Conception, IVF, and genetics
Key risks begin before implantation: chromosomal errors, early organogenesis, and modifiable exposures.
Preconception optimization
- Folic acid (commonly 400 μg/day) before conception and in early pregnancy reduces neural tube defects (e.g., spina bifida).[3]
- Iron/folate supplementation in pregnancy reduces maternal anemia and is associated with reduced low birth weight and preterm birth in WHO guidance.[1][2]
- Alcohol: no known safe amount, time, or type during pregnancy or when trying to get pregnant.[4][5]
- Chronic disease control: diabetes, hypertension, thyroid disease, epilepsy, obesity, and infections affect placentation and fetal growth; stabilize prior to conception.
Genetic and chromosomal risk
- Mechanisms: aneuploidy, single-gene disorders, copy-number variants, de novo mutations.
- Risk increases with parental age (especially maternal age for aneuploidy) and relevant family history.
- Screening: first-trimester combined screening and/or cfDNA/NIPT (context dependent). Screening ≠ diagnosis.
- Diagnosis: CVS or amniocentesis when indicated; counseling should be non-directive.
IVF / assisted reproductive technologies (ART)
- ART pregnancies are heterogeneous; outcomes reflect both treatment factors and underlying infertility.
- Large reviews consistently show higher rates of preterm birth and low birth weight in IVF/ICSI singletons compared with spontaneous conception (magnitude varies by study).
- Some guidance considers targeted fetal cardiac assessment in higher-risk pregnancies; congenital heart defects overall affect ~1% of births.[9]