Birth Cohort Study for Respiratory Infections

Inclusion Criteria: * Age: 18-35 years * Parity: any but with history of previous normal delivery * Weight: Body Mass Index greater than 18.5 but less than 35 * Past obstetric history: Uncomplicated pregnancy, unremarkable medical and obstetric conditions * Current pregnancy: Uneventful progression of pregnancy * General health: Normal health related functional status during pregnancy * Singleton pregnancy as determined by clinical examination and/or by ultrasonography * Cephalic presentation as determined by abdominal clinical examination * Expected to have normal pregnancy related outcome * Written informed consent Exclusion Criteria: * Medical history: Known history of diabetes, hypertension, or any systemic disorder * Gynecological history: History of major gynecological problem/treatment * Complications in previous pregnancy * Previous obstetric cholestasis * Previous acute fatty liver disease * Conditions during current pregnancy 1. RhD negative mother 2. APH/Placental abruption 3. Placenta Praevia 4. Unstable lie 5. Multiple pregnancy 6. Pregnancy induced hypertension (systolic \> 140 mm of Hg, diastolic \> 90 mm of Hg) 7. Severe pre-eclampsia or eclampsia 8. Gestational diabetes 9. Onstetric cholestasis 10. Current history of drug/alcohol abuse 11. BMI of less than 18.5 or more than 35. Severe pallor as detected clinically or by HB level (\< 7 gm/dL), and oedema 12. Blood samples drawn and tested for VDRL (Positive VDRL) Cephalopelvic disproportion (CPD) 13. History of taking antibiotic within 3 weeks prior to this study 14. Patient unwilling to comply with study protocol