Perinatal Outcome in Twin Pregnancy at Khaipur Medical College, Khairpur Mirs, Pakistan

Objective: To determine the perinatal outcome of twin pregnancy and to find out the frequency of twin deliveries in hospital based population. Study Design: Descriptive case series. Place and Duration of Study: The study was conducted over a period of 02 Year 1 st January 2018 to 31 st December 2019 in the Obstetrics and Gynaecology Department at KMC Khairpur Mirs, Sindh Pakistan. Original Research Article Pathan et al.; JPRI, 33(18): 46-52, 2021; Article no.JPRI.66846


INTRODUCTION
Twin pregnancy is considered high-risk pregnancy because perinatal mortality and morbidity in twin are higher as compared to singletons, mainly caused by low birth weight and prematurity, twin -twin transfusion syndrome but also by mal-presentation and mode of delivery [1]. The perinatal mortality rate in twin as reported to be 3-11 times higher than in singletons [2]. Multiple gestations are associated with increased complications in utero as compared to singleton gestation, with an increased reported incidence of early pregnancy loss, congenital anomalies, intrauterine demise, TIJGR, prematurity, low birth weight, Monochorioncity increases the risk of adverse perinatal outcome whereas the effect of zygosity is less clear [3]. Twin are dizgostic (dizygous, binovular, fraternal or non identical) result from the fertilization of two independently released ova by two different sperms. All these twins are dichorionic and diamniotic. Monozygotic twin (monozygous, uniovular, identical) arise from the splitting of single fertilized egg within the first 14 days after fertilization. Monozygous twins may be Monochromic diarnniotic (MCDA), Monochorionic monoamniotic (MCMA), or conjoined [4]. The considerable geographical and temporal variation influence the incidence of dizygotic or non-identical twins, twining occurs fr m 4/1000 births in Japan to 54/1000 in Nigeria and common in older mothers due to their rising FSH, in contrast monozygous occurs with constant incidence of 3.9/1000, the twinning rate in UK is from 9.8 to 14.7/1000 maternities, increase in incidence due to Assisted reproductive technique (ART) [5,6].
The aim of the study is to determine the perinatal outcome in twin pregnancy.
Intrauterine growth restriction (failure of the fetus to achieve its growth potential) 25

Data Management and Analysis
Data will be analyzed by SPSS version 20.0 numerical data like gestational age, perinatal mortality, prematurity, intrauterine growth restriction, weight of baby and APGAR score was expressed in terms of frequencies and percentages. 95% confidence interval will be computed for all outcome of interest. Stratification of age and parity will be due to seen their effect on outcome.

Inclusion criteria
Women with U/S determined twin pregnancy of 30 weeks and onwards. Between ages 22-35 years of age were included. Women who conceive after assisted reproductive techniques.

Exclusion criteria
Women with medical disorder example cardiovascular disease diabetes, known case hypertension, renal disease were excluded.

RESULTS
The mean age of patients in this study was 30.1 (SD) with a 95% Confidence interval of 29.18 to 31.01. The mean gestational age of patients in this study was 35.7(SD) with a95% confidence interval of 35.22 to 36.32. Mean APGAR score of twin-1 was 7.3 (SD) with a 95% confidence interval of 6.84 to 7.81. Mean APGAR score of twin-2 was 6.5 (SD) with a 95% confidence interval of 5.99 to 7.03 Table 1. Incidence of twin gestation in this study is 1.15%. Total numbers of deliveries 7200 were carried out here Table 2. In this study out of 83 women with twins, 20(24.1%) were booked antenatal patients, while 63(75.9%) were received through emergency or referred to KMC hospital khairpur Table 3. The highest percentage of twin gestation was between 31-35 years (49.4%) with lowest incidence at 20-25 years of maternal age (19.3%) Table 4. The percentage of twin gestation at parity 1-5 is highest 45(54.2%) and lowest percentage of twins who were primiparous 15(18.1%) Table 5. In this study total number of preterm deliveries were 45(54.2%) common gestation age at preterm delivery occurred was (35-36 + 6 days) weeks Table 6. Common presentation of twin at the time of delivery is vertex-vertex 38(45.8%) and less common is transverse-vertex 1 (1.2%) and transverse -Breech 1(1.2%) Table 7. 50(60.2%) twins delivered by vaginal route and 33(39.8%) delivered by caesarean section. In this study perinatal mortality was found total 38, still born in twin-1 5(13.2%), 7(18.4%) in twin-2 and 12(31.6%) were ENND in twin-1 and 14(36.8%) in twin-2 Table 8. The highest frequency of perinatal mortality was seen in 31-35 years of age group, 6 in twin-1 and in twin-2 Table 9. Parity stratification displayed separately in both twins, the highest frequency of perinatal mortality was seen in P1-5 years of age group, 8 in twin-1 and 9 in twin-2 Table 10.

DISCUSSION
Twin pregnancy still represents a high risk pregnancy. Management of twin pregnancy is effective when the diagnosis has been made early in pregnancy. We assessed the frequency of various maternal, fetal and neonatal complications. Incidence of twin deliveries in this one year done on 7200 maternities is 1.15% which is quite less than coated in other studies from eastern part of country like Malik [7] and Rana S [8]. The reason cloud be that eastern part of country is more populous and population is comparatively more aware and public services are utilized more often. However one of the US study has showed nearly same incidence [9]. In this study we have seen that highest frequency of twin pregnancies is among women between 31 to 35 years of age, the mean maternal age seen was 30.1±4.1(mean ±SD) other local and foreign studies show similar relation between  [12]. However other European studies also show a high incidence of prematurity near 50% 13 .This seems to be main cause of perinatal mortality. In my study and supported by other studies perinatal mortality is 10 times that of singletons [13][14][15]. The perinatal mortality rate associated with twin pregnancy is four times than the singleton pregnancy given by one Pakistani study81.However in some other coated studies, perinatal loss was seen 65/100082,102/1000 by Jeesa EO [16] and 40/1000 by Pons JC and colleagues [17]. In my study the incidence of IUGR was 12.04% which is comparable with the study by Chang YL36, but a high incidence is reported by Luesely DM, that is 33% [18]. Main indication for NICU admission was .pre-maturity and LBW and others were IUGR, birth asphyxia, neonatal jaundice and meconium aspiration. A good APGAR score was seen in first twin compared to the second twin, with mean APGAR score of twin-1 was 7.3±2.2 and in twin-2 was 6.5±2.3in my study so necessitate continuous EFM during all stages of labour for second twin to avoid birth asphyxia [19]. All though C/S does not improve fetal out come if done for fetal distress [20]. Regarding mode of delivery, vaginal delivery rate was 60.2% and common presentation was vertexvertex 45.8%, vertex-breech 15.7%, breechbreech 12%, breech-vertex was 14.5%, vertextransverse 7.2%, and transverse-vertex was 1.2%, breech-transverse 2.4% and transversebreech 1.2%. According to European data approximately 40% of twins will present with vertex-vertex about 40% vertex-non vertexes, about 20% vertex-either vertex or non vertex [21]. The incidence of normal vaginal deliveries and C/S given by one Pakistani study is 67% and 33% [22]. C/S rate is found quite high at our set up because of tertiary care hospital and the ratio of referral cases also took part in increased incidence of C/S but in another study by Melchor JC, the incidence of C/S is 21.9% to 47% [23], and abnormal presentation played a significant role in increased rate of C/S [24] but study by Samra found that incidence of vaginal delivery is 63.9% and C/S rate is 36.1% and she found common indications for C/S are previous C/S, breech presentation and fetal distress [25]. Caesarean section rate in this study was 39.8%, instrumental delivery rate was 8% for first twin and 12% for second twin, in study by Bangash, the instrumental delivery rate is 30% which is more than in my study. This may be because instrumental vaginal delivery is avoided by junior labour ward staff during odd hours of the day. Most common indication for C/S was malpresentation 36.4% others are pervious C/S, abnormal labour, pre-eclampsia, IUGR, fetal distress. In another study by Samra that incidence of vaginal delivery is 63.9% and C/S rate is 36.1%. Both are more than in my study common indications are previous C/S,breech presentation,and fetal distress [25]. The incidence of prematurity and low birth are more common in twin pregnancy, in my study mean LBW 2.2±0.4 was seen in twin-1 and 2.1±0.4 was seen in twin-2 which leads to high perinatal morbidity and mortality. Different treatment modalities have been advocated for the treatment of preterm labour like hospitalization, bed rest, tocolysis, but controversy exist over their beneficial role in the prevention of preterm labour. A high perinatal morbidity and mortality in this study is seen between ages of 31-35 years of age parity of 1-5, this may be because of more subjects fall into this group but further research with a largest sample will be needed to prove significance of this relation. Twin pregnancy should be managed as high risk pregnancy. Most of the complications can be avoided and perinatal outcome improved by early detection and regular follow up. The need for awareness of importance of regular antenatal surveillance, with realization of benefits of hospital delivery is essential this can be achieved by improving the standard of health care department and awareness in our country.

CONCLUSION
Twin pregnancy is a high risk pregnancy diagnosis before delivery is important. Perinatal morbidity and mortality remains very high in twin pregnancy. Our results showed that twin pregnancy is a high risk pregnancy, high rate of complications affect the perinatal outcome.
As multiple pregnancies is high risk pregnancy, so requires vigilant antepartum, intrapartum and postpartum care. Therefore twin delivery should be conducted in fully equipped hospital delivery is important. The mode of delivery should be based upon presentation, rather than the estimated birth weight. Combined obstetrical and pediatric care is needed to identify the complications, and proper antenatal follow up and hospital delivery at well equipped hospital, with NICU facility could be offered this may be the sole intervention to reduce perinatal morbidity and mortality in twin gestation. The successful management of these pregnancies results in two healthy babies. Good nutrition, adequate rest, early booking and regular antenatal visits can reduce complications and improve perinatal outcome.

CONSENT
Written consent was taken from subjects and next of kin.

ETHICAL APPROVAL
The Ethical Review Committee gave ethical review approval for this study.