Table 3. Maternal risk factors and estimated risk of stillbirth, and reported strategies for antepartum fetal surveillance.
| Condition | Prevalence | Estimated rate of stillbirth | Odds Ratio | GA to initiate testing | Testing mode and schedule | References |
|---|---|---|---|---|---|---|
| All pregnancies | -- | 6.4/1000 | 1.0 | -- | -- | (109) |
| Low-risk pregnancies | 80% | 4.0 – 5.5/1000 | 0.86 | -- | -- | (109) |
| Diabetes | ||||||
| Treated with diet (A1) | 2.5 – 5% | 6 – 10/1000 | 1.2 – 2.2 | Not indicated | -- | (54;109) |
| Treated with insulin | 2.4% | 6 – 35/1000 | 1.7 – 7.0 | A2, B, C, D without HTN, renal disease, or FGR: 32 w | CST/w, midweek NST | (52;109) |
| 32 w | NST or BPP 2x/w | (110) | ||||
| 34 w | NST 2x/w + AFI/w | (51) | ||||
| R, F: 26w | CST/w, midweek NST | (52) | ||||
| Any class with HTN, renal disease, FGR: 26 w | CST/w, midweek NST | (52) | ||||
| 28 w | NST or BPP 2x/w | (110) | ||||
| Hypertensive disorder | ||||||
| Chronic hypertension | 6 – 10% | 6 – 25/1000 | 1.5 – 2.7 | 26 w | NST, AFI 2x/w | (109;111) |
| 33 w | MBPP 2x/w | (29;112) | ||||
| With SLE or FGR or DM or PIH: 26 w | NST, AFI 2x/w | (112;113) | ||||
| Pregnancy-induced hypertension | ||||||
| Mild | 5.8 – 7.7% | 9 – 51/1000 | 1.2 – 4.0 | At diagnosis | MBPP 2x/w | (29;30;109) |
| Severe | 1.3 – 3.3% | 12 – 29/1000 | 1.8 – 4.4 | At diagnosis | NST/day with BPP if nonreactive; AFI 2x/w | (57;109) |
| Growth restricted fetus | 2.5 - 10% | 10 – 47/1000 | 7 – 11.8 | Suspected: at diagnosis | NST, AFI/w | (113-115) |
| UAD 1-2x/w | (18;116) | |||||
| Confirmed | MBPP 2x/w | (29;30) | ||||
| UAD 1-2x/w | (18;116) | |||||
| Multiple gestation | 2 – 3.5% | |||||
| Twins | 2.7% | 12/1000 | 1.0 – 2.8 | Concordant growth: 32 w | NST, AFI/w | (109;113) |
| Discordant growth: at diagnosis | MBPP 2x/w | (30) | ||||
| Triplets | 0.14% | 34/1000 | 2.8 – 3.7 | 28 w | BPP, 2x/w | (109;117) |
| Oligohydramnios | 2% | 14/1000 | 4.5 | At diagnosis | NST, AFI 2x/w | (113;118) |
| PPROM | At diagnosis | NST/day | (69;119) | |||
| BPP/day | (108;120) | |||||
| Postterm pregnancy (compared to 40w) | ||||||
| 41w | 9% | 1.6/1000 | 1.5 | 41 w | BPP 2x/w | (72;121;122) |
| 41 w | MBPP/w | (30) | ||||
| ≥ 42w | 5% | 2 – 3.5/1000 | 1.8 – 2.9 | 42 w | MBPP 2x/w | (30;72;121) |
| Previous stillbirth | 0.5 – 1.0% | 9 – 20/1000 | 1.4 – 3.2 | 32 w | MBPP 2x/w or BPP/w or CST/w | (29;82;109;120) |
| 34 w or 1 w prior to previous stillbirth | MBPP/w | (30) | ||||
| Decreased fetal movement | 4 – 15% | 13/1000 | 2.5 – 5.6 | At diagnosis | MBPP | (15;29;30;84;109) |
| SLE | < 1% | 40 – 150/1000 | 6 – 20 | 26 w | CST, BPP, or NST/w | (109;123) |
| Renal disease | < 1% | 15 – 200/1000 | 2.2 – 30 | 30 – 32 | BPP 2x/w | (109;124) |
| Cholestasis of pregnancy | < 0.1% | 12 – 30/1000 | 1.8 – 4.4 | 34 w | MBPP/w | (30;109) |
| Advanced maternal age (reference < 35 y) | ||||||
| 35 – 39 y | 15 – 18% | 11 – 14/1000 | 1.8 – 2.2 | ID | ID | (109) |
| 40 y + | 2% | 11 – 21/1000 | 1.8 – 3.3 | ID | ID | (109) |
| Black women compared with white women | 15% | 12 – 14/1000 | 2.0 – 2.2 | ID | ID | (109) |
| Maternal age < 20 | 4% | 7 – 13/1000 | 1.1 – 1.6 | ID | ID | (121;125) |
| Nulliparity | 40% | 3.8 (Sweden) | 1.2 (Sweden) | ID | ID | (93;126) |
| Very high (10-14) or extremely high (≥ 15) parity | 0.1% | 14 – 22/1000 | 2.0 – 2.2 | ID | ID | (94) |
| Assisted reproductive technology | 1% | 12/1000 | 2.6 | ID | ID | (127) |
| Abnormal serum markers | ||||||
| 1st trimester PAPP-A <5th Percentile | 5% | 9/1000 | 2.2 – 4.0 | ID | ID | (98;128) |
| 2 or more abnormal 2nd trimester quad screen markers | 0.1 – 2% | 8 – 18/1000 | 4.3 – 9.2 | ID | ID | (99) |
| Obesity (prepregnancy) | ||||||
| BMI 25 – 29.9 kg/m2 | 21% | 12 – 15/1000 | 1.9 – 2.7 | ID | ID | (109) |
| BMI ≥ 30 kg/m2 | 20% | 13 – 18/1000 | 2.1 – 2.8 | ID | ID | (109) |
| Low educational attainment (< 12 y vs. 12 y +) | 30% | 10 – 13/1000 | 1.6 – 2.0 | ID | ID | (109) |
| Smoking > 10 cigarettes/day | 10 – 20% | 10 – 15/1000 | 1.7 – 3.0 | ID | ID | (109) |
| Thrombophilia | 1 – 5% | 18 – 40/1000 | 2.8 – 5.0 | ID | ID | (109) |
| Thyroid disorders | 0.2 – 2% | 12 – 20/1000 | 2.2 – 3.0 | ID | ID | (109) |
GA, gestational age; CST, contraction stress test; w, week; HTN, hypertension; FGR, fetal growth restriction; NST, nonstress test; BPP, biophysical profile; AFI, amniotic fluid index; mBPP, modified biophysical profile; SLE, systemic lupus erythematosus; DM, diabetes mellitus; PIH, pregnancy-induced hypertension; y, years; ID, insufficient data; BMI, body-mass index.