Women are generally offered a first ultrasound during the first trimester of pregnancy.
Nausea and vomiting are worst in the first trimester when the developing baby is most susceptible to effects from other drugs, consequently, there are limited conventional treatments available.
In cases of aldosterone-producing adenoma, surgery in the second trimester is the most appropriate option to avoid a poor obstetric outcome.
Withdrawal symptoms occur in infants born to women who receive barbiturates during the last trimester of pregnancy.
Routine scanning in the second trimester was shown to be relatively cost-effective.