobar, 1 G. Riaño-Gamboa, 1 Judith Fortney 2 and Barbara Janowitz 2 Corporación Centro Regional de Población, Bogotá, Colombia International Fertility Research Program, Research Triangle Park, North Carolina, USA

ABSTRACT López-Escobar G, Riaño-Gamboa G, Fortney J, Janowitz B (Corporación Centro Regional de Población, Bogotá, Colombia, and the International Fertility Research Program, Research Triangle Park, NC, USA). Breech presentations in a sample of Colombian hospitals. IntJ Gynaecol Obstei 17: 284-289, 1979 All the breech presentations that occurred in a large sample of data on obstetric deliveries from a random sample of urban hospitals in Colombia are examined. The 463 breeches are analyzed by age and parity of the mother, type of breech presentation (frank or footling) and type of delivery (vaginal or abdominal). The data suggest that abdominal delivery reduces perinatal mortality although cell values are too small to adequately control for birth weight.

INTRODUCTION A breech presentation is a relatively rare event in obstetrics and occurs in about 3%-4% of all deliveries. Nevertheless, most obstetricians are confronted with a breech presentation often enough that some guidelines for the management of the presentation are desirable. M a n y factors affect the outcome of delivery of an infant presenting in the breech position (see, for example, a discussion of the management of breech deliveries in Contemporary OB/GYN, November 1977), and only some of these factors are known to the physician before he must decide on the appropriate management of the delivery. Among the factors that can be known (or estimated) in advance are the type of breech presentation (frank, footling, complete) and the gestational age of the fetus. Among the unknown factors are birth weight, sex and congenital anomalies. In addition to assessing the probability of survival of the infant, the physician must assess the relative risks a n d benefits to the mother of vaginal or ab-

IntJ Gynaecol Obstei 17

dominal delivery, as well as the implications for the future reproductive health of the mother. T h e following issues are beyond the scope of this paper, but nevertheless relevant to the physician's decisionmaking process. If a cesarean section is performed, what is the likelihood that the woman will deliver her next child outside the hospital? A cesarean section increases the possibility of a ruptured uterus in a subsequent delivery. If the woman is delivered by cesarean section, should a concurrent sterilization be performed? How important is it to this particular mother that a live child be delivered? If the woman has several living children, the increased risk of abdominal delivery may not be justified by her desire for an additional living child. These are ethical factors which the physician must consider. This paper will examine the incidence of perinatal and maternal mortality and morbidity as they are affected by: type of breech presentation, method of delivery, gestation, birth weight, mother's age and parity. T h e evaluation of these factors will allow a physician to better measure the relative benefits and risks of a cesarean versus a vaginal delivery. T h e final decision, of course, depends not only on these factors, but also on a number of unmeasured factors as explained above.

MATERIALS A N D M E T H O D S The Government of Colombia (Ministry of Health) in cooperation with the Programa Regional de Investigaciones en Fecundidad (PRIF) a n d the International Fertility Research Program (IFRP) selected a stratified random sample of hospitals in Colombia. Although the sample was designed to be statistically representative of all types of hospitals in all geographic areas, it includes only hospitals in urban areas. Each of the 40 urban hospitals participating in the study prospectively recorded data on deliveries occurring on assigned days of each month

Breech presentations

from March to October 1977. This amounted to a total of 13 140 deliveries or an estimated 8.3% of the total deliveries occurring in these hospitals. A two-ply Maternity Record (reprinted in Int J Gynaecol Obstei ¡5(5): 477, 1978) was completed for each patient included in the study. The completed forms were sent each month to the P R I F national headquarters at the Corporación Centro Regional de Población (CCRP) in Bogotá, where the overall quality was checked before the forms were keypunched and loaded into PRIF's computer. T h e top copy of the form is kept at the P R I F office and the duplicate copy remains with the participating hospital. Copies of tapes were sent to the IFRP where this analysis was performed. Out of the 13 140 deliveries, 463 were in the breech position and descriptive statistics are given for all breech presentations. Where the effect of the different methods of delivery are assessed, all antepartum deaths and congenital anomalies are removed. T h e remaining 424 breech presentations are compared with the 10 076 vertex occiput anterior vaginal deliveries. Thus, factors entirely beyond the physician's control are removed from the analysis. (These numbers refer to the number of mothers. The 463 mothers with a breech presentation had 493 babies, but not all the babies were necessarily in the breech position. When antepartum deaths and anomalies are eliminated, 424 mothers with 453 babies remain. T h e control group consists of 10 076 mothers with 10 155 babies.)

RESULTS T h e data set which forms the foundation of this study was thoroughly analyzed and then compared to other maternity data sets (particularly in regard to data involving breech presentations) to determine whether or not it is typical. A detailed review of the data set is presented below. Almost 40% of the mothers were primíparas and 20% were grand multiparas (at least four previous live births). T h e average age of these mothers was 25.5 years, 23.7% were teenagers (8.0% were under 18), and !3.0% were aged 35 or older. There were three primíparas aged 35 or older and three more in the 30-34 age group. In all these respects but one, mothers of breech babies do not differ significantly from all mothers delivering at these sample hospitals. T h e one exception is the percentage of mothers aged 35 or older (13.0% of the mothers of breech babies and 8.9% of all mothers) which is consistent with other reports [eg, Hall et al (2) who reported

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on 6000 cases of breech presentation in the United States]. As expected, breech babies accounted for more than their share of both multiple births and major congenital anomalies (1). (None of the multiple oirths involved major anomalies.) Only 1.0% of presentations other than breech involved multiple births, whereas 6.7% of breech presentations involved multiple births. Conversely, 18.9% of multiple births involved a breech presentation. Sharing the uterine environment does not appear to be an additional hazard to breech babies; only three of the 62 twins were not discharged alive (4.8%), compared with 63 of the 432 singletons (14.6%). It should be noted that it is not known which twin of a pair is the one who died, nor is the presentation of both twins known. Thus, it is possible that the three twins who died were not breech presentations. Of the 41 congenital anomalies found in the entire sample, nine were found in babies in the breech position. This translates into an incidence of 1.8% of breech babies with a major anomaly and 0.2% of nonbreech babies. A majority (70%-80%) of babies with major anomalies in both groups were either stillborn or died before discharge from the hospital. Approximately two fifths of all the breech presentations were footlings (this includes single and double footlings, knee presentations, etc). Again, this is consistent with other reported data (6). Table I shows that footling presentations had lower mortality rates; this difference, while small, was consistent for all three measures of mortality and with the weight advantage enjoyed by the footling breeches. T h e weight at birth of infants in each type of breech presentation varies with the age and parity of the mother in the same manner that the birth weight varies in normal presentation. Birth weight increases as maternal age increases in all six parity and presentation categories and in four of the six age and presentation categories. However, a comparison of the outcome of breech deliveries by the type of presentation a n d by the age and parity of the mother is hampered by the small cell values. In general, grand multiparas (four or more previous live births) have greater perinatal mortality than women of lower parity; when age is constant, primíparas with frank breech presentations do better than multiparas. In the case of footling presentations, very young primíparas have the highest rate of perinatal mortality and primíparas aged 18-29 years have the lowest rate. Clearly, this type of analysis must await a larger data set if it is to be useful. T o this point, we have examined breech births in some detail, and all breech births were included. From this point on, we

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which complications and, hence, mortality rates can be expected to be minimal. Table II compares the rates of stillbirths and neonatal and perinatal mortality of breech babies with the babies in the control group; two birthweight groups are compared. No matter what measure of mortality is used, it is apparent that the survival probabilities are lower for breech than for vertex presentations. It should be noted again that infants in the breech position tend to be smaller than vertex infants of the same gestational age, and that survival probabilities are lower for low-birthweight infants. In this data set, 8.7% of the vertex

shall exclude from the analysis all babies whose survival cannot be influenced by the physician, namely, those who were dead before the initiation of labor and those with major (ie, life-threatening) congenital anomalies. This more select group of breech presentations is compared with a control group of vertex presentations. T h e control group is further restricted to cases in which the presentation is vertex occiput anterior and the delivery is vaginal; cesarean vertex deliveries are excluded because the indication for the cesarean may be a condition which would jeopardize the life or well-being of the infant. Thus, the control group consists of cases in

Table I. Mortality rates of infants in frank and footling breech presentations, by maternal age and parity. Mortality Rate/1000 Infants

Mean Weight (gm) Maternal Age and Parity

No. of Mothers

No. of Infants

Single

All Infants

Stillbirths

Neonatal3

Perinatal"

47

50

2961

2780

120.0

68.2

180.0

1 97 27

1 106 28

2340 2863 2840

2340 2575 2726

113.2 71.4

63.8

160.4 71.4

20 86 3

20 91 4

2351 2737 2975

2351 2557 1967

150.0 65.9

58.8 23.5

150.0 65.9

281

300

2798

2594

96.7

44.3

123.3

24

26

2866

2555

192.3

47.6

230.8

1 69 17

1 74 18

3070 2951 3386

3070 2725 3209

81.1 111.1

44.1

95.6 111.1

15 53 3

15 57 3

2539 2816 2623

2539 2555 2623

133.3 17.5

153.8 53.6

266.7 70.2

182

194

2901

2684

82.5

50.6

118.6

Frank Breeches Grand multiparas Multiparas