Can a woman of any parity still be at risk for potential complications if she forgoes screening, even if her prior pregnancies have been normal?

Yes, Every Woman Remains at Risk for Pregnancy Complications Regardless of Prior Normal Pregnancies

A woman of any parity can develop new complications in subsequent pregnancies even with a completely normal obstetric history, and forgoing screening places both mother and fetus at risk for undetected conditions that could lead to serious morbidity or mortality. Each pregnancy represents an independent physiologic stress test with unique risks.

Why Prior Normal Pregnancies Do Not Eliminate Risk

Parity-Related Risk Patterns

• Nulliparous women face distinctly different risks than multiparous women, with higher rates of obstetric complications, neonatal morbidity, and perinatal mortality compared to women of low multiparity (parity 1-3) 1

• Grand multiparous women (parity ≥4) demonstrate significantly elevated risk for both maternal and fetal complications compared to women of lower parity, even when controlling for age, smoking, and socioeconomic status 1

• The risk profile changes with each pregnancy category, creating a U-shaped curve where both nulliparity and grand multiparity carry higher risks than low multiparity 1

Pregnancy as an Independent Cardiovascular Stress Test

• Each pregnancy reveals latent cardiovascular and metabolic dysfunction that may not have been present or detectable in prior pregnancies 2

• Common pregnancy complications including preeclampsia, gestational diabetes, fetal growth restriction, and preterm delivery are markers of subclinical vascular and metabolic dysfunction that can emerge in any pregnancy regardless of prior obstetric history 2

• These complications represent high-risk cardiovascular trajectories that warrant identification through screening, as they predict future cardiovascular disease risk 2

Essential Screening That Should Never Be Forgone

First Trimester and Early Pregnancy Screening

• HIV screening should be performed as early in pregnancy as possible using opt-out approach for all pregnant women, as early identification and treatment prevents neonatal infection and improves maternal health 3

• Repeat HIV testing in the third trimester (before 36 weeks) is recommended for high-risk women, those in high-prevalence areas, or those with signs of acute infection 3

• Rapid HIV screening during labor should be performed for women with unknown status, with results available within 1 hour 3

Gestational Diabetes Screening

• Women with risk factors (obesity, age >25, family history, prior gestational diabetes, certain ethnicities) should undergo early screening before 15 weeks gestation to identify pre-existing diabetes or early abnormal glucose metabolism 4

• Universal screening between 24-28 weeks gestation should be performed even in women without identified risk factors, as gestational diabetes can develop de novo in any pregnancy 4

• Early abnormal glucose metabolism (fasting glucose ≥110 mg/dL or A1C ≥5.9%) identifies women at higher risk for adverse outcomes including pre-eclampsia, macrosomia, shoulder dystocia, and perinatal death 4

Aneuploidy Screening Considerations

• Cell-free DNA (cfDNA/NIPT) screening after 10 weeks gestation provides detection rates of 99% for trisomy 21 with false positive rates of only 0.5%, representing the single best screening test for common trisomies 5

• Even after negative aneuploidy screening, the finding of isolated soft ultrasound markers does not substantially alter risk and should not prompt diagnostic testing in isolation 4

• Women who decline aneuploidy screening should have a standardized protocol for how isolated soft markers will be handled, established before the ultrasound examination 4

Critical Pitfalls When Forgoing Screening

The False Security of Prior Normal Pregnancies

• Between 28-64% of women age 65 and older have never had adequate cervical cancer screening, demonstrating how gaps in screening persist across the lifespan and increase disease burden 4

• Women who have never been screened have 3-4 times the incidence of cervical disease compared to those with at least one prior normal screening test 4

• Risk factors accumulate over time and across pregnancies, including multiple sexual partners, HPV exposure, HIV, smoking, and immunosuppression 4

Conditions That Emerge Independent of Prior History

• Gestational diabetes, preeclampsia, and other complications can occur in any pregnancy regardless of prior obstetric outcomes, as each pregnancy represents unique maternal-fetal-placental physiology 4, 2

• Maternal age, BMI changes, new medical conditions, and interval health changes between pregnancies all modify risk independent of prior pregnancy outcomes 4, 1

The Screening Algorithm for Any Pregnancy

Regardless of parity or prior pregnancy outcomes:

1. First prenatal visit (ideally preconception):

   • HIV screening with opt-out approach 3
   • Early diabetes screening if risk factors present 4
   • Carrier screening offered to all women 6

2. 10-14 weeks gestation:

   • NIPT/cfDNA screening for aneuploidy (if desired) 5
   • Repeat early glucose screening if initial screening negative but risk factors present 4

3. 18-22 weeks gestation:

   • Anatomic ultrasound for structural anomalies 5

4. 24-28 weeks gestation:

   • Universal gestational diabetes screening 4

5. Third trimester (before 36 weeks):

   • Repeat HIV testing for high-risk women 3

6. Labor and delivery:

   • Rapid HIV screening if status unknown 3

This screening framework applies universally—prior normal pregnancies do not exempt any woman from the independent risks of the current pregnancy. The physiologic stress of each pregnancy can unmask latent disease or create new pathology regardless of obstetric history.