The hormonal surges have both physical and emotional effects on the pregnant woman. In the first trimester when the hormone surges are at their peak, women suffer from nausea and morning sickness. They also suffer from mood swings and emotional volatility. Such emotional upset can be disruptive to the marital relationship, as their partners are most likely to take the brunt of it. By the second trimester, this tends to cool down. In fact the second trimester is known as the most enjoyable part of pregnancy. The mother is past the physical discomfort and emotional upheaval of the first trimester, yet still relatively physically nimble.