FREQUENCY OF PRETERM BIRTHS AMONG PREGNANT WOMEN WITH TWIN PREGNANCY AT A TERTIARY CARE HOSPITAL

Background; Twin pregnancies in lowand middle-income countries (LMICs) pose a high risk to mothers and newborns due to inherent biological risks and scarcity of health resources which translate into insufficient care during pregnancy and delivery. Due to inherent biological factors, twin pregnancies have increased rates of obstetric and perinatal complications such as preeclampsia, post-partum haemorrhage and preterm birth, which are known risk factors for maternal and perinatal mortality. Objective; To determine the frequency of preterm birth in twin pregnancies at a tertiary care hospital. Material and methods: A total of 181 patients with dichorionic diamniotic twin pregnancy on ultrasound having gestational age more than 24 weeks were taken in this cross-sectional study. Demographic information of patients (name, age, weight) was taken. Informed consent was taken from each patient, ensuring confidentiality and fact that there is no risk involved to the patient while taking part in this study. An obstetrical ultrasonography was done to confirm twin pregnancy. Blood samples were taken from all patients for assessment of anemia. Patients were followed up till delivery to determine preterm labor. Results; Mean age of these study cases was noted to be 34.35 ± 2.41 years. Mean gestational age of our study cases was 34.67 ± 2.25 weeks. Mean BMI of our study cases was noted to be 22.45 ± 1.67 kg/m (with minimum BMI was 19.4 kg/m and maximum BMI was 32 kg/m) and obesity was present in 27 (14.9 %) of our study cases. Of these 181 study cases, 126 (69.6%) delivered vaginally while 55 (30.4%) had to undergo cesarean section delivery. Mean hemoglobin level was noted to 8.67 ± 1.40 g/dl while anemia was seen in 126 (69.6%) of these study cases. Abruptio placentae in 19 (10.5%) and low birth weight in 123 (68 %) of our study cases. Frequency of preterm births was observed in 144 (79.6%). Conclusion; Twin pregnancy is associated with high risk of perinatal and pregnancy outcomes as very high frequency of preterm births was noted in our study. There was also higher frequency of anemia, cesarean section deliveries and low birth weight babies in our study. There is a need for specialised prenatal care to reduce complications and adverse outcome in multiple pregnancies, and the need for ongoing social and medical care beyond the prenatal and perinatal periods to improve perinatal outcomes in these patients. Keywords; Preterm labor, anemia, twin pregnancy. DOI: 10.7176/JMPB/62-11 Publication date: December 31 2019

Preterm birth is observed in approximately 54% of all twin pregnancies, half of these births have a iatrogenic origin and are related to maternal or fetal complication while the other half consists of cases of spontaneous premature labor or premature membrane rupture. 3 The average birth weight is 2367 g and about 52% of the newborns weigh less than 2500 g. The risk of growth restriction is three times higher than in singleton pregnancies. 6,7 When analyzed according to chorionicity, monochorionic pregnancies present a two to three times higher risk than dichorionic pregnancies. 8,9 The risk factors for multiple gestation births have been well documented. 10 These include family history of twins, heredity, advanced age, serum oestradiol concentration, race, and use of fertility treatment. as compared to women with singleton gestations. 11 In addition, multiple gestations are associated with increased cost to families and health care system. 12 All these factors are the reasons why multiple pregnancies remain a major public health problem as compared to singleton pregnancies, particularly in sub continent, given the high maternal mortality rate in the region. Rizwan N and her associates has found in a recent study that 84% patients presented with preterm labour, anaemia was found in 65.6%, Abruptio placentae occurred in 6.2% of cases and low birth weight was 32.8% in women of advanced age with twin pregnancy. 13 In another recent study has found that 76.6% had preterm deliveries, anaemia was found in 50%, 53% LSCS of cases and low birth weight was 57% in women of advanced age with twin pregnancy. 14

Material and methods:
A total of 181 patients with dichorionic diamniotic twin pregnancy on ultrasound having gestational age more than 24 weeks were taken in this cross-sectional study. While primigravidas, grand-multigravidas (>5), diabetic, hypertensive and patients having renal disorders were excluded. Demographic information of patients (name, age, weight) was taken. Informed consent was taken from each patient, ensuring confidentiality and fact that there is no risk involved to the patient while taking part in this study. An obstetrical ultrasonography was done to confirm twin pregnancy. Blood samples were taken from all patients for assessment of anemia. Patients were followed up until pregnancy outcome. Abruptio placentae and preterm labour were managed as per protocol. Maternal outcomes were noted while after delivery fetal outcome in shape of Low Birth Weight were recorded. Data was analyzed with statistical analysis program (SPSS version15).

Results;
In this study, a total 181 women with twin pregnancy were registered. Mean age of these study cases was noted to be 34.35 ± 2.41 years (with minimum age was 31 years while maximum age was 40 years). Our study results have indicated that majority of our study cases i.e. 118 (65.2%) had age ranging from 30 -35 years. Mean gestational age of our study cases was 34.67 ± 2.25 weeks (with lowest gestational age was 28 weeks while maximum gestational age was 38 weeks). Majority of our study cases i.e. 126 (69.6%) had gestational age up to 35 weeks. Mean BMI of our study cases was noted to be 22.45 ± 1.67 kg/m 2 (with minimum BMI was 19.4 kg/m 2 and maximum BMI was 32 kg/m 2 ) and obesity was present in 27 (14.9 %) of our study cases. Of these 181 study cases, 126 (69.6%) delivered vaginally while 55 (30.4%) had to undergo cesarean section delivery. Mean hemoglobin level was noted to 8.67 ± 1.40 g/dl (with minimum Hb level was 7 g/dl while maximum Hb level was 11.5 g/dl) while anemia was seen in 126 (69.6%) of these study cases. Abruptio placentae was noted in 19 (10.5%) and low birth weight in 123 (68 %) of our study cases. Preterm labor was observed in 144 (79.6%) of our study cases.

Discussion;
Twin pregnancy results from one of two distinct biological processes. The more common process is fertilisation of more than one ovum following multiple ovulation. Here the offspring may be of the same gender or not, are genetically no more similar than siblings, and have separate placental circulations and gestational sacs (dizygotic, diamniotic, dichorionic). In this study, a total 181 women with twin pregnancy were registered. Mean age of these study cases was noted to be 34.35 ± 2.41 years (with minimum age was 31 years while maximum age was 40 years). Our study results have indicated that majority of our study cases i.e. 118 (65.2%) had age ranging from 30 -35 years. Rizwan et al 13 16 reported 33 % cesarean sectional deliveries associated with twin pregnancies these findings are similar to that of our study results.
Mean hemoglobin level was noted to 8.67 ± 1.40 g/dl (with minimum Hb level was 7 g/dl while maximum Hb level was 11.5 g/dl) while anemia was seen in 126 (69.6%) of these study cases. Chowdhury et al 19

Conclusion;
Twin pregnancy is associated with high risk of perinatal and pregnancy outcomes as very high frequency of preterm births was noted in our study. There was also higher frequency of anemia, cesarean section deliveries and low birth weight babies in our study. There is a need for specialized prenatal care to reduce complications and adverse outcome in multiple pregnancies, and the need for ongoing social and medical care beyond the prenatal and perinatal periods to improve perinatal outcomes in these patients.