Study | Exposure and adjustment factors in primary studies included in each systematic review | Outcome | Follow-up postpartum | Overall etimate (95% CI), prediction interval (PI), number of studies (studies), number of participants (n), inconsistency (I2), heterogeneity (tau2) | Subgroup and sensitivity analysis (estimate (95% CI), number of studies (studies), number of participants (n), inconsistency (I2), heterogeneity (tau2) |
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Alonso-Ventura 2020 [16] | Exposure: preeclampsia/eclampsiac Common adjustment factors: the review only provided information on matching variables for controls which were gestational age, age, parity, time of delivery, ethnicity, weight, BMI, smoking habits and family history of DM, CVD and preeclampsia, contraceptive intake, alcohol consumption | Hypertension | Outcome measured at least 3 months after delivery | Hypertension: OR 3.76 (2.87 to 4.94), PI = (2.34 to 6.05), studies = 12, n = 2261, I2 = 0%, tau2 = 0.03 SBP: MD 8.28 mmHg (6.85 to 9.71), PI = (1.00 to 15.56), studies = 38, n = 17,267, I2 = 78%, tau2 = 12.37 DBP: MD 6.79 mmHg (5.62 to 7.96), PI = (0.55 to 13.03), studies = 37, n = 17,232, I2 = 83%, tau2 = 9.10 | Hypertension Time of follow-up Up to 5 years: OR 19.03 (2.47 to 146.49), studies = 2, n = 171, I2 = 0%, tau2 = 0 Up to 5 to 15 years: OR 4.13 (2.47 to 6.90), n = 1041, studies = 6, I2 = 0%, tau2 = 0.09 Above 15 years: OR 3.41 (2.41 TO 4.82), studies = 4, n = 1039, I2 = 0%, tau2 = 0.01 SBP Time of follow-up Up to 5 years: MD 9.88 (7.69 to 12.08), studies = 13, n = 1177, I2 = 58%, tau2 = 8.69 Up to 5 to 15 years: MD 6.82 (5.60 to 8.04), studies = 14, n = 3356, I2 = 0%, tau2 = 0 Above 15 years: MD 8.28 (4.99 to 11.58), studies = 11, n = 12,734, I2 = 92%, tau2 = 23.33 DBP Time of follow up Up to 5 years: MD 8.05 (6.50 to 9.60), studies = 12, n = 1142, I2 = 52%, tau2 = 3.53 Up to 5 to 15 years: MD 6.54 (4.85 to 8.23), studies = 14, n = 3356, I2 = 71%, tau2 = 6.30 Above 15 years: MD 5.78 (3.30 to 8.26), studies = 11, n = 12,734, I2 = 92%, tau2 = 14.24 |
Bellamy 2007 [17] | Exposure: preeclampsiad Common adjustment factors: BMI, smoking, socioeconomic status, hypercholesterolaemia, type 2 diabetes | Hypertension | Outcome measured at least 3 months after delivery | OR 6.20 (3.74 to 10.28), PI = (1.19 to 32.35), studies = 13, n = 19,758, I2 = 83%%, tau2 = 0.50 | Parity Preeclampsia in any pregnancy: RR 5.96 (3.42 to 10.38), studies = 4, n = np, I2 = np, tau2 = np Preeclampsia in first pregnancy only: RR 3.23 (2.32 to 4.52), n = np, studies = 9, I2 = NP, tau2 = np |
Brown 2013 [116] | Exposure: preeclampsiad Common adjustment factors: Not provided | Hypertension | Outcome measured at least 6 weeks after delivery | OR 3.90 (3.16 to 4.82), PI = (1.80 to 8.43), studies = 30, n = 822,555, I2 = 80%, tau2 = 0.13 |  |
Dall’Asta 2021 [117] | Exposure: preeclampsiad Common adjustment factors: Not provided | Hypertension | No restriction | OR 3.93 (3.08 to 5.02), PI = (1.40 to 11.05), studies = 21, n = 2711443, I2 = 99%, tau2 = 0.23 ORadj 3.74 (2.87 to 4.87), PI = 1.28 to 10.95, studies = 15, n = 2,695,024, I2 = 99%, tau2 = 0.23 |  |
Giorgione 2021 [14] | Exposure: hypertensive disorders of pregnancy (including gestational hypertension, preeclampsia, eclampsia and HELLP syndrome)a Common adjustment factors: not provided, however, the systematic review compares population statistics between controls and exposed groups by maternal age, ethnicity (black ethnicity), BMI and smoking | Hypertension | Outcome measured 6 weeks to 2 years after delivery | HDP: OR 5.75 (3.92 to 8.44), PI = 2.08 to 15.87, studies = 14, n = 7580, I2 = 49%, tau2 = 0.18 Preeclampsia: OR 6.83 (4.25 to 10.96), PI = (1.96 to 23.79), studies = 12, n = 7238, I2 = 53%, tau2 = 0.26 | HDP: Follow-up duration First 6 months: OR 13.39 (1.27 to 141.04), studies = 3, n = 392, I2 = 72%, tau2 = 3.05 6 months–1 year: OR 4.13 (2.82 to 6.07), studies = 3, n = 6741, I2 = 54%, tau2 = 0.06 1–2 years: OR 8.73 (4.66 to 16.35), studies = 8, n = 1364, I2 = 23%, tau2 = 0.18 Preeclampsia: follow-up duration First 6 months: OR 43.95 (5.72 to 338.04), studies = 2, n = 144, I2 = 0%, tau2 = 0 6 months–1 year: OR 4.46 (2.76 to 7.21), studies = 3, n = 5998, I2 = 56%, tau2 = 0.10 1–2 years: OR 8.91 (4.33 to 18.33), studies = 7, n = 1096, I2 = 33%, tau2 = 0.28 Estimates including cases with pre-existing chronic hypertension HDP: OR 6.28 (4.18 to 9.43), PI = (1.99 to 19.85), studies = 15, n = 8041, I2 = 56%, tau2 = 0.24 Preeclampsia: OR 7.49 (4.58 to 12.26), PI = (1.88 to 29.86), studies = 13, n = 7699, I2 = 60%, tau2 = 0.33 HDP: follow up duration First 6 months: OR 18.33 (1.35 to 249.48), studies = 3, n = 392, I2 = 84%, tau2 = 4.32 6 months–1 year: OR 4.36 (2.81 to 6.76), studies = 4, n = 7106, I2 = 56%, tau2 = 0.10 1–2 years: OR 7.24 (4.44 to 11.80), studies = 8, n = 1364, I2 = 9%, tau2 = 0.05 Preeclampsia: follow up duration First 6 months: OR 57.08 (11.00 to 296.07), studies = 2, n = 248, I2 = 0%, tau2 = 0 6 months–1 year: OR 4.83 (2.78 to 8.37), studies = 4, n = 6307, I2 = 58%, tau2 = 0.16 1–2 years: OR 7.44 (4.19 to 13.21), studies = 7, n = 1144, I2 = 20%, tau2 = 0.12 |
Pathirana 2021 [15] | Exposure: gestational diabetes mellitus Common adjustment factors: BMI, parity, age, history of diabetes, other pregnancy complications | Hypertension | No restriction | DBP: MD 1.89 mmHg (1.32 to 2.46), PI = (− 1.12 to 4.90), studies = 48, n = 49,495, I2 = 83%, tau2 = 2.18 SBP: MD 2.47 mmHg (1.74 to 3.4), PI = (− 2.22 to 7.36), studies = 48, n = 50118, I2 = 79%, tau2 = 5.56 | Follow-up duration (DBP)  < 1 year: MD 2.48 mmHg (0.58 to 4.37), studies = np, n = 1749, I2 = 64%, tau2 = np 1–5 years: MD 1.37 mmHg (0.20 to 2.54), studies = np, n = 19,676, I2=89%, tau2 = np 5–10 years: MD 7.17 mmHg (1.69 to 16.03), studies = np,n = 2184, 99%, tau2 = np  > 10 years: MD 1.23 mmHg (1.03 to 1.96), studies = np,n = 4948, I2 = 97%, tau2 = np Follow-up duration (SBP)  < 1 year: MD 3.47 mmHg (1.26 to 5.68), studies = np, n = 1826, I2 = 50%, tau2 = np 1–5 years: MD 2.26 mmHg (0.27 to 4.25), studies = np, n = 19,701, I2 = 93%, tau2 = np 5–10 years: MD 3.96 mmHg (2.36 to 5.56), studies = np, n = 1965, I2 = 17%, tau2 = np  > 10 years: MD 2.58 mmHg (1.05 to 4.11), studies = np, n = 4941, I2 = 23%, tau2 = np |
Sukmanee 2022 [113] | Exposure: hypertensive disorders of pregnancy (including gestational hypertension and preeclampsia)b Common adjustment factors: age, ethnicity, socioeconomic status, time of delivery, smoking status, BMI, family history of cardiovascular diseases, parity, history of diabetes mellitus and maternal education | Hypertension | Outcome measured at least 6 weeks after delivery | OR 4.33 (3.51 to 5.33), PI = (1.47 to 12.74), studies = 37, n = 1,517,583, I2 = 99%, tau2 = 0.27 | Follow-up duration  ≤ 5 years: OR 6.05 (3.55 to 10.30), studies = 7, n = 321,971, I2 = 98%, tau2 = 0.35 6–10 years: OR 5.95 (4.69 to 7.54), studies = 6, n = 285,947, I2 = 82%, tau2 = 0.05 11–15 years: OR 4.22 (2.44 to 7.32), studies = 7, n = 786,479, I2 = 93%, tau2 = 0.41  > 15 years: OR 2.44 (1.93 to 3.08), studies = 2, n = 4535, I2 = 65%, tau2 = 0.02 Duration unspecified: OR 3.74 (2.50 to 5.58), studies = 15, n = 118,651, I2 = 97%, tau2 = 0.40 Preeclampsia with severe features OR 7.43 (2.85 to 19.35), studies = 4, n = 751,128, I2 = 90%, tau2 = 0.66 |
Xu 2022 [112] | Exposure: hypertensive disorders of pregnancy (including preeclampsia and gestational hypertension)b Common adjustment factors: a list of adjustment factors in each primary study is not provided, however authors mention some studies adjusted for age and BMI at recruitment, pre-pregnancy BMI, age at first delivery and other factors | Hypertension | Included studies evaluating outcome at least 1 year after delivery | HDP: OR 3.61 (2.18 to 6.00), PI = (0.62 to 20.98), studies = 11, n = 228,317, I2 = 96%, tau2 = 0.84 HDPadj: OR 2.47 (1.67 to 3.64), PI = (0.71 to 8.63), studies = 5, n = 7137, I2 = 79%, tau2 = 0.12 Gestational hypertension: OR 6.24 (1.73 to 22.55), studies = 3, n = 933, I2 = 73%, tau2 = 0.90 Preeclampsia: OR 3.19 (1.52 to 6.70), PI = (0.22 to 46.88), studies = 13, n = 341,060, I2 = 97%, tau2 = 1.35 Preeclampsiaadj: OR 3.78 (2.05 to 6.98), PI = (0.23 to 62.05), studies = 4, n = 2549, I2 = 90%, tau2 = 0.33 | HDP Region North and South America: OR 2.11 (1.42 to 3.14), studies = 5, I2 = 82%, n = 6581, tau2 = 0.12 Asia: OR 4.26 (1.07 to 16.94), studies = 3, n = 1260, I2 = 88%, tau2 = 1.30 Europe: OR 5.52 (3.01 to 10.13), studies = 3, n = 220,476, I2 = 64%, tau2 = 0.17 Test of differences between regions: p-value = 0.03 Preeclampsia Region North and South America: OR 3.32 (1.26 to 8.74), studies = 6, n = 332,949, I2 = 95%, tau2 = 1.07 Asia: OR 7.54 (2.49 to 22.81), studies = 3, n = 6529, I2 = 36%, tau2 = 0.45 Europe: OR 2.19 (0.30 to 16.02), studies = 4, n = 1582, I2 = 98%, tau2 = 3.57 |
Vounzoulaki 2020 [114] | Exposure: gestational diabetes mellitus Common adjustment factors: maternal age, body mass index, family history of T2DM, parity, ethnicity, and socioeconomic status | T2DM | Included studies evaluating outcome at least 1 year after delivery | RRunadj 9.51 (7.14 to 12.67), PI = (3.31 to 27.30), studies = 20, n = 1,332,373, I2 = 96.5%, tau2 = 0.23 | 1. Ethnicity White population: RR 16.28 (15.01 to 17.66), studies = 6, n = 187,532, I2 = 0%, tau2 = 0 Non-white population: RR 10.38 (4.61 to 23.39), studies = 4, n = 2538, I2 = 78.2%, tau2 = 0.46 Mixed populations: RR 8.31 (5.44 to 12.69), studies = 10, n = 1,142,303, I2 = 97.8%, tau2 = 0.34 Test of differences between ethnicities: white vs mixed p-value = 0.26, white vs non-white p-value = 0.54) 2. Length of follow-up 1 to 5 years: RR 17.06 (8.95 to 32.55), studies = 6, n = 1566, I2 = 0%, tau2 = 0  > 5 to 10 years: RR 10.42 (5.68 to 19.11), studies = 7, n = 223,945, I2 = 98%, tau2 = 0.52  > 10 years: RR 8.09 (4.34 to 15.08), studies = 7, n = 1,106,862, I2 = 97%, tau2 = 0.52 Test of differences between ethnicities: 1–5 years vs 5–10 years p-value = 0.63, 1–5 years vs > 10 years p-value = 0.38) |
Zhao 2021 [115] | Exposure: hypertensive disorders of pregnancy (HDP) (including gestational hypertension and preeclampsia)a Common adjustment factors: maternal age, body mass index, socioeconomic status, smoking status, pre-pregnancy and current BMI, parity, ethnicity and time of delivery | T2DM | Included studies evaluating outcome at least 1 year after delivery | HDP: HRadj 2.24 (1.95 to 2.58), PI = (1.14 to 4.40), studies = 15, n = 3,095,457, I2 = 94%, tau2 = 0.10 Gestational hypertension: HRadj 2.19 (1.69 to 2.84), PI = (1.02 to 4.37) studies = 7, n = 2,735,586, I2 = 87%, tau2 = 0.07 Preeclampsia: HRadj: 2.56 (2.02 to 3.24), PI = (1.07 to 5.67), studies = 11, n = 3,007,543, I2 = 94%, tau2 = 0.23 | Preterm preeclampsia: HRadj 3.05 (2.05 to 4.56), studies = 3, n = np, I2 = 82%, tau2 = 0.09 Follow-up duration Less than 20 years: HRadj 2.64 (2.23 to 3.12), studies = 7, n = np, I2 = 95%, tau2 = np Greater or equal to 20 years: HRadj 1.34 (1.20 to 1.50), studies = 2, n = np, I2 = 0%, tau2 = np |