wikiHow to Raise Low Blood Pressure. Low blood pressure â often defined as lower than 90 mm Hg systolic or 60 mm Hg diastolic â is a common medical condition with a variety of causes, including pregnancy, heart problems, some severe infections or allergies, blood loss, and even dehydration.
You may have an ultrasound between 18 to 20 weeks to evaluate dates, a multiples pregnancy, placenta location or complications. It may also be possible to determine the gender of your baby during this ultrasound.
While most practitioners wait until at least 6 weeks to perform the first ultrasound, a gestational sac can be seen as early as 4 1/2 weeks after your last period; a heartbeat can be detected as early as 5 to 6 weeks (though it might not be detected that early in all cases).