At the first OB appointment, ideally between 6 and 10 weeks, your doctor orders the first-trimester tests: complete blood count, fasting glucose, thyroid function, serologies for infections, blood type and Rh, urinalysis with culture, and an obstetric transvaginal ultrasound. Each one looks for something specific, from anemia and pre-existing diabetes to Rh incompatibility and fetal viability.
| Test | What it assesses |
|---|---|
| Complete blood count | Anemia, infections |
| Fasting glucose | Pre-existing diabetes |
| TSH and free T4 | Thyroid function |
| Serologies (HIV, syphilis, hepatitis) | Infections with fetal impact |
| Toxoplasmosis serology | Immunity or risk of infection |
| Rubella, cytomegalovirus serology | Immunity |
| Blood type + Rh | Rh incompatibility |
| Urinalysis + culture | Urinary tract infection |
| Obstetric transvaginal ultrasound | Fetal viability, gestational age |
Source: Map to the Positive, Chapter 39.
At the same visit, your OB will discuss genetic testing (NIPT) and the anatomy scan. One of the questions the book suggests you bring is exactly this: which tests are routine and which are optional (genetic)?
The ultrasound depends on timing: from 6 weeks, a transvaginal scan can show the embryo and the heartbeat. Before that there is still little to see, which is one reason the first appointment is best between 6 and 10 weeks. The anatomy scan comes later, usually between 11 and 13 weeks and between 20 and 24 weeks.
Not necessarily. The book warns that frequent ultrasounds and repeated beta-hCGs give relief for 5 minutes and amplify anxiety for hours. Agree with your doctor on which tests are necessary, and stick to them.
Complete documentation saves time and money, and gives your OB the full picture from the first visit. The book's list:
The first-trimester tests are in Chapter 39 of Map to the Positive, in Station V (Positive). The same book opens, in Station I, with the 11 preconception tests, so the results you bring to this appointment can include the ones you did before conceiving. It covers the whole road from preparing to conceive to the first 30 days after a positive, which makes it worth keeping, or giving to someone who is still trying.
Take 30 days. If it does not give you more clarity than everything you have read for free so far, ask for a refund and you get every cent back. We cannot promise you a pregnancy. We can promise you will not be guessing.