Weijin Zhou

Induced abortion and subsequent pregnancy duration

OBJECTIVE To examine whether induced abortion influences subsequent pregnancy duration. METHODS Women who had their first pregnancies during 1980, 1981, and 1982 were identified in three Danish national registries. A total of 15,727 women whose pregnancies were terminated by first-trimester induced abortions were compared with 46,026 whose pregnancies were not terminated by induced abortions. All subsequent pregnancies until 1994 were identified by register linkage. RESULTS Preterm and post-term singleton live births were more frequent in women with one, two, or more previous induced abortions. After adjusting for potential confounders and stratifying by gravidity, the odds ratios of preterm singleton live births in women with one, two, or more previous induced abortions were 1.89 (95% confidence interval [CI] 1.70, 2.11), 2.66 (95% CI 2.09, 3.37), and 2.03 (95% CI 1.29, 3.19), respectively. Odds ratios of post-term singleton live births in women with one, two, or more previous induced abortions were 1.34 (95% CI 1.24, 1.44), 1.50 (95% CI 1.26, 1.78), and 1.58 (95% CI 1.09, 2.28), respectively. CONCLUSION The study showed an increase in preterm and post-term pregnancies after induced abortions. The risk of post-term delivery was high regardless of the interpregnancy interval, whereas increased risk of preterm delivery was seen mainly when interpregnancy intervals were longer than 12 months.

Short-term complications after surgically induced abortions: a register-based study of 56 117 abortions

Background.  Performing an induced abortion is a rather simple medical procedure which is frequently done and side‐effects will have public health implications unless they are very rare. We estimated the incidence of side‐effects detected during the stay at the hospital and 2 weeks after the discharge. We only include side‐effects reported by clinics or hospitals.

The Pharmacoepidemiologic Prescription Database of North Jutland – a valid tool in pharmacoepidemiological research

In this paper we describe the options of a pharmacoepidemiologic database comprising data on all reimbursed prescriptions taken up at pharmacies in the County of Northern Jutland since 1991 including precise identification of the individual person for whom the medicin was prescribed. The County comprises 487,000 inhabitants equal to approximately 10% of the total Danish population.

Induced abortion and placenta complications in the subsequent pregnancy.

Background. To study the risk of placenta complications following an induced abortion as a function of the interpregnancy interval.

Risk of spontaneous abortion following induced abortion is only increased with short interpregnancy interval

We set out to study the risk of spontaneous abortion following a first trimester induced abortion as a function of the interpregnancy interval between two pregnancies. The cohort study is based on the following databases: Danish national registries: the Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), and the induced Abortion Registry (IAR). All primigravid women in the time period from 1980 to 1982 were identified in the MBR, the HDR and the IAR. A total of 15 727 women who terminated the pregnancy with a first trimester induced abortion were selected as the induced abortion cohort, and 46 026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies which were not terminated by induced abortion were identifled from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected. Women whose first pregnancy was terminated following a first trimester induced abortion had a risk of spontaneous abortion of 11.0% vs. 9.4% in the control cohort. This relative difference of 1.17 was not statistically significant in logistic regression analyses. An increased risk was only found for women who had an interpregnancy interval of less than 3 months (OR=4.06, 95% C.I.=1.98-8.31). The abortion method, vacuum aspiration with dilatation or evacuation with dilatation did not modify this elevated risk. Overall the study did not show an increased risk of spontaneous abortion following one or more induced abortions, except for women with a short interpregnancy interval between an induced abortion and a subsequent pregnancy. We recommend women who have a first trimester induced abortion be advised to wait at least 3-6 months before trying to become pregnant again.We set out to study the risk of spontaneous abortion following a first trimester induced abortion as a function of the interpregnancy interval between two pregnancies. The cohort study is based on the following databases: Danish national registries: the Medical Birth Registry (MBR), the Hospital Discharge Registry (HDR), and the induced Abortion Registry (IAR). All primigravid women in the time period from 1980 to 1982 were identified in the MBR, the HDR and the IAR. A total of 15 727 women who terminated the pregnancy with a first trimester induced abortion were selected as the induced abortion cohort, and 46 026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies which were not terminated by induced abortion were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected. Women whose first pregnancy was terminated following a first trimester induced abortion had a risk of spontaneous abortion of 11.0% vs. 9.4% in the control cohort. This relative difference of 1.17 was not statistically significant in logistic regression analyses. An increased risk was only found for women who had an interpregnancy interval of less than 3 months (OR=4.06, 95% C.I.=1.98-8.31). The abortion method, vacuum aspiration with dilatation or evacuation with dilatation did not modify this elevated risk. Overall the study did not show an increased risk of spontaneous abortion following one or more induced abortions, except for women with a short interpregnancy interval between an induced abortion and a subsequent pregnancy. We recommend women who have a first trimester induced abortion be advised to wait at least 3-6 months before trying to become pregnant again.

Are complications after an induced abortion associated with reproductive failures in a subsequent pregnancy

Background. We have previously shown that induced abortions result in a slightly increased risk of spontaneous abortion and preterm delivery in subsequent pregnancies. Danish records show that approximately 4% of women who undergo surgically induced abortions have complications related to the procedure. We examined whether it was women who had the short‐term complications that carried an excess risk of spontaneous abortion and preterm delivery in the subsequent pregnancy.

Induced abortion and duration of third stage labour in a subsequent pregnancy.

We set out to evaluate the impact of first trimester induced abortion on the duration of third stage labour and related complications in a subsequent pregnancy. The study was conducted in Shanghai city at 15 general hospitals (or maternity and infant health institutes) from November 1993 to March 1998. We identified all nulliparae who came for antenatal care within the first 63 days of pregnancy (2953); the women were divided into two cohorts according to their previous history of first trimester induced abortion. After enrollment, the women were interviewed five times from recruitment until 42 days after delivery. We included in the study all 1363 women who had a singleton vaginal live birth. Of these women, 703 were primigravida (non-exposed), 534 had had one previous first trimester induced abortion, and 126 women had had two or more first trimester induced abortions. The duration of third stage labour in minutes was longer in women with one or more previous induced abortions (mean=7.32 minutes) compared with primigravid women (mean=6.79 minutes). Prolonged third stage labour (>30 minutes) following one or more induced abortions was seen for 3.4% versus 1.0% in primigravid women. After adjusting for a number of potential confounders, women with one or more previous first trimester induced abortions had an odds ratio of prolonged third stage labour of 2.59 (95%C.I.=1.06-6.37) compared with primigravida, especially after an interpregnancy interval of more than 6 months (OR=3.24, 95%C.I.=1.29-8.13). The odds ratio of prolonged third stage labour was 3.14 (95%C.I.=1.22-8.09) if gestational age at the time of the induced abortion exceeded 49 days. Women with a first trimester induced abortion had no significantly increased risk of postpartum haemorrhage or retained placenta. It was concluded that a history of one or more first trimester induced abortions was related to an increased risk of prolonged third stage labour in the following pregnancy, particularly if the induced abortion was performed after 49 days of gestation.

Drug Use in Pregnancy. Principal Problems and a Review of Newer Utilization Studies

AbstractThe thalidomide disaster set focus on the problems of drug utilization and safety during pregnancy, particularly with respect to malformations, but other, and more subtle, side effects may also occur as a result of drug consumption in pregnancy. Our knowledge of adverse drug effects in pregnancy is still sparse, especially with respect to side-effects other than malformations. As consumption of medicine in pregnancy is common we need large epidemiological studies are needed to address this issue. Our knowledge of the long-term effects of drugs on the childs function, its mental and motor development, is at best sporadic. Studies on drug use by pregnant women have shown that at least 50% take one or often several drugs during pregnancy, most of the drugs have been analgesics and antibiotics. In summary, our knowledge in this field is limited and insufficient. Hopefully three new Danish studies will give more insight in this very complex subject with substantial public health relevance.

Uterine cavity-shaped device used in China.

Objective To assess the effectiveness, side effects, and acceptability of copper uter-ine cavity - shaped intrauterine devices (UCD) with and without indomethacin. Methods We used electronic search and hand search to identify relevant literatures. Included papers were systematically reviewed according to previous established guidelines. Results A total of 39 related papers were identified. Of them, 9 papers were included in this review: 4 associated with medicated or non-medicated UCD200 (containing copper 200 mm2) and 5 associated with medicated or non-medicated UCD300 (containing copper 300 mm2). The contraceptive effectiveness, cumulative one-year and two-year continuation rates were similar between medicated UCD200, non-medicated UCD200 and TCu220C. The effectiveness of non-medicated UCD300 was similar to that of TCu220C and TCu200. The effectiveness of medicated UCD300 was similar to that of MLCu375 and TCu220C but lower than that of TCu380A. The cumulative one-year, three-year and five-year continuation rates were similar between medicated, non-medicated UCD300 and TCu380A or MLCu375. The problem of bleeding was less common among medicated UCD users than among non-medicated devices. Conclusions Uterine cavity-shaped devices should continue to be used in the National Family Planning Proramme. However, priority should be given to the 300 mm 2 copper containing device. A large multicenter randomized comparative trial of UCD300 and TCu380A is needed.