Final answer:
The risk of miscarriage decreases significantly after the first trimester, with a marked decrease after the 20th week, as the pregnancy enters the more stable period of the second and third trimesters.
Step-by-step explanation:
Risk of Miscarriage Across Different Pregnancy Weeks
The risk of miscarriage decreases significantly as a pregnancy progresses. The first trimester, especially the first few weeks, is generally considered to be the period with the highest risk for miscarriage. By the time a woman reaches the second trimester, particularly after the 20th week, the risk of miscarriage drops markedly.
During the second trimester, starting from weeks 13 to 28, various developmental milestones occur, and the fetus begins to grow more noticeably. Around week 20, the fetus is often large enough for the mother to start feeling its movements, indicating a well-established pregnancy. Furthermore, the second trimester often brings relief from early pregnancy symptoms like nausea.
By the third trimester, which spans from weeks 29 to 40, the fetus's bones complete their development, and rapid growth occurs, both signs of a healthy advancing pregnancy.