Final answer:
The second and third trimesters of pregnancy are times of growth and potential complications, including gestational diabetes, preeclampsia, and placenta previa. Maternal diseases, fetal anomalies, and risk factors like age and pre-existing conditions may also affect pregnancy outcomes, sometimes requiring specialized procedures.
Step-by-step explanation:
The second trimester of pregnancy covers weeks 13 to 28. During this period, expectant mothers often experience relief from earlier nausea and vomiting but will notice an increase in weight gain. Feeling fetal movements is a significant milestone typically occurring around week 20. However, complications can emerge, such as gestational diabetes and preeclampsia, sometimes necessitating closer medical supervision and potential procedures like amniocentesis. The third trimester, spanning weeks 29 to birth, is characterized by rapid uterine expansion and significant weight gain. It's during this phase that the fetus undergoes its greatest growth, leading to common discomforts such as back pain, varicose veins, frequent urination, and heartburn. More serious complications might include placenta previa, preterm labor, or fetal growth restriction. Labor is the culmination of this trimester, occurring in three stages: contractions, delivery of the baby, and expulsion of the placenta. Maternal diseases like hypertension and diabetes can exacerbate or emerge as complications during these trimesters. Maternal obesity, age, and previous medical history are considered risk factors, potentially leading to complicated delivery procedures or caesarean sections. Fetal anomalies can also be discovered or monitored more closely during this time, facilitated by ultrasound or other diagnostic tests.