2006-07-03 18:34:56 · 6 answers · asked by wahidsaiyed_007 1 in Pregnancy & Parenting ➔ Pregnancy
usually, he bases it on the date the baby was conceived.
2006-07-03 18:37:16 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Experience has shown that human gestation lasts about 266 days, on average. Since it is often difficult to know exactly when the baby was conceived doctors rely on another average. That is that a woman ovulates 14 days before her next period, and the average length from one period to the next is 28 days. So doctors ask when was the first day of the last period, add 2 weeks (14 days) to gestation, and count forward 280 days from there to find the due date.
If a woman is sure when she ovulated, then she can count 266 days forward from there. Still that is only an average. Women gestate anywhere from 245 days to 285 days. Every pregnancy is different.
2006-07-04 04:39:07 · answer #2 · answered by tianjingabi 5 · 0⤊ 0⤋
the first week of a woman's pregnancy is actually their last period. Doctors and other health officials calculate the womans due date by counting 40 weeks from the start of the woman's last cycle, counding the start of her period even though the child hasnt been conceived yet. Conception typically occurs about 2 weeks after the start of her last period.
2006-07-06 03:16:17 · answer #3 · answered by ~*Iverson*~ 2 · 0⤊ 0⤋
The doctor uses the date of the womans last period and then 40 weeks from then is the due date.
2006-07-04 01:39:24 · answer #4 · answered by cynthia_0516 2 · 0⤊ 0⤋
40 weeks from the last period. However, he can also check the size of the baby (exam and/or ultrasound). This is sometimes necessary because a woman could still have a period when she is pregnant, especially the 1st month.
2006-07-04 01:41:58 · answer #5 · answered by curiouschick18 4 · 0⤊ 0⤋
he adds 9 months to conception
2006-07-04 01:38:54 · answer #6 · answered by sball124 3 · 0⤊ 0⤋