Intrauterine device expulsion after postpartum placement

Abstract

OBJECTIVE:

To estimate expulsion rates among women with postpartum intrauterine device (IUD) placement by timing of insertion, IUD type, and delivery method.

DATA SOURCES:

We searched PubMed, Cochrane Library, and ClinicalTrials.gov from 1974 to May 2018.

METHODS OF STUDY SELECTION:

We searched databases for any published studies that examined post-partum placement of a copper IUD or levonorgestrel intrauterine system and reported counts of expulsions. We assessed study quality using the U.S. Preventive Services Task Force evidence grading system. We calculated pooled absolute rates of IUD expulsion and estimated adjusted relative risks (RRs) for timing of postpartum placement, delivery method, and IUD type using log-binomial multivariable regression model.

TABULATION, INTEGRATION, AND RESULTS:

We identified 48 level I to II-3 studies of poor to good quality. Pooled rates of expulsion varied by timing of IUD placement, ranging from 1.9% with interval placements (4 weeks postpartum or greater), 10.0% for immediate placements (10 minutes or less after placental delivery), and 29.7% for early placements (greater than 10 minutes to less than 4 weeks postpartum). Immediate and early postpartum placements were associated with increased risk of expulsion compared with interval placement (adjusted RR 7.63, 95% CI 4.31–13.51; adjusted RR 6.17, 95% CI 3.19–11.93, respectively). Postpartum placement less than 4 weeks after vaginal delivery was associated with an increased risk of expulsion compared with cesarean delivery (adjusted RR 5.19, 95% CI 3.85–6.99). Analysis of expulsion rates at less than 4 weeks postpartum also indicated that the levonorgestrel intrauterine system was associated with a higher risk of expulsion (adjusted RR 1.91, 95% CI 1.50–2.43) compared with CuT380A.

CONCLUSION:

Postpartum IUD expulsion rates vary by timing of placement, delivery method, and IUD type. These results can aid in counseling women to make an informed choice about when to initiate their IUD and to help institutions implement postpartum contraception programs.

Postpartum intrauterine device (IUD) placement provides safe and highly effective contraception at a time when women are accessing medical care.^1–4 Previously published systematic reviews of postpartum IUD placement generally report low rates of complications such as perforations and infections.^2–4 The U.S. Medical Eligibility Criteria for Contraceptive Use (2016)⁵ and professional organizations including the American College of Obstetricians and Gynecologists support the safety of immediate post-partum IUD placement.⁶ However, previous reviews suggest that rates of IUD expulsions are higher when placed in the immediate or early postpartum period compared with placement later at a postpartum or interval visit.³ Expulsions may compromise effectiveness, especially when replacement IUDs are not easily accessible. However, because many postpartum women do not return for a postpartum visit and therefore never have an IUD placed, the benefit of placing an IUD immediately or soon after delivery may outweigh the risk of expulsion.^3,7 Recent studies have shown high continuation rates among women receiving immediate postpartum IUDs as well as cost-effectiveness, despite higher expulsion rates.^8–11 Although previous narrative systematic reviews have concluded that IUD expulsion rates are increased with postpartum placement compared with interval placement,^2–4 absolute rates vary widely across studies and it has been difficult to quantify the magnitude of increased risk.¹ With this review, our aim was to calculate pooled absolute rates of IUD expulsion and to estimate relative risk of expulsion for timing of placement in the postpartum period, delivery method, and IUD type.

SOURCES

We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting this review.¹² We searched PubMed, Cochrane Library, and ClinicalTrials.gov for all primary research studies of any study design, in any language, published from database inception through May 2018 that examined postpartum placement of IUDs. We searched PubMed using the following search strategy: ((((“Intrauterine Devices”[Mesh] OR “Intrauterine Devices, Copper”[Mesh] OR “Intrauterine Devices, Medicated”[Mesh] OR ((intrauterine OR intrauterine) AND (device OR system OR contracept*)) OR IUD OR IUC OR IUCD OR IUS OR mirena OR Skyla OR liletta OR paragard OR “Copper T380” OR CuT380 OR “Copper T380a” OR “Cu T380a”) AND (postpartum OR Puerperium*) NOT (“Animals”[Mesh] NOT “Humans”[Mesh])))). We searched Cochrane Library and ClinicalTrials.gov for any published reviews or additional studies including “Postpartum AND IUD.” We hand-searched relevant articles and reviews for additional references.

STUDY SELECTION

We included studies that examined immediate post-partum placement (10 minutes or less after placental delivery) or early postpartum placement (greater than 10 minutes to less than 4 weeks) and reported counts of expulsion and counts of women with follow-up. We included studies with any length of follow-up and any rate of follow-up. We excluded studies that did not report counts of women with IUD placement and occurrence of expulsion, which were required for calculation of pooled estimates of expulsions across studies. We included studies that examined copper-bearing IUDs that are currently available (CuT380A) or were previously available in the United States (Copper 7, TCu200) and the levonorgestrel intrauterine system (LNG-IUS). We excluded studies that evaluated IUDs that were modified from their standard structure and were not commercially available (eg, sutures added to the IUD to anchor the IUD to the endometrium). We included studies that examined IUD placement after vaginal delivery, cesarean delivery, or both.

Two coauthors (T.C.J. and M.K.W.) independently screened all titles and abstracts identified from the initial search to determine whether the studies met inclusion criteria. Full-text articles were reviewed as needed. Pertinent non-English articles were professionally translated by U.S. Centers for Disease Control and Prevention translation services. The lead author (T.C.J.) and one additional coauthor (M.K.W., E.B.-B., N.K.T.) reviewed each included study and abstracted the following information: study author, year of publication, country, funding source, study design, IUD type, timing of IUD placement, delivery method, length of study follow-up, number of women enrolled or randomized, number of IUDs initially placed, number of women with any follow-up, and counts of expulsion (overall, complete, and partial). To assess risk of bias, two coauthors independently reviewed each study according to the U.S. Preventive Services Task Force system to evaluate study design and methodologic features such as potential for selection bias (eg, groups not comparable at baseline for randomized controlled trials), mis-classification (eg, outcome of expulsion diagnosed inconsistently by nonblinded health care provider), and confounding (eg, parity and breastfeeding status not collected or adjusted for).¹³ Two coauthors (E.B.-B. and N.K.T.) assessed one study that was authored by the lead author of this review.¹⁴ Any discrepancies between authors for selection, abstraction, or risk of bias assessment were resolved through discussion.

DATA SYNTHESIS

We calculated expulsion rates by pooling the number of women with IUD placements and the number of IUD expulsions reported for each individual study for women with any follow-up. This calculation of the proportion of a pooled number of expulsions over a pooled number of IUD placements is equivalent to a sum of individual expulsion rates weighed by their corresponding study size. We assumed expulsions were complete expulsions if not otherwise defined, and we excluded partial expulsions from our primary analysis, because not all studies reported them, definitions varied or were absent from studies, or malpositioned IUDs were reported as partial expulsions. Because many of the included randomized controlled trials reported follow-up by intent-to-treat analyses, we were unable to determine how many women received IUDs at the assigned time period per protocol and returned for follow-up; therefore, for those studies that reported only intent-to-treat results, we used the number of women randomized who had follow-up as our denominator.

We calculated pooled expulsion rates within strata defined by factors including: timing of post-partum placement (immediate, early, either immediate or early [mixed], or interval placement at 4 weeks postpartum or greater), delivery method (cesarean, vaginal, either cesarean or vaginal [mixed], or unknown), IUD type (CuT380A, LNG-IUS, either CuT380A or LNG-IUS [mixed], Copper 7, or TCu200), length of study follow-up, study region (defined by the World Health Organization, www.who.int/about/regions/en/), and study quality (defined by U.S. Preventive Services Task Force¹³). The calculations were weighted by number of women in each individual study with respect to different factors listed. We included interval placements only when describing expulsions by placement timing because we wanted to compare the various postpartum periods with interval placements; for other comparisons, we focused only on immediate or early postpartum placements.

Using a log-binomial regression model, we estimated adjusted relative risks (RRs) of IUD expulsion and their associated 95% CIs with inclusion of potential risk factors (timing of IUD placement, delivery method, and IUD type) while adjusting for other covariates including World Health Organization study region, study quality, and length of study follow-up. Finally, we performed a number of sensitivity analyses related to our exclusions based on losses to follow-up and partial expulsion reporting. Women who had an IUD placement and were lost to follow-up were excluded from the primary analysis. To assess the possible effect of loss to follow-up, we included studies with a follow-up rate of at least 70% for additional analyses by assuming that all women lost to follow-up either continued their IUD or experienced an expulsion.¹⁵ In separate analyses, we also estimated adjusted RRs of overall expulsions (complete and partial expulsions together) for timing of placement, delivery method, and IUD type. All analyses were conducted using SAS 9.4.

RESULTS

We identified 1,112 articles in PubMed, 19 studies in ClinicalTrials.gov, and three Cochrane reviews, for a total of 1,134 records (Fig. 1). After removing 69 duplicates and excluding 117 articles published before 1974, the first year when IUDs of interest were initially studied and available, we screened the title and abstract of the 948 articles. We excluded 816 not relevant to our search and then reviewed the full text of 132 articles. Based on full-text review, we excluded 84 articles that did not include IUDs that met inclusion criteria, did not include postpartum IUD placements, or did not provide individual counts for expulsions. We did not identify any additional completed studies with published data from ClinicalTrials.gov. From our Cochrane search, we identified one updated Cochrane review that included 15 trials, of which five met inclusion criteria.³ A total of 48 studies met our inclusion criteria. Two of the articles that met our inclusion criteria were translated from Spanish or French^16,17 and the remaining were published in English.

Fig. 1.

Flow diagram of publication selection for inclusion into the review.

We describe study characteristics in Table 1. The body of evidence included studies largely published in the past 10 years, from all World Health Organization regions, with levels of evidence of I, II-2, and II-3 and with quality ratings assessed most frequently as fair or poor (compared with good for three studies).^7,18,19 Twenty-two studies included only CuT380A IUDs,^{8,16–18,20–37} 13 included only LNG-IUS,^19,38–49 and nine included a mix of the two^{7,9,10,14,50–54}; the remaining four studies included CuT200^55–57 or Cu7 IUDs.⁵⁸ Twenty-eight studied women with IUDs placed only in the immediate postpartum period,^{9,10,14,17,18,21,23,24,26–30,32–37,40–43,52–54,57,58} four studied only early postpartum placements,^44,47,55,56 and the remaining 16 studied more than one placement period.^{7,8,16,19,20,22,25,31,38,39,45,46,48–50,51} Similar numbers of studies evaluated vaginal and cesarean deliveries, with 14 including only vaginal deliveries,^{14,16,19,20,22,31,34,39,42,44,45,48,53,58,16} including only cesarean deliveries,^{7,8,17,18,27–30,35,37,38,40,41,43,46,54} 16 including both delivery methods,^{9,10,21,23–26,32,33,36,47,49,50,51,52,57} and two not reporting delivery method.^55,56 Sample sizes ranged from 7–2,733 women; follow-up duration ranged from 4 weeks–5 years, and follow-up rates ranged from 29–100%.

Table 1.

Characteristics of Included Studies Reporting Counts of Expulsions Among Postpartum Women

Study Author, Year	Region*	Level of Evidence†	Study Quality‡	IUD Type§	Placement Timingǁ	Delivery Method¶	Length of Follow-up	No. Enrolled or Randomized	No. of Women With lUDs Placed	No. of Women With IUDs Placed With Follow-up (%)
Agarwal, 201 735	Southeast Asia	II-3	Fair	CuT380A	Immediate	Cesarean	3 mo	50	50	50 (100)
Baldwin, 201650	North America	I	Fair	Mixed	Mixed	Mixed	6 mo	201	139	Unknown (66#)
Bonilla Rosales, 200516	South America	II-2	Fair	CuT380A	Mixed	Vaginal	3 mo	250	250	239 (96)
Braniff, 201538	Western Pacific	I	Fair	LNG-IUS	Mixed	Cesarean	6 mo	48	42	Unknown (84#)
Bryant, 201320	Africa	I	Poor	CuT380A	Mixed	Vaginal	12 wk	49	28	28 (100)
Celen, 201118	Eastern Mediterranean	II-3	Good	CuT380A	Immediate	Cesarean	12 mo	245	245	245 (100)
Chen, 201019	North America	I	Good	LNG-IUS	Mixed	Vaginal	6 mo	124	96	84 (88)
Chen, 201751	North America	II-2	Poor	Mixed	Mixed	Mixed	6 mo	74	74	59 (80)
Cohen, 20169	North America	II-3	Poor	Mixed	Immediate	Mixed	12 mo	82	82	67 (82)
Colwill, 201836	North America	II-2	Fair	CuT380A	Immediate	Mixed	6 wk	210	210	169 (81)
Dahlke, 201139	North America	I	Poor	LNG-IUS	Mixed	Vaginal	6 mo	53	46	45 (98)
Dias, 201521	Southeast Asia	II-2	Poor	CuT380A	Immediate	Mixed	6 wk	91	91	91 (100)
Eggebroten, 201752	North America	II-2	Poor	Mixed	Immediate	Mixed	6 mo	211	211	186 (88)
Elsedeek, 201241	Eastern Mediterranean	II-3	Fair	LNG-IUS	Immediate	Cesarean	2y	65	65	62 (95)
Elsedeek, 201540	Eastern Mediterranean	II-3	Fair	LNG-IUS	Immediate	Cesarean	5y	80	80	80 (100)
Eroglu, 20 0622	Eastern Mediterranean	II-2	Fair	CuT380A	Mixed	Vaginal	12 mo	268	268	257 (96)
Goldthwaite, 201753	North America	II-2	Fair	Mixed	Immediate	Vaginal	12 wk	123	123	96 (78)
Gueye, 201317	Africa	II-3	Fair	CuT380A	Immediate	Cesarean	6 mo	46	46	39 (85)
Gupta, 201 423	Southeast Asia	II-3	Fair	CuT380A	Immediate	Mixed	6 mo	100	100	92 (92)
Hayes, 200742	North America	II-3	Fair	LNG-IUS	Immediate	Vaginal	10 wk	20	20	16 (80)
Heller, 201754	Europe	II-3	Fair	Mixed	Immediate	Cesarean	12 mo	120	114	99 (87)
Hooda, 201 624	Southeast Asia	II-2	Poor	CuT380A	Immediate	Mixed	6 wk	593	593	171 (29)
Jatlaoui, 201414	North America	II-3	Fair	Mixed	Immediate	Vaginal	6 mo	99	99	88 (89)
Kumar, 201 425	Southeast Asia	II-3	Poor	CuT380A	Mixed	Mixed	6 wk	2,733	2,733	1,730 (63)
Laes, 197555	Europe	II-3	Poor	CuT200	Early	Unknown	12 mo	197	197	197 (100)
Lavin, 198356	South America	II-3	Poor	CuT200	Early	Unknown	12 mo	1,142	1,142	945 (83)
Lester, 20158	Africa	I	Poor	CuT380A	Mixed	Cesarean	6 mo	68	52	Unknown (90#)
Letti Muller, 200526	South America	II-2	Fair	CuT380A	Immediate	Mixed	1 mo	38	38	37 (97)
Levi, 201227	North America	II-3	Fair	CuT380A	Immediate	Cesarean	6 mo	90	90	42 (47)
Levi, 20157	North America	I	Good	Mixed	Mixed	Cesarean	6 mo	112	87	Unknown (88#)
Mishra, 201433	Southeast Asia	II-3	Poor	CuT380A	Immediate	Mixed	4–6 wk	564	564	434 (77)
Nelson, 200928	North America	II-3	Fair	CuT380A	Immediate	Cesarean	6 wk	7	7	7 (100)
Newton, 197758	Europe	II-3	Poor	Cu7	Immediate	Vaginal	6 wk	123	123	123 (100)
Puzey, 200543	Africa	II-3	Poor	LNG-IUS	Immediate	Cesarean	6 mo	33	33	20 (61)
Ragab, 201529	Eastern Mediterranean	II-3	Fair	CuT380A	Immediate	Cesarean	12 mo	40	40	40 (100)
Shukla, 201257	Southeast Asia	II-3	Poor	CuT200	Immediate	Mixed	6 wk	1,317	1,317	1,037 (79)
Singal, 201430	Southeast Asia	II-3	Fair	CuT380A	Immediate	Cesarean	12 mo	300	300	300 (100)
Singh, 20 1 631	Southeast Asia	II-3	Fair	CuT380A	Mixed	Vaginal	8 wk	80	80	80 (100)
Soon, 201848	North America	I	Poor	LNG-IUS	Mixed	Vaginal	6 mo	11	8	7 (88)
Stuart, 201244	North America	II-3	Fair	LNG-IUS	Early	Vaginal	6 mo	40	29	27 (93)
Stuart, 201545	North America	I	Poor	LNG-IUS	Mixed	Vaginal	6 mo	35	31	Unknown (80#)
Sucak, 201532	Eastern Mediterranean	II-2	Fair	CuT380A	Immediate	Mixed	12 mo	160	160	153 (96)
Turok, 201749	North America	I	Poor	LNG-IUS	Mixed	Mixed	8 wk	285	228	214 (94)
Unal, 201837	Eastern Mediterranean	II-3	Fair	CuT380A	Immediate	Cesarean	3 mo	70	70	68 (97)
Whitaker, 201446	North America	I	Poor	LNG-IUS	Mixed	Cesarean	12 mo	42	37	Unknown (81#)
Woo, 201510	North America	II-3	Poor	Mixed	Immediate	Mixed	12 mo	76	76	43 (57)
Xu, 199934	Western Pacific	II-3	Fair	CuT380A	Immediate	Vaginal	36 mo	384	384	381 (99)
Zerden, 201747	North America	II-3	Fair	LNG-IUS	Early	Mixed	6 mo	50	50	43 (86)

IUD, intrauterine device; Cu, copper; LNG-IUS, levonorgestrel intrauterine system.

^*Based on World Health Organization regions with region of the Americas separated into North and South American regions.

^†Level of evidence: I, a randomized, controlled trial; II-2, a cohort or case-controlled study that includes a comparison group; III, an uncontrolled descriptive study including case series.

^‡Defined by U.S. Preventive Services Task Force (Harris RP, Helfand M, Woolf SH, Lohr KN, Mulrow CD, Teutsch SM, et al. Current methods of the U.S. Preventive Services Task Force: a review of the process.

^§Mixed=CuT380A and LNG-IUS combined.

^ǁImmediate=10 min or less after placental delivery; Early=greater than 10 min to less than 4 wk postpartum; Mixed=Immediate and early placements or, immediate or early placements and interval placements (4 wk or greater postpartum).

^¶Mixed=vaginal or cesarean delivery.

^#Number of women with IUDs placed having follow-up not reported; therefore, percentage represents number of women with IUD placements among all women randomized.

We describe the crude pooled rates of expulsion by placement timing, delivery method, and IUD type among women with any follow-up in Table 2. Expulsion rates from individual studies ranged from 0% to 46.7% and generally increased with increasing length of study follow-up, ranging from 7.3% (range 0.0–21.4) for studies with follow-up less than 3 months to 18.4% (range 0.0–39.4) for studies with follow-up greater than 6 months. Although the most frequent study follow-up time period was 3–6 months, those with follow-up less than 3 months contributed the largest total number of women to our primary analysis.

Table 2.

Pooled Expulsion Rates by Study Follow-up Length

				Study Follow-up (mo)			Study Follow-up (mo)
	All Studies			Longer Than 6			3–6			Less Than 3
	No. of Studies	No. of Women With IUDs Placed With Follow-up	Complete Expulsion Rate*	No. of Studies	No. of Women With lUDs Placed With Follow-up	Complete Expulsion Rate*	No. of Studies	No. of Women With IUDs Placed With Follow-up	Complete Expulsion Rate*	No. of Studies	No. of Women With IUDs Placed With Follow-up	Complete Expulsion Rate*
Placement timing†‡
Total	48	8,569	11.3 (0.0–46.7)	14	2,906	18.4 (0.0–39.4)	20	1,430	8.6 (0.0–46.7)	14	4,233	7.3 (0.0–21.4)
Immediate	39	4,754	10.0 (0.0–26.7)	12	1,573	9.2 (0.0–25.4)	15	876	11.1 (0.0–26.7)	12	2,305	10.2 (0.0–21.4)
Early	9	1,372	29.7 (0.0–46.7)	3	1,185	32.7 (3.6–39.4)	6	187	11.2 (0.0–46.7)	0	NA	NA
Interval	14	633	1.9 (0.0–3.9)	2	148	3.4 (0.0–3.9)	10	367	1.4 (0.0–2.9)	2	118	1.7 (0.0–2.0)
Early or immediate	2	1,810	3.8 (3.6–7.5)	0	NA	NA	0	NA	NA	2	1,810	3.8 (3.6–7.5)
Delivery method†§
Total	48	7,936	12.0 (0.0–46.7)	14	2,758	19.3 (0.0–39.4)	20	1,063	11.1 (0.0–46.7)	14	4,115	7.4 (0.0–22.2)
Cesarean	22	1,512	3.6 (0.0–21.1)	8	936	3.9 (0.0–21.1)	9	369	4.3 (0.0–11.8)	5	207	1.5 (0.0–3.2)
Vaginal	20	1,543	14.9 (3.3–46.7)	3	570	15.8 (4.8–7.6)	8	378	21.4 (16.0–46.7)	9	595	9.9 (3.3–22.2)
Cesarean or vaginal	10	3,739	7.8 (0.0–25.4)	2	110	23.6 (20.9–25.4)	4	316	6.7 (0.0–11.3)	4	3,313	7.3 (3.6–21.4)
Unknown	2	1,142	33.2 (3.6–39.4)	2	1,142	33.2 (3.6–39.4)	0	NA	NA	0	NA	NA
IUD type†§
Total	48	7,936	12.0 (0.0–46.7)	14	2,758	19.3 (0.0–39.4)	20	1,063	11.1 (0.0–46.7)	14	4,115	7.4 (0.0–27.3)
CuT380A	25	4,567	6.7 (0.0–19.2)	6	1,246	9.4 (2.0–17.6)	9	549	8.9 (0.0–19.2)	10	2,772	5.1 (0.0–10.8)
LNG	16	718	15.5 (0.0–46.7)	3	161	2.5 (0.0–21.1)	10	374	17.4 (0.0–46.7)	3	183	22.9 (18.8–27.3)
CuT380A or LNG	6	349	10.0 (0.0–25.4)	3	209	14.8 (5.1–25.4)	3	140	2.9 (0.0–7.6)	0	NA	NA
Cu7	1	123	3.3 (NA)	0	NA	NA	0	NA	NA	1	123	3.3 (NA)
CuT200	3	2,179	22.8 (3.6–39.4)	2	1,142	33.2 (3.6–39.4)	0	NA	NA	1	1,037	11.3 (NA)

IUDs, intrauterine devices; NA, not applicable; Cu, copper; LNG, levonorgestrel

^*Among women with IUDs placed with any follow-up; data are % (range among studies).

^†Some studies included and reported more than one category.

^‡Immediates=10 min or less after placental delivery; early=greater than 10 min to less than 4 wk postpartum; early or immediate=immediate and early combined; interval=4 wk or greater postpartum.

^§Among immediate and early postpartum placements.

By IUD placement timing (n58,569 women with immediate, early, or interval placements), immediate placement had a pooled expulsion rate of 10.0% (range 0.0–26.7%; n54,754), whereas early placement had a pooled expulsion rate of 29.7% (range 0.0–46.7%; n51,372) compared with 1.9% (range 0.0–3.9%; n5633) for interval placement when including all lengths of follow-up (Table 2). By delivery method (n57,936 women with immediate or early placements), the pooled expulsion rate for vaginal deliveries was 14.9% (range 3.3–46.7%; n51,543) and for cesarean deliveries was 3.6% (range 0.0–21.1%; n51,512) with higher rates for vaginal deliveries compared with cesarean delivery for all follow-up intervals. By IUD type including immediate and early placements (n57,936 women with immediate or early placements), pooled expulsion rates were highest for CuT200 IUDs (22.8%, range 3.6–39.4%; n52,179), and rates were higher for LNG-IUS (15.5%, range 0.0–46.7%; n5718) compared with CuT380A (6.7%, range 0.0–19.2%; n54,567). Although CuT380A pooled expulsion rates varied from 5.1%, 8.9%, and 9.4% among studies with less than 3 months, 3–6 months, and longer than 6 months follow-up, respectively, pooled rates of LNG-IUS expulsion decreased among studies with longer follow-up (22.9% during less than 3 months follow-up, 17.4% during 3–6 months follow-up, and 2.5% for follow-up longer than 6 months).

Studies from Africa (n54), Europe (n53), eastern Mediterranean (n57), and Southeast Asia (n59) had pooled postpartum expulsion rates of 2.2%, 3.8%,6.3%, and 6.4%, respectively, whereas three studies pooled from South America had rates of 32.7%. The expulsion rate from 20 studies in North America was 11.3% in comparison with 15.8% from two studies in the Western Pacific. Expulsion rates did not differ by study quality (data not shown).

In multivariable analysis, examining complete expulsions among the sample of women with any follow-up, placement timing, delivery method, and IUD type were associated with risk of expulsion (Table 3). Compared with interval placement, both immediate and early placement had a more than sixfold higher risk of expulsion (adjusted RR 7.63, 95% CI 4.31–13.51; adjusted RR 6.17, 95% CI 3.19–11.93, respectively). Compared with cesarean delivery, IUD placement after vaginal delivery had a fivefold higher risk of expulsion (adjusted RR 5.19, 95% CI 3.85–6.99). Compared with CuT380A, risk of expulsion was higher for the LNG-IUS (adjusted RR 1.91, 95% CI 1.50–2.43) and CuT200 (adjusted RR 1.42, 95% CI 1.06–1.90); however, risk was lower for Cu7 (adjusted RR 0.21, 95% CI 0.08–0.56).

Table 3.

Risk Ratio for Intrauterine Device Expulsion Among Postpartum Women by Placement Timing, Delivery Method, and Intrauterine Device Type

			Sensitivity Analyses
	Complete Expulsions*		Complete Expulsions LTFU, Expulsions†	Complete Expulsions LTFU, No Expulsion†
	RR (95% CI)	aRR (95% CI)‡	aRR (95% CI)‡	aRR (95% CI)‡
Placement timing§
Interval	1.00 (referent)	1.00 (referent)	1.00 (referent)	1.00 (referent)
Immediate	5.29 (3.00–9.33)	7.63 (4.31–13.51)	3.70 (2.73–5.01)	4.75 (2.98–7.56)
Early	15.69 (8.9–27.64)	6.17 (3.19–11.93)	2.67 (1.79–3.97)	4.03 (2.27–7.14)
Early or immediate	2.01 (1.10–3.69)	3.57 (1.86–6.84)	1.04 (0.45–2.40)	3.39 (1.30–8.83)
Delivery methodǁ
Cesarean	1.00 (referent)	1.00 (referent)	1.00 (referent)	1.00 (referent)
Vaginal	4.10 (3.08–5.45)	5.19 (3.85–6.99)	2.56 (2.07–3.18)	4.70 (3.46–6.37)
Cesarean or vaginal	2.13 (1.61–2.83)	2.60 (1.76–3.84)	2.02 (1.52–2.69)	2.78 (1.94–3.99)
Unknown	9.12 (6.95–11.98)	6.47 (3.43–12.19)	6.16 (3.72–10.20)	7.85 (4.42–13.94)
IUD typeǁ
CuT380A	1.00 (referent)	1.00 (referent)	1.00 (referent)	1.00 (referent)
LNG	2.29 (1.87–2.81)	1.91 (1.50–2.43)	1.35 (1.16–1.58)	1.81 (1.42–2.29)
CuT380A or LNG	1.49 (1.07–2.07)	1.59 (1.07–2.35)	1.71 (1.28–2.27)	1.38 (0.89–2.14)
Cu7	0.48 (0.18–1.27)	0.21 (0.08–0.56)	0.10 (0.04–0.26)	0.28 (0.11–0.77)
CuT200	3.38 (2.96–3.85)	1.42 (1.06–1.90)	1.14 (0.98–1.32)	1.31 (0.98–1.76)

LTFU, lost to follow-up; RR, unadjusted risk ratios; aRR, adjusted risk ratios; IUD, intrauterine device; Cu, copper; LNG, levonorgestrel.

^*Among women with IUDs placed with any follow-up.

^†Including 43 studies with a follow-up rate of at least 70%.

^‡Adjusted for IUD type, delivery method, placement timing, study region, study quality, and length of follow-up.

^§Immediate=10 min or less after placental delivery; early=greater than 10 min to less than 4 wk postpartum; early or immediate=immediate and early combined; interval=4 wk or greater postpartum.

^ǁAmong immediate and early postpartum placements.

For our sensitivity analyses that included women lost to follow-up (n510,948) (Table 3), we only included 43 studies with a follow-up rate of at least 70%. We first assumed all women lost to follow-up (n52,379) experienced an expulsion and then assumed all women lost to follow-up retained their IUD. Although some variations of estimated risks of complete expulsions existed for both assumptions in comparison with the primary analysis, in general, results were similar with regard to placement timing, delivery methods, and IUD type.

For our sensitivity analysis that examined all expulsions (complete and partial expulsions), the adjusted RR of overall expulsion for early compared with interval placement was nearly twofold higher compared with our primary analysis (adjusted RR 11.17, 95% CI 6.74–18.52) (data not shown). The significantly higher risk of expulsion for immediate placement compared with interval placement remained when examining risk for overall expulsions as did the higher risk of expulsion for vaginal delivery compared with cesarean delivery (data not shown). When examining overall expulsions by IUD type, the higher risk of expulsion for LNG-IUS and CuT200 compared with CuT380A and lower risk for Cu7 remained (data not shown).

DISCUSSION

This analysis describes pooled postpartum expulsion rates of Cu-IUDs and LNG-IUS and adjusted RRs of expulsion by timing of placement, delivery method, and IUD type. In adjusted multivariable analyses, RRs of expulsion were higher for immediate placement and early placement compared with interval placement, for vaginal compared with cesarean delivery, and for LNG-IUS and CuT200 compared with CuT380A.

These results generally confirm previous findings from narrative systematic reviews^2–4 and provide new information regarding absolute expulsion rates for IUDs placed in the postpartum period. Although several studies have been published recently, most have been pilots or small studies designed to look at continuation rates; sample sizes were too small to detect differences in expulsion rates between groups by timing of placement, delivery method, or IUD type—key clinical factors that may influence expulsion rates. High attrition rates also have been common, and most studies have follow-up periods of 3–6 months. By pooling these data, we had a sample of approximately 8,000 women with follow-up data who had an IUD placed in the postpartum period from study locations across the world, with more than 90% receiving a copper IUD. In addition to our factors of interest, we adjusted for study quality, which varied from poor to good, and length of follow-up. We also included study region because certain areas (eg, Southeast Asia) have had more experience with postpartum IUD placements and thus may have lower expulsion rates.

This analysis is subject to several limitations. First, expulsions were not always clearly defined in the studies, diagnostic criteria were rarely reported, and expulsions may have been ascertained by varied methods, including clinic visit, patient report, or chart review. We assumed when studies reported expulsions not further characterized as complete or partial that these were complete expulsions, which may overestimate our primary outcome. Even for those reporting complete and partial expulsions, definitions distinguishing the two types were rarely reported. The ranges of pooled expulsion rates highlight the lack of data precision even when stratified by placement timing, delivery method, IUD type, and length of follow-up. We were unable to examine potential factors for IUD expulsion such as health care provider experience, insertion technique, or ultrasound use because studies did not consistently report these variables. Because our analysis focused on factors at the study level, we were not able to examine potential confounders at the patient level such as age, parity, and breastfeeding status, which may also influence expulsion. Additionally, we were not able to pinpoint when expulsions most commonly occur because studies did not consistently report timing of expulsions after placement.

To improve this body of evidence and inform a future pooled expulsion analysis, we recommend studies include clear diagnostic criteria for complete and partial expulsions, timing of expulsion, IUD type, insertion technique (eg, manual, ring forceps, or inserter), level of health care provider experience, and breastfeeding status.

Although complete expulsions may be less prone to misclassification, partial expulsions may or may not include malpositioned IUDs, whose clinical significance remains unknown. Our sensitivity analysis examining complete and partial expulsions confirms findings from our primary analysis of complete expulsions and suggests women with early postpartum IUD placements may be at much higher risk for complete and partial expulsions compared with women with interval placements. One recent case–control study found more pregnancies among women with malpositioned IUDs than those with IUDs in normal position as a result of high rates of IUD removal and lack of subsequent highly effective contraception.⁵⁹ None of 28 women with malpositioned IUDs who kept the IUD experienced a pregnancy within 2 years.

Our results, along with safety data and other recommendations, can be used to support essential postpartum contraception initiatives^1–5,60 and aid in counseling women to make an informed choice as to when to initiate their IUD. Although expulsion risk is increased with IUD placement in the immediate and early postpartum periods compared with interval placement, providing contraceptive access to women may outweigh expulsion risk for women who prefer the convenience and other beneficial factors of postpartum IUD placement or who may face additional barriers to placement at a later time. When feasible, provision of IUDs immediately postpartum (within 10 minutes after placental delivery) may result in a lower expulsion risk than early postpartum placement.