Epidemiological Analysis of 1000 Cases of Preterm Labor to Assess the Risk Factors and Outcome and to Evaluate the Significance of Vaginal Infections in Unexplained Preterm Births.

Tinu, Zachariah (2007) Epidemiological Analysis of 1000 Cases of Preterm Labor to Assess the Risk Factors and Outcome and to Evaluate the Significance of Vaginal Infections in Unexplained Preterm Births. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION: Preterm birth (delivery before 37 completed weeks) is a major contributor of neonatal mortality and morbidity. The term is used interchangeably with premature birth. The worldwide incidence of preterm labor ranges from 7% -11%. About two thirds of these occur between 34 and 37 weeks. In India an ICMR study in 1990 showed the incidence of preterm labor as 10% -15%. The rate of preterm birth has steadily increased over the past two decades70. There are about 13 million preterm births every year worldwide. The Perinatal Research Centre reports that 250 preterm babies are born every ten minutes. One out of every ten women has a risk of preterm birth. Despite advances in perinatal medicine in recent decades, preterm delivery continues to pose a challenge to both the obstetrician and the neonatologist. Preterm birth contributes to 75% of all perinatal deaths 40, 72. When lethal anomalies are excluded 85% of neonatal deaths occur in preterm babies. Prematurity accounts for half of the long term neurological morbidity in childhood40 and the amount of material, effort and money spend on these are enormous. AIMS OF THE STUDY: The study was done in two phases. The objectives of the first phase were to: 1. Study the epidemiology of preterm labor. 2. Study the perinatal morbidity and mortality associated with preterm labor. The objectives of the second phase were to: 1. Study the association of vaginal infection in unexplained preterm labor. 2. Study the outcome of pregnancy in preterm labor associated with infection. MATERIALS AND METHODS: The present study was conducted at the Institute of Obstetrics and Gynecology, Women and Children’s Hospital, Chennai, a tertiary level government institution for obstetrics and gynecology. There are 17,000 to 18,000 deliveries annually. This study analyzed one thousand consecutive preterm pregnancies from 2005 to 2006. The study was divided into two phases. In the first phase, which was a descriptive study, 1000 consecutive cases of preterm labor, both spontaneous and induced, which presented to the labor ward, were included in the study. These cases were analyzed for demographic data and obstetric history. The second phase was a case control study in which one hundred cases out of these thousand which were categorized as due to idiopathic factors underwent vaginal smear study when presenting in preterm labor. Equal numbers of patients with uncomplicated term deliveries were included in the control arm. The pregnancy outcome in these hundred cases was also analyzed separately. Inclusion Criteria: For phase one, all cases of established preterm labor presenting to the labor ward during the study period were included. These included patients who had spontaneous preterm labor and those in whom it had to be induced due to medical or obstetric indications. These cases were either booked or unbooked. Referral cases were also included in the study. In patients who had reliable dates, gestational age was calculated from their last menstrual period. In those without reliable dates, an early ultrasound (<24wks) was used to confirm gestational age. The subset analysis of 100 cases which formed the second phase to study the association of infection and unexplained preterm labor however included only spontaneous preterm labor with or without rupture of membranes. Cases where a known triggering factor for preterm labor existed were not included in this subset analysis. Exclusion Criteria: Cases in which neither the last menstrual period was known, nor was an early ultrasound report (<24wks) available were excluded from the study. The sample size for the first phase was 1000 consecutive preterm births which occurred between 2005 to 2006. For the second phase, 100 cases of preterm labor with no known triggering factor was the study group. Control arm had 100 cases of uncomplicated term pregnancies. CONCLUSION: The problem of preterm labor will continue to puzzle the obstetrician and neonatologist in the future too. The poor survival and high morbidity of preterm babies is due to the functional immaturity of various systems and poor tolerance to stress of labor and delivery. The perinatal outcome can be improved by inutero transfer of preterm babies from the peripheral centres to centers with level III neonatal services and the use of antenatal steroids in cases where preterm labor is anticipated. As proved by our study, infection is a significant risk factor for unexplained preterm labor, one should be looking at whether routine infective screening should be carried out for high risk cases and those presenting with symptoms suggestive of infections.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Epidemiological Analysis ; 1000 Cases ; Preterm Labor ; Risk Factors ; Outcome ; Significance ; Vaginal Infections ; Unexplained Preterm Births.
Subjects: MEDICAL > Obstetrics and Gynaecology
Depositing User: Subramani R
Date Deposited: 03 Dec 2017 11:24
Last Modified: 09 Dec 2017 02:14
URI: http://repository-tnmgrmu.ac.in/id/eprint/4171

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