Dear Suresh, The due date of delivery that is informed to you is approximate date of delivery. The pregnancy is of 280 days. Since it was very difficult to pinpoint the exact date of conception, the due date of delivery (DD) used to be calculated from the date of last menstrual period considering the pregnancy takes place of the 14th day after LMP. Though now with advanced technique the exact date of conception can be located, still clinically the due date is calculated considering the date of last menstrual period (LMP). The formula for calculating due date is very simple: DD = LMP + 9months + 7 days. Now with the availability of the ultrasonography, the foetal age is calculated from the different growth parameters of the foetus and based on it, due date of delivery is calculated, still it is approximate. However, considering the maturity of the baby and the placenta, delivery any time between 3 weeks earlier to one week later than the DD; i.e. from 37 weeks to 41 weeks of gestation is considered within normal limits and safe for the baby. Your wife s DD was calculated as 16th June. So she might have had her LMP on 9th September. Her delivery from 23rd May to 23rd June should be considered as full term delivery and in normal circumstances, neither she nor the baby should face any problem. Since the date is crossed, she can assess the safety of the baby by counting the movements of the baby. If the baby is moving about 10 times during 12 hours, baby is safe. However, if she finds that the movements are becoming less, she should immediately report to the Obstetrician. Also it is advisable that she reports to the Obstetrician on 22nd or 21st June to assess the health of the foetus. If the pregnancy crosses the duration of 41 weeks, the risk to the baby increased and there are more chances of Caesarean delivery. Under no circumstances, pregnancy should cross 42 weeks. I hope this has given you appropriate guidance. Dr. Nishikant Shrotri