17

Inr J Gynecol Ohsrc~t, 1991, 36: II-22 International

Federation

of Gynecology

and Obstetricr

Perinatal morbidity A.J. Herruzo, Hospirul

Regionul

(Received

March

and mortality

L. Martinez, Virpn

30th.

de Ius Nieves.

E. Biel, R. Robles, Mukvniclud.

E-18014

Grunutlu

M.A. Rosales

and J.A. Miranda

(Spin)

1990)

(Revised and accepted August

30th.

1990)

Abstract We reviewed 488 twin pregnancies that resulted in the birth of neonates weighing 1000 g or more. Complications were present in _56.7’%of all pregnancies; most common were threat of premature labor (17.4(X) and preeclampsia (14.5%). Perinatal mortality was 31.8 per thousand, Eighty percent of neonatal deaths in twin pregnancies involved newborns weighing less than 2000 g. Twin pregnancies are high risk pregnancies and benefit from early diagnosis, prevention and treatment of the threat of premature birth.

Keywords: Twins; Twin gestation; morbidity; Perinatal mortality.

Perinatal

Introduction

Twin pregnancy entails a high degree of risk; outcome results should be analysed with particular care and approached as one of the great challenges in obstetrics. In general, perinatal mortality rate (PNM) in twin pregnancies is four times higher than in singleton pregnancies [1,8]. It ranges from 7.2 to 17.3% for fetuses 2 500 g at birth [2,12], and from 2.3 to 7.7% for fetuses ~1000 g at birth [3,6]. 0020-729219 I /$03.50 0 1991 International

in twin pregnancies

Preterm delivery and its complications, mainly low birthweight, are the main causes of mortality in twin pregnancies [2,15,18]. From 21 to 50% of all multiple births deliver preterm [3,10]; decreasing the rate of preterm multiple deliveries would improve the survival rates. Most authors agree on the need for early diagnosis and adequate prenatal care [5,16]. However, specific prenatal measures such as bed rest, cervical cerclage or tocolytic agents have not been shown to be universally helpful [11,14,16,19]. Materials and methods

Between January lst, 1980 and December 31st, 1988, a total of 54 037 fetuses weighing L 1000 g were delivered at the Hospital Maternal e Infantil Virgen de las Nieves in Granada (Spain). Of these, 519 were multiple births (0.96%). Only 6 pregnancies produced triplets, hence these were excluded from the present study and 513 produced twins. Of these, clinical records were complete for 488 multiple pregnancies with newborns weighing 2 1000 g (95.1%). In all, we studied 1005 newborns from twin gestations (97.9% of all twin fetuses born at our center during the period of study). Prenatal maternal morbidity, length of gestation and perinatal mortality were analysed with particular attention to early neonatal mortality (perinatal death within Clinicul

Federation

Published and Printed in Ireland

of Gynecology

and Obstetrics

und Clinical

Rrscwrch

18

Herrtco et al.

gestation, was however more frequent in the control group (15.1%) than in the group of twin pregnancies (8.4%, P < 0.001). In 183 cases, twin pregnancy terminated before 37 weeks (Table 2), giving a prematurity rate of 37.4% as compared to only 4.0% in single pregnancies (P < 0.0005). Slightly more than 1% (7 cases) of the twin pregnancies lasted longer than 42 weeks, as compared to 4.8% in the control group.

the first 7 days). These results were compared with those from the remainder of the newborn (singleton) population, and other parameters were compared with those recorded in a group of 1652 consecutive births in our center during 1988 for those cases in which comparison with all patients was, for technical reasons, unfeasible. The statistical analysis was performed with Pearson’s (chi-square) test, a probability of less than 0.05 being considered significant.

Perinatal results

Results

Sometimes more neonates from twin pregnancies (43%) than from singleton pregnancies (4%) weighed less than 2500 g at birth (Table 2). Early neonatal mortality (death within the first 7 days) among fetuses weighing ~1000 g (Table 3) was 31 .S/lOOO(32 cases). There were 14 antenatal (44”/0)and 18 postnatal deaths (56%). The most frequent cause of prenatal death was hypoxia (7/14), while postnatal death resulted most frequently from respiratory distress syndrome (12/18). Early neonatal mortality in twin pregnancies was four times higher (P < 0.001) than in singleton pregnancies (18.2/1000 vs. 4.7/1000).

Complications

Pregnancy complications were present in 57% of the twin pregnancies studied, compared to only 32% of controls (P < 0.001). There was a threat of premature labor in 85 pregnancies (17.40/o), and preeclampsia occurred in 71 cases (14.5%), anemia in 45 (9.2%), documented urinary tract infection in 42 (8.6%), and hyperemesis in 26 cases (5.3%). Other, less frequent complications are summarized in Table 1. Threat of abortion, defined as pain or metrorrhagia before 20 weeks of

Table I.

Morbidity

in twin pregnancies. Twins (N = 488)

Complications during One complication

pregnancy

More than one complication Threat of premature Toxemia

delivery

Anemia Urinary tract infection Threat of abortion Hyperemesis Peripheral vascular pathology Placenta previa Other third trimester hemorrhages Hydramnios “Not known.

Inf J G.wrecol Obsrer 36

P

Control (N = 1652)

(x?)

No.

‘K

No.

1%)

271 21.5 62

56.7 44.0 12.7

534 456

32.3 27.6

78

4.7

85 71

Il.4 14.5

43 78

2.6 4.7

45 42 41 26 IO 5 7 5

9.2 8.6 8.4 5.3 2.0

49 59 249 I2 IO 6 _a

3.0 3.6 15.1 0.7 0.6 0.4 _a

4

0.2

I .o 1.4 I.0